Date Added: Sep 2011
Varying speed machinery condition detection and fault diagnosis are more difficult due to non-stationary machine dynamics and vibration. Therefore, most conventional signal processing methods based on time invariant carried out in constant time interval are frequently unable to provide meaningful results. This paper deals with the detection of bearing 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 rundown vibration signals effectively, the order bi-spectrum technique is presented.