Experimental Investigation of Film Thickness Behaviour at Very High Speeds

Abstract

At very high speeds, elastohydrodynamic (EHD) films may be considerably thinner than is predicted by classical isothermal regression equations such as that due to Hamrock and Dowson. This may arise because of viscous dissipation, frictional heating or starvation. In this paper, the contact between a steel ball and a glass disc was studied. The disc was driven at speeds of up to 20 ms−1, and the ball was driven by tractive rolling against the disc, its speed being determined using a magnetic method. It is shown that the results, which fall well below classical predictions, are consistent with inlet shear heating at the observed sliding speeds.