A Lubricant Model Considering Wall-Slip in EHL Line Contacts

Abstract

A wall-slip model including limiting shear stress and the occurrence of slip at the interfaces between the lubricant and the adjacent surfaces is presented. The lubricant model is applied to EHL line contacts using smooth surfaces and isothermal conditions. The main part of the model concerns the lubricant velocities at the surfaces that are decoupled from the corresponding surface velocity giving two new variables in the EHL equations. The lubricant velocities at the surfaces are related to the corresponding shear stresses. As long as the value of the shear stress is below the limiting shear stress, the lubricant velocity is equal to the surface velocity. However, when the shear stress reaches the limiting shear stress, interfacial slip appears and the lubricant velocity differs from the surface velocity. Some initial results are presented and compared to a Newtonian analysis.