汽轮机-行星齿轮减速器耦合动力学特性分析

摘要

大功率齿轮箱是船舶轮机系统的重要设备之一,汽轮机通过齿轮箱将动力输出,齿轮系统与转子系统耦合在一起.为研究齿轮的啮合与振动对转子系统动力学特性的影响,针对某船舶动力系统,利用有限元法分别建立转子系统与转子-齿轮耦合系统的动力学方程,考虑齿轮系统的时变啮合刚度,求解并对比两种模型的振动特性.计算结果表明,齿轮的振动会降低转子系统的支撑刚度,使转子系统的临界转速降低,并增大振动响应幅值.另外,齿轮啮合刚度的时变性引起的振动属于参激振动,这种高频激励会传递到转子上.为了更精确计算整个轮机转子轴系动力学特性,需要考虑与转子相耦合的齿轮系统的振动.%High-power gear box is one of the important equipment of marine turbine system. The power of the turbine is exported through the gear system. Since the gear system is coupled with the rotor system, meshing of the gear system will have a great influence on the rotor system. In this paper, the influence of gear meshing and vibration on the dynamic characteristics of the rotor system is studied. The dynamic models of the rotor system and the rotor-gear coupled system are built for a turbine power system by means of finite element method. Considering the time-varying mesh stiffness, the dynamic characteristics of the two systems are solved. Results of computation show that stiffness of the support of the rotor system can be reduced by the gear system vibration. Thus, the critical speed of the system will be lowered and the amplitude of the vibration response will be enlarged. The vibration of the gear system should be considered when calculating the turbine power system. The time-varying of the mesh stiffness is a parametric excitation, which also has effect on the rotor dynamic response. Thus, the rotor and gear coupled effect should also be considered when calculating the rotor's dynamic response.