A Numerical Model to Predict Damaged Bearing Vibrations

Abstract

This work aims to develop the theoretical fundamentals and numerical details of new software, dedicated to the simulation of the dynamic behavior of rotating ball bearings in the presence of localized surface defects. In this article, the generation of vibration by a point defect in a rolling element bearing is modeled as a function of the rotation of the bearing, of the distribution of the load in the bearing, of the bearing structure elasticity, of the oil film characteristics, and of the transfer path between the bearing and the transducer. The numerical model is developed with the assumption that the dynamic behavior of the bearing can be represented by a coupled three-degree-of-freedom system, after which the governing equations of the simulation model are solved using computer simulation techniques. A new application, called BEAT (BEAring Toolbox), was developed in order to simulate bearings' vibratory response to the excitations produced by localized defects. By adding a noisy response due to the sliding friction occurring between the moving parts to the impulsive response caused by localized defects, the BEAT software is able to provide realistic results, similar to those produced by a sensor during experimental measurements.