Behavior of a Bingham Solid in Hydrodynamic Lubrication : Part 2, Application to Step Bearing

Abstract

There are few papers in which the effects of the core formation on bearing performances were investigated experimentally and compared with the theoretical results. The process of the core formation has not been observed precisely.We have investigated the behavior of a Bingham solid in hydrodynamic lubrication. The general theory on a Bingham solid was already presented in the first paper.In this paper, we applied this theory to the step bearing and clarified theoretically how the existence of a yield value in shear stress affects the core formation and the bearing performances.After confirming that grease had the behavior of a Bingham solid, we observed the core distribution in the step bearing using grease as a lubricant. And comparing the experimental results with the theory, we found that both agreed and the film pressure and the range of the core formation increased as the dimensionless yield stress increased.