Innovative use of ceramics by maxon increased gearhead performance by 100 per cent

Citation

(2000), "Innovative use of ceramics by maxon increased gearhead performance by 100 per cent", Industrial Robot, Vol. 27 No. 3. https://doi.org/10.1108/ir.2000.04927cad.006

Innovative use of ceramics by maxon increased gearhead performance by 100 per cent

Innovative use of ceramics by maxon increased gearhead performance by 100 per cent

Keywords: Gears, Motors

Up to five-fold improvement in life expectancy is claimed by maxon motor - a world leader in precision motor technology - which has launched a range of miniature, high performance gearheads that dramatically increase power density and extend operating life (see Plate 6).

Developed for demanding planetary gear train applications - where planet gears, supported on shafts, revolve around the sun gear - the bearing surfaces employ zirconium oxide ceramics that are tough, machinable and virtually wear-free. Importantly, this new material can be combined with other steel components because their thermal coefficients are almost identical.

"The use of zirconium oxide offers immense benefits in a wide range of demanding applications", explains Keith Ellenden, chief executive of maxon motor uk ltd. In a typical planetary gearhead, space constraints make it impossible to use roller bearings between the shaft and planet gear, yet the loads imposed on the bearing surfaces are immense.

Plate 6maxon motor launch a new range of miniature, high performance gearheads that dramatically increase power density and extend operating life

In trials involving a 22mm planetary gearhead operating at continuous torque (1Nm) in one direction, temperatures of 1,500°C were generated between the planet gear and the shaft. This extreme heat caused a rapid breakdown of even the most advanced lubricants - which cannot be changed because gearheads are lifetime lubricated and, therefore, sealed. The result was accelerated wear, affecting mesh alignment and causing gearhead failure.

In trials using the same gearhead but with ceramic shafts, the contrast was remarkable and decisive. The bearing system patented by maxon motor showed almost no wear and actually increased the operational life of the gearhead by a factor of 3 to 5.

Extended life, however, is just one of the benefits being claimed by maxon motor. According to Keith Ellenden, the use of ceramics enables designers to achieve the same output from a smaller diameter gearhead. Indeed, power density can be increased by anything from 50 to 100 per cent. "Which will be the single most important factor influencing designers as the trend towards miniaturisation accelerates", he states.

For more information contact maxon motor uk ltd, Alberto House, Marino Way, Hogwood Lane, Finchampstead, Berks, RG40 4RF. Tel: +44 (0) 1189 733337; Fax: +44 (0) 1189 737472; E-mail: sales@maxonmotor.co.uk