高速转子跌落在保护轴承上的碰撞力研究

发布时间：2018-04-19 12:32

本文选题：磁悬浮轴承 + 转子跌落　；参考：《南京航空航天大学》2012年硕士论文

【摘要】：建立了转子跌落在保护轴承上全过程的动力学方程，得到了转子在不同初始条件(θ,θ)下跌落后的运动相图，讨论了不同滑动摩擦系数和保护间隙对转子跌落后运动轨迹的影响。基于Hertz接触理论，建立了转子跌落在保护轴承上的非线性碰撞力模型，使碰撞力模型更加接近真实情况下的碰撞力。提出了转子跌落在保护轴承上的碰撞力测量方案，并设计了碰撞力测量装置，将整个测量过程分为标定和测量两个步骤，考虑到碰撞力测量装置的非线性影响，运用冲击力锤分别在不同大小的冲击力下对碰撞力测量装置进行了标定，然后由转子跌落后支撑环的振动加速度信号反推碰撞力。对不同初始转速下转子跌落在保护轴承上的碰撞力进行了试验研究，得到了转子跌落后支撑环的振动加速度信号、转子轴心轨迹和跌落持续时间。试验结果表明：初始转速越高，转子跌落后保护轴承受到的振动冲击越大，跌落持续时间越长，越容易出现涡动现象。转子跌落后0.1s范围内，保护轴承受到的振动和冲击达到最大值，但并非出现在初次碰撞时。以转子初始转速为4500r/min的跌落试验为例，给出了转子跌落在保护轴承上的碰撞力试验测量和结果处理的详细分析过程，，并得到了该初始转速下转子跌落在保护轴承上的初次碰撞力和最大恢复力。根据初次碰撞力的试验结果对碰撞力模型进行了评估，准确识别出了所建立的非线性碰撞力模型中的等效质量me和等效刚度系数ke。最后通过对国内外的研究成果以及本文得出的相关结论归纳总结出了保护轴承的相关设计准则。
[Abstract]:The dynamic equation of rotor falling on protective bearing is established, and the motion phase diagram of rotor falling behind in different initial conditions (胃, 胃) is obtained. The influence of different sliding friction coefficient and protection clearance on the motion track of rotor after falling is discussed.Based on the Hertz contact theory, the nonlinear collision force model of rotor dropping on the protective bearing is established, which makes the collision force model more close to the real impact force.In this paper, a scheme for measuring the impact force of a rotor falling on a protective bearing is proposed, and a collision force measuring device is designed. The whole measurement process is divided into two steps: calibration and measurement, taking into account the nonlinear effect of the impact force measuring device.The impact force measurement device was calibrated under different impact forces by using impact force hammer, and then the impact force was pushed back by the vibration acceleration signal of the supporting ring after the rotor fell.The impact force of the rotor dropping on the protective bearing at different initial speeds was experimentally studied. The vibration acceleration signal of the supporting ring after the rotor drop, the rotor axis trajectory and the drop duration were obtained.The experimental results show that the higher the initial rotational speed, the greater the vibration shock of the protection bearing after the rotor falls, the longer the drop duration, the more likely to appear the vortex phenomenon.In the range of 0.1 s after the rotor falls, the vibration and impact of the protection bearing reach the maximum value, but not during the initial collision.Taking the drop test of rotor with initial speed of 4500r/min as an example, the process of measuring the impact force and processing the result of the rotor drop on the protective bearing is given in detail.The initial impact force and the maximum recovery force of the rotor drop on the protective bearing at the initial speed are obtained.According to the experimental results of the initial collision force, the impact force model is evaluated, and the equivalent mass me and the equivalent stiffness coefficient kee of the established nonlinear collision force model are accurately identified.Finally, through the research results at home and abroad and the relevant conclusions of this paper summarized the relevant design criteria of protective bearings.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH113

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