A Novel Piecewise Modification of Cycloidal Gear and Tooth Contact Analysis

Abstract

AbstractAiming at the cycloid gear of RV reducer for robots, a novel piecewise modification of cycloidal gear was proposed. Based on the change rule of pressure angle, the tooth profile of cycloidal gear is divided into the working segment and non-working segment. The angle modification is applied to the working segment. The value of angle modification is determined by the design hysteresis, the maximum contact deformation angle and the minimum oil film thickness. The quartic fitting curve is applied to the non-working segment ensuring a reasonable meshing backlash to facilitate lubrication and assembly. It is proved by an example that the piecewise modified profile is closer to the ideal profile. Moreover, the modification value of the working segment is independent of the modification value of tooth top and tooth root. Based on the tooth contact analysis, the maximum contact stress of the piecewise modified tooth surface is 35.2% of the traditional “negative isometric + positive shift” combined modification. Compared with the traditional “negative isometric + positive displacement” modification, the number of multi-tooth mesh of the piecewise modified cycloidal gear is more. The transmission accuracy of the piecewise modified cycloidal gear is improved.KeywordsCycloidal gearPiecewise modificationRV reducerQuartic fitting curveTooth contact analysis