Novel Comb-filter and Envelope-demodulation Method Applied in Fault Diagnosis of Rolling Element Bearing

According to the insufficiency of band-pass filter based on Morlet wavelet and Harmonic wavelet,a novel complex analytical band-pass filter with the characteristics of nearly box on frequency-domain and rapid decay on time-domain is proposed.Then aiming at the fault diagnosis of rolling bearings,a comb-filter and envelope-demodulation method is presented based on the band-pass filter.The simulation results show the effectiveness of the method to pass fault modulating signal in narrow bands and suppress the noise than a broadband filter,and the fault characteristic information can be demodulated directly from the output signal.