Analyzing Vibration as a Useful Domain for Getting Bearing Fault Signals in Induction Motors

Due to widespread usage of induction motor (IM) in various industries, the requirement for its condition monitoring have been considerably raised. It is essential to detect faults that happened in IMs in a short time with high accuracy because they may cause considerable financial losses. Bearing faults contribute to a large percentage of IM failures. In this paper, vibration signal is analyzed for getting reliable indicator for faulty modes of the bearings of the IMs. The proper direction for measuring the vibration signal is analyzed first. This analysis shows that the fault-related vibration frequency components along the Z-axis, i.e. the axis perpendicular to the motor's installing surface, usually have the largest magnitude. Thus, it is recommended to measure the vibration signal in the Z-axis. Then, the bearing fault diagnosis using the vibration signal is investigated in various scenarios. The results confirm that the vibration indicators are not sensitive to environmental parameters like temperature and also load variation of the IM but the severity of the fault has a considerable influence on them.