Vibration signature analysis of a high speed rotor supported on ball bearings due to localized defects

This paper presents the vibration signature analysis of the high speed rolling element bearings due to localized defects with an un-cracked and a cracked rotor. In rotating machines, one of the main causes of breakdown is faults in ball bearings and crack in rotors. Thus, accurate prediction of severe vibration conditions and characteristic defect frequencies is crucial for the reliable operation. A test rig of a high speed rotor supported on healthy and defective ball bearings is used. The vibration response is obtained and analyzed for the un-cracked and cracked rotor with and without defects on bearing components. The defects such as spalls on the outer race, inner race and on the rolling elements are considered for the study. Combined parametric effects have been analyzed to predict the dynamic response of a rotor-bearing system using response surface method. It is also observed that the severe vibrations occur under bearings with spall on the inner race surface and on a ball under high speed rotor condition.