A nonlinear dynamic model of the vibration response of defective rolling element bearings

Abstract

This paper presents a nonlinear dynamic model of the contact forces and vibration generated in rolling element bearings due to a surface defect in a raceway. A rectangular shape defect with sharp edges is selected for modelling because previous models were not able to predict the low frequency vibration event that occurs when a rolling element enters the defect. Simulations are presented for two defect sizes. In the first simulation, the defect length is small such that the rolling elements do not strike the bottom of the defect. The simulated results compare well with experimental results, and predict the low and high frequency events that occur when a rolling element passes through the defect observed in the experimental results. In the second simulation, the defect length is increased such that a rolling element strikes the bottom of the defect. This simulation demonstrates the benefits over models that do not consider the mass of the rolling elements. The benefits are illustrated by a detailed analysis of the contact forces that occur as a rolling element passes through the defect. The developed model can be used to simulate the vibration response of bearings with a defect in the raceway to aid in the development of new diagnostic algorithms.