同转/对转双转子系统的动力学特性

Dynamic characteristics of co-rotating/counter-rotating dual-rotor system

建立了双转子动力学模型,引入中介轴承刚度和高、低压转子陀螺力矩的影响,利用数值分析和实验验证,揭示了同转/对转双转子系统临界转速特性和不平衡响应存在的差异,以及转速比对同转/对转双转子临界转速特性和不平衡响应的影响.结果表明:陀螺力矩是影响带有中介支承的双转子系统转子刚度的主要原因,其刚度变化与内、外转子的转速比大小和相对旋转方向有关,进而导致同转/对转双转子系统临界转速特性和不平衡响应发生改变;相比同结构的同转双转子,在相同的不平衡量作用下,对转双转子的不平衡响应更为显著.对转双转子进行动平衡时,应更加严格的控制内、外转子的不平衡量.

A dynamic model of dual-rotor was set up.The influence of inter-shaft bearing stiffness and the gyroscopic moments of high and low pressure rotors were considered in this model.The difference of co-rotating or counter-rotating dual-rotor＇s critical speed characteristics and unbalance response and the influence of speed ratio on co-rotating or counter-rotating dual-rotor＇s critical speed characteristics and unbalance response were revealed by numerical analysis and experiments.The results show that,gyroscopic moment is a main influential factor to the rotor stiffness of dual-rotor system with inter-shaft bearing,and the changes of stiffness are related to the speed ratio and the relative rotating direction of inner and outer rotors,further causing the change of co-rotating or counter-rotating dual-rotor＇s critical speed characteristics and unbalance response.Compared with the co-rotating dual-rotor of the same structure with the counter-rotating dual-rotor,the counter-rotating dual-rotor＇s unbalance response is more obvious than the co-rotating dual-rotor＇s under the same unbalance mass,and for this reason the unbalance mass of counter-rotating dual-rotor＇s inner and outer rotors should be controlled more strictly during the dynamic balance.