含松动与碰摩的转子-轴承系统非线性行为分析

以含松动与碰摩的转子-轴承系统为研究对象,采用一种新的短轴承非稳态油膜力公式和非稳态油膜转子-轴承系统碰摩的刚性约束非光滑模型建立系统的动力学方程,利用4阶Rounge-Kutta法求解非线性动力学方程,运用Mat-lab对系统进行数值模拟,通过分析相图、分岔图、Poincare截面图以及幅值谱图,得出系统丰富的非线性特性。结果表明含松动与碰摩的转子-轴承系统在工作转速较低时,轴承支座作微幅振动,随着转速增加,振动幅度也增加,在高速运转下系统处于混沌运动状态;含松动与碰摩的转子-轴承系统中松动端轴承支座在拟周期和混沌运动状态下的轴心轨迹松散,呈“柱状”结构,而未松动端在相同状态下轴心轨迹图结构紧凑,由此可以判断转子-轴承系统的松动故障。

Nonlinear Dynamical Behaviours of the Rotor-bearing System with Rub and Pedestal Looseness Faults

The moving equations of a rotor-bearing system with unsteady,nonlinear oil film force and a non lubricious rigid restriction were estabilished.The nonlinear dynamical behaviours of the system were studied using Rounge-Kutta method and its dynamical characters were analyzed with the help of Poincare maps and spctrum analysis.The complicated dynamical behaviours such as double-period bifurcation,Hopf bifurcation, K-T periodic solution,quasi-periodic and chaotic motions were found. The conclusions are,with the increase of rotating speed,the vibration of the pedestal will respectively be light,acute and chaotic;the faults of pedestal looseness may be decided in terms of the shapes of the orbits of the shaf center.