Effect of Wear on the Performance of Non-Recessed Orifice Compensated Hybrid Journal Bearing

Abstract

A bearing subjected to frequent start/stop operations is worn progressively due to rubbing. As a consequence, the geometry of the bearing changes and the performance is affected. This paper presents a theoretical study of the performance of an orifice compensated worn non-recessed hole-entry hybrid journal bearing system. The finite element method has been used to solve the Reynolds equation, governing the flow of the lubricant in the clearance space between the journal and the bearing, along with a restrictor flow equation. The global system equation with the orifice restrictor is nonlinear, which is solved by an iterative technique using the Newton-Raphson method. Two types of journal bearing configurations, having symmetrical and asymmetrical distribution of supply holes around the circumferential direction, have been investigated in the present study. The effect of the wear depth on the journal bearing performance characteristics have been presented for a wide range of restrictor design parameters and external loads. The study demonstrates that the wear affects the bearing performance parameters and the degree of variation is affected by the operating condition, the bearing configuration, and the type of restrictor used. The influence of wear can be reduced by a proper selection of the bearing configuration (symmetrical/asymmetrical), the restrictor, and its design parameter.