Study on Fault Diagnosis of Gear with Spall Using Ferrography and Vibration Analysis

Ferrographic technique and vibration analysis are the two main identification techniques for condition monitoring and fault diagnosis in machinery. Wear mechanisms and changes are investigated for gear with spall fault using ferrographic analysis technique. Furthermore, the features of time and frequency spectrums have been investigated using the time and frequency spectrums of vibration analysis technology in this study. Analysis results show that quantity and size of wear debris and four eigenvalues of the time spectrum gradually become greater in order of the gear with minor spall, the gear with moderate spall and the gear with severe spall. Frequency spectrums of spalling gear appear some sidebands that meshing frequency of output terminal as centre frequency, the rotating frequencies of output terminal as modulating frequency occur. The investigation on wear and vibration characteristics of simulating spall fault gear provides the auxiliary basis to determine fault for the fatiguing spall failure of the actual using gear.