Cycloidal Gearbox VS Planetary Gearbox

1,Cycloidal gears versus planetary gears

Applications with especially high precision – whether in plant engineering, robotics, machine tool construction or medical technology – require robust precision gears designed for a long life. Two types of gears are available for such applications: planetary and cycloidal gears. Although the areas of use for these two gear types overlap, cycloidal gears can replace planetary gears in many applications.

2,Cycloidal gears have the better performance specifications

If features like backlash and positioning accuracy are important, cycloidal gears deliver better performance in every respect. They have a more robust design than planetary gears, which means they also last longer. In addition, the increase of backlash in cycloidal gears is very low over extended periods – a significant advantage over normal planetary gears, which often develop increased backlash during the course of their service life.

Cycloidal gears enable reduction ratios from 30:1 to more than 300:1 – without additional pre-stages such as those that are necessary in standard planetary gears. Due to their design, cycloidal gears are much more rigid and more compact (about 50% shorter), and also lighter than multi-stage planetary gears. In addition, they offer 500% higher overload protection.

3,Cycloidal gears offer unbeatable advantages

The two-stage reduction of cycloidal gears makes solutions from Nabtesco so successful. The reason is that the speed is reduced by the double cams. In addition, vibration is reduced by the two-stage reduction principle and low inertia. The force is also distributed very evenly, thanks to the roller cam design, and this contributes to the minimum hysteresis loss and enormous resistance to shock loading. Consequently, cycloidal gears are as versatile as they are resilient.

The drive or servomotor is connected to the spur gear stage of the gearbox via a pinion. The rotating speed reduces at this point relative to the reduction ratio between the pinion and planetary gear. The planetary gears are connected to crankshafts which drive the cams using needle bearings. These cams rotate inside the case which is lined with pins.