Numerical insight into heat transfer and power losses in spinning EHD non-Newtonian point contacts

Abstract

This article focuses on thermal effects and their consequences in elastohydrodynamically lubricated spinning non-Newtonian point contacts. The particular kinematics of spin is of major interest for the understanding of flange contact in bearings (also known as rib-roller end contact) as well as in the field of continuously variable transmission where energetic efficiency is directly related to spin. A versatile finite element thermal non-Newtonian model is presented and results in terms of pressure, film thickness, temperature, heat fluxes, friction, and power losses are discussed. As spin increases, the central and minimum film thicknesses decrease drastically, the contact temperature rises, and the shearing heat source increases. The heat fluxes are totally reorganized in terms of direction and intensity. Friction values in both longitudinal and transverse directions need to be completed with the calculation of the frictional torque due to spin to take into account the total power losses in the contact. This study intends to draw attention to the necessity of an energetic approach when dealing with spinning contacts.