Design And Implementation Of Fault Diagnosis Instrument For Rolling Bearing Based On Vibration Signal Analysis

The vibration signal of rolling element bearing is known as the best symptomextraction quantity. Its response to the change of bearing working state is rapid,comprehensive and true. And, it can reflect the nature, extent and severity of rollingelement bearing fault rightly. What’s more, there are a lot of advanced and effectiveanalysis methods to choose. In this paper, a bearing fault diagnosis instrument wasdesigned with a combination of the fault diagnosis method based on vibration signal andvirtual instrument technology. The system’s validity and practicability were verified viaexperimental tests.Firstly, we have studied the damage forms, fault mechanism and faultcharacteristics of rolling element bearings, theoretically based on rolling bearingstructure, load distribution and movement relationship between each component.Secondly, the signal processing methods of rolling element bearings fault diagnosis areanalyzed, studied and compared in time domain, frequency domain and time-frequencydomain. And its effectiveness in practical application are discussed. We introducedsimple diagnosis methods such as amplitude value diagnosis method, waveform factordiagnosis method, crest factor diagnosis method, probability density diagnostics,kurtosis coefficient diagnosis method in time domain. Frequency domain analysismainly contains spectral analysis method, inverse spectrum analysis method, detailedspectral analysis and envelope demodulation analysis, etc, in which envelopedemodulation analysis method is the most effective method of existing bearing faultdiagnosis methods. Time-frequency domain analysis is the description of signalspectrum changes over time. In this paper, we have further studied the window Fouriertransform, wavelet transform and Hilbert-Huang transform, and analyzed theadvantages and disadvantages in the practical application. Then, based on the theory ofsignal processing method and the virtual instrument technology, the rolling elementbearing fault diagnosis system is developed. We have introduced the realization of faultdiagnosis instrument function module in software part, and the design of the rollingbearing test rig, the types selection and installation of sensor and acquisition card ofbearing in hardware part.Finally, on the basis of the above work, fault diagnosis system of rolling bearing isdeveloped and test bench is put up. In order to know performance of the rolling bearing fault diagnosis instrument, a large number of experiments are done. The experimentalresults show that the rolling bearing fault diagnosis instrument which is developed inthis paper can effectively identify typical fault of bearings, so can be applied to the faultdiagnosis of rolling bearings.