Temperature measurements of both sliding surfaces and an estimation of temperature profile across film thickness under EHL conditions

An experimental study of temperature measurements of both sliding surfaces and estimation of film temperature profile across film thickness under point EHL conditions was carried out. An increase of a speed difference between both sliding surfaces resulted in a larger temperature difference between both sliding surfaces, which led to a change of the form of temperature distribution. The temperature of slower surface was higher than that of the faster surface as the velocity difference increased, and that the temperature gradient across film thickness also existed at the inlet region because the heat generated at the contact region was transferred back from the slower surface to this region. At a slip ratio of 0.6:1, the temperature distribution on both sliding surfaces did not show any significant difference, either in the forms or in their magnitudes, When the temperature distribution on both sliding surfaces changed, the temperature distribution in oil films varied as well. At slip ratios of 1:1 and 1.8:1, a temperature gradient in the direction of the clearance occurred and the highest temperature showed a local rise close to the outlet region at slip ratios of 0.6:1 and 1:1, but a slip ratio of 1.8:1, if shifted closer to the center of the contact zone on the disk surface.