Research On Gear Broken Detection Based On Acoustic Emission Technology

In the process of mechanical operation,the core gear of the transmission is exposed to high temperature,heavy load,and cyclic operation for a long time.After a certain degree of working time,the gear operation reliability is poorly.Downtime inspection affects work efficiency and increases unnecessary work.Research must be done on gears to detect faults online.Aiming at the problem that it is difficult to extract features in gear fault detection,the gear acoustic emission signal is taken as the research object.Firstly,determined the number of wavelet decomposition layers,selected a suitable wavelet basis,and then the wavelet transform is performed on the acoustic emission signal.The signal is reconstructed according to the change of the energy spectrum coefficient of the signal before and after the tooth broken.Finally,spectrum analysis is performed on the reconstructed signal of broken tooth.The results show that the characteristics of broken tooth faults are prominent,indicating that the method can effectively diagnose faults.The specific content is arranged as follows:(1)Investigate several common damage types of gears and analyze the cause of failure.A variety of fault detection methods are analyzed,and the acoustic emission method is used as a method to study the signal collection in this paper.Then it analyzes the detection principle and application of the acoustic emission method,analyzes a variety of signal detection systems and selects the best one for collecting the experimental signals in this paper,and analyzes various signal processing methods.(2)Construct the gear's analog signal,analyze the signal processing method with the analog signal as the object,and analyze the disadvantages and advantages of wavelet transform.Determine the number of wavelet decomposition layers,and select the wavelet basis suitable for analyzing the gear running signal.The energy spectrum of the normal signal is analyzed for comparison with the broken tooth signal later.(3)A platform for collecting acoustic emission signals of gears was set up to collect acoustic emission signals when the speed of the motor is 1400 r / min,900 r / min,600 r / min under normal and broken gear conditions.Firstly,decrease the noise,then calculate the energy spectrum of each layer of the signal under the broken tooth state and compare it under normal conditions,and reconstruct the signal according to the energy spectrum changes before and after the broken tooth.Finally,a frequency spectrum analysis of the reconstructed signal of the broken tooth show the fault characteristics clearly.