Design And Implementation Of Portable Fault Diagnosis Instrument

Bearing is an important part in rotating machinery,its running status is normal or not directly affects the stability and reliability of the whole machine.Thus,in some critical rotating machines they are often equipped with on-line fault diagnosis system.Because of the large volume and high cost of the on-line fault diagnosis system,the application of the fault diagnosis system in industry is limited.In view of the portable fault diagnosis instrument has the advantages of small volume,low price,high function integration,easy to popularize and application.This paper designs and makes a portable fault diagnosis instrument.Fault diagnosis instrument based on fault diagnosis theory,built the hardware platform with DSP as processor,realized the vibration signal of conditioning,all kinds of sampling index settings and data acquisition,the micro impulse signal of bearing fault is extracted by using the resonance demodulation circuit,which improves the accuracy of fault diagnosis.Time domain analysis,frequency domain analysis and Hilbert transform is realized by DSP,time domain analysis is to calculate the time domain parameters such as mean,variance and skew and the function of frequency domain analysis is to analyze the vibration signal by FFT,power spectrum and reverse spectrum.In order to improve the function of the diagnostic instrument,the author made a deep research on Hilbert transform in diagnosis theory,and obtained a very good application effect in the diagnosis instrument.After the completion of the fault diagnosis instrument,the functions of the diagnosis instrument were tested in fault diagnosis platform,test results show that resonance demodulation circuit,time domain analysis,frequency domain analysis and Hilbert transform has good application effect and can accurately calculate the characteristic frequency of bearing fault.The diagnostic instrument can easily access the Internet and realize the remote transmission of the field data,which is of great significance to the remote fault diagnosis of the field equipment.