Wear study and EHD lubrication analysis on connecting rod big end bearings of off-highway application engine

Abstract

The connecting rod big end bearings are under dynamic lubrication during working cycle, and in most of the time, the con rod is subjected to compressive stress. The conventional method of performing an EHL analysis on a bearing involves development of complex mathematical equations and simplification of actual physical model. This paper presents a methodology to model and simulate the elastohydrodynamic lubrication and wear study of connecting rod big end bearings of off-highway application engine using the application of computational fluid dynamics (CFD) and computational structural dynamics (CSD) approaches. The pressure field for a full journal bearing operating under laminar flow regime with various eccentricities was obtained by CFD, and fluid pressure distribution and deformation in the bearing liner due to pressure were evaluated using FSI approach. Relevant parameters of lubrication characteristics were analyzed to optimize the eccentricity value. The maximum bearing load value of 21 kN was noticed at TDC position for the optimum eccentricity. The load distribution indicated critical points in the bearing, and the data obtained from bearing load and sliding velocity of journal were used in Archard's wear relation to determine the wear depth along the bearing width. The simulated wear results were compared with three-cylinder off-highway application engine con rod big end bearings, which ran for 1000 hours at full load condition, and satisfactory agreement was observed between experiment and simulation values. � 2020 John Wiley & Sons, Ltd