关键词: 滚动轴承;航空发动机;主轴轴承+;故障诊断;小波包分解+;特征提取+

Abstract: Vibration analysis is widely used in the condition monitoring and fault detection of the rolling elernent bearings.When locally scathed,the bearings would bump the other parts periodically with the result that the seasonal impulses come into being.With enough broad band to overcast each connatural frequency of the whole bearings,the impulses necessarily arose each connatural vibrations and thereby the stationary vibrations turn into transients.Although well localized in frequency,the Fourier transform was localized none too well in time which makes it a cumbersome tool for transients.Moreover,a local time-frequency composition as the windowed Fourier transform,the short-time Fourier transform namely,it has the same resolution across the time-frequency plane because of the same spread of the window on which the resolution depends.If using conventional method for the vibration signal analysis,the non-stationary signals are hard to analyze.This paper investigates rolling bearings fault diagnosis based on wavelet analysis method,and the surface damnification fault signals are diagnosed by using the frequency domain analysis method of wavelet package decomposition.Experimental results show that the analysis methods of wavelet transform are reliable and accurate.They are useful for the condition monitoring and fault diagnosis to aero-engine rolling bearings.

Key words: Rolling bearing;Aircraft-engine;Main shaft bearings+;Fault diagnosis;Wavelet package decomposition+;Fault feature extraction+