A Study of the Behaviour of Connecting Rod Bearings Using an EHL Predictive Tool

The behaviour of connecting rod bearings has been studied using a predictive tool which takes into account the influence of the elastic compliance of bearing and housing structure on the hydrodynamic action of the bearing. The first part of the study investigated the effects of different operating conditions on bearing performance. This analysis provided some insight to the problems experienced with some high speed engine connecting rod bearings. The study proceeded to assess the suitability of using a uni-axially loaded test rig for the simulation of bearing behaviour. Results indicated that the pinch effect on the cap half bearing increased with the bearing inertial loading, which correlated well with some of the bearing problems experienced in high speed engines. It was also shown that the behaviour of bearings was significantly influenced by the loading patterns applied to the bearings. The inertial component of bearing loading could dramatically worsen the lubrication condition of the bearing. In contrast, the kinematics of the cylinder system has only a modest effect upon the bearing performance.