Research On Fault Diagnosis Of Rolling Bearing By Resonance Demodulation And Order Spectrum Of Rotating Speed

Rolling element bearing is widely used and takes great important part in the rotating machinery. It is also the core element in the large and significant equipment, like express railway, high-precision lathe and wind power device. There is a great bearing production in China, but the skill of the design, manufactory and fault diagnosis of the bearing are not strong enough. Therefore, there is a good reason to take out the research in the principle of the bearing fault and the method of fault diagnosis of the bearing. The research in fault diagnosis of the rolling bearing has been carried out in this thesis. Several results have been carried out as follows:1) Research in bearing fault diagnosis by resonance demodulation principle;The resonance demodulation method is a good method in diagnosis of bearing fault when the rotating speed is constant. Firstly, the principle, algorithm and calculation steps of the resonance demodulation method have been proposed in this thesis. Then the key point of this method has been studied, and analysis software has been developed on the basis of the resonance demodulation method. The fault diagnosis experiment has been carried out by the analysis software.2) Research in bearing fault diagnosis by order spectrum of the instantaneous rotating speed analyses.The fault diagnosis method based on vibration sampling can not satisfy the actual variable speed operation condition. This thesis proposes the angular sampling method with constant angle step to extract fault information taking advantage of the angular speed fluctuation. We intend to obtain order spectrum of the instantaneous speed and find the order which associate with the damages of the roller bearing. The test rig has been designed for the research of order spectrum of the instantaneous rotating speed. The fault diagnosis experiment has been proposed according to the instantaneous speed method in the last part of the thesis. And the instantaneous speed method has been proved effective.