多级齿轮传动转子系统的模态缩减与振动特性分析

提出了一种适用于多级齿轮传动转子系统的模态缩减法,以某透平驱动水泵系统为研究对象,采用有限元法建立了系统的动力学模型,并利用模态缩减法减少了系统自由度。在此基础上研究了系统的固有特性、不平衡量与静态传递误差引起的稳态响应、启动状态下的瞬态响应以及稳定运转下突加不平衡时的瞬态响应。结果表明,在计算系统的固有频率和稳态响应时,缩减后的模型相比于原模型依然具有较高的精度。静态传递误差激励在低转速范围内即可激发系统的高阶模态,为保证计算精度,在计算静态传递误差激励引起的响应时应保留一定数量的自由度。在计算瞬态响应时,缩减后的自由度模型相比完整模型节省计算时间超过90%,且偏差很小。综上所述,提出的模态缩减法在保证计算准确性的同时大大缩减了计算时间,为多级齿轮传动转子系统动力学特性的准确预测和分析提供了高效可靠的方法。

Modal reduction and vibration analysis for a multi-stage geared rotors system

Taking a turbine driven pump system as the research object,modal reduction suitable for multi-stage geared rotors system was proposed.A dynamic model of the system was established by the finite element modeling method.And the degree of freedom of the system was reduced by the modal reduction.Based on this,inherent characteristic,steady state response due to mass unbalance and static transfer error,transient response in start-up state,and transient response when sudden unbalance occurs under steady operation were studied.Results show that the reduced model still has higher precision than the original model in calculating natural frequency and steady state response of the system.Static transfer error excitation can excite high order modes of the system in low rotation speed range.To ensure the calculation accuracy,the certain number of degree of freedom should be retained when calculating the response caused by the static transfer error excitation.When calculating the transient response,the reduced model saves more than 90%of calculation time compared to the original model,and deviation is small.In summary,the proposed modal reduction greatly reduces calculation time while ensuring calculation accuracy,and provides an efficient and reliable method for accurate prediction and analysis of the dynamic characteristic of the multi-stage geared rotors system.