Thermal Effects on the Film Thickness in Elliptic EHL Contacts With Entrainment Along the Major Contact Axis

The effects of thermal conductivity and kinematics of contacting surfaces and viscosity-pressure coefficient on the film thickness in an elliptical contact under pure sliding conditions in which lubricant entrainment vector is directed along the major principal axis of the contact ellipse are discussed on the basis of experimental and numerical results. In the system where the conjunction is composed of surfaces having a large difference in their thermal conductivities, the film thickness is influenced markedly by the kinematics, in particular when a lubricating oil with a rather high viscosity-pressure coefficient is used. That is, the film thickness is much smaller when the surface having a low thermal conductivity is moving and that having a high thermal conductivity is stationary than in the opposite case. It is also found that a rather large dimple occurred in former case under rather high sliding condition moves toward the exit.