关键词: 径向游隙；整机振动；有限元模型；赫兹接触力；不平衡力

Abstract: For the sensitivity problem of the effects of rolling bearing radial clearance on the whole vibration at different supports in the aero-engine support system，a model is established for a real engine rotor-bearing-casing. The rotor and casing systems are modeled by means of the finite element model. The support systems are modeled by lumped-mass model. Rolling bearing radial clearance and strong-nonlinearity of Hertz contact force at four different supports are considered. The coupled system response is obtained by the numerical integral method. The characteristics of the whole vibration response are analyzed. For the support S2，which influences the whole vibration larger，the rotor，outer ring of rolling bearing and casing response characteristics at different rotating speeds are analyzed. The nonlinear contact force law which changed with time and rolling numbers and the changed load law of the rolling bearing are analyzed. The influence on contact force by the radical clearance is analyzed. The results show that the higher the rotating speed，as the clearance increases，the more obviously acceleration amplitude jumps and lags and due to the variable stiffness of the rolling bearing，when the stiffness changes fiercely，the natural frequency is excited，that is frequency-locked phenomenon. When the radical clearance is large and the rotating speed is between two order radical speed，the rotor sometimes squeezes and sometimes does not squeeze the outer ring，that is，instability phenomenon occurs. Reducing the radical clearance can increase the rotor stability and reduce the whole vibration.

Key words: Radial clearance；Whole vibration；Finite element model；Hertz contact force；Unbalanced force