Tooth profile piecewise modification method for cycloid gear of RV reducer based on meshing interval optimization

Abstract

Rotate vector (RV) reducer is a high-precision deceleration mechanism featuring advantages such as a large transmission ratio and load-bearing capacity. It is widely applied in fields of industrial robots. As a key component of RV reducer, the cycloid gear plays a decisive role in reducer's performance, and the cycloidal shape significantly affects the meshing performance. In this study, taking the RV-40E reducer as the object, a piecewise modification for the cycloidal gear based on meshing interval optimization was proposed. The working segment of cycloidal profile was modified by the rotated angular method, and the influence of meshing interval on transmission performance was analyzed. Then, taking the meshing-in and meshing-out phase angles as variables, the friction power loss and gluing coefficient as objectives, an optimization model for meshing interval was established. The single- and multi-objective optimizations were solved based on the genetic algorithm. The dedendum and addendum of cycloidal profiles were adopted spline curves. According to the continuity conditions at endpoints, the tooth profile equations of the non-working segments were obtained by spline interpolation method. The results demonstrated after optimization, the friction loss and gluing coefficient reduced by 6.30% and 10.50%, respectively, the reasonable radial clearances were maintained at the dedendum and addendum. Finally, the finite element simulation verification was carried out through ANSYS software. The proposed piecewise modification method not only ensures conjugate meshing in working segment, but also can flexibly control the gaps of non-working segments according to specific requirements, which provides the design ideas for gear tooth modification in engineering applications.