Modeling of contact load distribution of planetary threaded roller bearing based on deformation coordination

Abstract

Planetary threaded roller bearing (PTRB) mainly consists of an outer ring, an inner ring, and rollers and all these parts have multiple annular threads. The PTRB is used in heavy loading linear transmission mechanisms because of its high-power density. It has been designed mainly to bear the axial load, and its load carrying capacity is determined by the contact load distribution characteristics of the threads in the axial direction. In this study, axial static stiffness model of the PTRB was developed to obtain the deformation of threaded teeth, threaded contact zone, and shaft sections. Based on the coordination of the above-mentioned deformations, contact load distribution of PTRB was calculated. Moreover, the contact load distribution coefficient was proposed to evaluate the distribution regularity of contact load. The validity of the proposed mathematical model was verified by the results of finite element simulation. Finally, the effects of external load, pitch, and number of threaded teeth on the contact load distribution regularity were analyzed.