Mathematical analysis of the meshing performance of planetary roller screws applying different roller thread shapes

This article investigates the meshing performance of planetary roller screws applying rollers with circular, elliptical, and parabolic threads. A mathematical model is established for the thread surface, and a method for analytically calculating the meshing points was developed. The meshing point distributions and interference risk area are calculated to analyze the meshing characteristics of the thread shapes considered. The possibility of applying elliptical thread and parabolic thread to the rollers of planetary roller screws in place of the commonly employed circular thread was explored, and elliptical threads were determined to provide better meshing positions, achieve higher transmission speeds, and obtain longer working lifetimes.