Current/Voltage Based Detection of Faults in Gears Coupled to Electric Motors

Gears form a critical part of many electro-mechanical systems. Since gear faults cause vibrations, and vibration-based diagnostics is very reliable, this has traditionally been the most commonly used approach to detecting gear faults. However, it is expensive due to the use of high-priced accelerometers and sensor wiring. This paper proposes an alternative way of detecting faults in gears coupled to BLDC motors by monitoring either the motor current or voltage. It is shown that gear faults create unique spectral components in the voltage and current spectrums. The faults investigated in this paper include damage to gear teeth and loss of lubrication. Experimental and simulation results demonstrate that motor current/voltage signature analysis is a viable tool to detect these gear faults, and is a cheaper alternative than vibration based fault detection schemes