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 cumulative wear of thread pairs, which will reduce its transmission accuracy and reliability. Hence, it is significant to investigate the cumulative 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 modeled, respectively. The effects of eccentric errors on the sliding velocities and cumulative wear depth of PRSM are investigated. It has been determined that the eccentric errors of the screw and nut do not cause the sliding motion in the nut–roller contact region (NRCR). However, there are noticeable variations in sliding velocity and cumulative wear depth in the screw–roller contact region (SRCR). The eccentric errors of the screw and nut have a combined effect on the sliding velocity and wear between the screw and roller. This investigation and finding can provide a valuable reference for the processing and assembly of PRSM.