Oil-Film Behaviour of Reciprocating Slider with Circular Profile : Observation of Oil-Film by Means of Thin-Film Interferometry

Abstract

The oil film behaviour of a piston ring is an important matter worthy to be clarified. However, because of a too complicated phenomenon to be satisfactorily analyzed and of difficulty in measurement with high accuracy, information available on the oil film behaviour in an actuating engine is insufficient. This paper refers to an experimental work which has been carried out with a specially designed reciprocating test equipment, in which the oil film thickness between a piston-ring specimen and a plane glass plate substituting for a cylinder surface can be measured by means of a thin film interferometry. By this procedure (1) variation of oil film thickness with the reciprocating motion and (2) effective pressure built-up region of oil film have been examined and the results of the experiments have been compared with those of theoretical analyses based on the assumption that the pressure region of oil film varies according to the Reynolds boundary condition.