Turning of gear blanks as well as spacers and shafts in their case-hardened state has started to replace grinding at the Bradford factory of Hindle Gears, with the result that bore and face machining is now completed in one operation instead of two, handling has been eliminated at this stage in the process and overall cycle time has been halved. Said technical manager, Chris Verity, 'After researching the technology, we invested last year (2004) in our first Okuma lathe from NCMT, a Space Turn LB300-M lathe, due to the Japanese manufacturer's reputation for building rigid machines capable of good hard turning performance.' Verity adds: 'It is the first lathe on this site with driven tooling, which adds versatility to soft machining applications as well and further reduces set-ups'. 'Cutting the number of separate operations is critical for us to keep production costs down, as cycle times tend to be short so unproductive load/unload times are long by comparison.' Hindle Gears was established in 1930 and has a reputation for supplying high quality gearboxes, gear sets and other power transmission components for diesel engines used in power generation and some defence and marine applications.
However, like many British manufacturers, the family-owned company is coming under increasing pressure from competition in low-wage countries, notably China, India and the Czech Republic.
So adopting lean production techniques, which includes reducing cycle times and the number of set-ups, is paramount to the company's future prosperity.
Over 90% of gears produced at the Bradford works are of hardened steel.
The traditional manufacturing route is to (1) soft turn the bore, faces and OD of a billet, (2) shape, hob or shave the gear teeth, (3) case harden, (4) grind the bore and one face on a specialist bore grinder, (5) grind the other face on a surface grinder, and (6) grind the teeth.
By contrast, the hard turning route using CBN tooling replaces two of the operations - (4) and (5) - with one operation on the Okuma lathe whereby the bore and both faces are machined in a single set-up.
This is achieved on the 3-axis LB300-M, without the expense of investing in a sub-spindle machine, by using a boring bar with a rear-facing tool to turn the reverse face.
Not only is the total cycle time halved, but accuracy is also improved by eliminating tolerance build-up.
Parallelism between the faces of 10 microns total is routinely held, which provides better location for subsequent grinding of the teeth and contributes to smoother running of the finished gear.
Clearly one 3-axis lathe costs significantly less than two grinding machines, so capital outlay is reduced by hard turning.
Furthermore, the lathe is also able to turn the OD of shafts, so is more flexible than a grinder unless an even more expensive universal model is bought.
An example of the savings achieved by mill/turning sawn steel billets in the soft state using carbide tooling is the production of gear blanks for a vacuum pump, each of which requires bore drilling and face turning followed by manual component reversal for second operations.
These comprise face turning, edge chamfering and drilling and tapping three through-holes using the live tooling.
Previously the part was produced in three operations - two on different lathes and a separate set-up on a small machining centre - so some handling has been eliminated and overall cycle time has been reduced as well.
Off-line programming of all CNC machines at the Bradford plant is assisted by Edgecam software with DNC links to the machines.
Batch sizes vary widely from one-offs to one thousand, sometimes even two thousand.
That the Okuma joins a shop full of other major suppliers' lathes is in part testament to the installation of a twin-pallet, horizontal machining centre from the same supplier in 2002.
Power transmission solutions on show
Power transmission solutions for the widest range of mechanical drive applications from food manufacturing, packaging, energy, mining and metal industries through to rail and marine propulsion will be on show at Hanover from Textron Power Transmission, comprising David Brown, Benzlers, Cone Drive and Weco. Stand D34 in Hall 26 will feature dedicated displays for specific duties and industry sectors demonstrating the world-leading gear solutions offered by specialist engineered drives and standard products. Innovation in concept, ease of use in application, and reliability in operation are the hallmarks of engineering excellence provided by Textron Power Transmission (TPT), and the products on show reflect almost every possible requirement for efficiently delivering power.
TPT offers a worldwide capability for creating and supporting engineered solutions that range from massive girth gears for the mining industry, through sugar milling and bulk handling to energy and petrochemicals industries.
TPT is able to demonstrate its skills at the most sophisticated level in partnerships with aerospace, marine and defence giants across the globe, designing innovative approaches to a variety of tasks from deploying the solar arrays on satellites to delivering the motive power for warships and main battle tanks.
TPT gearboxes have also become the preferred solution for the most arduous services, including driving fans in cooling towers and operating the hoists in steelworks.
On standard drive solutions, TPT offers a comprehensive range of options including helical inline geared motors and reducers, right angle helical bevel gearmotors and reducers and shaft mounted helical gearmotors and reducers spanning a total power handling capability.
The inherent flexibility of these products is linked to the unique patented motor adapter system which reduces downtime and cuts costs by offering the option of fitting standard electric moors to a huge choice of geared units.
The system accepts all sizes of standard NEMA and IEC flange-mounted motors without the need for modifications or interface connectors.
Further flexibility is demonstrated with the Series J shaft mounted Sala speed reducers.
Designed for motor powers up to 600kW, Sala employs the exclusive KIBO tapered bushing which securely installs the gearbox but enables easy replacement of hollow shaft units.
Worm drive gearmotors are the proven solution of many OEMS, and TPT has created class-leading efficiency in its Series C right angle helical worm gearmotors and reducers, while the ultimate power pack for small spaces is found in the Series BS worm gears.
Precise and silent movement of heavy loads within a production environmental is now the acknowledged role of the TPT BD screw jack linear drives.
Mechanical operation eliminates the pipelines and possible pressure losses of pneumatic and hydraulic jacks, and BD drives offer long, virtually maintenance free service for handling static loads of up to 100t and linear speeds up to 33mm/s.
TPT offers a worldwide capability for creating and supporting engineered solutions that range from massive girth gears for the mining industry, through sugar milling and bulk handling to energy and petrochemicals industries.
TPT is able to demonstrate its skills at the most sophisticated level in partnerships with aerospace, marine and defence giants across the globe, designing innovative approaches to a variety of tasks from deploying the solar arrays on satellites to delivering the motive power for warships and main battle tanks.
TPT gearboxes have also become the preferred solution for the most arduous services, including driving fans in cooling towers and operating the hoists in steelworks.
On standard drive solutions, TPT offers a comprehensive range of options including helical inline geared motors and reducers, right angle helical bevel gearmotors and reducers and shaft mounted helical gearmotors and reducers spanning a total power handling capability.
The inherent flexibility of these products is linked to the unique patented motor adapter system which reduces downtime and cuts costs by offering the option of fitting standard electric moors to a huge choice of geared units.
The system accepts all sizes of standard NEMA and IEC flange-mounted motors without the need for modifications or interface connectors.
Further flexibility is demonstrated with the Series J shaft mounted Sala speed reducers.
Designed for motor powers up to 600kW, Sala employs the exclusive KIBO tapered bushing which securely installs the gearbox but enables easy replacement of hollow shaft units.
Worm drive gearmotors are the proven solution of many OEMS, and TPT has created class-leading efficiency in its Series C right angle helical worm gearmotors and reducers, while the ultimate power pack for small spaces is found in the Series BS worm gears.
Precise and silent movement of heavy loads within a production environmental is now the acknowledged role of the TPT BD screw jack linear drives.
Mechanical operation eliminates the pipelines and possible pressure losses of pneumatic and hydraulic jacks, and BD drives offer long, virtually maintenance free service for handling static loads of up to 100t and linear speeds up to 33mm/s.
Mechanical gear change provides two-speed option
The Type RC mechanical gear change is available as an option on the Series 2000 planetary gearbox from Reggiana Riduttori. Installed on the input side of its linear reduction gears and fully integrated into the unit, the two-speed selector is available from only GBP 500. Ideal for applications requiring both high speed/low torque and low speed/high torque modes of operation, it also has considerable potential as a disconnect mechanism, by using the neutral position.
Already the winch and marine sectors have shown interest in the product, and occasional two-speed applications like drilling augers and process conveyors are also considered viable, especially as the compact, modular configuration of planetary gearing can be exploited to build multiple reduction stages and virtually unlimited ratios.
Listed in the current Reggiana Riduttori Series 2000 print and CD-Rom catalogues, the standard RC mechanical gear change is designed to integrate with male and female versions of the RR510 linear reduction gears, nominally rated at 6000Nm output torque, and adds only 85mm in length to the standard box.
With a diameter of just 195mm, the lightweight, compact 1:1 gear change can be combined with any of the standard catalogue gear ratios (1:3.4/4/5/5.8/7), then additional reduction stages fitted to give yet further ratio options.
Maximum input speeds range from 850 to 1750rev/min and engagement is normally carried out when static, although changeovers may be carried out at creep speeds up to 15rpm.
As well as lending themselves to a broad range of stand-alone applications, the RC/RR510 combination can also be used as the primary stage for bigger Series 2000 gear units, with much higher torque capacities, exploiting the fact that the gear change is installed at the low-torque/low-cost end of the drive chain.
Other special RC versions are additionally available to order, for matching gearboxes up to the RR 50000 M/FS models, which are continuously rated at 600kNm.
While a standard gearshift lever is normally used to operate the RC unit manually, it can be alternatively connected to a hydraulic/pneumatic controller or an electric servomotor to facilitate remote operation, thereby expanding its suitability for many industrial and offshore applications.
As there are no ratios built into the gear change itself, specification is relatively straightforward as the ratios are effectively those of the gearbox attached.
Potential applications for a two-speed device include deep sea recovery and cable inspection vehicles, where unladen cable could be wound in far quicker; drilling machines, where a high torque mode could retrieve an embedded auger or a low torque/high speed drive could be used for routine withdrawal and discharge; and industrial conveyors and other plant, where a mechanical speed change offers more flexibility than inverter-controlled motors alone.
As a disconnect mechanism, normally used in conjunction with a fail-to-safe brake to prevent the load running away, the RC also has considerable potential: to disconnect or engage a standby drive in a multiple drive configuration, for example, to disengage a winch and assist 'heave compensation' in deep sea exploration or to enable 'free rise' in hot air balloon recovery operations.
Moreover, the affordable price and simple mechanical design this Series 2000 modular addon enables designers to enjoy the luxury of including 'another gearbox' or a mechanical disconnect, without paying a premium price.
Already the winch and marine sectors have shown interest in the product, and occasional two-speed applications like drilling augers and process conveyors are also considered viable, especially as the compact, modular configuration of planetary gearing can be exploited to build multiple reduction stages and virtually unlimited ratios.
Listed in the current Reggiana Riduttori Series 2000 print and CD-Rom catalogues, the standard RC mechanical gear change is designed to integrate with male and female versions of the RR510 linear reduction gears, nominally rated at 6000Nm output torque, and adds only 85mm in length to the standard box.
With a diameter of just 195mm, the lightweight, compact 1:1 gear change can be combined with any of the standard catalogue gear ratios (1:3.4/4/5/5.8/7), then additional reduction stages fitted to give yet further ratio options.
Maximum input speeds range from 850 to 1750rev/min and engagement is normally carried out when static, although changeovers may be carried out at creep speeds up to 15rpm.
As well as lending themselves to a broad range of stand-alone applications, the RC/RR510 combination can also be used as the primary stage for bigger Series 2000 gear units, with much higher torque capacities, exploiting the fact that the gear change is installed at the low-torque/low-cost end of the drive chain.
Other special RC versions are additionally available to order, for matching gearboxes up to the RR 50000 M/FS models, which are continuously rated at 600kNm.
While a standard gearshift lever is normally used to operate the RC unit manually, it can be alternatively connected to a hydraulic/pneumatic controller or an electric servomotor to facilitate remote operation, thereby expanding its suitability for many industrial and offshore applications.
As there are no ratios built into the gear change itself, specification is relatively straightforward as the ratios are effectively those of the gearbox attached.
Potential applications for a two-speed device include deep sea recovery and cable inspection vehicles, where unladen cable could be wound in far quicker; drilling machines, where a high torque mode could retrieve an embedded auger or a low torque/high speed drive could be used for routine withdrawal and discharge; and industrial conveyors and other plant, where a mechanical speed change offers more flexibility than inverter-controlled motors alone.
As a disconnect mechanism, normally used in conjunction with a fail-to-safe brake to prevent the load running away, the RC also has considerable potential: to disconnect or engage a standby drive in a multiple drive configuration, for example, to disengage a winch and assist 'heave compensation' in deep sea exploration or to enable 'free rise' in hot air balloon recovery operations.
Moreover, the affordable price and simple mechanical design this Series 2000 modular addon enables designers to enjoy the luxury of including 'another gearbox' or a mechanical disconnect, without paying a premium price.
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