Vibration analysis on rolling elements bearing with localized defects: Part I. A single defect in outer race

On basis of the two degrees of freedom vibration model of the normal rolling elements bearing established by using the elastic mechanics and consideration of the influence of the width and depth of the local defect, the vibration model of rolling elements bearings with an outer race defect was constructed through adding the change of the contact deflection between the rolling element and races which took place when the rolling element passed the defect. Through the numerical simulation, it was verified that the frequency components of the vibration signal of the of rolling elements bearings with an outer race defect in low frequency region were the frequency of the rolling element passing the defect and its multiple frequencies, which often was used in faults diagnosis of the rolling element bearing. The reason of occurrence of the multiple frequencies was explained reasonably. The experiment further testified the validity of the model and the simulated results.