Fault Diagnosis Technology Of Vehicle Drive Shaft Based On Resonance Demodulation Strategy

Rolling bearings in the driveshafts of running parts of rail transit vehicles are one of the components closely related to operational safety.At present,the detection of bearing faults in the running department depends on the maintenance of the factory,monitoring of the shaft temperature,low sensitivity,poor flexibility,and difficulty in early warning of faults.Therefore,it is of great significance to study the method that can effectively detect the early failure of the rolling bearing in the running section.This paper proposes the use of resonant demodulation strategies for fault diagnosis.In view of the problems existing in the practical application of resonance demodulation method,an improved scheme based on Empirical Mode Decomposition(EMD)and spectral kurtosis is proposed.This paper first studies the fault diagnosis method and development history of rolling bearings,analyzes the limitations and the advantages of resonance demodulation strategy over other methods.Starting from the failure mechanism of the rolling bearing,the mechanism of vibration in its structure and operation,as well as several forms of failure,are analyzed.For the different component failures of the bearing,the corresponding characteristic frequency formulas were deduced respectively.Next,the basic principle of resonance demodulation strategy was studied.The superiority of this method in extracting fault impulse signals was proved by simulation.Emphasis is placed on the related issues of EMD and spectral kurtosis in improving the resonance demodulation method,including its basic theory,existing problems and methods of obtaining.The algorithm is validated by simulation signal and laboratory measurement signal.The measured signal includes single point faults of the three components of bearing outer ring,inner ring and rolling element.The results show that the proposed method can accurately detect the bearing in actual operation.There are faults in these three locations.Finally,the fault diagnosis software system designed in the Matlab App Designer environment can import and process measured vibration data.The method studied in this paper is only for bearing single-point fault diagnosis under the condition that the shaft rotation speed is unchanged,and the method for the composite fault diagnosis under the condition of variable speed and bearing remains to be further studied.