Determination of the Shear Stresses of Lubricants in Elastohydrodynamic Contacts

Abstract

The need for increased efficiency in transmissions has focussed attention upon the traction characteristics of lubrication in elastohydrodynamic contacts. Until now most studies in this field have employed a disc machine to obtain mean values of traction coefficient across an entire elastohydrodynamic contact. This obscures details of the way the lubricant responds to the varying pressure and temperature across the contact.

This paper describes a method of obtaining local shear stresses of lubricants as they vary across a sliding contact. Infrared radiometry is employed to measure the surface temperature profile of a lubricated steel surface sliding against a static sapphire window. Mean shear stress profiles are obtained from these temperatures using standard heat conduction theory for a finite width, finite length moving heat source. Results are compared with data obtained using conventional traction and shear stress measurements.

Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988

Notes

Presented at the 43rd Annual Meeting in Cleveland, Ohio May 9–12, 1988