The Fault Diagnosis And Its Industrial Application For Rolling Bearings

As one of the key components and main failure resource in mechanical equipments, there is millions of failed equipments every year in the world which cost excessively. So the effective fault diagnosis for rolling bearings is becoming more and more important in all kinds of applications.Some deep and systemic research about the rolling bearings fault diagnosis and its industrial application, the main points as below:In this thesis, the selection of basis and resource of this subject is introduced first, then bearings fault models ISO classification and failure cause are reviewed and also describe and analyze the motion traction on the bearings raceways or rolling bodies in the second chapter, and end this chapter to divide the bearings failure into four steps with detailed explanation.In the third chapter, firstly, eight different fault diagnosis methods,such as the vibration method,lubricant method,temperature method etc., are stated and discussed basing on different methods and working principles. Linked with practice experience, the bearings vibration features,typical vibration types and its resource,effective improving actions are introduced to make the bearings fault diagnosis and improving methods to be understood better and can be controlled in a better way.As one critical input for the bearings fault diagnosis, the characteristics and performance of vibration velocity sensor,vibration acceleration sensor and eddy-current sensor are introduced in details and also the sensor selection principles,sensor distribution principle,mounting method etc. also are mentioned together. Then it introduce several vibration diagnosis methods for rolling bearings faults, such as vibration low frequency and amplitude method,stable vibration signal diagnosis,circulating stable vibration signal diagnosis,unstable vibration signal diagnosis etc.In the forth part, take the low frequency method and its application case as an example, the theoretical models are defined for the single defects on the IR (Inner Ring) or OR (Outer Ring) raceway or RE (Rolling component). Then basing on the automobile alternator failure case, diagnosis with low frequency diagnosis method and bearings inspection & analysis are made to validate the vibration frequency method is one precise and reliable way to detect the local damage on the rolling surface. In the fifth part, to explain the vibration acceleration enveloping detection method in rolling bearings fault diagnosis with application case as an example, its working principle and the comparison to vibration velocity analysis are introduced firstly, then show its diagnosis results for the rolling bearings local damage and industrial electrical motor as two cases to prove this method is valid to prevent rolling bearings from the possible premature failure.Lastly, the summary and trend forecasting for the rolling bearings fault diagnosis are given and also the next research work in the future.