Gear Fault Diagnosis Based on Order Tracking and Hilbert-Huang Transform

Varying speed machinery condition detection and fault diagnosis are more difficult due to non-stationary machine dynamics and vibration. A new approach to fault diagnosis of bearing under running up based on order tracking and Hilbert-Huang transform (HHT) is presented. The non-stationary vibration signals are transformed from the time domain transient signal to angle domain stationary one using order tracking. EMD can adaptively decompose the vibration signal into a series of zero mean amplitude modulation-frequency modulation (AM-FM) intrinsic mode functions (IMFs). Hilbert transform can track the instantaneous amplitude and instantaneous frequency of the AM-FM component at any instant. Hilbert-Huang transform can effectively diagnose the faults of gear crack, thus providing a viable processing tool for gearbox fault diagnosis.