The dual rotor-ball bearing-stator coupling dynamic model was established for the aero-engine with dual rotor as to research object.The model concerned the coupling effect of inter-rotor bearing between the low pressure rotor and high pressure rotor

between the outer race of ball bearing and bearing housing

and between the flexible support and squeeze film damper.In the model of ball bearings

the clearance of bearing

nonlinear Hertzian contract force between balls and races and the varying compliance vibration were considered.The beat vibration response and whirl orbit of co-rotating or counter-rotating dual-rotor system were analyzed by using the model.The results show that the beat vibration response occurs obviously when two rotors operate at approximate speed

the whirl orbit of the counter-rotating dual-rotor system will be the petal shape.Finally

the results of numerical integral and the model were validated with the experiments of the dual rotor rig.