Diagnosis and root cause analysis of bearing failure using vibration analysis techniques

Abstract

This paper is presented to diagnose and root cause analysis of the bearing failure. For this purpose, a vibration investigation was carried out on a motor with a 2300 kW power, 1489 rpm speed. Bearing failure was diagnosed by trending and analyzing vibration parameters. By investigating the bearing damage morphologies, a false brinelling pattern was observed. To find the failure cause, the machine was evaluated for two aspects; vibrations and lubrication. The resonance in the fan and the lack of full lubrication film formation were considered root causes of failure. To mitigate resonance, changing the operating speed was considered as a corrective action. By increasing the operating speed (1491 to 1530), the vibration amplitude decreased by nearly 21%. Also, the thickness of the lubricating film was improved by installing an airflow hose. Using this method, the time between failures increased from 3 to 11 months.