Study On Gear Fault Diagnosis Technology Based On The Method Of Transmission Error

It is of great significance for fault detection of gear transmission system for the reason that gear system is the important driving component in mechanical equipments and is also the failure part with high fault rate in the gearbox. There are some disadvantages for traditional vibration detection, such as low signal-to-noise rate and difficult fault extraction. To solve the above problems, a method of gear fault diagnosis based on the transmission error is proposed in this thesis. It is verified as relatively satisfactory to diagnose gear fault by analyzing the signals of transmission error.Study on the theory modeling of transmission error, the detection method of gear system transmission error signals and the analysis of transmission error signals is focused on in this thesis. The mathematical model of gear system transmission error was established through the in-depth analysis of the changes of transmission error of gear system with tooth surface local fault in the process of meshing. In view of the requirements analysis of the acquisition system, the data acquisition system based on single chip microcomputer was designed to measure the input shaft and output shaft of angular displacement signals in the gearbox and acquire the instantaneous transmission ratio signals of gear system. Then, the transmission error signals of gear system were analyzed by using the method of combining of EMD decomposition and order spectrum in order to extract the IMF components containing fault so that the periodic fault signals were gained by order analysis. Finally, the fault diagnosis system based on support vector machine was established to identify different gear state, which selected the energy values of different orders containing fault component as input feature vectors and discriminated the types of gear system according to the output value of the classifier.The results of experiment prove that the method based on the transmission error can effectively locate the fault of gear tooth and discriminate the type of fault gear, which also provides a new research idea and method for the fault diagnosis of gear system.