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Novel gears offer high torque
Zeitlauf is offering a new gearhead that the company says could spell the end of the worm gear in certain applications. The Etacrown delivers high torque in a small-profile gearmotor, is almost silent and has high efficiency. Key benefits of the new gearmotors are the compact size, high torque and near-silent running. Furthermore, they can be flush-mounted, making them useful for applications such as door actuation, and they will also find many applications in the medical industry and other applications. Losses from the Etacrown are minimised so that, for example, the single-stage box delivers 92 per cent efficiency, while even the two-stage version gives 80 per cent. A typical worm gear has no better than 50-60 per cent efficiency. There is also no axial displacement between the drive shaft and the geared output shaft. This shaft also has two bearings and therefore delivers high radial load capacity. Zeitlauf says the Etacrown represents a breakthrough - albeit from an original design patented shortly after the turn of the last century. In spite of the old concept, nobody had been able to manufacture the new style of crown gear on which the gearbox relies. Indeed, it took Zeitlauf 10 years of development to perfect the manufacture. The Etacrown has power transmitted to its primary spur gear via single- or two-stage helical gears made from high-strength acetal resin. These run within a helical ring gear and the use of the plastics material is one of the factors in the near-silent running. Options of a metal crown or an acetal resin crown are also offered, both driven by a metal spur gear. It is the geometry of the tooth form on the crown gear that enables the high torque transmission. Each tooth tapers from a 40-degree angle to 10 degrees, moving from the outside edge towards the centre. The crown gear can be fitted with a single shaft, double shaft and a range of options including hollow shafts. The gearboxes come with reductions from 4:1 with a torque of 1.1Nm up to a 113:1 reduction delivering 10Nm torque. Higher ratios and torques are available on request. They come as standard equipped with an EBM-Papst motor, but can be fitted with all common ac, dc or ec motors. Top Stories from Engineer Live: Torque tools brave Mozambique deluge on gas pipeline | | Printed electronics: the giants get involved | | Climate change: oil and gas companies face upheaval | | High-efficiency ac/dc power supplies | | World's ‘largest renewable energy city’ | | Six-axis robot is claimed to be the strongest | | Explosion proof and marine beacons | | USB key resistant to industrial environments Top Stories from Scientist Live: Alternative farming cleans up water | | Challenging Ice Age assumptions | | Nuclear plants linked to leukemia | | The mystery of throbbing oil | | Origins of bipedalism in humans | | Historically, climate change spurs wars | | The truth about organic farming |
