Film thickness predictions for elastohydrodynamic elliptical contacts over a wide range of radius ratios with consideration of side starvation

Abstract

The paper presents numerical solutions obtained for a wide range of elliptical elastohydrodynamic lubrication (EHL) problems. The conditions considered encompass relative principal radii of curvature ratios from 20:1 with entrainment in the minor axis direction, to 50:1 with entrainment in the major axis direction. The problems considered derive from investigations of practical machine elements where the width of contact (perpendicular to entrainment) is limited by the extent of the metal surfaces on either side. Two sets of results have been obtained: one with the width of the lubricated contact approximately twice that of the Hertzian dry contact, and the other where the ratio of these widths is 1.2. Taken as a whole the results present a complete range of conditions obtained using the same numerical model throughout. The film thickness predictions are compared with those given by well-known published formulae and design charts.