A comparison of some condition monitoring techniques for the detection of defect in induction motor ball bearings

Rolling element bearings are critical components in induction motors and monitoring their condition is important to avoid failures. Several condition monitoring techniques for the bearings are available. Out of these stator current monitoring is a relatively new technique. Vibration, stator current, acoustic emission and shock pulse methods (SPMs) for the detection of a defect in the outer race of induction motor ball bearing have been compared. The measurements were performed at different loads. The defect in the bearing could be detected by all the methods. Acoustic emission monitoring proved to be the best method followed by SPM when the increase in the levels of the measured parameters were compared with respect to those of healthy bearings.