Lost motion analysis of CBR reducer

A new one-stage cycloid-pin gear reducer with a simple structure, a wide range of size and high rigidity is proposed named China Bearing Reducer(CBR). This paper presents the design of CBR and its lost motion analysis. The profile equation with modification of cycloid gear is derived by the method of gear train analysis. The initial gap distribution caused by profile modification is analyzed. To reduce the lost motion, a method of compound modifications based on negative isometry and negative offset is presented. The best values of modifications are obtained by optimization method considering manufacturing error. Then the causes of the lost motion of CBR reducer are analyzed, and the calculation formula for every cause is derived. The physical prototype is manufactured and the lost motion experiment is carried out. The experimental results show that the CBR reducer has a small lost motion which could meet the requirements of robot.