转盘偏心距对不对中-碰摩转子动力学响应的影响

Influence of Rotor Eccentricity on the Dynamic Response of Misalignment-Rubbing Rotor

针对含转盘偏心的不对中-碰摩转子系统耦合故障导致的振动问题,建立不对中-碰摩耦合条件下的滑动轴承-转子系统动力学模型,考虑齿式联轴器不对中作用力、滑动轴承油膜力、转盘偏心距和碰摩等一系列强非线性的耦合。基于多参数、多目标协同仿真得到关键参数与系统响应的关联关系,并引入最大碰摩力和电信领域中占空比的概念对转子模型的动力学特性进行量化表征。研究结果表明:不对中的存在导致系统产生了2×、4×等偶数倍频,系统的轴心轨迹呈现出“8”字形,偏心距的变化直接影响了系统的周期运动类型和分布,当偏心距由小变大时,系统的一二阶临界转速显著提高,直接限制了油膜力的响应幅值,但不会影响不对中产生的2×频率幅值。最后得到此模型合理的偏心距取值范围。

For vibration problems caused by coupling faults in misalignment-rubbing rotor systems with rotor eccentricity,a dynamic model of the sliding bearing-rotor system was established under the condition of misalignment-rubbing coupling,and a series of strong nonlinear couplings were considered,such as the misalignment force of the gear coupling,the oil film force of the sliding bearing,the rotor eccentricity and rubbing.Based on multi-parameter and multi-objective co-simulation,the relationship between key parameters and system response was obtained,and the concepts of maximum rubbing force and duty cycle in the field of telecommunications were introduced to quantitatively characterize the dynamic characteristics of the rotor model.The results show that the existence of misalignment leads to even frequency multipliers such as 2×and 4×in the system,and the axis center trajectory of system shows the shape of“8”.The change of eccentricity directly affects the type and distribution of periodic motion of the system.When the eccentricity changes from small to large,the first-order and second-order critical speeds of the system increase significantly,which directly limit the response amplitude of the oil film force.However,the 2×frequency amplitude generated by misalignment is unaffected.Finally the reasonable value range of eccentricity is obtained.