水电机组转子轴承系统弯扭耦合振动影响因素研究

Study of influencing factors on coupled flexural and torsional vibrations of rotor-bearing system of water turbine generator set

建立了水电机组转子-轴承系统的弯扭耦合振动模型,应用数值算法求解了不同导轴承刚度情况下,转子的弯振和扭振响应时程曲线,研究了轴承集中刚度和阻尼、陀螺力矩及转动惯量等对转子轴承系统弯扭耦合振动的影响。结果表明,轴承在弯曲方向上的集中刚度和阻尼对转子的弯振和扭振均有重要影响,而扭转方向上的阻尼对弯振和扭振影响相对较小,陀螺力矩中的扭转力矩对系统的响应起主要的影响作用,转动惯量增大使得系统的弯振和扭振响应降低。

A model of coupled flexural and torsional vibrations was developed for the rotor-bearing system of hydroelectric generating set in this work. Using this model, the system＇s responses to such vibrations were obtained for different supporting conditions, and the influences on the vibrations by concentrated stiffness and damping of the bearings, gyroscopic moment, and moment of inertia were studied. The results show that the flexural stiffness and damping of the bearing has a great influence on the flexural and torsional vibrations, but the torsional damping has comparatively less effect. The torsional gyroscopic moment has more influence on the system responses than flexural gyroscopic moment. An increase in the moment of inertia would lead to a decrease in the responses.