Wear of Lubricant Films : Part 2, Effects of Load and Speed

Abstract

In this paper is described how the wear properties of lubricant films are affected by load and speed. The wear property of lubricant film is studied by stick-slip analyser, which allows to find the critical number of runs with no abrupt rise of friction coefficient N_c during repetition of sliding on the same track of lubricated surface. From the experiment it is found that N_c changes in proportion to P^-0.55 (P is load), which is explained to be deduced reasonably when analysing the above relation taking the frictional stress into consideration. Wearing process of thin lubricant film is also analysed and by taking the relation between frictional coefficient and the thickness of lubricant film into consideration, the following relation is obtained ; [numerical formula] where μ=friction coefficient ; μ₀=friction coefficient for abundant quantity of lubricant ; y₀=given thickness of lubricant film ; N=number of runs on the same track ; c₁, c₂=constants.