Thermal Effects on Traction in EHD Lubrication

Abstract

The effects of heat generation and the resulting temperature profiles on the traction coefficient for two rollers in EHD contact are determined. An exact solution for the velocity profile through the film thickness is obtained to simultaneously satisfy the momentum balance and the nonlinear Maxwell model where the viscous term follows the Eyring “sinh” law. These results are coupled with the heat diffusion equation to yield simultaneous solutions for temperature and shear stress distributions in the film. Several cases are investigated for LVI 260 lubricant and are compared with experimental observations. The thermal theory is in good agreement with the experimental data. It is shown that the thermal theory predicts a maximum traction while the isothermal theory predicts increasing traction with increasing sliding speed.