综合考虑导轴承和推力轴承的支撑刚度对轴系的横—纵—扭耦合影响,应用Ansys Workbench软件建立了悬式三支点水轮发电机组轴系的三维有限元模型,采用Block Lanczos模态分析法分析了轴系的固有频率及其振型,借助Design Exploration优化设计模块计算了机组实际运行时轴系的预应力模态,获得了水流冲击和转速变化等因素对机组轴系固有频率值的影响规律。结果表明,机组在运行过程中转速变化对轴系的低阶横向振动频率影响较大,而对其扭转振动频率影响很小。 Considering the influence of the bearing stiffness of the guide bearing and the thrust bearing on the coupling between the shaft and the shaft, Ansys Workbench software was used to establish the three-dimensional finite element model of the shaft of the suspension three-point hydroelectric generating set. Block Lanczos modal analysis Method was used to analyze the natural frequency and vibration mode of the shaft system. With the help of Design Exploration optimization module, the prestress modal of the shaft system in actual operation was calculated and the natural frequency of turbine shaft system Affect the law. The results show that the change of rotational speed during operation of the unit has a great influence on the low-order transverse vibration frequency of the shaft system, but has little effect on the torsional vibration frequency.