Particle Entrapment in Rolling Element Bearings: The Effect of Ellipticity,Nature of Materials,and Sliding

This study on particle entrapment within elastohydrodynamic contacts reports experimental tests mimicking rolling element bearing contacts using a twin-disc machine with a contaminated lubricant as well as numerical simulations. The ball bearing contacts might be nonideally circular, composed of a hybrid couple of contact materials, and operated under rolling–sliding conditions. This study focused on the relative importance of each of these configurations to the mechanisms responsible for particle entrapment. It was found experimentally and confirmed numerically that the contact ellipticity is of primary importance to entrapment probability. Tests mixing two-by-two pure rolling and non-zero slide-to-roll ratios (SRRs) and different materials and contact configurations revealed combined mechanisms leading to entrapment and surface damage.