Effects of EHD Contacts Upon the Bearing and Housing Behavior

With the progress in technologies and design concepts, engine bearings are now subject to much higher specific loads, and supported by more flexible housing structures. During the engine operation, a bearing is expected to go through a complex sequence of distortion. The development of an EHL analytical technique lends us a powerful tool for understanding the behaviour of such bearings. Up to now, however, the use of such a tool has mainly been confined to the analysis of bearing lubrication. Few efforts were made to extend its application for the bearing/housing structural analysis, and for the understanding of the fatigue and life of engine bearings.

This paper reports some of the work carried out to address the issue. EHL and structural analyses are employed to investigate the behaviour of the bearing used in the Sapphire test rig. The analysis indicates that the circumferential cracks produced at the bonding interface between the bearing material and the steel backing is likely to be caused by the presence of successively high cyclical shear strain.