Gearboxes go into hypoid drive

Mark Fletcher discovers a new range of hypoid gearboxes which have already taken Asia and the US by storm. And Europe is the next target

Hypoid gearing, an arrangement which covers the ground between helical gears and worm gears, will offer even more functional gains thanks to development work by Sumitomo. The company’s new NEO Hyponic gear motor range has already had a successful launch in Asia and the US and is now set to enter the European market with an even more compact offering. The NEO range, according to the firm, offers higher reduction ratios than conventional bevel and bevel-helical geared motors and will provide greater efficiency across the complete range of ratios – from 5:1 up to 1,440:1. This is combined with lower noise and a lightweight, compact design. Applications for this gearmotor range are seen in conveyor lines, breweries, crushers, baggage handling and sorting equipment. Worm gears and bevel gears interact with the driven gear tangentially, either on its edge or on its face respectively. Hypoidal gears, on the other hand, interact with the face but not at 90° to a radius of the driven gear (see diagram). The gear profile is more complex but it does offer a raft of advantages over other right-angle gear drives. Running noise is reduced due to an increase in the contact intervals and, as the pinion meshes below the centre axis of the driven gear, the driven shaft and the centre of gravity can be lowered. The development of hypoidal profiles has come hand-in-hand with the creation of extreme pressure oils which are capable of resisting the pressures produced by the sliding contact developed by the gears. Sumitomo’s original development work was spurred on by its leading customer, which demanded higher efficiencies than conventional helical/worm products, robustness and reliability of wormgears, lower noise, smaller size and maintenance free – quite a wish list really. In response to these demands, Sumitomo developed its first generation of Hyponic geared motors. Yuki Nakamura, Sumitomo’s product specialist explains: “The overall efficiency of the Hyponic geared motor is far superior to the conventional helical-worm product. Where helical-worm and wormgear reducers start at approximately 93% efficiency, they reduce dramatically with the increase in ratio to below 50%. Hyponic geared motors maintain an overall efficiency of between 88 and 85% between the ratios of 5:1 and 1,440:1.” The new NEO range boasts a number of improvements including a lighter weight, more compact design, lower noise and vibration, interchangeability with all the major European manufacturers without any loss of performance and a design which has been developed to be maintenance free for life – making it ideal for remote or hard to reach applications.