Study on the Anti-seizure Capacities of EP Oils by Two Cylinder Test

Abstract

In this paper, to contribute to the establishment of a calculation method for load carrying capacity of a gear pair for scoring, the effects of specific sliding and sliding velocity on the anti-seizure capacities of EP oils were examined by two cylinder test. As the result, the following conclusions are deduced : (1) EP films formation is closely related to the lubrication states of frictional surfaces and chemical properties of EP additives. In mixed lubrication, EP films are formed only locally. (2) In EP oils also, seizure tends to occur in mixed lubrication and the anti-seizure capacities decrease as specific sliding and sliding velocity increase. (3) In the case when frictional surfaces are in boundary lubrication, the maximum contact surface temperature, and in the case when they are in mixed lubrication, the bulk temperature of outer surface of cylinder can be employed as the index temperatures for seizure respectively. However, these temperatures at seizure occurrence decrease as specific sliding increases.