Abstract： The dynamic behavior and the coupling relationship between radial clearance and backlash of gear-rotor system including multiple clearances were investigated in this paper. A new dynamic model of gear-rotor system with multiple clearances coupled was developed which includes nonlinearity associated with radial clearance and dynamic backlash. In the dynamic model, the contact model in radial clearance was established using nonlinear contact force model. And the torsional vibration model with dynamic backlash was established using geometrical relationship between center distance and backlash. And then, the dynamic characteristics of gear-rotor system are analysed based on the new dynamic model with multiple clearances coupled. The numerical results for a spur gear pair with multiple clearances are presented and discussed. The effect of radial clearance size and initial backlash size on system dynamic characteristics are analysed separately. The conclusions have important theoretical and practical significance engineering value for gear-rotor system with clearance.
