Helical-bevel gearboxes provide a speed reducer function that can deliver power transmission efficiencies of over 95% for machinery builders. This can be up to twice that of the worm style gears that are commonly used, providing major savings in energy consumption. Nord Drivesystems has now lowered the entry costs to this advanced reducer technology with a new range of two-stage helical-bevel gearboxes in lightweight diecast aluminium housings — providing considerable savings compared with established cast-iron products. In addition to energy savings, the highly efficient gearboxes allow automation builders to reduce costs by specifying smaller sizes of electric motor.
Nord's SK 92 series of helical-bevel gearboxes provide a right angled drive capability that can be configured to provide speed reduction ratios from 3:1 to 72:1, satisfying a very wide range of applications from baggage handling and conveying, to packaging and processing machinery. Five reducer sizes are available spanning a power range from 0.12 to 9.2 kW.
The new reducer gearboxes can significantly reduce system building costs for automation vendors. Two-stage helical-bevel gearboxes support a wider choice of ratios than is possible with worm gears. Each SK 92 case size can be configured with a choice of up to 21 ratios, compared with perhaps nine for single worm gearboxes. In many applications, this can eliminate additional components such as a belt or chain system. Most helical-bevel reducers on the market are also typically based on three stages, with a helical input, followed by bevel and helical reductions. SK 92 gearboxes are implemented using just two stages, eliminating gear, bearing, shaft and other minor component parts — minimising the implementation costs of the technology while maintaining higher power transmission performance.
Longer operating life is another important attribute of helical bevel gears. Compared with worm gears, helical bevel units are virtually wear free, and run cooler.
Modular design principles allow the SK 92 series of reducers to be customised using a broad range of accessories, to provide optimised power transmission for virtually any application. As standard, units offer foot mounting on two sides, B14 face mounts on two sides, and either a hollow or solid output shaft. Nord's range of accessories and its UK assembly facilities ensures that a wide variety of gear designs can be configured using just a few modular parts, giving great design flexibility, as well as interchangeability with other European manufacturers for repair and refurbishment applications. Among the accessories available are bolt-on type flanges and torque arms. Nord can also supply the units in ATEX compatible form, and as complete geared motors rated up to EFF 1 — with accessories including encoders, brakes and forced ventilation.
Assembly of gear units takes just a few minutes, and Nord's Abingdon, UK facility carries stock of the basic housings and gears, and the accessory range, allowing application-specific solutions to be built and shipped the same day if required. Nord's facility also includes an automated painting line, allowing gearboxes or geared motors to be delivered in an OEM's livery, ready for assembly into the finished product.