Elastohydrodynamic Lubrication of Squeeze Films : Part 1 Two Cylinders Lubricated with Grease

Abstract

The elastohydrodynamic squeeze problem between two cylinders lubricated with grease is studied in the paper. In the analysis, grease is assumed to be a Bingham solid whose plastic viscosity and yield stress are dependent on the pressure, and the effect of surface velocities due to local deformation is considered. It is discussed by solving the time-dependent elastohydrodynamic equation for a Bingham solid with an iterative procedure how the core formation which is the inherent property of a Bingham flow affects the film pressure and the deformation of cylinder surfaces. Using an interferometric method of measuring the separation of a cylinder dropping onto the lubricated optical flat, the film profiles between them are photographed by a high speed cinecamera. The results are compared with the analytical ones.