Modeling and Analysis of Outer Race Defects in Rolling Element Bearings

This paper deals with the development and analysis of a model for outer race defects in rolling element bearings. Detailed models such as the one presented here can be used to improve the detection, estimation and prediction of failure in rotating machines. The model parameterizes the defect and other operating conditions so that it can be used along with experiments to develop novel fault monitoring algorithms which are applicable for health management of these critical machine components. In this paper the rotor-bearing system is modeled as a rigid rotor and the defects are modeled as pits in the bearing race. In this model the position of the bearing in the defect is also modeled in detail and is not assumed to be a predetermined function. It is dynamically determined based on the clearance and the position of the shaft. Using this nonlinear model the motion of the shaft is simulated and the effect of the rolling element passing through the defect is studied. The effect of the shaft parameters and the defect parameters on the dynamics of the shaft and the overall performance of the system is studied.