Experiment And Analysis Of Planetary Gearbox Based On Torsional Signal

Planetary gearbox has the advantages of small volume,light weight,large transmission ratio and high transmission efficiency.It is the key component of the helicopter and wind power transmission system.However,planetary gearbox compared with the fixed-axis gearbox has a more complex structure and movement forms,and because of poor working conditions,local wear damage easily happened gear and gear tooth broken fault,so of planetary gearbox fault diagnosis research for preventing major safety accidents have important meaning.However,planetary gearbox structure and movement forms are more complex than that of fixed-axis gearbox,the fault such as gear local wear damage and broken tooth occur easily under the poor working conditions.Therefore,planetary gearbox fault diagnosis research for preventing major safety accidents is of great importance.So far,most planetary gear fault diagnosis reference fixed-axis gear fault diagnosis technology to carried out,usually by installed in the gearbox body acceleration sensor collected reciprocating vibration signals are analyzed.Due to the planetary gear train compared to a fixed gear train meshing relationship is complex,from reciprocating vibration signal extracted corresponding gear meshing vibration signal information is extremely difficult.It is relatively easy to obtain the meshing vibration information of the torsional vibration signal of the gear shaft.Therefore,this paper studies the fault diagnosis of planetary gear based on torsional signal analysis.The main contents are as follows:1.Collection and test of the torsional vibration signal of planetary gearbox.Using installed in planetary gearbox of shafting of incremental encoder collection torsional vibration signal.Through the configuration of hardware,the fault diagnosis test bed of planetary gear is established.The system of planetary gear reciprocating vibration signal and planetary gear torsional signal acquisition system was developed through LABVIEW graphical language.In order to more close to the engineering actual situation,a certain load is applied to the output shaft of the planetary gearbox by magnetic powder brake,the speed controller is used to control the rotation speed of the planetary gearbox input shaft at the working conditions of one,two and three working conditions respectively.The input shaft and output shaft torsional signal of the planetary gearbox in the normal state of the planetary gearbox,the local wear damage of the planetary gear and the partial fracture of the planetary gear arerespectively collected.2.Time frequency domain analysis of the torsional signal of the planetary gearbox.The torsional signal of the planetary gearbox is analyzed by using time-domain and frequency-domain and time-frequency demodulation analysis method under certain conditions.When analyzing the time domain of torsional vibration signal,it is found that the output shaft torsional signal is more capable of responding to fault characteristics in time domain than the input axis torsional vibration signal.When the output axis torsional signal signal time-frequency demodulation analysis,it is found that the output shaft torsional vibration signal can accurately reveal the fault characteristics of the planetary gear in the time-frequency demodulation analysis.3.Aiming at the fault feature extraction of planetary gearbox input shaft torsional vibration signal,put forward a novel method application of spectral kurtosis method based on minimum entropy deconvolution to fault diagnosis of planetary gearbox.This method is applied to the simulation signal and the actual input shaft torsional vibration signal.The analysis shows that this method can accurately extract the fault features of planetary gear.The advantages of the proposed method are highlighted by comparison of wavelet de-noising envelop analysis.