A Theoretical Model to Predict the Vibration Response of Rolling Bearings in a Rotor Bearing System to Distributed Defects Under Radial Load

Abstract

A theoretical model to predict the vibration response of rolling element bearing in a rotor bearing system to distributed defects under radial load has been developed. The rotor bearing system has been considered as a three degrees of freedom model. The distributed defects considered are, the waviness of outer and inner races, and off size rolling element. The model predicts discrete spectrum with specific frequency components for each order of waviness. For outer race waviness, the spectrum has components at outer race defect frequency and its harmonics. In the case of inner race waviness, the waviness orders equal to number of rolling elements and its multiples give rise to spectral components at inner race defect frequency and its multiples. Other orders of waviness generate sidebands at multiples of shaft frequency about these peaks. The model predicts the amplitudes of the spectral components due to outer race waviness to be much higher as compared to those due to inner race waviness. In the case of an off-size rolling element, the model predicts discrete spectra having significant components at multiples of cage frequency. [S0742-4787(00)00603-2]