Aiming at the problem that how the stability of a flexible rotor system is influenced by thrust bearing

the nonlinear force and moment provided by the thrust bearing are derived and a finite element model of the flexible rotor with a disk is established.And the dynamic equation of the system is formed by combing the axial equation with the lateral equation after reducing the linear degree of freedom. The shooting method and Floquet theory are employed to analyze the effects of thrust bearing and mass eccentricity of the disks on the nonlinear dynamic characteristics of the rotor system. The numerical results show that thrust bearing has great influence on stability and bifurcation of the motion of system. Thrust bearing can postpone the bifurcation of the periodic motion of system

heighten the critical speed and the stability threshold speed and lower the resonant amplitude of the rotor. Thus

thrust bearing improves the stability of the rotor system.