Modelling of Elastohydrodynamic Step Bearing Considering Adsorbed Layer and Surface Roughness

Abstract

The operation of the elastohydrodynamic lubricated step bearing is analytically investigated when operating with low clearance and surface roughness. In this bearing, there is a sandwich film containing two adsorbed layers and an intermediate fluid film. Using Zhang’s multiscale flow model, the calculations were performed numerically to determine the film pressure and lubricating film thickness distributions. The results show that the elastic deformations of the coupled surfaces greatly affect the performance of the bearing, especially when the adsorption of the adhering layer is stronger or/and the surface is rougher; For a given load, it significantly reduces the magnitude of the highest pressure and modifies the pressure distribution, and it also reduces the minimum clearance and modifies the surface separation profil.