Numerical and Experimental Study of Elastohydrodynamic Grease Lubrication of Surfaces with Longitudinal and Transverse Pattern

Abstract

The interaction of non-Newtonian grease with patterned surfaces was considered as a promising approach to find an effective method for reducing friction and wear in rolling contacts. Longitudinal and transverse patterns can retain the lubricant in the contact area and prevent it from escaping under high loads. In this paper, a model has been developed for grease elastohydrodynamic lubrication of surfaces with different patterns to estimate the lubrication parameters such as lubricant film thickness, pressure distribution, and viscous friction. Then several experimental tests are rolled out for different loads, velocities, and surface patterns. Because the friction model estimates only viscous friction, a correlation is recommended for considering the friction due to asperity interaction. This relation is based on average lubricant film thickness results which are calculated from the model. The calculated friction and experimental results have a good agreement. According to the experimental tests, transverse, longitudinal, and isotropic pattern had a lower friction coefficient, respectively. While the isotropic viscous friction coefficient estimated by the model is lower than others. Higher loads and lower velocities cause a higher friction coefficient in all surface patterns.