转子-轴承-密封系统的非线性振动特性

将非线性油膜力和密封力模型相结合,建立了具有非线性转子-轴承-密封系统的动力学模型.利用数值积分方法,对系统由于密封力引起的非线性动力学行为进行了研究,给出了系统响应随转子转速、偏心量和密封间隙变化的分叉图和最大Lyapunov指数曲线图,以及一些典型的Poincaré截面图、轴心轨迹图和频谱图.通过比较转子系统是否考虑密封力时的响应,发现非线性密封力提高了转子系统的稳定性区域,抑制了系统出现倍周期分叉,并且综合考虑非线性油膜力和密封力的耦合系统具有周期、拟周期和混沌等复杂的动力学行为.

The Nonlinear Dynamical Behaviors of a Rotor-Bearing-Seal System

The dynamic model of nonlinear rotor-bearing-seal system was set up, combining the nonlinear bearing forces and seal forces models. The nonlinear dynamic behaviors of the coupled system caused by seal forces were studied using the numerical value integral method. The bifurcation diagram and maximal Lyapunov exponent curves of the response to the changing of rotation speeds, eccentricity and seal clearance were given. Some typical Poincare maps, state trajectory and frequency spectra were also given. The dynamic phenomena of the rotor-bearing-seal system are clearly distinct depending on whether the seal force is taken into account or not. The computational results show that the seal force will increase the stability region of the system. And the coupled system exhibits rich forms of periodic motion, doublingperiodic motion, approximate-periodic motion and chaos motion.