Effects of eccentric errors on sliding velocity and accumulative wear depth of planetary roller screw mechanism

Abstract The eccentric errors of planetary roller screw mechanism (PRSM) affect the contact kinematic characteristics and exacerbate the accumulative wear of thread pairs, which will reduce its transmission accuracy and reliability. Hence, it is significant to investigate the accumulative wear of PRSM with the eccentric errors. In this work, based on the conjugate surface contact condition and Archard wear theory, the sliding speed and cumulative wear depth of PRSM with eccentricity errors are modelled respectively. The effects of eccentric errors on sliding velocities and accumulative wear depth of PRSM are investigated. It is found that the eccentric errors of the screw and nut cannot cause the sliding motion in nut-roller contact region (NRCR), but the sliding velocity and accumulative wear depth in screw-roller contact region (SRCR) have obvious variations. The eccentric errors of the screw and nut have a superimposed effect on the sliding velocity and wear between screw and roller. This investigation and finding can provide an important reference for the processing and assembly of PRSM.