Early health diagnosis method of amplifying abnormal motor vibration characteristic signals using base screw loosening

In response to early characteristic signals are not obvious and easily affected by other signals such as noise, which makes it difficult to effectively extract characteristic components when motor is in mildly abnormal conditions such as broken rotor bars and rotor eccentricity, this paper proposed an early health diagnosis method of amplifying abnormal vibration characteristic signals using base screw loosening. Comparative study of radial electromagnetic force at air-gap under three cases of normal operation, rotor eccentricity and broken rotor bars reveals that the slight change in electromagnetic force features in rotor eccentricity is the main reason why vibration features are difficult to be extracted. The vibration response of motor housing is simulated for three cases under the base screw fixed and the base screw loose. Comparing the simulation results, it is found that the rotor eccentricity case can be effectively highlighted vibration features by the proposed method, thus carrying out more early and accurate health diagnosis of abnormal state, and providing a new idea for online early motor health diagnosis.