不对中-碰摩转子系统动力学响应分析

Dynamic Response Analysis of Misalignment-Rubbing Rotor System

建立不对中-碰摩-不平衡条件下的滑动轴承-转子系统动力学模型,综合考虑不对中、滑动轴承油膜力、转盘偏心量和碰摩等一系列强非线性的耦合。运用C语言环境下的四阶Runge-Kutta数值积分法,引入碰撞振子系统的分析方法对转子系统的碰摩分岔转迁行为进行分析,同时引入最大碰摩力和占空比概念对转子模型的参数变化引起的系统响应进行量化表征。结果表明:不对中故障导致转子系统产生2×、4×等偶数倍频率,并且2×频率幅值不随转速和系统参数的改变发生变化;轴承间隙和润滑油黏度的改变对系统响应产生了显著影响,具体表现为系统的稳定性随着轴承间隙的减小和润滑油黏度的增大而提高,特别是润滑油黏度的增大使得系统一、二阶临界转速明显增大。

A dynamic model of the sliding bearing-rotor system under the conditions of misalignment,rubbing and unbalance was established,and a series of strong nonlinear couplings such as misalignment,sliding bearing oil film force,turntable eccentricity and rubbing were comprehensively considered.Using the fourth-order Runge-Kutta numerical integration method in the C language environment,the analysis method of the collision oscillator system was introduced to analyze the rubbing bifurcation transition behavior of the rotor system,and the maximum rubbing force and duty cycle were introduced at the same time to quantitatively characterize the system response caused by the parameter change of the rotor model.The research shows that the misalignment fault causes the rotor system to generate even multiple frequencies such as 2× and 4×,and the amplitude of the 2× frequency does not change with the change of the speed and system parameters.Changes in bearing clearance and lubricating oil viscosity have a significant impact on the system response,which is manifested in the fact that the stability of the system increases with the reduction of bearing clearance and the increase of lubricating oil viscosity,especially the increase of lubricating oil viscosity makes the system critical speeds of the first and second order increase significantly.