含轴裂纹汽车水泵转子系统动力学特性分析

Analysis on Dynamic Characteristics of the Water Pump Rotor System of Automobile with a Cracked Shaft

为了获得含轴裂纹故障的汽车水泵转子系统的动力学特性,本文将该系统简化为水平悬臂转子,建立了叶轮受液体阻力矩的含轴裂纹水泵转子系统力学模型。基于该模型,对水泵转子动力特性进行数值仿真。结果表明,水泵转子出现轴裂纹故障时,频率成分新增了二、三倍频,且二、三倍频成分幅值随裂纹深度增加而递增,轴心轨迹的形状及幅值随裂纹深度变化较大。分析结果可为水泵安全设计和裂纹故障检测提供理论参考。

In order to get dynamic characteristics of the water pump rotor system of automobile with a cracked shaft, in this paper, the system is simplified to a horizontal over-hung rotor, and a mechanical model of the water pump rotor system considering the drag torque acting on the impeller is founded. Based on this model, the dynamic characteristics of the rotor system are investigated by numerical simulation. The results show that, when crack appears on the shaft of the water pump, second and third harmonics newly appear compared to without the action of crack,and the amplitudes of each frequency component are all increasing with the increasing of the crack depth. In addition, the shapes of orbit of the rotor center become more complicated when the crack depth is increasing. The results can provide theoretical references for the safety design and crack faults detection of water pump.