Research On A H-Type Gearbox Fault Diagnosis Method

The gearbox is an important component part of the car, but the complexity of istructural components and mode of operation lead to the car prone to fault.The gearbox fault will directly affect the performance of the whole vehicle, and will seriously affect the safety performance of the car lead to the driver and the people in the car sink -into potential safety hazard. So its has very practical practical significance in researching the gearbox fault diagnosis methods of a car.Wavelet analysis technique as a new theory has developed rapidly in recent years, and its has been successfully applied in many research fields such as imaging process,communications, and geophysics.In this paper, the wavelet analysis technique is applied to the gearbox fault diagnosis, and researched the theory and case analysis on the basis of this technique.This paper analyzed the mechanical structure,the main parameters and and assemblies of the H-type gearbox.Both analyzed the common type of fault and failure pattern of the gearbox, and detaiy analyzed the gears and bearing’s vibration mechanism andor the reasons of coused the vibration.This paper discussed in detail about the basic theory of wavelet analysis and correlative algorithms,and in order to effectively and accurately extract fault features of the gearbox fault signals,using a wavelet packet multi-layer decomposit and reconstruct to extract fault feature information of the gearbox.And usd the simulational signal validated the effectiveness of wavelet analysis technique de-noising the vibration signal.Finally,based on the theoretical analysis of wavelet energy fault diagnosis method,using wavelet packet energy method draw the wavelet packet energy scalogram of vibration signals,and in this way accurately identified the failure for a car of H-type gearbox.Combinated wavelet energy method and wavelet envelope demodulation method,and compared the different of wavelet packet energy scalogram with fult-free and bearng inner race,bearing outer ring,next analyzed the energy concentrated node’s power spectrum of envelope demodulation and accurately identified the failure for bearng inner race,bearing outer ring of gearbox in this way.