Research On Technology Of Gearbox Fault Diagnosis Based On Order Analysis Method

The car is the main vehicle for people to travel at present, and as an important part of the car, gearbox plays an important role in the automobile transmission. Whether there is a fault in gearbox will directly affect the stability of the whole vehicle system, and even affect the life and property safety of the people in the car, so the fault diagnosis technology of automobile gearbox has been one of the hot issues in academia and engineering field.This paper studied the develop history and development trend of fault diagnosis technology at home and abroad, analyzed the structure and the working principle of gearbox, and on this basis, studied the common fault types and the mechanism of failure vibration.Secondly, the traditional analysis methods such as time domain, frequency domain and short time Fourier transform were described in detail, this paper introduced the order analysis technology for there are some shortcomings when using them to analysis the non-stationary signal. The order analysis method has obvious advantages in the analysis of non-stationary signal, and it can effectively avoid the "frequency aliasing" phenomenon.Then the theoretical basis of order analysis was studied, then introduced the principle and the calculation methods of order analysis and the definition of order tracking spectrum.The basic concept of order tracking method was discussed, and researched the hardware order tracking and the computed order tracking,by comparing the characteristics and combined with the research content of this paper finally choice the computed order tracking method for signal resampling. Then researched the signal resampling process, this process is to transform the equal time intervals sampled signal into the equal angular intervals sampled signal, finally the frequency of resampling is analyzed in detail, through reasonably setting up the sampling frequency can avoid the "frequency aliasing" and prevent the information missing.Finally, this paper proved the reliability of the order analysis technology by using the experimental method, through the test that based on the H-type gearbox(including qualified and unqualified gearbox) 3rd, 4th gear shifting conditions, and compared the order spectrum of the two types gearbox, through the comparison can successfully diagnose whether a gearbox has failures, it shows that the order analysis technology can play a good role in the gearbox fault diagnosis.