Research On Fault Identification Method Based On Rolling Bearing

CNC machine tools play an increasingly important role in production and processing.As one of the key components of CNC machine tools,rolling bearings are related to the working status of the entire machine tool.Failure of rolling bearings will have a direct impact on the smoothness of the transmission system of CNC machine tools,which in turn will lead to a reduction in the machining accuracy of the machine tool,and a serious cause mechanical failure.Therefore,the fault identification of rolling bearings is of great significance.The dissertation studies the method of fault identification for rolling bearing.The main contents of the dissertation are as follows:1.The failure mechanism of the rolling bearing is studied,and the vibration characteristics of the bearing in different parts of the rolling bearing are analyzed,and the vibration signal models of the rolling bearing outer ring fault,the inner ring fault and the rolling element fault are established in turn.2.For the case that the resonance demodulation method cannot accurately identify the failure of the rolling element,a segmented correlation resonance demodulation method is proposed.Correlative analysis was used to extract signal segments containing more fault signals in the vibration signal,and the signal was demodulated based on Hilbert transform to obtain the envelope signal.The experimental analysis shows that this method is useful for identifying the effectiveness of rolling element faults.3.The effects of wavelet analysis and wavelet packet analysis on the noise reduction processing of vibration signals are studied.Their decomposition and reconstruction theory are described.Through experimental analysis,it shows that wavelet packet analysis has a good protection effect on the impact components in fault signals.The wavelet packet analysis was used as a signal pre-processing method.4.The spectral kurtosis theory is applied to the filter design of high-frequency band-pass filter.The kurtosis diagram analysis can be used to adaptively determine the relevant parameters of the high-frequency resonant frequency band based on the vibration signal.The experimental analysis results show that the parameters of the high-frequency resonant frequency band in which the failure occurs in different parts of the scroll are different.5.The general working process of fault identification for rolling bearings is analyzed,and the development status of the current development process of the vibration signal processing technology based on rolling bearings and the feature extraction technology are summarized.