Gear Fault Monitoring Based on Order Tracking and Bi-spectrum under Running-Up Condition

This paper deals with the detection of gear crack faults in gearbox under non-stationary run-up of gear drives. In order to process the non-stationary vibration signals such as run-up or run-down vibration signals effectively, the order bi-spectrum technique is presented. This new method combines computed order tracking technique with bi-spectrum analysis. Firstly, the vibration signal is sampled at constant time increments during run-up of gearbox and then uses numerical techniques to resample the data at constant angle increments. Therefore, the vibration signals are transformed from the time domain transient signal to angle domain stationary one. In the end, the re- sampled signals are processed by bi-spectrum analysis method. The experimental results show that order tracking and bi-spectrum technique can effectively diagnosis the gear faults.