Successful gear analysis is integral in preventing gear failure. Use the same rigorous process a gear failure analyst does.
PlantServices.com
By Robert Errichello
Successful gear failure analysis requires proper investigation, a strong team leader and a qualified gear failure analyst. These components are what it takes to determine the root cause of gear failure and maximize your chances for preventing failure recurrence.
Failure analysis is important
A properly managed failure investigation can provide valuable feedback about how a component performs. It might uncover shortcomings or weakness in design, manufacture or quality control. It can provide information for improvements that prevent future failure. In some cases, the failure investigation can assess liability and determine whether the failure was a unique event or a symptom of a wider problem. Rigorous root cause determination might lead to machinery improvements that yield:
* Greater safety
* Improved reliability
* Higher performance
* Greater efficiency
* Easier maintenance
* Reduced life-cycle costs
* Reduced impact on environment
The team leader
The most effective and efficient gear failure investigation is headed by a team leader who is high enough in your corporate hierarchy to be able to establish four items at the outset:
* The investigation’s priority
* Available resources
* Constraints imposed
* The investigation’s goal
The leader must be a good communicator with the ability to integrate the team and select the best expert for each role in the investigation. The leader should have a broad background and must be skilled in failure analysis techniques such as fault tree analysis (FTA), failure mode assessment (FMA) and root cause analysis (RCA).
The team leader needs a clear understanding of the investigation’s scope to organize it effectively. Time and money are always constrained. Therefore, the scope of the investigation is controlled by what you want to know and how much you’re willing to spend.
After considering all interests, the team leader should define a clearly stated goal before launching an investigation. This involves a detailed, well-documented investigation plan that makes clear to all involved what information is expected from each step of the investigation. The documentation should address:
* What is to be done
* Why is it to be done
* The findings expected to be determined
The specific investigative plan can vary depending on when and where the investigation is made, the nature of the failure and time constraints. In any case, the team leader needs to ensure that everyone involved understands the priorities, the analyst has the necessary resources, the investigation stays within imposed constraints and that the investigation will achieve its goal. This is a collaborative effort.
Additional team staffing should include a gear failure analyst who answers directly to the team leader, and metallurgists and tribologists who collaborate with the analyst and report to the team leader.
In some cases, a gear failure analyst with the necessary skills can be the team leader. Otherwise, the analyst should be responsible for technical details of the analysis, but work under the team leader’s supervision. This arrangement frees the analyst to concentrate on technical detail and permits the team leader to manage resources and logistics necessary to implement the plan.
The gear failure analyst
Gear failure analysis, a subset of general failure analysis, is conducted by an investigator who specializes in it. The requisite qualifications for the analyst include experience in gear design, stress analysis, gear manufacturing plus an understanding of how gearbox components are supposed to function and how they can malfunction. Furthermore, the analyst should have a thorough knowledge of gear metallurgy and tribology, and understand the capabilities and limitations of the analytical procedures both disciplines use.
There’s no real alternative to including an analyst. If you don’t have a qualified gear failure analyst on your staff, either train someone or hire an outside consultant. A metallurgist is unlikely to be familiar with the gear’s function, modes of operation and service characteristics, and is unlikely to be acquainted with manufacturing procedures, accepted workmanship and appropriate materials for a specific gear application.
Costs depend on gearbox complexity, nature of the failure, available resources for the investigation and risks associated with recurrence. The costs details might not be readily apparent. Therefore, cost estimates might need to be revised as the investigation progresses and the team leader needs to assess whether the budget is adequate to achieve the investigation’s goal.
The usual goal is to discover the root cause of a failure and determine the best corrective actions to prevent recurrence. In some cases, the goal might be to assess gearbox performance to improve the design. In other cases, the goal might be to assign responsibility for a failure.
Often there’s pressure to repair or replace failed components quickly and return the gear system to service. Because gear failures provide valuable data that can help prevent future failures, however, you should follow a systematic inspection procedure before repair or replacement begins. This entails a complete disassembly and thorough inspection of gearbox components.
Getting organized
As the investigation proceeds, it might become apparent that other resources are needed to corroborate evidence, such as metallurgical tests or tribological analyses. It’s often the case that investigation resources and budget must be reviewed and revised continually. Unless time and budget are adequate, it might be best not to investigate at all. The gear failure analyst should have access to:
* Design data
* Technical data
* Analysis reports
* Test reports
* Maintenance records
* Operational logs
The analyst should interview witnesses to the failure, operators, maintenance personnel, system designers and other people involved in gearbox design, operation and maintenance. The team leader should identify those responsible for operating the gearbox to provide information and resources the analyst needs.
Gear failures often attract onlookers or other curious parties. However, it’s imperative to preserve evidence and it’s in the best interest of the investigation to restrict access to the failed gearbox. If possible, the team leader should arrange to quarantine the gearbox and schedule an inspection as soon after the gear failure as possible. Failure conditions can determine when and how to conduct an analysis. It’s best to shutdown a failing gearbox as soon as possible to limit damage. To preserve evidence, carefully plan the failure investigation to include shutdown, in-situ inspections, gearbox removal, transport, storage and disassembly.
Prepare for inspection
Before visiting the failure site, the team should explain to the site contact person what is needed for the gearbox inspection, including personnel, equipment and working conditions. Ideally, the analyst should visit the site as soon as possible after failure. If an early inspection isn’t possible, someone at the site must take measures to preserve the evidence.
The analyst needs as much background information as possible, including manufacturer’s specifications, service history, load data and lubricant analyses. The analyst might send the site’s contact person a questionnaire to help expedite information gathering (Download Figure 1 using the "Download Now" button at the bottom of the page).
Before starting the inspection, the analyst should review background information and gearbox service history before interviewing those involved in the design, installation, startup, operation, maintenance and failure of the gearbox. Plant personnel should reveal all they know about the gearbox, even if some facts seem unimportant.
In some situations, the high cost of shutdown will limit the time available for inspection, in which case careful planning is required. It may require dividing tasks between two or more analysts to reduce downtime.
Keep it running?
If the gears are damaged but still functional, you may decide to continue operation and monitor damage progression. In this case, monitor the gear system under the analyst’s supervision. The analyst should ensure there are no risks to human life. For critical applications, the analyst should examine the gears with magnetic particle inspection to ensure there aren’t any cracks that prevent safe continued operation.
Other routine analysis actions the analyst should perform are a visual inspection and measurement of temperature, sound and vibration. The analyst should collect samples of lubricant for analysis and examine the oil filter for wear debris and contaminants, and inspect magnetic plugs for wear debris.
Then, it’s time to drain, flush and refill the reservoir.
Gear tooth contact patterns
The next steps to follow are important. Clean the inspection port cover and the surrounding area. Remove the cover, being careful not to contaminate the gearbox interior. Observe the condition of gears, shafts and bearings.
If there’s evidence of gear misalignment such as macropitting concentrated at ends of teeth, but no broken teeth or other failures that would prohibit rotating the gears, record the gear tooth contact patterns. The way gear teeth touch indicates how they’re aligned. Tooth contact patterns may be recorded under loaded or unloaded conditions (Figure 2). No-load patterns aren’t as reliable as loaded patterns for detecting misalignment because the marking compound is relatively thick and no-load tests don’t include misalignment caused by load, speed or temperature. Therefore, follow any no-load tests with loaded tests.
For no-load tests, paint the teeth of one gear with a soft marking compound and roll the teeth through the mesh so compound transfers to the unpainted gear. Turn the pinion by hand while applying a light load to the gear shaft by hand or brake. Use clear tape to lift the patterns from the gear and mount the tape on white paper to form a permanent record (Figure 3). The compound PT-650 Tooth Marking Grease available from Products/Techniques, Inc. (909) 877-3951, works best. Scotch No. 845 Book Tape (2-in. width) works well for lifting contact patterns.
For loaded tests, thoroughly clean the teeth with a solvent. Brush paint several teeth on one or both gears with a thin coat of machinist’s layout fluid (Dykem). Run the gears under load for sufficient time to wear off the lacquer and establish the contact pattern. Photograph patterns for a permanent record.
Record loaded contact patterns under several loads, for example, 25%, 50%, 75%, and 100%. Inspect patterns after running about one hour at each load to monitor how patterns change with load. Ideally, the patterns shouldn’t vary with load. Optimum contact patterns cover nearly 100% of the active face of gear teeth under full load, except at extremes along tooth tips, roots and ends, where contact is lighter as evidenced by traces of lacquer.
Automatic transmission
An automatic transmission is an automobile gearbox that can change gear ratios automatically as the car or truck moves, thus freeing the driver from having to shift gears manually. (Similar but larger devices are also used for railroad locomotives.)
Most cars sold in the United States since the 1950s have been equipped with an automatic transmission. This has, however, not been the case in Europe and much of the rest of the world. Automatic transmissions, particularly earlier ones, reduce fuel efficiency and power. Where fuel is expensive and, thus, engines generally smaller, these penalties are more burdensome. In recent years, automatic transmissions have significantly improved in their ability to support high fuel efficiency but manual transmissions are still generally more efficient. (This balance may finally shift with the introduction of practical continuously variable transmissions; see below.)
Most automatic transmissions have a set selection of possible gear ranges, often with a parking pawl feature that will lock the output shaft of the transmission.
However, some simple machines with limited speed ranges and/or fixed engine speeds only use a torque converter to provide a variable gearing of the engine to the wheels. Typical examples include forklift trucks and some modern lawn mowers.
Recently manufacturers have begun to make continuously variable transmissions commonly available (earlier models such as the Subaru Justy did not popularize CVT). These designs can change the ratios over a range rather than between set gear ratios. Even though prototypes for CVT have been around for decades, it is just now reaching commercial practicability.
Hydraulic automatic transmissions
The automatic transmission selector lever in a Ford Five Hundred car.
The automatic transmission selector lever in a Ford Five Hundred car.
The predominant form of automatic transmission is hydraulically operated, using a fluid coupling or torque converter and a set of planetary gearsets to provide a range of torque multiplication.
Parts and operation
A hydraulic automatic transmission consists of the following parts:
* Fluid coupling or torque converter: A hydraulic device connecting the engine and the transmission. It takes the place of a mechanical clutch, allowing the engine to remain running at rest without stalling. A torque converter is a fluid coupling that also provides a variable amount of torque multiplication at low engine speeds, increasing "breakaway" acceleration.
* Planetary gearset: A compound planetary set whose bands and clutches are actuated by hydraulic servos controlled by the valve body, providing two or more gear ratios.
* Valve body: hydraulic control center that receives pressurised fluid from a main pump operated by the fluid coupling/torque converter. The pressure coming from this pump is regulated and used to run a network of spring-loaded valves, check balls and servo pistons. The valves use the pump pressure and the pressure from a centrifugal governor on the output side (as well as hydraulic signals from the range selector valves and the throttle valve or modulator) to control which ratio is selected on the gearset; as the car and engine change speed, the difference between the pressures changes, causing different sets of valves to open and close. The hydraulic pressure controlled by these valves drives the various clutch and brake band actuators, thereby controlling the operation of the planetary gearset to select the optimum gear ratio for the current operating conditions. However, in many modern automatic transmissions, the valves are controlled by electro-mechanical servos which are controlled by the Engine Management System or a separate transmission controller. (See History and improvements below.)
The multitude of parts, along with the complex design of the valve body, originally made hydraulic automatic transmissions much more complicated (and expensive) to build and repair than manual transmissions. In most cars (except US family, luxury, sport-utility vehicle, and minivan models) they have usually been extra-cost options for this reason. Mass manufacturing and decades of improvement have reduced this cost gap.
History and improvements
Oldsmobile's 1940 models featured Hydra-Matic drive, the first mass-production fully automatic transmissions. Initially an Olds exclusive, Hydra-Matic had a fluid coupling (not a torque converter) and three planetary gearsets providing four speeds plus reverse. Hydra-Matic was subsequently adopted by Cadillac and Pontiac, and was sold to various other automakers, including Bentley, Hudson, Kaiser, Nash, and Rolls-Royce. From 1950 to 1954 Lincoln cars were also available with GM Hydra-Matic. Mercedes-Benz subsequently devised a four-speed fluid coupling transmission that was similar in principle to Hydra-Matic, but did not share the same design.
The first torque converter automatic, Buick's Dynaflow, was introduced for the 1948 model year. It was followed by Chevrolet's Powerglide and Packard's Ultramatic for the 1950 model year. Each of these transmissions had only two forward speeds, relying on the torque converter for additional gear reduction.
In the early 1950s Borg-Warner developed a series of three-speed torque converter automatics for Ford Motor Company, Studebaker, and several foreign and independent makes.
Chrysler was late in developing its own true automatic, introducing the two-speed torque converter PowerFlite in 1953 and the three-speed TorqueFlite in 1956.
By the late 1960s most of the fluid-coupling four-speeds and two-speed transmissions had disappeared in favor of three-speed units with torque converters. By the early 1980s these were being supplemented and eventually replaced by overdrive-equipped transmissions providing four or more forward speeds. Many transmissions also adopted the lock-up torque converter (a mechanical clutch locking the torque converter impeller and turbine together to eliminate slip at cruising speed) to improve fuel economy.
As the engine computers became more and more capable, even more of the valve body's functionality was offloaded to them. These transmissions, introduced in the late 1980s and early 1990s, remove almost all of the control logic from the valve body, and place it in into the engine computer. (Some manufacturers use a separate computer dedicated to the transmission but sharing information with the engine management computer.) In this case, solenoids turned on and off by the computer control shift patterns and gear ratios, rather than the spring-loaded valves in the valve body. This allows for more precise control of shift points, shift quality, lower shift times and (on some newer cars) semi-automatic control, where the driver tells the computer when to shift. The result is an impressive combination of efficiency and smoothness. Some computers even identify the driver's style and adapt to best suit it.
ZF Friedrichshafen AG and BMW were responsible for introducing the first five-speed automatic (the ZF 5HP18 in the 1992 BMW E34 5-Series) and the first six-speed (the ZF 6HP26 in the 2002 BMW E65 7-Series). Mercedes-Benz's 7G-TRONIC was the first seven-speed in 2003, with Toyota Motor Company introducing an 8-speed in 2007 on the Lexus LS.
Automatic Transmission Models
Some of the best known automatic transmission families include:
* General Motors — Powerglide, Turbo-Hydramatic 350 and 400, 4L60-E, 4L80-E
* Ford: Cruise-O-Matic, C4, C6, AOD/AODE, E4OD, ATX, AXOD/AX4S/AX4N
* Chrysler: TorqueFlite 727 and 904, A500, A518, 45RFE, 545RFE
* BorgWarner (later Aisin AW)
* ZF Friedrichshafen AG
* Allison Transmission
* Voith Turbo
* Aisin AW; Aisin AW is a Japanese automotive parts supplier, known for its automatic transmissions and navigation systems
* Honda
* Nissan/Jatco
Automatic transmission families are usually based on Ravigneaux, Lepelletier, or Simpson planetary gearsets. Each uses some arrangement of one or two central sun gears, and a ring gear, with differing arrangements of planet gears that surround the sun and mesh with the ring. An exception to this is the Hondamatic line from Honda, which uses sliding gears on parallel axes like a manual transmission without any planetary gearsets. Although the Honda is quite different from all other automatics, it is also quite different from an automated manual transmission.
Continuously variable transmissions
Main article: continuously variable transmission
A different type of automatic transmission is the continuously variable transmission or CVT, which can smoothly alter its gear ratio by varying the diameter of a pair of belt or chain-linked pulleys, wheels or cones. Some continuously variable transmissions use a hydrostatic drive consisting of a variable displacement pump and a hydraulic motor to transmit power without gears. CVT designs are usually as fuel efficient as manual transmissions in city driving, but early designs lose efficiency as engine speed increases.
A slightly different approach to CVT is the concept of toroidal CVT or IVT (from infinitely variable transmission). These concepts provide zero and reverse gear ratios.
Some current hybrid vehicles, notably those of Toyota, Lexus and Ford Motor Company, have an "electronically-controlled CVT" (E-CVT). In this system, the transmission has fixed gears, but the ratio of wheel-speed to engine-speed can be continuously varied by controlling the speed of the third input to a differential using an electric motor-generator.
Manually controlled automatic transmissions
Most automatic transmissions offer the driver a certain amount of manual control over the transmission's shifts (beyond the obvious selection of forward, reverse, or neutral). Those controls take several forms:
* Throttle kickdown: Most automatic transmissions include a switch on the throttle linkage that will force the transmission to downshift into the next lower ratio if the throttle is fully engaged. The switch generally only functions up to a certain road speed, so as to prevent a downshift that would overrev the engine. Some transmissions also had a part-throttle kickdown, obviating the need to "floorboard" the throttle to downshift.
* Low gear ranges: Many transmissions have switches or selector positions that allow the driver to limit the maximum ratio that the transmission may engage. On older transmissions, this was accomplished by a mechanical lockout in the transmission valve body preventing an upshift until the lockout was disengaged; on computer- controlled transmissions, the same effect is accomplished electronically. The transmission can still upshift and downshift automatically between the remaining ratios: for example, in the 3 range, a transmission could shift from first to second to third, but not into fourth or higher ratios. Some transmissions will still upshift automatically into the higher ratio if the engine reaches its maximum permissible speed in the selected range.
* Manual controls: Some transmissions have a mode in which the driver has full control of ratio changes (either by moving the selector or through the use of buttons or paddles), completely overriding the hydraulic controller. Such control is particularly useful in cornering, to avoid unwanted upshifts or downshifts that could compromise the vehicle's balance or traction. "Manumatic" shifters, first popularized by Porsche in the 1990s under the trade name Tiptronic, have become a popular option on sports cars and other performance vehicles. With the near-universal prevalence of electronically controlled transmissions, they are comparatively simple and inexpensive, requiring only software changes and the provision of the actual manual controls for the driver. The amount of true manual control provided is highly variable: some systems will override the driver's selections under certain conditions, generally in the interest of preventing engine damage.
Some automatic transmissions modified or designed specifically for drag racing may also incorporate a transmission brake, or "trans-brake," as part of a manual valve body. Activated by electrical solenoid control, a trans-brake simultaneously engages the first and reverse gears, locking the transmission and preventing the input shaft from turning. This allows the driver of the car to raise the engine rpm against the resistance of the torque converter, then launch the car by simply releasing the trans-brake switch.
Most cars sold in the United States since the 1950s have been equipped with an automatic transmission. This has, however, not been the case in Europe and much of the rest of the world. Automatic transmissions, particularly earlier ones, reduce fuel efficiency and power. Where fuel is expensive and, thus, engines generally smaller, these penalties are more burdensome. In recent years, automatic transmissions have significantly improved in their ability to support high fuel efficiency but manual transmissions are still generally more efficient. (This balance may finally shift with the introduction of practical continuously variable transmissions; see below.)
Most automatic transmissions have a set selection of possible gear ranges, often with a parking pawl feature that will lock the output shaft of the transmission.
However, some simple machines with limited speed ranges and/or fixed engine speeds only use a torque converter to provide a variable gearing of the engine to the wheels. Typical examples include forklift trucks and some modern lawn mowers.
Recently manufacturers have begun to make continuously variable transmissions commonly available (earlier models such as the Subaru Justy did not popularize CVT). These designs can change the ratios over a range rather than between set gear ratios. Even though prototypes for CVT have been around for decades, it is just now reaching commercial practicability.
Hydraulic automatic transmissions
The automatic transmission selector lever in a Ford Five Hundred car.
The automatic transmission selector lever in a Ford Five Hundred car.
The predominant form of automatic transmission is hydraulically operated, using a fluid coupling or torque converter and a set of planetary gearsets to provide a range of torque multiplication.
Parts and operation
A hydraulic automatic transmission consists of the following parts:
* Fluid coupling or torque converter: A hydraulic device connecting the engine and the transmission. It takes the place of a mechanical clutch, allowing the engine to remain running at rest without stalling. A torque converter is a fluid coupling that also provides a variable amount of torque multiplication at low engine speeds, increasing "breakaway" acceleration.
* Planetary gearset: A compound planetary set whose bands and clutches are actuated by hydraulic servos controlled by the valve body, providing two or more gear ratios.
* Valve body: hydraulic control center that receives pressurised fluid from a main pump operated by the fluid coupling/torque converter. The pressure coming from this pump is regulated and used to run a network of spring-loaded valves, check balls and servo pistons. The valves use the pump pressure and the pressure from a centrifugal governor on the output side (as well as hydraulic signals from the range selector valves and the throttle valve or modulator) to control which ratio is selected on the gearset; as the car and engine change speed, the difference between the pressures changes, causing different sets of valves to open and close. The hydraulic pressure controlled by these valves drives the various clutch and brake band actuators, thereby controlling the operation of the planetary gearset to select the optimum gear ratio for the current operating conditions. However, in many modern automatic transmissions, the valves are controlled by electro-mechanical servos which are controlled by the Engine Management System or a separate transmission controller. (See History and improvements below.)
The multitude of parts, along with the complex design of the valve body, originally made hydraulic automatic transmissions much more complicated (and expensive) to build and repair than manual transmissions. In most cars (except US family, luxury, sport-utility vehicle, and minivan models) they have usually been extra-cost options for this reason. Mass manufacturing and decades of improvement have reduced this cost gap.
History and improvements
Oldsmobile's 1940 models featured Hydra-Matic drive, the first mass-production fully automatic transmissions. Initially an Olds exclusive, Hydra-Matic had a fluid coupling (not a torque converter) and three planetary gearsets providing four speeds plus reverse. Hydra-Matic was subsequently adopted by Cadillac and Pontiac, and was sold to various other automakers, including Bentley, Hudson, Kaiser, Nash, and Rolls-Royce. From 1950 to 1954 Lincoln cars were also available with GM Hydra-Matic. Mercedes-Benz subsequently devised a four-speed fluid coupling transmission that was similar in principle to Hydra-Matic, but did not share the same design.
The first torque converter automatic, Buick's Dynaflow, was introduced for the 1948 model year. It was followed by Chevrolet's Powerglide and Packard's Ultramatic for the 1950 model year. Each of these transmissions had only two forward speeds, relying on the torque converter for additional gear reduction.
In the early 1950s Borg-Warner developed a series of three-speed torque converter automatics for Ford Motor Company, Studebaker, and several foreign and independent makes.
Chrysler was late in developing its own true automatic, introducing the two-speed torque converter PowerFlite in 1953 and the three-speed TorqueFlite in 1956.
By the late 1960s most of the fluid-coupling four-speeds and two-speed transmissions had disappeared in favor of three-speed units with torque converters. By the early 1980s these were being supplemented and eventually replaced by overdrive-equipped transmissions providing four or more forward speeds. Many transmissions also adopted the lock-up torque converter (a mechanical clutch locking the torque converter impeller and turbine together to eliminate slip at cruising speed) to improve fuel economy.
As the engine computers became more and more capable, even more of the valve body's functionality was offloaded to them. These transmissions, introduced in the late 1980s and early 1990s, remove almost all of the control logic from the valve body, and place it in into the engine computer. (Some manufacturers use a separate computer dedicated to the transmission but sharing information with the engine management computer.) In this case, solenoids turned on and off by the computer control shift patterns and gear ratios, rather than the spring-loaded valves in the valve body. This allows for more precise control of shift points, shift quality, lower shift times and (on some newer cars) semi-automatic control, where the driver tells the computer when to shift. The result is an impressive combination of efficiency and smoothness. Some computers even identify the driver's style and adapt to best suit it.
ZF Friedrichshafen AG and BMW were responsible for introducing the first five-speed automatic (the ZF 5HP18 in the 1992 BMW E34 5-Series) and the first six-speed (the ZF 6HP26 in the 2002 BMW E65 7-Series). Mercedes-Benz's 7G-TRONIC was the first seven-speed in 2003, with Toyota Motor Company introducing an 8-speed in 2007 on the Lexus LS.
Automatic Transmission Models
Some of the best known automatic transmission families include:
* General Motors — Powerglide, Turbo-Hydramatic 350 and 400, 4L60-E, 4L80-E
* Ford: Cruise-O-Matic, C4, C6, AOD/AODE, E4OD, ATX, AXOD/AX4S/AX4N
* Chrysler: TorqueFlite 727 and 904, A500, A518, 45RFE, 545RFE
* BorgWarner (later Aisin AW)
* ZF Friedrichshafen AG
* Allison Transmission
* Voith Turbo
* Aisin AW; Aisin AW is a Japanese automotive parts supplier, known for its automatic transmissions and navigation systems
* Honda
* Nissan/Jatco
Automatic transmission families are usually based on Ravigneaux, Lepelletier, or Simpson planetary gearsets. Each uses some arrangement of one or two central sun gears, and a ring gear, with differing arrangements of planet gears that surround the sun and mesh with the ring. An exception to this is the Hondamatic line from Honda, which uses sliding gears on parallel axes like a manual transmission without any planetary gearsets. Although the Honda is quite different from all other automatics, it is also quite different from an automated manual transmission.
Continuously variable transmissions
Main article: continuously variable transmission
A different type of automatic transmission is the continuously variable transmission or CVT, which can smoothly alter its gear ratio by varying the diameter of a pair of belt or chain-linked pulleys, wheels or cones. Some continuously variable transmissions use a hydrostatic drive consisting of a variable displacement pump and a hydraulic motor to transmit power without gears. CVT designs are usually as fuel efficient as manual transmissions in city driving, but early designs lose efficiency as engine speed increases.
A slightly different approach to CVT is the concept of toroidal CVT or IVT (from infinitely variable transmission). These concepts provide zero and reverse gear ratios.
Some current hybrid vehicles, notably those of Toyota, Lexus and Ford Motor Company, have an "electronically-controlled CVT" (E-CVT). In this system, the transmission has fixed gears, but the ratio of wheel-speed to engine-speed can be continuously varied by controlling the speed of the third input to a differential using an electric motor-generator.
Manually controlled automatic transmissions
Most automatic transmissions offer the driver a certain amount of manual control over the transmission's shifts (beyond the obvious selection of forward, reverse, or neutral). Those controls take several forms:
* Throttle kickdown: Most automatic transmissions include a switch on the throttle linkage that will force the transmission to downshift into the next lower ratio if the throttle is fully engaged. The switch generally only functions up to a certain road speed, so as to prevent a downshift that would overrev the engine. Some transmissions also had a part-throttle kickdown, obviating the need to "floorboard" the throttle to downshift.
* Low gear ranges: Many transmissions have switches or selector positions that allow the driver to limit the maximum ratio that the transmission may engage. On older transmissions, this was accomplished by a mechanical lockout in the transmission valve body preventing an upshift until the lockout was disengaged; on computer- controlled transmissions, the same effect is accomplished electronically. The transmission can still upshift and downshift automatically between the remaining ratios: for example, in the 3 range, a transmission could shift from first to second to third, but not into fourth or higher ratios. Some transmissions will still upshift automatically into the higher ratio if the engine reaches its maximum permissible speed in the selected range.
* Manual controls: Some transmissions have a mode in which the driver has full control of ratio changes (either by moving the selector or through the use of buttons or paddles), completely overriding the hydraulic controller. Such control is particularly useful in cornering, to avoid unwanted upshifts or downshifts that could compromise the vehicle's balance or traction. "Manumatic" shifters, first popularized by Porsche in the 1990s under the trade name Tiptronic, have become a popular option on sports cars and other performance vehicles. With the near-universal prevalence of electronically controlled transmissions, they are comparatively simple and inexpensive, requiring only software changes and the provision of the actual manual controls for the driver. The amount of true manual control provided is highly variable: some systems will override the driver's selections under certain conditions, generally in the interest of preventing engine damage.
Some automatic transmissions modified or designed specifically for drag racing may also incorporate a transmission brake, or "trans-brake," as part of a manual valve body. Activated by electrical solenoid control, a trans-brake simultaneously engages the first and reverse gears, locking the transmission and preventing the input shaft from turning. This allows the driver of the car to raise the engine rpm against the resistance of the torque converter, then launch the car by simply releasing the trans-brake switch.
Twin-clutch Gearbox
A Twin-clutch gearbox is a semi-automatic transmission with separate clutches for odd and even gears. Shifts can be accomplished without interrupting power by transferring torque between these two clutches. A dual clutch gearbox eliminates the torque converter, which is a major source of parasitic loss in a traditional automatic transmission. This type of gearbox was invented by Andolphe Kégresse just before the outbreak of World War II.
Essentially, the engine drives two clutch packs simultaneously. The outer clutch pack drives gears 1, 3, and 5 (and reverse). The inner clutch pack drives gears 2, 4, and 6. The synchronizers that select an odd gear can be moved while driving in an even gear and vice versa. Dual clutch transmissions that are currently on the market use wet multi-plate clutches, similar to the clutches used in traditional automatic transmissions. Versions that use dry clutches, like those usually associated with manual transmissions, are rumored to be in development by several manufacturers.
BorgWarner is currently the leading manufacturer of this type of transmission. They are most commonly sold under the name Direct-Shift Gearbox, as sold by Volkswagen Group. In August 2005 BorgWarner, who call their technology "DualTronic", signed further agreements with two other (unnamed) European automotive manufacturers to incorporate their gearbox.
Essentially, the engine drives two clutch packs simultaneously. The outer clutch pack drives gears 1, 3, and 5 (and reverse). The inner clutch pack drives gears 2, 4, and 6. The synchronizers that select an odd gear can be moved while driving in an even gear and vice versa. Dual clutch transmissions that are currently on the market use wet multi-plate clutches, similar to the clutches used in traditional automatic transmissions. Versions that use dry clutches, like those usually associated with manual transmissions, are rumored to be in development by several manufacturers.
BorgWarner is currently the leading manufacturer of this type of transmission. They are most commonly sold under the name Direct-Shift Gearbox, as sold by Volkswagen Group. In August 2005 BorgWarner, who call their technology "DualTronic", signed further agreements with two other (unnamed) European automotive manufacturers to incorporate their gearbox.
Right Angle Worm Gear Boxes
The AGNEE Worm Gear Boxes have Cast Iron Gear Case of streamlined design completely air tight, dust proof and capable of being installed in open without any cover. The Worm Shaft is made of Alloy Steel, duly hardened and tempered. The Worm Wheel is made of Chill Cast Phosphorous Bronze and teeth accurately Generated on Gear Hobbing Machines. They are supported on Extra Heavy Duty Taper Roller anti friction Bearings of ample margin of safety to allow adequate journals as well as thrust loads. Lubrication is effected by splash of oil from the sump. Thus, no special care is required except for occasional oil topping to the required level. Air cooling is effected by means of standard polypropylene or metal fans. Please read the Selection of Correct Worm gear box for choosing the correct one for your application. They are available in:
*
Vast range of Models suit every individual's requirement *
Some Models like C.D. 50, 60, 75, 85, 100 mm, Ratio 30:1 or 40:1 are usually available Ex-stock or on short notice *
Center Distances from 40 mm to 400 mm *
In Single or Double Stage Reductions *
Ratios from 5:1 to 4900:1 *
Also made as per customer's specifications, Drawing, requirements *
Overhauling of Old Gear Boxes also undertaken, Early delivery schedules *
Adaptable Worm Gear Boxes, range from CD 25mm to 85mm
Right angle gear boxes contain input shafts that are positioned perpendicular to the output shafts. Right angle gearboxes have up to 98% efficiency levels, and are common in printing presses and glass cutting equipment.
*
Vast range of Models suit every individual's requirement *
Some Models like C.D. 50, 60, 75, 85, 100 mm, Ratio 30:1 or 40:1 are usually available Ex-stock or on short notice *
Center Distances from 40 mm to 400 mm *
In Single or Double Stage Reductions *
Ratios from 5:1 to 4900:1 *
Also made as per customer's specifications, Drawing, requirements *
Overhauling of Old Gear Boxes also undertaken, Early delivery schedules *
Adaptable Worm Gear Boxes, range from CD 25mm to 85mm
Right angle gear boxes contain input shafts that are positioned perpendicular to the output shafts. Right angle gearboxes have up to 98% efficiency levels, and are common in printing presses and glass cutting equipment.
Semi Automatic Transmission
Semi-automatic transmission is a system that makes use of electronic sensors, processors and actuators for gear shifting. The system removes the need of a clutch pedal required for gear changing. This system is widely used in the automobile industry.
Types of Semi Automatic Transmission Direct Shift Gearbox Dual Clutch Gearbox The system allows for only forward and backward shift into higher and lower gears. It does not make use of the traditional H-pattern, normally used in automobiles. The system is also equipped with sensors that sense the direction of the shift. The input, combines with the sensor placed in the gearbox senses the current speed and selected gear. The unit also determines the torque required for smooth functioning. The system also reduces fuel consumption significantly.
Types of Semi Automatic Transmission Direct Shift Gearbox Dual Clutch Gearbox The system allows for only forward and backward shift into higher and lower gears. It does not make use of the traditional H-pattern, normally used in automobiles. The system is also equipped with sensors that sense the direction of the shift. The input, combines with the sensor placed in the gearbox senses the current speed and selected gear. The unit also determines the torque required for smooth functioning. The system also reduces fuel consumption significantly.
Automatic Transmission
Automatic transmission is a type of gearbox, especially used in the automobile industry for changing gear ratios automatically. It does not require manual shifting of gears. The gearbox has a set of selected gear range.
The system is hydraulically operated and makes use of a torque converter and a set of planetary gears.
Parts of an Automatic Transmission SystemAn automatic transmission consists of the following parts: Torque Converter: It is a device connecting engine and transmission. The instrument takes place of a mechanical clutch, allowing the engine to remain running. A torque converter that provides a variable amount of torque multiplication at low engine speeds. Planetary Gearbox Set: The bands and clutches of this gear set are actuated with the help of hydraulic servos controlled by the valve body, thereby providing two or more gear ratios. Valve Body: The system receives pressurized fluid from a main pump operated torque converter. The pressure coming from this pump is regulated used to run a network of spring-loaded valves, check balls and servo pistons. The valves make use of pump pressure and the pressure from a centrifugal controller on the output side. Use of Automatic Transmission Automobiles Forklift trucks Lawn mowers
The system is hydraulically operated and makes use of a torque converter and a set of planetary gears.
Parts of an Automatic Transmission SystemAn automatic transmission consists of the following parts: Torque Converter: It is a device connecting engine and transmission. The instrument takes place of a mechanical clutch, allowing the engine to remain running. A torque converter that provides a variable amount of torque multiplication at low engine speeds. Planetary Gearbox Set: The bands and clutches of this gear set are actuated with the help of hydraulic servos controlled by the valve body, thereby providing two or more gear ratios. Valve Body: The system receives pressurized fluid from a main pump operated torque converter. The pressure coming from this pump is regulated used to run a network of spring-loaded valves, check balls and servo pistons. The valves make use of pump pressure and the pressure from a centrifugal controller on the output side. Use of Automatic Transmission Automobiles Forklift trucks Lawn mowers
Information on Gearbox
Gearboxes are used in almost every industry right from power to marine, and also include agriculture, textile, automobiles, aerospace, shipping etc. There are different types of gearboxes available for varying uses. These gearboxes are constructed from a variety of materials depending on their end use and the kind of industry they are being used in. The product has numerous industrial applications for providing high torque and smooth speed reductions. These gearboxes are also manufactured keeping certain specifications in mind, which will also vary depending on the application.
SPUR GEARS WITH INTEGRAL HUB FASTENING SYSTEM
Module 0.5, 0.8, and 1 spur gears feature a patented Fairloc integral hub fastening system, which has been engineered to eliminate marred shafts. The 20-degree pressure angle precision gears conform to JIS B 1702 Grade 4 standards.
These 303 stainless steel units are identified as the SUSL Series. The hub fastener allows phase adjustment, timing, position adjustment, and frequent removal of the component.
The gears fit shafts ranging from 4 to 10 mm in diameter. They are stocked with face widths from 5 to 8 mm. Their sizes range from 14 to 120 teeth.
These 303 stainless steel units are identified as the SUSL Series. The hub fastener allows phase adjustment, timing, position adjustment, and frequent removal of the component.
The gears fit shafts ranging from 4 to 10 mm in diameter. They are stocked with face widths from 5 to 8 mm. Their sizes range from 14 to 120 teeth.
Chemical Resistant Gears
Chemical resistant gears are designed to help guard against corrosion in chemical processing industries. There is a complete line of readily available gears including stainless steel, Delrin and bronze styles to retard rust and corrosion. There are 30,000 sizes of replacement gears available. Many are hard-to-find gears in various non-corrosive materials and types including spur, helical bevel and miter, worm and worm gears and gear racks.
Gearing care and feeding
Gearing serves a critical role in plant operations, often as a crucial link in the power transmission chain. From providing power to operate complex machinery to supporting mission-critical functions, the importance of gearboxes and related machinery in maintaining successful, profitable operations can't be understated.
Gearing's role
Gearboxes play an important role in the everyday operations at processing and manufacturing facilities. For example, the steel and primary metal industry uses gearing components, such as precision shell pinion gearing, rolling mill drives and reducers, each engineered for large loads. In other industries, such as pulp and paper, gearing units ensure that sometimes difficult-to-maintain production machines are available to run continuously at high speeds.
Gearbox maintenance
For plant professionals, the ultimate goal is to achieve a return on investment (ROI) by maximizing machinery output, reliability and efficiency while minimizing downtime and operating costs. Gearing plays an important role in achieving that ROI. That's why a gearbox failure can be such a costly setback to overall plant operations.
When gearing equipment fails, the greatest concern is getting it running again. As important as getting it back online is discovering why it failed and how to prevent such a failure in the future. Oftentimes, plant managers and maintenance technicians aren't equipped to identify the root cause of such problems, which ultimately can lead to a recurrence.
An important first step in any preventive maintenance program is learning to identify the causes of gearing equipment failure. Then, one can take steps to avoid a repetition. Providing plant managers and service technicians with the knowledge to identify causes of gearbox failure allows them to establish an effective preventive maintenance program of their own.
Lubrication/oil analysis
Always important when there is potential metal-to-metal contact, effective lubrication is extremely critical to every gearbox. Proper lubrication helps prevent both gear and bearing failure. In contrast, many gear and bearing failures result from insufficient or interrupted lubrication.
Proper lubrication means following proper lubrication practices. These include using the correct lubricant, keeping oil clean and free of foreign materials, and maintaining a sufficient supply of lubricant. Because lubricant selection is based on so many independent variables , gear type, load type, speed, operating temperature, input power, reduction ratio , it's best to leave lube selection to a gear lubrication specialist. This is especially true when you consider the technical sophistication found in gearing today, along with increased speeds and loads, and the specialized lubricants and additives now available.
Ineffective lubrication causes several gear problems. Failures, such as scoring and galling, are generally caused by metal-to-metal contact. The tooth surface damage results from oil film breakdown and high temperatures. Continued operation without adequate lubrication degrades the gear's tooth profile to the point where replacement is the only remedy. Further, abrasive wear is often the result of foreign materials present in the lubricant.
Maintenance professionals have several tools at their disposal for diagnosing gearbox lubrication problems. Oil analysis prevents problems by assessing overall equipment health. By analyzing particulate content and concentration in the oil, engineers can monitor the condition of an operating gearbox. Advanced oil analysis yields vital information about the lubricant's fitness for use.
Lube oil analysis can alert plant professionals to possible problems in the lubrication system. Equipment that exhibits frequent mechanical problems or can cause downtime if it fails needs to be checked regularly for lubrication problems.
Further, wear patterns on gears can reveal lubrication problems. Gear tooth "pitting," characterized by a large number of very small pits evenly distributed over the gear's working surface, is usually an indication of overload, but also may indicate a problem associated with lubricant choice.
Avoid this
Use effective preventive maintenance to avoid having to shut down a line to perform shop repairs.
Vibration analysis
Vibration is a key diagnostic of machine faults. Machine geometry and operating speed determine vibration frequency. Each machine fault generates a specific vibration profile, and a single vibration signature can provide information about multiple components.
By analyzing shaft vibration, one can determine whether the cause -- imbalance, misalignment, general looseness, wear, bearing defects, gear defects or some other unforeseen problem.
High radial peaks, low axial vibration, low harmonics or sinusoidal speed pattern in the time domain at shaft speed characterize imbalance, which can cause other faults to appear. Once a structure is vibrating, any number of ancillary components can loosen.
Misalignment can occur as offset (shafts are meeting square, but not on a common centerline), angular (shafts are meeting at a slight angle), or both. Misalignment can cause a fracture originating at one end of a gear tooth and propagating along a diagonal line. Misalignment is also a common cause of broken teeth on helical and bevel gears.
Often, misalignment is the result of loose bearings, resulting in localized gear tooth loading and, later, a possible gear tooth fracture. A preventive maintenance program should include an inspection of bearings to ensure they have proper clearance and are in satisfactory condition. Checking proper adjustment is often part of such a program.
As well as revealing gear wear, vibration analysis can cover a broader range of damage , from scoring and galling, to abrasive wear, to plastic yielding. Plastic yielding , a severe flow of surface material resulting in lip ledges at the end of gear teeth , may occur on gears subjected to heavy, continuous load, as well as gears subject to intermittent heavy loads or overload.
Machinery optimization
Preventive maintenance measures not only ensure equipment keeps running, but running at peak output. This often means rerating a gearbox for optimum output based on its application. A detailed review of a gearbox and its application identifies the rerate potential, and in many instances, a gearbox can be rerated by upgrading rotational elements without adversely affecting existing gearbox interface requirements.
If equipment is maintained irregularly, operated at off-peak levels, or worse, at levels exceeding maximum output recommendations, preventive maintenance can be used to calibrate machinery so it operates at optimum levels , before it becomes a problem.
Stop, look, listen
Audiometric predictive technologies can bolster your oil analysis and vibration measurements.
Environmental factors
Environmental factors, such as corrosion in a humid environment and lack of maintenance, are as potentially damaging as equipment failures. For example, lack of accessibility to cooling tower drives, which can be 80 ft. above grade, may result in poor-to-nonexistent maintenance. In addition, equipment in moist, humid environments is more susceptible to corrosion as moisture accumulates inside the gearbox and destroys the bearings.
Compounding the problem, safety concerns often don't allow for inspection of the units while they're operating. Consequently, this limits inspection and repair routines, making cooling tower drive failures a mystery.
The PM program
Whereas identifying the cause of equipment failure sometimes can be as simple as looking at the damage closely, discovering the root cause of a problem is often considerably more difficult. The bottom line is that most plants don't have the sophisticated equipment needed to identify shaft vibration anomalies or analyze oil samples for foreign materials. Without these resources, it's difficult to establish a PM program.
Outsourcing preventive maintenance functions is certainly an option that allows plants to focus on core competencies, while letting experts, with access to both a strong knowledge base and the necessary equipment, handle maintenance and repair duties.
Several key services should be included in any service agreement. Repair and overhaul services are a necessity; all equipment will need maintenance sooner or later. Such services should cover breakdowns, scheduled maintenance, parts reconditioning, service upgrades, reverse engineering, alignment and balancing, and on-site as well as off-site diagnostic services. Providers should be thoroughly skilled in performing gearbox failure root cause analysis. For repairs, full disassembly and cleaning, inspection and measurement, engineering evaluation, rerate recommendations, repairs and spin test throughout the entire operating range should be part of the package. Failure analysis is another important service in the case of catastrophic failure.
Troubleshooting is another necessary part of a comprehensive preventive maintenance program. This should include assistance in identifying and resolving operational problems swiftly. Other services include vibration and oil analysis, the keystone monitoring techniques that are paramount in identifying equipment anomalies before they become a problem.
Any good PM contract should include a strong warranty. Also, as important as any warranty is proper gearbox installation to ensure years of trouble-free operation, provided that adequate preventive maintenance procedures are performed.
While identifying the cause of gearbox equipment failure is only the first step in establishing an overall preventive maintenance program, it is an important step. The information gathered will ultimately serve as the foundation for planning future preventive maintenance , a particular necessity when working with mission-critical equipment. Such information also will help service technicians avoid making the same mistakes after initial equipment repairs. Once this information is determined, working with a service provider to establish a complete preventive maintenance program is important in maintaining equipment for future use, as well as reducing equipment life-cycle costs.
Gearing's role
Gearboxes play an important role in the everyday operations at processing and manufacturing facilities. For example, the steel and primary metal industry uses gearing components, such as precision shell pinion gearing, rolling mill drives and reducers, each engineered for large loads. In other industries, such as pulp and paper, gearing units ensure that sometimes difficult-to-maintain production machines are available to run continuously at high speeds.
Gearbox maintenance
For plant professionals, the ultimate goal is to achieve a return on investment (ROI) by maximizing machinery output, reliability and efficiency while minimizing downtime and operating costs. Gearing plays an important role in achieving that ROI. That's why a gearbox failure can be such a costly setback to overall plant operations.
When gearing equipment fails, the greatest concern is getting it running again. As important as getting it back online is discovering why it failed and how to prevent such a failure in the future. Oftentimes, plant managers and maintenance technicians aren't equipped to identify the root cause of such problems, which ultimately can lead to a recurrence.
An important first step in any preventive maintenance program is learning to identify the causes of gearing equipment failure. Then, one can take steps to avoid a repetition. Providing plant managers and service technicians with the knowledge to identify causes of gearbox failure allows them to establish an effective preventive maintenance program of their own.
Lubrication/oil analysis
Always important when there is potential metal-to-metal contact, effective lubrication is extremely critical to every gearbox. Proper lubrication helps prevent both gear and bearing failure. In contrast, many gear and bearing failures result from insufficient or interrupted lubrication.
Proper lubrication means following proper lubrication practices. These include using the correct lubricant, keeping oil clean and free of foreign materials, and maintaining a sufficient supply of lubricant. Because lubricant selection is based on so many independent variables , gear type, load type, speed, operating temperature, input power, reduction ratio , it's best to leave lube selection to a gear lubrication specialist. This is especially true when you consider the technical sophistication found in gearing today, along with increased speeds and loads, and the specialized lubricants and additives now available.
Ineffective lubrication causes several gear problems. Failures, such as scoring and galling, are generally caused by metal-to-metal contact. The tooth surface damage results from oil film breakdown and high temperatures. Continued operation without adequate lubrication degrades the gear's tooth profile to the point where replacement is the only remedy. Further, abrasive wear is often the result of foreign materials present in the lubricant.
Maintenance professionals have several tools at their disposal for diagnosing gearbox lubrication problems. Oil analysis prevents problems by assessing overall equipment health. By analyzing particulate content and concentration in the oil, engineers can monitor the condition of an operating gearbox. Advanced oil analysis yields vital information about the lubricant's fitness for use.
Lube oil analysis can alert plant professionals to possible problems in the lubrication system. Equipment that exhibits frequent mechanical problems or can cause downtime if it fails needs to be checked regularly for lubrication problems.
Further, wear patterns on gears can reveal lubrication problems. Gear tooth "pitting," characterized by a large number of very small pits evenly distributed over the gear's working surface, is usually an indication of overload, but also may indicate a problem associated with lubricant choice.
Avoid this
Use effective preventive maintenance to avoid having to shut down a line to perform shop repairs.
Vibration analysis
Vibration is a key diagnostic of machine faults. Machine geometry and operating speed determine vibration frequency. Each machine fault generates a specific vibration profile, and a single vibration signature can provide information about multiple components.
By analyzing shaft vibration, one can determine whether the cause -- imbalance, misalignment, general looseness, wear, bearing defects, gear defects or some other unforeseen problem.
High radial peaks, low axial vibration, low harmonics or sinusoidal speed pattern in the time domain at shaft speed characterize imbalance, which can cause other faults to appear. Once a structure is vibrating, any number of ancillary components can loosen.
Misalignment can occur as offset (shafts are meeting square, but not on a common centerline), angular (shafts are meeting at a slight angle), or both. Misalignment can cause a fracture originating at one end of a gear tooth and propagating along a diagonal line. Misalignment is also a common cause of broken teeth on helical and bevel gears.
Often, misalignment is the result of loose bearings, resulting in localized gear tooth loading and, later, a possible gear tooth fracture. A preventive maintenance program should include an inspection of bearings to ensure they have proper clearance and are in satisfactory condition. Checking proper adjustment is often part of such a program.
As well as revealing gear wear, vibration analysis can cover a broader range of damage , from scoring and galling, to abrasive wear, to plastic yielding. Plastic yielding , a severe flow of surface material resulting in lip ledges at the end of gear teeth , may occur on gears subjected to heavy, continuous load, as well as gears subject to intermittent heavy loads or overload.
Machinery optimization
Preventive maintenance measures not only ensure equipment keeps running, but running at peak output. This often means rerating a gearbox for optimum output based on its application. A detailed review of a gearbox and its application identifies the rerate potential, and in many instances, a gearbox can be rerated by upgrading rotational elements without adversely affecting existing gearbox interface requirements.
If equipment is maintained irregularly, operated at off-peak levels, or worse, at levels exceeding maximum output recommendations, preventive maintenance can be used to calibrate machinery so it operates at optimum levels , before it becomes a problem.
Stop, look, listen
Audiometric predictive technologies can bolster your oil analysis and vibration measurements.
Environmental factors
Environmental factors, such as corrosion in a humid environment and lack of maintenance, are as potentially damaging as equipment failures. For example, lack of accessibility to cooling tower drives, which can be 80 ft. above grade, may result in poor-to-nonexistent maintenance. In addition, equipment in moist, humid environments is more susceptible to corrosion as moisture accumulates inside the gearbox and destroys the bearings.
Compounding the problem, safety concerns often don't allow for inspection of the units while they're operating. Consequently, this limits inspection and repair routines, making cooling tower drive failures a mystery.
The PM program
Whereas identifying the cause of equipment failure sometimes can be as simple as looking at the damage closely, discovering the root cause of a problem is often considerably more difficult. The bottom line is that most plants don't have the sophisticated equipment needed to identify shaft vibration anomalies or analyze oil samples for foreign materials. Without these resources, it's difficult to establish a PM program.
Outsourcing preventive maintenance functions is certainly an option that allows plants to focus on core competencies, while letting experts, with access to both a strong knowledge base and the necessary equipment, handle maintenance and repair duties.
Several key services should be included in any service agreement. Repair and overhaul services are a necessity; all equipment will need maintenance sooner or later. Such services should cover breakdowns, scheduled maintenance, parts reconditioning, service upgrades, reverse engineering, alignment and balancing, and on-site as well as off-site diagnostic services. Providers should be thoroughly skilled in performing gearbox failure root cause analysis. For repairs, full disassembly and cleaning, inspection and measurement, engineering evaluation, rerate recommendations, repairs and spin test throughout the entire operating range should be part of the package. Failure analysis is another important service in the case of catastrophic failure.
Troubleshooting is another necessary part of a comprehensive preventive maintenance program. This should include assistance in identifying and resolving operational problems swiftly. Other services include vibration and oil analysis, the keystone monitoring techniques that are paramount in identifying equipment anomalies before they become a problem.
Any good PM contract should include a strong warranty. Also, as important as any warranty is proper gearbox installation to ensure years of trouble-free operation, provided that adequate preventive maintenance procedures are performed.
While identifying the cause of gearbox equipment failure is only the first step in establishing an overall preventive maintenance program, it is an important step. The information gathered will ultimately serve as the foundation for planning future preventive maintenance , a particular necessity when working with mission-critical equipment. Such information also will help service technicians avoid making the same mistakes after initial equipment repairs. Once this information is determined, working with a service provider to establish a complete preventive maintenance program is important in maintaining equipment for future use, as well as reducing equipment life-cycle costs.
Gearboxes drive huge X-ray machine in Middle East
Huge plattons carrying driverless lorries through a giant X-ray machine glide smoothly across a series of wheels driven by gearboxes secured to spring-loaded base plates.
A company in the UK has designed and constructed a huge X-ray machine capable of scanning an entire articulated lorry, in one go, for a government in the Middle East. The machine has been installed to increase efficiency at a border crossing by scanning entire lorries like suitcases at airport security points. The machine increases the speed with which lorries are processed and eliminates the risk of error, which is inherent with manual security checks.
The driverless lorries are taken through the X-ray machine on plattons driven by a power transmission system designed by Renold Gears of Milnrow, Lancashire.
The huge plattons glide smoothly across a series of wheels driven by gearboxes secured to spring-loaded base plates.
The wheels are fitted with tyres to create the right degree of cushioning and friction with the plattons.
As the platton carrying the lorry moves from one set of wheels to the next, the weight of the lorry depresses the spring-loaded plate creating tension with the driving wheel sufficient to propel the platton forwards.
A long line of gearboxes takes each lorry from a start point, where the driver disembarks, through the machine and out the other side where the driver rejoins the vehicle and waits for security clearance to continue the journey.
The gearboxes had to be fitted in pits below ground with limited space so Renold's engineers selected PB50 and PB40 helical bevel helical gearboxes that provide high torque from a compact design.
A special case was designed for the gearboxes, which included removing the corner of the standard case to ensure they fitted into the limiting space of the pit.
Renold Gears also supplied the gearboxes that open and close the huge lead doors that protect security personnel from harmful radiation while lorries are being scanned inside the machine.
Simon McClean, Renold Gears Project Manager, said: 'It was Renold Gears' ability to provide complete designs and supply within the given timescale that helped us to win this contract'.
A company in the UK has designed and constructed a huge X-ray machine capable of scanning an entire articulated lorry, in one go, for a government in the Middle East. The machine has been installed to increase efficiency at a border crossing by scanning entire lorries like suitcases at airport security points. The machine increases the speed with which lorries are processed and eliminates the risk of error, which is inherent with manual security checks.
The driverless lorries are taken through the X-ray machine on plattons driven by a power transmission system designed by Renold Gears of Milnrow, Lancashire.
The huge plattons glide smoothly across a series of wheels driven by gearboxes secured to spring-loaded base plates.
The wheels are fitted with tyres to create the right degree of cushioning and friction with the plattons.
As the platton carrying the lorry moves from one set of wheels to the next, the weight of the lorry depresses the spring-loaded plate creating tension with the driving wheel sufficient to propel the platton forwards.
A long line of gearboxes takes each lorry from a start point, where the driver disembarks, through the machine and out the other side where the driver rejoins the vehicle and waits for security clearance to continue the journey.
The gearboxes had to be fitted in pits below ground with limited space so Renold's engineers selected PB50 and PB40 helical bevel helical gearboxes that provide high torque from a compact design.
A special case was designed for the gearboxes, which included removing the corner of the standard case to ensure they fitted into the limiting space of the pit.
Renold Gears also supplied the gearboxes that open and close the huge lead doors that protect security personnel from harmful radiation while lorries are being scanned inside the machine.
Simon McClean, Renold Gears Project Manager, said: 'It was Renold Gears' ability to provide complete designs and supply within the given timescale that helped us to win this contract'.
Gearboxes extend to heavy duty applications
Renold Gears has extended its SMXtra range of shaft mounted helical gearboxes, for heavy duty applications, to include sizes 11 and 12 that match the largest equivalent units from Fenner, Benzler Sala and Dodge. The ATEX approved range is now available in 12 sizes up to 235kW capacity with a choice of single or double reduction units with ratios of up to 25:1 and output speeds from 10 to 400rev/min. The SMXtra gearbox range is manufactured with hardened, profile ground single helical gears with high capacity bearings to ensure maximum power transmission, maximum load carrying capacity and longer life.
The units mount directly onto the shaft of the driven machine completely eliminating alignment problems as there is no need for couplings, base plates, slide rails or support structures.
They are ideally suited to heavy-duty applications in hostile environments and provide the ideal drive for many types of machinery.
Depending on requirements the SMXtra range can be fitted with advanced seals to optimise protection from dust and moisture.
Additionally, by reversing one element of the standard design, the seal can provide additional security to prevent the egress of oil into sensitive environments such as in food manufacturing.
Renold Gears has produced a new catalogue for all the gearboxes in its SMXtra range, including the new sizes 11 and 12, with details of the power ratings for each unit.
The units mount directly onto the shaft of the driven machine completely eliminating alignment problems as there is no need for couplings, base plates, slide rails or support structures.
They are ideally suited to heavy-duty applications in hostile environments and provide the ideal drive for many types of machinery.
Depending on requirements the SMXtra range can be fitted with advanced seals to optimise protection from dust and moisture.
Additionally, by reversing one element of the standard design, the seal can provide additional security to prevent the egress of oil into sensitive environments such as in food manufacturing.
Renold Gears has produced a new catalogue for all the gearboxes in its SMXtra range, including the new sizes 11 and 12, with details of the power ratings for each unit.
Repair service gears up for big job
Renold Gears' gearbox repair service was put to the test just recently when it won the contract from steel maker Corus to refurbish the massive dog-bar gearboxes at its Teesside Beam Mill.
The gearboxes are among the biggest Renold has ever repaired, standing over 1.5m high and weighing in at around 10t each. They are over 40 years old and now require re-engineering to a very high standard.Renold's ability to repair old gearboxes and improve on the original specification was one of the key factors that helped the company win the prestigious contract.
Corus' Beam Mill manufactures a range of steel sections for the construction industry at its large plant on Teesside, measuring around 1km.
The sections are produced from 10 tonne steel blooms or larger slabs weighing up to 30 tonnes, following which they are cut to length and then stacked in cooling banks where they are allowed to cool to ambient temperature prior to despatch.
It is here, in pits beneath the floor of the cooling banks that the dog-bar gearboxes are found.
Cam arms attached to the output shafts of the gearboxes rise up when rotated and transfer the hot sections over to the cooling banks.
The gearboxes were originally manufactured in 1964 by Crofts Engineers, of Bradford, a company that was acquired by Renold just three years later in 1967.
The original blueprints were found in the company's archives and so components for the gearboxes could be manufactured to their original specifications, but modified for enhanced performance.
The gearboxes are being refurbished one at a time and the first of four was returned to its Teesside home in May 2006.
Renold's repair team improved the original specification in several ways so that the repaired unit was better than when it was new.
The team redesigned and upgraded the material of the output shaft and fitted an internal pumping system to feed lubrication directly to the gears and bearings.
The case was also ultrasonically tested for leaks prior to reassembly with the new gears, shafts, bearings and the new pumping system.
The second gearbox is due to be installed during the plant's shutdown when the next gearbox will be taken away for repair.
Modes of Management - Shifting Management Gears as Your Company Grows
Modes of Management
Adjusting Your Management Style To Your Company's Stage
By Bob Norton
From the moment a new company is founded to its appearance on the Fortune 500 list, executives must be able to transform the way they manage a company — shifting gears, often dramatically to a different management style — to ensure the company’s optimum development. I am not referring to individual executive style here. What I am talking about is the total adjustment and evolution of the context in which major management decisions are made. I call this the “Mode of Management”, which is very dependent on the company’s current developmental stage.
Would you make the same product development decisions in an identical way with one hundred dollars in the bank and no customers as you would with $50 million in the bank and 1,000 customers? Of course not! So why do many managers often run an organization in the same way despite the many gradual and often sudden changes that happen between these two extremes? It is human nature to continue to do what we have always done; to simplify and repeat what worked in the past, despite vastly differing circumstances. We need a system or context for adjusting and teaching the different “modes of management” as companies evolve. Some of these changes come naturally, but most are very subtle and linger far longer than they should. A failure to change can do substantial damage to a company before adjustments are made, or even doom the company to flat sales in the long term.
A key to ensuring corporate success is to let the various stages of a company's development determine it’s overall management “mode”. It is a given that we must use the appropriate management mode for each and every decision and action we take in a company. The company's existing condition and/or stage of development is always the major determining factor or context for almost every significant decision.
Companies can reap enormous benefits when the style by which they are managed is adjusted quickly to accommodate the company’s shifting complexities, stages and sensitivities. In fact, quickly adjusting this mode of management can be a huge competitive advantage since most companies fail to adjust quickly enough. Just about every company exhibits often-overlooked, but critical, stress points that signal the need for decisive action or gradual reorganization. Recognizing these signs during a company’s gradual metamorphosis, and responding to them appropriately, may mean the difference between bankruptcy and survival, or at least will help avoid stagnation.
Any good manager knows an adjustment in style and tone is warranted for different individuals and situations. People have different motivations and often respond differently to the exact same circumstance. This is natural; people react to other people’s tone and body language in very individual ways. We receive immediate feedback in the form of facial expression, body language and actions, and adjust our reactions accordingly. However, a company, which is a much more complex organism that consists of many individuals interacting with complex outside market conditions, provides little immediate feedback. Therefore, it is very difficult to use direct feedback to fine-tune your management mode. Only years of experience can build enough data to form theories and adjust management modes.
Why We Simplify Too Much
Millions of years of evolution have taught us to run from danger and created a mind that adheres to simple "rules" that have worked for us in the past. Our mind wants basic rules we can reuse and has been designed to use these learned shortcuts again and again. For example, we all know that fire is hot, don’t touch it. The more pain (failure) or pleasure (success) that results from a lesson, the deeper these rules are ingrained. This is why people who experience a single, huge success often have a tougher time changing or accepting input from outside sources. They take this success as proof that they are “always” right and begin to repeat what has worked for them before. If they use their one learned mode in a different context then they are very likely to fail.
Unfortunately, the world is much more complex, and changes much more rapidly, than ever before. In fact, this trend is accelerating because human knowledge is now doubling every few years. One hundred years ago, most people still used horses to get around and technology of any kind was primitive by today’s standards. Because life is currently so much more complex, we need these mental simplifications more than ever. Yet now, we must overcome these past evolutionary behaviors and discipline ourselves to take hundreds of variables into account for complex and unique decisions we may never again make under the same circumstances.
Overcoming evolution can be difficult, but it is simply an exercise in conscious thinking that can be facilitated by some simple methodologies that force us to review important circumstances. The challenge as an executive is to force ourselves to think through all the variables of a given situation and make a decision in the proper, current context, not simply by referring to past experiences or rules of thumb.
Cognitive dissonance, the mind's tendency to see only those factors that reinforce what we are expecting to see, greatly aggravates this problem. We tend to distinguish only those things that reinforce our beliefs and actively avoid or explain away those things that disprove these beliefs. At the extreme, this can become the proverbial ostrich with its head in the sand — the "What I don't know can't hurt me" pose. Of course, this statement couldn’t be further from the truth. Any company that fails to adjust to rapidly changing world, economic, and market conditions is doomed. Even great Fortune 500 companies are rarely still there 25 years later. As managers we have to overcome human nature and cognitive dissonance in order to make the proper contextual decisions for the benefit of our company.
Cognitive Dissonance – The strong tendency to see and acknowledge only that which reinforces what you already know and ignore or easily explain away data that conflicts with your beliefs. The desire to avoid dissonance, or inconsistency, that would make you rethink things you already believe to be true.
The 5 Stages of a Company's Development
1) Raw Startup No revenue (by definition) 0-50
a) Innovation as a priority
b) Always in flux, high risk
c) More unknowns than knowns
d) Product or service looking to prove its market exists
e) Everything is fragile
2) Early Revenue $100 to $5MM, 5 to 100 employees, Product delivered proving some value proposition, but still no proven sustainable or profitable business model. Most companies slow or stop growing here due to organizational and people limits. This is often the hardest leap to make which requires the most changes in the smallest period of time.
3) Established Customer Base $500,000 to $20MM in sales, 20 to 200 employees
a) Profitable or clear path to profits based on scaling business.
b) A proven market and value or price formula, with profits clearly available in a steady state world when scaled.
4) Expansion/Growth Phase $1MM to $1 billion in sales, 100 to 1,000 employees
Market opportunity is many times larger than the company and there is a desire and ability for significant market share and/or revenue growth.
5) Mature (or large) $2MM to $100+ billion in sales, 100 to ∞ employees
a) Slow growth, stagnation of market or company, or focused on harvesting past investments.
b) Slow/little change in market and/or company or commoditization of products forcing a focus on costs above innovation.
c) Consolidation of competitors and focus on finding new distribution and/or leverage.
Companies come in many types, styles and sizes, and an approach that works tremendously well at one company can be a miserable failure at a different place and time. Every company and situation is different, so there are literally hundreds of possible “styles” or “management modes.” For practical purposes, it is necessary to create a simpler, more workable model, which can be used to illustrate a company’s major plateaus and organize this infinite spectrum into useful stages. Then we can probe along the required dimensions for key issues.
Only experience at executive levels in large, medium and small companies can help to identify the pivotal developmental stages that dramatically affect the context of a given company’s decisions. Success comes from implementing a management mode that is a direct function of the company’s current stage, industry and market conditions. The risk is that a company will be run in the same way as its VPs, managers and/or CEO have always run their past companies or departments, irrespective of the important and differing macro variables created by this stage of development.
What is Different about This Philosophy?
Conduct a search via Amazon.com or the Internet on the term “management” and you will literally find tens of thousands of books on the subject. From project management to company management, lots of authors push their particular methods and styles. These range from micromanagement and the One-Minute Manager to how to transform “good” into “great” behavior. What you will not find is much discussion in any of these books about an approach that helps you define and implement a management mode that clearly correlates to your company’s current status and position in the market. Yes, there are a few good books and some successful startups, but, in general, there is little on this topic available in the millions of books in print! I don’t know if the lack of discourse is just because authors want to appeal to the broadest possible audience, or if they are actually naive as to how one must manage differently according to the different stages of a company. I am certainly not the first person to recognize this natural phenomenon. I suspect that authors are addressing the stage of company they are most familiar with without much thought to the others. Unfortunately, for the bulk of their readers, this can make the majority of their recommendations and advice wrong, which is of little help. When making a major decision, too little credence is given to the enormous number of variables that make every corporate situation unique.
Actually, I have seen very successful executives with significant experience in large company environments give perfectly good talks on management that are 100 percent true for large companies — and almost 100 percent wrong and potentially fatal if followed by smaller companies. They are talking about steering an oil tanker when their audience consists of nothing but little speedboat captains. These executives must have little experience and perspective beyond that large company perch, and they often wind up preaching to a crowd of entrepreneurs about things they must do, when in fact, following that advice could kill their companies. The problem is that there was no context defined for the lecture and no language or thinking in the advice about a company’s current stage. If it had been qualified as advice for companies over $70 million in sales, for example, it would not have been a potentially lethal lecture for the many startups and entrepreneurs in attendance that day. It seems we pay little heed to the simple fact that what can be right for a small company can be totally disastrous for a larger company and vice versa.
Of course, the opposite situation can also be true, wherein entrepreneurs, more often than not, fail to change their company’s and personal management styles from raw startup mode to the next level. They cannot “let go” and delegate to others. This is why entrepreneurs are often replaced by “professional management” or people with specific experience in that stage of company development. It is also a major reason why most companies stagnate at a certain level, which is ultimately the maximum level or size at which a controlling entrepreneur can be effective or remain in their comfort zone. A Board of Directors of any company with more than a single shareholder has a fiduciary responsibility to replace such a CEO as soon as there are signs the entrepreneur is not evolving with the company so as to ensure that stockholder value continues to grow. I believe a solid, well thought-out system can allow many entrepreneurs to make this evolutionary transition as their company grows.
Adjusting to the Best Management Mode
My goal is to shine a light on this failure to preach in context and to create a methodology to qualify these recommendations and comments and adjust our mode of management. This needs a system of definitions, models and language. To be successful, we must also have some guidelines for management modes that are appropriate for certain stages and situations in a company’s life. This would allow us to benchmark our management mode and proactively evolve it as a company grows.
Unfortunately, there are not many people who have experience and perspective in various different size companies and can speak to these vast differences. Academia cannot properly recognize and study this problem without first establishing a framework by someone with experience across most stages of a company’s development. After all, this is not so much a theoretical problem as a real world experiential learning issue and therefore it is hard to define and bound properly.
Each decision we make is highly context-sensitive to many macro factors. Sometimes, these macro factors are developed or institutionalized over time. For example, IBM would never go after a very small market because doing so would distract management and resources from bigger market opportunities that would better serve its corporate size, overhead and growth needs. Everyone at IBM knows this and, accordingly, would not present a plan to the IBM corporate machinery for a product with a very small market opportunity. However at the other extreme, younger companies have not had the time or experience to develop such rules or systems, forcing executives of small and medium-sized firms to make them up as they go along based on the specific circumstances of the day. People may attempt to adopt their own "rules of thumb" from their former companies, but the odds that these are also appropriate for their new company are slim indeed. I have seen many young companies enter markets that were way too big for them to be successful in because larger companies will replicate what they do quickly and because they have not already secured a beachhead they can protect before evolving into the larger market. This classic startup without a market entry strategy is common in technology where technologists do not have enough experience in building businesses and attaching markets. I cannot possibly count the number of companies with a superior product that ultimately failed because they did not adjust their market entry strategy to the size of their company’s resources or because they managed the company like a large one when it was just in its infancy.
An executive’s ability to shift gears in the face of a situation that appears familiar, but is actually ALMOST ALWAYS a different context compared to what they have seen in the past, can make or break a company. When a decision’s context is very different due to the corporation’s current stage, it must be recognized immediately to produce a vibrant, growing company.
So what do you do differently along the spectrum from a raw startup to a mature company? There is enough information for an entire book or at least a long series of articles. It requires many examples and structural models to aid the decision-context management. The first step toward success is acknowledging the need for a decision-context management framework and an understanding that the biggest factor in almost any corporate decision is this framework. Upcoming articles will compare and contrast management modes for a wide range of companies, from small through large.
Motoring: New style gearbox on the way
OF THE many Heath Robinson-like contraptions that make up the modern car, none is so needlessly complicated as the manual gearbox. For starters, it demands that a car has three pedals when, to paraphrase Dickens, popular prejudice runs in favour of people having only two feet.
Even Grand Prix drivers have given up the challenge. Modern F1 cars do not have foot clutches, the technical boffins having discovered a better way. The clutches of F1 cars are engaged automatically, as drivers change gear using steering column-mounted paddles.
Yet modern road cars still make do with a stick having to be negotiated through an awkward H-pattern and a clutch which, in concert with the brake and the accelerator, demand the most dextrous of feet movements. Even if you are good at it, it can still be a pain. Juggling with clutch, throttle and gears as you fight your way home in nose-to-tail traffic is irritating, tiring and bad for wearing out the soles of good shoes.
Until recently, the only alternative has been the automatic gearbox. In America, where motorists are less macho than in Europe and take less pleasure in driving, almost everybody buys automatic. In the past year or so, new style semi-automatic gear changes have also surfaced, the Porsche 911 Tiptronic was the first, which seek to replicate clutchless F1 gear shifts using paddles, buttons or a stick. Most are at least partly a con, for they use automatic gearboxes as their base. As a result, power is not parcelled to the wheels as efficiently as on a manual gearbox.
That is changing. The large car makers are on the verge of releasing gearboxes which can double as both manuals and automatics. Of the mass makers, Renault is likely to be there first. Next year it launches a new transmission called the BVR (boite de vitesses robotise, or robotised gearbox). I drove a prototype version recently, fitted to a Twingo. At the touch of a button, your fully automatic gearbox (ideal in traffic) can be converted into a five- speed manual. Hit some traffic again, or lose interest in DIY gear changing? Then go back to full auto mode.
There is no clutch, even in manual form. On the prototype I drove, you changed gear by using a conventional stick. In production form, gear changes will be made by F1-style steering column paddles and the change pattern will be sequential, as in a motorcycle. Push a button, and you are back in full auto mode.
The BVR system is likely to be offered in the Clio and Megane from next autumn. Other clutchless manual gearboxes from other manufacturers are imminent.
For those who like to labour, the clutch will probably always have its place. But for those who like their machinery to shoulder as much of the responsibility as possible, the "third pedal" is on its way out. Although few will admit it, most drivers must privately be rather glad.
Hey buddy, can you spare a gear? Expect more - and less - from transmissions - Column
Mike Kluger manager-automatic transmission technology section at Southwest Research Institute (SWRI), has authored or co-authored numerous SAE papers relating to transmission technology and SWRI tests. He also evaluates transmissions for many of the world's major automakers. Mr. Kluger recently shared his thoughts on near-term automatic-transmission development with WAW.
The industry has experienced numerous interesting developments in automatic transmission configurations in recent years, some of which appear almost contradictory. In the next five years we'll see an accelerated degree of engineering research focused on transmissions.
In particular, there will be increased demand to, reduce manufacturing costs while simultaneously improving transmission efficiency. These goals will partially be realized through material advaces and with a heavy emphasis on reducing parasitic, or "spin" losses.
A sampling of some near-term automatic transmission trends and advances: Future transmission configurations At the top end of the market, a recent trend has been the move toward 5-speed automatics, now beginning to appear in a number of luxury and near-luxury passenger cars. The impetus behind this development is a typical 5% improvement in fuel economy over vehicles with 4-speed transmissions. To transition to 5-speed configuration, some existing 4-speed automatics comprised of three planetary gear sets will obtain the additional gear ratio by "swap" shifting, which allows two clutch packs to be shifted simultaneously. During swap shifting, one clutch pack is engaging while the other is disengaging. The additional precision hydraulic control required for this procedure is provided with fast-acting solenoids and by installing increased memory in the powertrain control module.
Coincidentally, consumers concerned about the cost of new vehicles show an emerging industry need for inexpensive vehicles with simple, serviceable automatic transmissions.
For this reason, we will see a return to traditional 3-speed automatic transmissions. Although they reduce fuel efficiency by approximately 12%, they are significantly less costly because of the reduced number of parts.
To obtain improved shift quality in the future, automatic transmission clutch bands will no longer be used - they do not provide the precise engagement control clutch packs offer.
Automatic transmission fluid (ATF)
In future transmission designs, the automatic transmission will incorporate a fill-for-life ATF system. In addition to eliminating the need for a dipstick and tube, sealing prevents incorrect ATF levels, a condition that today accounts for a large degree of serious transmission damage.
Sealing transmission fluids, however, places a considerable burden on the quality and composition of the ATF. More stable friction modifiers are necessary to withstand continuously slipping torque converter operation. Sealing the ATF also requires increased oxidation protection, as well as the use of thinner, less viscous transmisision fluids that may need to include synthetic base stocks for improved efficiency - and will certainly make ATF more expensive.
Torque converters
In an effort to improve fuel economy, shift quality and NVH characteristics, there have been attempts in recent years to adopt continuously slipping torque converter they allow transmisisons to transition easily from the "unlocked" to the "locked" mode. Current transmission designs are torque-limited because the friction load-carrying capabilities of today's standard lock-up clutch permits low-torque operation only in third and fourth gear.
Future advances will incorporate locked-up converter operation in all but the lower two-thirds of first gear. Test results using the recommended Environmental Protection Agency (EPA) city-cycle guidelines show a 7% improvement in fuel economy in the locked converter mode.
Solenoids
Fast-acting solenoids - providing better control and more "precise" transmission performance - were first introduced eight years ago for torque converter lockup clutch engagement. Since then, the use of solenoids has increased exponentially to the point where certain quality transmissions contain more than eight, overseeing such tasks as gearshift selection and pressure control. Most current transmissions use only four solenoids, but the number undoubtedly will increase in the future.
Pump systems
Pumping loss accounts for a disproportionately high percentage of the overall power consumed by an automatic transmission and can be as high as 20% in some cases. To reduce these losses, manufacturers have developed new, duocentric and hypocycloid gear designs for the fixed-displacement, internal gear tooth forms.
The advantage of a hypocycloid design, for example, is that it requires only half as many teeth as a conventional internal-external gear form, is at least 15% more efficient and is less expensive.
In some new automatics, there is increasing use of a fluid-recirculation "boost" loop that returns unused, pressurized fluid to the pump inlet. The boost loop dramatically improves fluid flow at crankshaft speeds greater than 3,500 rpm and helps forestall the damaging effects of cavitation at high speeds. Cavitation can be a critical problem for new vehicles with advanced engines delivering shift speeds as high as 7,200 rpm.
Machine gear producer synchronizes engineering changes and documentation - Pro/ENGINEER software and BPS Industries
Companies often move into new areas of business because of changing technology or the introduction of new products by a key customer, who requires their support. Such a scenario unfolded for BPS Industries, Baltimore, Maryland, a firm that machines industrial plastics. The customer was Flowdata, Inc., a manufacturer of precision flow-metering systems. The product was a radically new gear-like impeller called the Vector.
Flowmeters measure liquid flows with paired impellers, and great accuracy is required in machining their complex geometries. To work properly, Flowdata's impellers have to mesh perfectly. The patented Vectors mesh so well and run so smoothly that Flowdata eliminated the synchronizing gearboxes, a system common among competing flowmeter designs. Based in Richardson, Texas, Flowdata designs, assembles, tests and calibrates but does not cut metal. It relies on BPS, 1400 miles away, for machining.
Vector impellers are true gears but contain only three or four oversized teeth known as lobes that twist around the impeller's core. Although elegant, Vector's lobes are generated like any other gear teeth, with a mathematical formula called an involute curve. Machining the curved surface of the product, however, is a challenge using standard approaches.
Cutting the teeth of the Vectors required a breakthrough in metal cutting. BPS bridged the chasm between gear cutting and CNC machining by mastering the mechanical design through manufacturing software, Pro/ENGINEER, from Parametric Technology Corp. (PTC) in Waltham, Massachusetts.
The most important aspect of any gear design is the profile of its teeth. These are machined with a tool called a hob. The hob itself is generated from mathematical and kinematic formulas unique to gear making. Though Flowdata's Vector is a standard gear profile - a double-helical similar to a herringbone - it could not be hobbed.
In its search for smoother-running and tighter-meshing gears, Flowdata modified the characteristic V of the herringbone tooth into a gracefully rounded U. "We softened the edges and added a gentle nose twist, which lets BPS machine the lobe in just one pass," said Pedro Fernandez, lead Vector designer.
The biggest challenge of the new involute design was machining the root surfaces between the Vector's lobes. BPS and Flowdata quickly realized that four- and five-axis CNC machining was their only alternative. However, CNC machining requires complete geometric surface data, not just the involute's mathematics.
BPS and Flowdata realized that machinable tooth profiles could not be generated simply by plugging the involute calculations into the 3D solid modeler into a CAM package. Flowdata painstakingly converted the mathematics of the involute into surface data points accurate to 0.00001 inch.
When BPS received Flowdata's impeller work, it invested several million dollars for new machine tools and a coordinate measuring machine (CMM). Seven new vertical machining centers with 10,000 rpm main spindles were bought. Two have five-axis capability and three have four-axis controls. The other two VMCs are three-axis machines with automatic pallet changers. For years, BPS had made nearly all of Flowdata's plastic impellers and gearing. But until the Vector, BPS had cut very few metal parts for Flowdata.
Having designed the Vectors using Pro/ENGINEER, Flowdata urged BPS to buy the system. "Having 3D solid modeling and parametric-design capability was the only way to design these impellers effectively," said Flowdata President Dave Foran. "We did in weeks, days and sometimes only hours would have taken us months with our old CAD system." After testing a few other CAD packages, BPS concurred. Using the same system "means more than just avoiding IGES transfers and eliminating geometry translations and cleanups," said BPS President Richard G. Scherr. "It lets us look at the model the same way the customer does. It's all about embedding design intent among critical features of the part."
"Using Pro/ENGINEER, I can modify designs from two lobes to ten in just a few minutes," explained Mr. Fernandez. "I can re-size the impellers anywhere in a one-to-ten range. I can change the helical twist, which determines the amount of lobe contact, from zero (that is a simple spur gear) to 180 degrees, which wraps the lobes halfway around the shaft. With each change, the 3D solid model of the gear is automatically reconstructed, and it is completely accurate."
At BPS, parametric capability plays a major role in keeping up with changes like these and dozens of Vector engineering iterations. Of particular importance is the fact that new surfaces can be substituted quickly and easily in the 3D solid model. Each time Flowdata makes changes, BPS obtains a Pro/ENGINEER file in self-extracting zipped (compressed) format on its electronic bulletin board system.
Lead BPS Programmer Jim Narimatsu explained how the engineering-change process works. "The first step is to replicate the lobes and assemble the new impeller model in the software along with the accompanying fixture using Pro/ENGINEER's assembly mode. This enables us to visualize potential part or cutting tool interference problems and collisions. We graphically compare the new model with the previous version, then develop new cutting strategies, redesign the fixtures and select new tools," he explained.
Textron Acquires ALSTOM Gears; Acquisition Establishes Preferred Supplier Relationship and Enhances Technological Offerings
Textron Inc. (NYSE:TXT) announced today the acquisition of U.K.-based ALSTOM Gears, part of ALSTOM, a leading supplier of components, systems and services to the world's energy and transport infrastructure markets. ALSTOM Gears manufactures and sells a range of gears and gearboxes, including high-speed epicyclic and parallel shaft gearboxes, for the industrial, rail and marine industries. The acquisition will be fully integrated into Textron's Power Transmission Products business, part of the company's Fluid & Power Systems Group. For the fiscal year-ended March 1999, ALSTOM Gear's revenues were approximately $10 million. Terms of the transaction were not disclosed.
"Textron's acquisition of ALSTOM Gears further strengthens our power transmission capabilities, adding a range of technologically advanced gearbox systems to our existing product brands, including David Brown, Cone Drive and Textron Industrial gears," said Textron Fluid & Power Systems President Bob Geckle. "Furthermore, the acquisition establishes a multi-year preferred supplier agreement for Textron with ALSTOM for power transmission products," he added.
With approximately $1 billion in annualized revenues and locations in 23 countries, Textron's Fluid & Power Systems Group is a leading manufacturer of mechanical power transmission, motion control, fluid handling and electronic systems and components. The Fluid & Power Systems Group is part of Textron's $4 billion Industrial Segment.
Textron Inc. (NYSE:TXT) is a $10 billion, global, multi-industry company with market-leading businesses in Aircraft, Automotive, Industrial and Finance. Textron has a workforce of over 64,000 employees and major manufacturing facilities in 23 countries. Textron is among Fortune magazine's "America's Most Admired Companies," and Industry Week magazine's "Best Managed Companies."
Multispeed gear transmissions - Andantex USA Inc.'s new products
A new line of multispeed gear transmissions from Andantex features two, three, four, six or nine speeds within one gearbox housing and from 12 to 288 speeds by coupling up to four boxes. Applications include agitators, capstan drives, vertical drilling machines and track drives.
The gearboxes feature form-ground gears that are shrunk onto the shafts, eliminating the use of keys, which eliminates fretting, the company said. The housings are manufactured from precision iron castings with a cubic configuration which allows installation in any position. When coupled in tandem, overall length is held to a minimum by a design which eliminates the need for external shaft couplings.
Available in seven sizes over the entire ratio range, the gear boxes are 96 percent efficient with ratings from 5 to 800 hp at 1500 rpm, the company said. Output shafts can be supplied to rotate in the same direction as input, or in the opposite direction. Reversing boxes can change direction either manually or electrically. Motor flanges are available for direct motor coupling.
New gearbox assembler set for smaller, high-volume production
With all that has been chronicled regarding the trend toward OEM outsourcing, it's easy to believe that most equipment manufacturers have shopped out large portions of their sub-assembly work. Seeking to capitalize further on this trend, a new gearbox assembly operation has been established to serve the higher volume, smaller size assembly requirements of off-highway OEMs.
Drive Systems, Inc., located in a 6000 sq.ft. facility in Antigo, Wis., traces its roots directly to both the gear and gearbox industries through its two principal policymakers. Bill Sims, Drive System's president, was formerly with Cotta Transmission and Terrell Gear Drives, while Eric Schumann, a financial partner in Drive Systems, is also the president and owner of Merit Gear Corp.
"The springboard for Drive Systems was the fact that Merit Gear customers had begun expressing the desire to buy an assembled gearbox, as opposed to doing their own work," explained Sims. "From the beginning, our actual and anticipated accounts are the companies that are already buying the gears, but would prefer to buy one ready-to-use product, rather than the multiple components needed to assemble these units."
Initially the company will focus on assembly operations for a variety of geared products that have been previously designed and built by OEMs. These will include special motor drives and right angle gearboxes, as well as worm and planetary drives. "One of our first products, for example, is a very special, hydraulically driven two-speed planetary gear reducer," said Sims.
As the company develops, Sims added, Drive Systems would offer drive packages which might incorporate hydraulic motors and pumps or brakes. Sales and engineering support will be a combination of factory-direct and manufacturers representatives.
"The concept of Drive Systems is to eventually be able to control the engineering input for the drive package design and assembly," said Schumann. Stressing that the new company is an entity completely separate from Merit Gear, Schumann said Drive Systems will compete for the best component prices on everything from gears and shafts, to bearings, housings and seals.
"Right now, by being an assembly operation, we're going to focus on being a very efficient operation," Sims noted. "We won't have manufacturing as an issue. It's white walls and a very clean operation - no chip-making anywhere, We'll be purchasing the components of our assemblies from extremely high-tech, high-quality machining houses - buying from companies that specialize in that size, that type - whatever it may be. If we are asked to quote on a certain volume, then we'll go to those companies that specialize in that volume and that specific size."
Schumann added, "Merit Gear has done a good job as a gear manufacturer, which is basically a raw material conversion process. Whereas with gear assembly, the gearbox has various components coming together in a particular fashion at some future point of time. It's a different system.
"At Drive Systems we can specialize in assembly and really make that cost effective and then start looking at design. It has been interesting to separate the manufacturing of gears from assembly, inasmuch as the two companies are in more of a niche at either end of the process."
Composite gearboxes could fly
The Center of Excellence for Composites Manufacturing Technology (CECMT), operated for the Navy by the Great Lakes Composites Consortium (Kenosha, WI), is working to demonstrate the viability of resin transfer molding (RTM) in complex structures such as aircraft accessory gearboxes. As a class, these types of parts, currently fabricated of cast aluminum or magnesium, are costly to machine, require corrosion and fatigue-crack preventative maintenance, and produce high noise levels. The weight of the metal components degrades lift efficiency and reduces aircraft payload capacity. According to CECMT, resin transfer molding could reduce part weight by about 30 and life cycle and acquisition costs by some 15 over current conventional machining processes for cast housings.
Researchers chose an accessory gearbox currently in service on the Chinook helicopter's T-55 engine to demonstrate resin transfer molding's payback. They had access to an operational experience database for composite component comparison, as well as an existing T-55 dynamic testing facility for ground evaluations of the composite gearbox under fully loaded in-service conditions. Although significantly smaller than accessory gearboxes for the Navy's V-22 Osprey, the T55 accessory gearbox meets all essential design and fabrication challenges of the larger gearboxes. Once resin transfer molding is proven on this part, researchers will scale up the technology to fabricate and test full-scale composite gearbox housings for the V22 in parallel with the currently base-lined metal design.
Gear Units produce torque up to 370.000 Nm
Designed for medium- and high-power transmission markets, High Power Series features configurable, space-saving design that combines S series planetary gearboxes with PIV's modular POSIRED 2 family of helical and bevel-helical gearboxes. Products come in 5 harmonically developed sizes that offer nominal torque from 37.000-370.000 Nm, transmission ratios from 100-670, and nominal power from 160-950 kW.
(Vernon Hills, IL - July 2005) Brevini's High Power Series is a new development in gear technology, designed to provide the medium and high power transmission markets with a family of products that are easy to configure, offer the highest levels of torque, and are both space saving and extremely reliable. The High Power Series provides these benefits by combining the high efficiency and reduced size and weight of Brevini's new S series planetary gearboxes with the flexibility and modularity of PIV's POSIRED 2 family of helical and bevel- helical gearboxes.
The main features of the new "High Power" Series are:
o 5 harmonically developed sizes
o Nominal Torque from 37.000 to 370.000 Nm
o Transmission ratios from 100 to 670
o Nominal Power from 160 to 950 kW
About Brevini USA
Brevini USA is a supplier of high quality planetary and helical gearboxes for a wide range of industries and applications - from manufacturing to agriculture, transport to mining. The company is headquartered in Vernon Hills, Illinois, a Chicago suburb. Its facility includes a large warehouse and assembly area, where the company builds most gearboxes from stock. The quality system of Brevini USA, including manufacturing and design, is registered to the ISO 9000:2000 standard. Brevini USA is a division of the power transmission group of Brevini Riduttorti, S.p.A., Reggio Emilia, Italy, a worldwide manufacturer of planetary and helical gears.
Motorized Pulleys offer integrated shaft encoder
BDL motorized pulleys allow conveyor system operators to synchronize product movements. Shaft encoders utilize SKF or SNR pulse outputs to monitor motorized pulley movement and control conveyor belt speed, position, torque, and rotational direction. Accurate conveyor belt movements, up to [+ or -]0.0002 in. at speeds of 19-500 fpm, are achievable. Mounted with 2 brackets, pulleys range from 3.18-12.6 in. in diameter with face widths from 7.8-67 in.
Motorized pulleys with integrated shaft encoders, that allow conveyor system operators to accurately synchronize product movements, are available from BDL America, Wilmington, N.C. The encoders utilize either SKF or SNR pulse outputs to precisely monitor motorized pulley movement to control conveyor belt speed, position, torque and rotational direction. The motorized pulleys have been successfully applied in applications requiring properly timed conveyor movement, such as: positioning, dispensing, adjusting, cutting, tape winding, pick and place operations, and constant speed applications, among others.
The encoders are hermetically sealed within a stainless steel housing, eliminating the possibility of external influences and providing an extremely reliable control system. Accurate conveyor belt movements up to [+ or -]0.0002-inches at speeds of 19 to 500 fpm are achievable with the motorized pulley and integrated encoder design. The motorized pulleys are protected from dust and moisture, meeting class IP66 and IP67 standards.
The integrated encoders are available on the complete line of BDL motorized pulleys ranging from diameters of 3.18 to 12.6 inches, and face widths from 7.8 to 67 inches. Power from the motor is transmitted through the gearbox which is coupled to a geared rim fixed to the drum and housing.
Mounted with just two (2) brackets, there is no need for multiple parts - and multiple vendors. Ordering and installation are quick and easy requiring less than half the time needed to install external drives. The motorized pulley requires no external component maintenance.
Motorized pulleys in the BDL family feature durable steel gears with precision cut and honed teeth - reducing noise levels to only 50dB to meet OSHA requirements. Efficient and reliable, the motors run at 96 percent efficiency, saving up to 32 percent (unloaded) and 47 percent (loaded) on power consumption when compared to exposed drives.
Industrial Gear Oils help prolong gear life
Mineral-based Shell Omala, suited for highly loaded gearboxes operating under normal temperatures, exhibits water separation properties critical for operations in wet environments. Formulated for harsh industrial environments, Shell Omala HD synthetic oil is based on PAO and other select additives and exhibits thermal and oxidative stability. Synthetic Shell Tivela S is designed for enclosed, sealed-for-life or worm-helical gear units operating at higher temperatures.
Shell lubricants companies have launched a revitalized range of mineral and synthetic industrial gear oils for the US market. Shell Omala, Shell Omala HD and Shell Tivela S gear oils, have been specially formulated to help prolong gear life and reduce unscheduled downtime, which can help industrial companies reduce their overall operating costs.
The revitalized range of Shell gear oils has been developed to meet the challenges placed on modern gear systems, which are becoming increasingly sophisticated, smaller and designed to run longer. In a recent survey conducted by Shell of US industrial companies, 50% of respondents said that industrial gearboxes were one of their most critical components, while 30% said that they had experienced a lubricant related gearbox failure within the last 12 months.
Darren Cross, Shell's Industrial Lubricants Sector Marketing Manager, explains: "Today's industrial environment is more demanding than ever with trends towards smaller equipment and commercial pressures to raise throughput. The result is equipment needs to be able to run at higher operating temperatures, handle increased loads and cope with exposure to water and other contaminants. In these tough conditions, operators need a gear oil that is designed to tackle the problems that can affect operational efficiency. Shell has invested heavily in lubricants R&D to ensure that we can provide a revitalized range of gear oils for the US that meets these new challenges."
Transmission considerations: beyond the manual gearbox
As far as the majority of European drivers are concerned, the only transmission worth considering is the manual, which accounts for four out of every five gearboxes found in new cars sold in the region. There are two key factors in this dominance: (1) the extra cost in purchase price of automatic transmissions; (2) the in-built prejudice against automatics. The typical European driver still believes that not having a shift stick dilutes control of the car. "In Europe, if a customer can obtain an air conditioning system or light-alloy sports wheels for the same extra cost as an automatic transmission, the majority choose the other options," said Dr--Ing Gerhard Wagner, group vice president, ZF in his plenary speech at the Innovative Automotive Transmissions conference organized by the Car Training Institute in Berlin at the beginning of December 2005. "However, it should be noted that the extra cost charged for an automatic transmission is not in any way related to their manufacturing costs. Instead, the whole issue is governed by the pricing policy of the vehicle manufacturers which still determines that some items of equipment are cost options."
Wagner continued, "The figures quoted in sales brochures for fuel economy, emission levels and 0-100 km/h acceleration times are the next obstacle to overcome when selling a vehicle equipped with an automatic transmission. If these figures are significantly worse than those of a vehicle with a manual transmission, European customers tend as a general rule to favor the manual transmission. As a consequence, the requirement for low fuel consumption and good performance figures form an essential component in any automatic transmission development work."
Things, though, could be about to change in Europe as the transmission has now come into the front line in the carmakers' quest to meet emissions legislation. "The primary requirements and customer benefits underpinning the further development of automatic transmissions," said Wagner, "include a reduction of fuel consumption, a reduction of pollution, vehicle performance improvement, increasing torque capacity, greater comfort, sportiness, noise reduction, resource conservation, and competitiveness."
Clutches, clutch brakes, gearboxes - Mechanical Powertrain Component Report - North American Clutch Co
North American Clutch Co. (Noram) continues to develop its designs of clutches, clutch brakes and mechanical gearboxes for small engine applications. Clutches are designed to fit engines ranging from fractional horsepower up through 50 hp applications. They are available in standard off-the-shelf configurations or designed to fit an OEM'S specific requirement.
Noram centrifugal and mechanical clutches are designed to allow for safe, no-load, quiet starting of power equipment, the company said. Once engaged, the clutches reduce vibration, utilize peak torque for more efficient engine performance and provide overload protection for operator and equipment safety.
The company's reduction gearboxes are designed to fit most small (3/4 in. bore) and medium frame (1 in. bore) four-stroke engines available. Gearboxes are made of rugged aluminum castings, and precision machined gears. Noram's high-torque clutch brake has a variety of uses in the outdoor power equipment marketplace and industrial applications such as pump drives, blowers and agricultural seeders.
Gear Grinder rough and finish grinds gears in one setup
Built on mineral-filled cast polymer base, 6-axis GS:G2 produces gears from 1-12 in. dia, employs near net-shaped or hobbed gears, and requires 15 min of setup. Machine requires users to install proper tooling and enter part form, dress, and grind parameters into control in order to start-up new jobs, while menu-driven screens and Gear Smart(TM) Programming facilitate operation. Product features dual wheel machining and infinitely variable wheel speeds and feeds.
Sometimes a new machine is just destined to happen. Markets evolve, new technologies emerge, and an experienced machine tool builder seizes the opportunity. The result: the right machine, at the right time, at the right price.
Drake Manufacturing in Warren, OH is putting the finishing touches on a highly productive 6-axis gear grinder that will be grinding quality parts after just 15-minutes of setup. Best part is - like Drake's other gear and thread manufacturing machines - it's priced to provide high return on investment for the job shop owner as well as the large, automotive supplier.
Drake is best known for its line of CNC gear hobbers, thread and worm grinders, rack mills and bore grinders. The GS:G2 is a machine that blends the best of Drake's specialty grinding and gear making expertise.
As the basis of competition in the power transmission and speed reducer markets increasingly shifts toward quiet operation and efficiency, more and more manufacturers are calling for precision ground gears. The Drake GS:G2 enables manufacturers to source near net-shaped or hobbed gears from low-cost suppliers and still control the final product quality. "This is a high value-added grinder, that with minimal capital outlay, can help our customers remain globally competitive for years to come," said Stig Mowatt-Larssen, Drake's Manager of Research and Development.
A flexible grinder
The GS:G2 has the flexibility and capability to handle a variety of grinding roles: job shop work, manufacturing cell environments, high volume grinding - even prototype work. Fast changeovers with menu-driven setup screens-no more change gears or dressing thread wheels-make it easy to switch from job to job.
Gearboxes provide torque from 25-5,200 Nm
Lubricated for life, PowerGear Gearboxes are available in 8 sizes, with 6 standard ratios from 1:1-5:1 and efficiencies to 98%. Units feature taper roller bearings, Gleason cut gears, and spheroidal graphite iron housing and flanges. They provide fretting-free torque transfer using friction-locked fit between shaft and gear. Units come with solid or hollow shafts in 2-way, 3-way, and 4-way shaft arrangements, and can be mounted from all sides.
The New PowerGear range of products have been produced following the increasing technical demands from our customers, which has lead to the merging of the old Universal and Power Gear ranges, the main technical features of the two older ranges have been taken into account when producing the New range which replaces them.
The New PowerGear series has been produced to meet with a specific torque / speed spectrum. The advantages of this approach are:
o The compact and rigid design assures highest performance at small dimensions and low weight
o Lubricated for life, the gearboxes are, depending on their size, maintenance-free, if operated under normal conditions
o The high efficiency of the gearbox, 98%, saves energy costs
o Housing/Flanges made of spheroidal graphite iron for maximum rigidity
o Fretting-free torque transfer using a friction-locked fit between shaft and gear
o High quality taper roller bearings taking axial and radial loads and guaranteeing long operational life
o Gleason cut gears for high torque ratings
o Optimized gear tooth contact pattern during assembly leading to uniform load distribution
The units are available in 8 sizes, with 6 standard ratios from 1:1 to 5:1. Shaft arrangements include 2 way, 3 way and 4 way and are available with solid shafts and hollow output shafts, the units are also available with motor input flanges allowing many standard IEC framed motors to be fitted. Torque range from 25Nm to 5200Nm with input speeds up to 6500rpm.
The units have been designed, with universal mounting, allowing the units to be mounted from all sides.
Additional accessories include
Shrink Disc - with hollow shaft extension for friction locked connections Keyless Shafts - for attachment via clamping connections Minimum Backlash - for greater accuracy than already offered as standard Cooling packs - gearboxes fitted with aluminium cooling fins, with or without the addition of an axial fan to provide increased heat dissipation from the unit.
Textron Acquires ALSTOM Gears; Acquisition Establishes Preferred Supplier Relationship and Enhances Technological Offerings
Textron Inc. (NYSE:TXT) announced today the acquisition of U.K.-based ALSTOM Gears, part of ALSTOM, a leading supplier of components, systems and services to the world's energy and transport infrastructure markets. ALSTOM Gears manufactures and sells a range of gears and gearboxes, including high-speed epicyclic and parallel shaft gearboxes, for the industrial, rail and marine industries. The acquisition will be fully integrated into Textron's Power Transmission Products business, part of the company's Fluid & Power Systems Group. For the fiscal year-ended March 1999, ALSTOM Gear's revenues were approximately $10 million. Terms of the transaction were not disclosed.
"Textron's acquisition of ALSTOM Gears further strengthens our power transmission capabilities, adding a range of technologically advanced gearbox systems to our existing product brands, including David Brown, Cone Drive and Textron Industrial gears," said Textron Fluid & Power Systems President Bob Geckle. "Furthermore, the acquisition establishes a multi-year preferred supplier agreement for Textron with ALSTOM for power transmission products," he added.
With approximately $1 billion in annualized revenues and locations in 23 countries, Textron's Fluid & Power Systems Group is a leading manufacturer of mechanical power transmission, motion control, fluid handling and electronic systems and components. The Fluid & Power Systems Group is part of Textron's $4 billion Industrial Segment.
Textron Inc. (NYSE:TXT) is a $10 billion, global, multi-industry company with market-leading businesses in Aircraft, Automotive, Industrial and Finance. Textron has a workforce of over 64,000 employees and major manufacturing facilities in 23 countries. Textron is among Fortune magazine's "America's Most Admired Companies," and Industry Week magazine's "Best Managed Companies."
Gear Grinder rough and finish grinds gears in one setup
Built on mineral-filled cast polymer base, 6-axis GS:G2 produces gears from 1-12 in. dia, employs near net-shaped or hobbed gears, and requires 15 min of setup. Machine requires users to install proper tooling and enter part form, dress, and grind parameters into control in order to start-up new jobs, while menu-driven screens and Gear Smart(TM) Programming facilitate operation. Product features dual wheel machining and infinitely variable wheel speeds and feeds.
Sometimes a new machine is just destined to happen. Markets evolve, new technologies emerge, and an experienced machine tool builder seizes the opportunity. The result: the right machine, at the right time, at the right price.
Drake Manufacturing in Warren, OH is putting the finishing touches on a highly productive 6-axis gear grinder that will be grinding quality parts after just 15-minutes of setup. Best part is - like Drake's other gear and thread manufacturing machines - it's priced to provide high return on investment for the job shop owner as well as the large, automotive supplier.
Drake is best known for its line of CNC gear hobbers, thread and worm grinders, rack mills and bore grinders. The GS:G2 is a machine that blends the best of Drake's specialty grinding and gear making expertise.
As the basis of competition in the power transmission and speed reducer markets increasingly shifts toward quiet operation and efficiency, more and more manufacturers are calling for precision ground gears. The Drake GS:G2 enables manufacturers to source near net-shaped or hobbed gears from low-cost suppliers and still control the final product quality. "This is a high value-added grinder, that with minimal capital outlay, can help our customers remain globally competitive for years to come," said Stig Mowatt-Larssen, Drake's Manager of Research and Development.
A flexible grinder
The GS:G2 has the flexibility and capability to handle a variety of grinding roles: job shop work, manufacturing cell environments, high volume grinding - even prototype work. Fast changeovers with menu-driven setup screens-no more change gears or dressing thread wheels-make it easy to switch from job to job.
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