用线性和非线性油膜力分析轴承动力系统

DYNAMIC BEHAVIORS OF FINITE JOURNAL BEARINGS UTILIZING LINEAR AND NONLINEAR OIL-FILM FORCE

采用单圆盘对称刚性转子轴承系统的运动模型和四阶龙格—库塔法 ,利用有限长滑动轴承的非线性油膜力 ,求解系统运动方程。使用牛顿迭代法得到系统的周期解。分析线性失稳转速在稳定性分析中的局限性。分别用线性和非线性油膜力计算系统的不平衡响应。分析表明 ,只有在小偏心激励的情况下 。

Equations of motion are adopted for the symmetrical rigid rotor-bearing system, and the nonlinear oil-film force of finite journal bearings is calculated. The journal's transient trajectory is simulated with the fourth-rank Runge-Kutta method, and Newtonian iterative method is employed to gain the periodic solutions of the system. The threshold speed based on the linear theory is given and its localization in stability analysis is exhibited. Responses of unbalanced rotor are investigated with the linear and nonlinear methods respectively, and it has been found that the linear theory can be used only when the unbalanced eccentricity is small.