Development and Evaluation of a Low Backlash Crown Reducer

Abstract

Generally, low backlash mechanisms are required for robot joints to perform tasks accurately. In this paper, we propose a new concept of a low backlash reducer using precessing crown gears. We call it the crown reducer. The features of this reducer are low backlash, high reduction ratio and ease of downsizing which we believe will contribute to the design of small mechanisms such as finger joints of robot hands. Firstly, the parts of the reducer suitable for downsizing are discussed. This will show that a layered construction of the nutation drive is most suitable. An explanation of the operation of the reducer and the method for generating the tooth profile of the stator gear that achieves multi-contact between rotor and stator gears will follow. And finally, evaluation of the performance of a prototype reducer will be discussed.