Film Thickness of Grease in Rolling Contacts

Abstract

Optical Interferometry is used to study the film thickness of greases, and of soap suspensions and of their base oils in point or line contact. In one case, samples were taken from a grease-lubricated plain-bearing test after 5 1/2- and 25-million revolutions. The effective viscosity of a grease under the very high shear rates of the order of 1/2 × 10-6 s-1 encountered in rolling contacts can be calculated.