Small-Angle Oscillatory Performance of Solid-Lubricant Film-Coated Ball Bearings for Vacuum Applications

Abstract

The purpose of this work is to clarify the oscillatory performances of ball bearing for vacuum application. The friction properties of several solid-lubricant films were examined by using a reciprocating tribometer in a vacuum and in air. Ball bearings lubricated with the same solid-lubricant films were then tested under small-angle oscillatory conditions. Bearing lubricated with Ag + MoS₂ show the lowest starting torque and surface damage. This result corresponds to sliding tests results. The damage profile of oscillatory bearings corresponds to the profile of the contact elliptic area. The rolling scars are mainly caused by the differential slip between balls and races.