Abstract: Bending fatigue crack is a dangerous and insidious mode of failure
in gears. As it produces no debris in its early stages, it gives little warning
during its progression, and usually results in either immediate loss of
serviceability or greatly reduced power transmitting capacity. This paper
presents the applications of vibration-based techniques (i.e. conventional time
and frequency domain analysis, cepstrum, and continuous wavelet transform) to
real gear vibrations in the early detection, diagnosis and advancement
monitoring of a real tooth fatigue crack and compares their detection and
diagnostic capabilities on the basis of experimental results. Gear fatigue
damage is achieved under heavy-loading conditions and the gearbox is allowed to
run until the gears suffer badly from complete tooth breakage. It has been
found that the initiation and progression of fatigue crack cannot be easily
detected by conventional time and frequency domain approaches until the fault
is significantly developed. On the contrary, the wavelet transform is quite
sensitive to any change in gear vibration and reveals fault features earlier
than other methods considered.
Keywords: Real time gear fatigue, gear vibration, cepstrum, continuous wavelet transform
