Abstract:A similarity model considering the nonlinear dynamic characteristics of rolling ball bearing in rotorbearing system was put forward to examine the problem of dynamic similarity. The nonlinear vibration differential equation of rolling ball bearing was firstly established. The similarity relationship on the nonlinear dynamic characteristics was deduced by the integral simulation method, and the similarity design criteria of the rolling ball bearing was then achieved. Afterwards, the groove ball bearing of C204JUT and 6208 were set as a prototype and a model for numerical simulation, respectively. The effect of rotational speed, radial load Fr, damping C and radial clearance on the vibration displacement and velocity of rolling ball bearing system were investigated by bifurcation. Finally, through comparing the bifurcation range, the stable parameter value, the response value for the stable motion in the bifurcation diagram, the similarity criteria was verified. The conclusions were obtained as follow: i)The similarity relationship of the nonlinear vibration characteristics for the rolling ball bearing can be established by its structural similarity. ii)The bifurcation shape of the prototype and the model was consistent, and the steady response of the model matched that of the prototype very well.