橡胶轴承耦合转子系统动力学研究

摘要

Mathematical model of a large rotor system supported on rubber bearings is proposed and its dynamics is discussed in this paper. Firstly under the assumption of small perturbation, the dynamic characteristics of rubber bearing is described by Kelvin-voigt model. Then based on the analytical mechanics the motion equations are deduced. For a typical ship propulsion system, a numerical analysis is carried out. The results show that the vibration of the lowest modal is mainly from the propeller, and even at the low rotating speed theamplitude on the propeller rubber bearing under propeller unbalance is larger than the thickness of water film of the rubber bearing in general, consequently phenomena of the stick-slip, spirant and wear between rubber staves and rotor may be produced.%讨论橡胶轴承支承下大型转子系统的动力学建模和动力学特性.首先采用Kelvin-voigt材料模型和微振动假设,建立橡胶轴承的力学模型,然后根据分析力学方法推导橡胶轴承耦合转子系统的运动微分方程.通过对典型推进轴系的动力学分析表明,在一般情况下系统的低阶模态是以螺旋桨振动为主,螺旋桨的不平衡所引起的稳态响应,即使在转速较低时,螺旋桨轴承的振幅有可能比水润滑橡胶轴承的水膜厚度要大,可能造成橡胶体与轴颈间的"粘着-滑动",进而发生鸣音现象和橡胶体的磨损.