A Resonance Demodulation Method Based on Harmonic Wavelet Transform for Rolling Bearing Fault Diagnosis

Resonance demodulation technique is widely employed to diagnose faults of rolling bearings. In order to reduce the energy leakage influence of the traditional demodulated resonance method, a new approach based on harmonic wavelet transform (HWT) is proposed to extract the fault characteristics of rolling bearing. From the results of the numerical simulation analysis, this method is proven to be efficient in detecting the impact signal clouded in noises. Moreover, this article proposes a resonance demodulation scheme, which can obtain the optimal HWT parameters automatically to construct the proper sub-frequency band filter by calculating the relative wavelet energy of the different sub-frequency band. It solves the shortcoming in which a resonance frequency band filter is chosen manually. The proposed scheme is successfully applied to detect the fault of rolling bearings of a tilting mechanism in a converter mill.