机车转子非线性系统的动力学分析

Dynamic behavior of a locomotive nonlinear rotor system

随着机车速度的提高,对机车的运行安全性和稳定性提出了更高的要求。主要研究了非线性双转子连续-质量转子系统的动力学模型,综合考虑转子支撑、齿轮啮合刚度等复合非线性因素影响。基于哈密尔顿最小势能原理,建立连续-质量非线性转子系统的动力学模型,对系统进行无量纲化处理,并求解了固有振动频率及振型。采用MR-K迭代法求解强非线性转子系统的数值解。定量分析在支撑刚度、阻尼及其齿轮刚度参数作用下,转子系统的幅频响应变化。结果表明:复杂边界条件下,系统的固有频率对传动系统振动响应影响较明显。当齿面磨损及间隙变化时,齿轮啮合刚度变大,转子系统在固有频率处位移显著增大。轮轨激励的变化,引起系统从动轴横向弯曲幅值变大。

With continuous increase in locomotive speed,higher requirements are needed for the stability and operation safety of locomotives. Here,the dynamic model of a continuous mass dual-rotor system was studied considering nonlinear factors of elastic supports and gear mesh stiffness. Firstly,the dimensionless dynamic model of the continuous mass dual-rotor system was established based on Hamilton principle of minimum potential energy,and the system ＇s natural frequencies and corresponding vibration shapes were solved. Secondly,the numerical solution to this strong nonlinear system was solved with the MR-K iteration method. Finally,the amplitude-frequency response variations of the rotor system were analyzed quantitatively under the action of support stiffness,damping and gear time-varying stiffness.The results showed that under complex boundary conditions,the system＇s natural frequencies have obvious effects on vibration responses of the transmission system; when gear tooth surface wear increases and backlash changes,the gear mesh stiffness rises,displacements of the rotor system at its natural frequencies significantly increase; changes of wheelrail excitation cause the lateral bending amplitude of the system＇s driven shaft to be larger.