Test System For Bearing Defects And Experimental Research

The variable pitch bearing is an important supporting part of the Blade Adjusting Angle of the wind turbine,its working state will affect the reliability of the variable pitch system,and then affect the whole working performance of the wind turbine,wind turbine failures caused by damaged propeller bearings are relatively high.Therefore,more and more attention has been paid to the research on the working state detection technology and the fault diagnosis technology of the variable pitch bearing of wind turbine.Based on the analysis of the working principle and fault characteristics of the rotor bearing of the Wind Turbine,the envelope demodulation method is proposed to detect the fault of the rotor bearing,the fault characteristics are obtained by vibration detection and envelope demodulation techniques,and then the fault of variable size rolling bearing is diagnosed.The main research contents of this paper are as follows: Based on the principle of envelope demodulation,the analog hardware circuit is designed,including the selection of sensors,design of signal amplification circuit,low-pass filter,high-pass filter,16-channel frequency-selective band-pass Filter Circuit,full-wave precision rectification circuit and peak circuit;The signal processed by analog circuit is collected by USB3202 Data Acquisition Card and transmitted to computer through data bus.The application software of the fault detection system is written by high-level language VB,the functions of time domain waveform display,time domain index analysis,segmented waveform display,Fourier transform and its inverse fourier Transform,Hilbert Transform,spectrum thinning and cepstrum are realized The monitoring and recording equipment of vibration signal and the application of wireless transmission technology in the monitoring equipment are made.The designed fault detection system is encapsulated and the fault test of the propeller bearing is carried out in the propeller bearing experimental base.The test results show that the fault detection system of the rotor bearing of the wind turbine accords with the envelope demodulation principle,the signal processing circuit is correctly designed,the function is perfect,and the data acquisition module is reliable The application software has the advantages of good man-machine interaction,correct calculation and reliable operation.