Elastohydrodynamic Lubrication of Rollers

Abstract

IT is now well known that the lubrication at such nominal line contacts as are found in roller races and between gear teeth is hydrodynamic in character. It is also known that this lubrication possesses peculiar features not found in journal bearings and which arise from the high pressure—a pressure, for example, of tens of tons per square inch as compared with 100 lb. in.⁻². Because of the pressure the surfaces are deformed, in general elastically, and in addition within the pressure zone the oil acquires a much higher viscosity than it normally possesses; the viscosity might be greater by a thousand-fold. These circumstances have excited much inquiry as to the shape in cross-section of the hydrodynamic film. This communication reports an experimental measurement of that shape.