Dynamic characteristics of gear-rotor system with gear eccentricity and wear fault

Due to installation errors and poor lubrication conditions, the gear system has both eccentricity and wear fault. The eccentricity effect of the gear affects the contact area of the tooth surface, which in turn influences the wear state of the tooth surface. Therefore, it is necessary to study coupling effect of eccentricity and wear fault. A new dynamic model and an improved load tooth contact analysis (LTCA) method are proposed in this paper, both of which can consider the coupling effects of eccentricity and wear fault. The time-varying meshing stiffness (TVMS), tooth contact stress, and wear depth of the gear under eccentricity and wear fault are studied. Finally, the vibration mechanism and spectrum characteristics under speed, eccentricity error, and wear degree are analyzed. Under the coupling effects of eccentricity error and wear fault, the time varying meshing stiffness has a fluctuation period, which is the product of the meshing period and the number of teeth of the eccentric gear. To a certain extent, wear reduce the impact effect caused by eccentricity. The increase of eccentricity error leads to an increase in frequency component on the modulation side. The results provide support for the wear resistance design of gear and the basis for the fault diagnosis of gear-rotor system.