局部旋转惯性对转子系统动力特性的影响

Influence of local rotary inertia on the dynamic properties of rotor systems

提出了基于质心和惯性主轴空间位置的转子旋转惯性描述方法,推导了旋转惯性载荷在不同运动状态下的完整表达式,建立了考虑轮盘质心横向运动和惯性主轴角向运动的连续梁转子模型及运动微分方程。分析表明:高转速下轮盘具有“质心自动定心”与“惯性主轴自动掰正”的趋势,这种旋转惯性将提高转子系统正进动模态频率,并增大转子支点动载荷,盘-轴连接局部角向刚度是决定其影响程度的关键。在此基础上,解释了高转速下转子支点动载荷随转速提高而持续增大的原因,探究了盘-轴连接局部角向刚度对转子系统固有特性和动力学响应的影响规律,为高转速复杂结构转子动力学设计与振动故障排查,提供了理论支撑。

The spatial location of center of mass and principal axis of inertia was utilized to describe the motion status of rotors.From the general definition of inertial load,the complete expressions of rotary inertial load were derived.Based on this,the continuous shaft model and its differential equations including the local rotary inertial load were established.Results showed that,the rotary inertia of high-speed-spinning disk can be categorized into self-centering of center of mass and self-centering of principle axis of inertia,which increases the forward processing natural frequencies and the bearing dynamic loads;the key to these influences is local angular stiffness between disk and shaft.On this basis,the reason was illustrated for the consistent increase of bearing dynamic load in high-speed range,while the influence of local angular stiffness between disk and shaft on the modal and response characteristics was investigated.The results above are of benefit to the vibrational fault detection and design of rotor structures during the engineering application.