Application of EMD denoising and spectral kurtosis in early fault diagnosis of rolling element bearings

It is difficult to select the band-pass filter parameters in resonance demodulation which is one of common methods for fault diagnosing of rolling element bearings,but they can be automatically determined by use of spectral kurtosis based on the principle of maxkurtosis.Even though some diagnosis effects have been achieved by this method,it is not obvious enough sometimes due to the strong background noise involved in the early fault signal of rolling element bearings.Therefore,a new early fault diagnosis method based on EMD denoising and spectral kurtosis was proposed.The sampled signal was preprocessed by EMD denoising,combining with the criterions of cross-correlation coefficient and kurtosis to highlight the high-frequency resonance components.The optimal band-pass filter parameters were selected with the help of spectral kurtosis.Then,the fault diagnosis was implemented by band-pass filter and envelope demodulation.The application in a practical engineering signal verified its capability.