Tooth modification and loaded tooth contact analysis of China Bearing Reducer

Abstract

China Bearing Reducer (CBR) is a one-stage cycloid speed reducer, which has the advantages of large transmission ratio, large load, high precision, high stiffness, and compact structure. The profile modification quality and manufacturing error of cycloid gear are the key factors affecting the transmission accuracy. In this paper, the structure of CBR is introduced first. By means of tooth contact analysis, a new parabolic profile modification method is proposed to improve the transmission accuracy. Then, by using Hertzian contact theory, force equilibrium equations and deformation compatibility conditions, a loaded tooth contact analysis algorithm of CBR is proposed to analyze the loaded transmission characteristics. According to the designed manufacturing error, the objective function is established to minimize the transmission error under nonload condition, and the particle swarm optimization algorithm is used to solve the optimal modification coefficients. Finally, the CBR25 is manufactured with the optimum modification coefficients, and the manufacturing error is measured in coordinate measuring machine to verify that it meets the design requirements. The optimal modification coefficients of CBR25 under nonload are solved based on particle swarm optimization model. Then the optimal modification coefficients are substituted to loaded tooth contact analysis to analyze the meshing contact force, contact deformation, and transmission error of CBR25. The transmission error of the CBR25 is tested on the testing rig. The error between the measured results and the calculated results of loaded tooth contact analysis is within 5%, which shows the correctness of the loaded tooth contact analysis algorithm. At the same time, the operation stability of the CBR25 is improved by using the optimal modification method.