On Formulation of a Non-Steady Lubrication Problem for a Non-Conformal Contact©

Abstract

A formulation of a non-steady problem for elastohydrodynamically lubricated (EHL) non-conformal contact is considered. It takes into account elasticity of contact bodies, lubricant viscosity and changing in time location of the inlet boundary, velocities of the contact surfaces and applied load. The main goal of this paper is to propose a “modified” formulation of the problem free of certain defects. A “traditional” and “modified” formulations of the problem, leading to discontinuous and smooth solutions in cases of abrupt changes in external load applied to a contact and linear velocities of its surfaces, are considered. For the case of purely squeezed lubrication film, an analytical and numerical analysis of the dynamic response of a lubricated contact to abrupt changes in external load is performed. It is shown that in the case of purely squeezed rigid surfaces it takes infinite time to bring the surfaces in direct contact, i.e. theoretically, the film thickness never reaches zero. Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in Toronto, Ontario, Canada, October 26–28, 1998