Effects of Compressive Heating on Traction Force and Film Thickness in Point EHL Contacts

Abstract

The effects of compressive and viscous heatings of lubricating fluid on the traction force and film thickness are investigated under low slide-roll ratios by thermal EHL analyses based on the Newtonian and Eyring fluid models. The effects of the thermal conductivity of contacting surfaces and oil viscosity on EHL performance are also studied using combinations of actual and virtual contacting materials. It is found that the film thickness is hardly influenced by fluid models but is influenced very much by the atmospheric oil viscosity and the thermal conductivity of contacting materials even under the same set of dimensionless parameters G, U and W. It is also found that the compressive heating as well as non-Newtonian fluid behavior plays a very important role for the traction force in EHL contacts under low slide-roll ratios depending on the thermal conductivity of contacting surfaces and atmospheric oil viscosity.