Analysis of transient elastohydrodynamic lubrication of point contact subjected to sinusoidal dynamic loads

Abstract

Vibration is inevitable from all machine elements operations since the load, surface velocities or contact radii change in time. In the case of a ball bearing application, the load changes as the ball elements rotate around the track. This change will be more rapidly when the external load changes. The vibrations induce a sinusoidal dynamic load working on the contact. On the other hand, the imperfect waviness on the contacting surfaces causes the vibration effects on the film thickness to become more pronounced. This paper numerically investigates the influence of the sinusoidal varying loads due to vibrations on the film thickness and pressure profile of the isothermal, elastohydrodynamically lubricated point contact with a wavy surface. For that purpose, a single contact between ball element and inner raceway is modeled as a contact between a spherical ball and a flat plate. The results reveal that the external sinusoidal dynamic load induces the modulations on the film thickness and pressure profile. The waviness on one contacting surface causes the changes in the EHL behaviors to become more pronounced.