带弹性环保护轴承的动力学特性

Dynamical Analysis of Catcher Bearing with Elastic Ring

提出在传统保护轴承外圈加弹性环来提高其在主动磁悬浮轴承(Active magnetic bearing,AMB)系统中的工作性能。为完善转子跌落仿真模型,得到AMB失效前转子准确的运动状态,理论推导得到AMB的支撑动刚度曲线,进而基于有限元分析方法得到转子在其支撑下的模态,并与试验结果进行对比,验证所得刚度曲线的正确性。在刚性转子理论基础上,建立转子在AMB系统中的动力学模型。基于Hertz接触理论,分别建立AMB失效后转子与保护轴承内圈之间的碰撞模型和保护轴承的实时动刚度模型。根据所建立的模型,对不同弹性环支撑刚度阻尼在不同初始转速下跌落后的动力学响应进行仿真计算,并与无弹性环状态下跌落结果进行对比。仿真分析结果表明,选用合适的弹性环有利于降低转子跌落后的振动幅值和碰撞力。分别在不同初始状态下进行跌落试验研究,试验结果与理论分析结果基本相符。

A new type catcher bearing with an elastic ring is proposed to enhance its working performance in active magnetic bearing（AMB） system.In order to improve the simulation model of rotor drop and obtain the accurate rotor vibration characteristics before AMB failure,the dynamic support stiffness of AMB is derived.The rotor model is obtained using the dynamic stiffness based on Finite element analysis.Model experiments are also carried out to verify the correctness of the stiffness curve.The rigid rotor dynamic model in AMB system is established to analyze the dynamic responses.Based on the Hertz contact theory,the collision model between rotor and catcher bearing inner race and the real-time dynamic stiffness of the bearing after AMB failure are respectively established.Utilizing those established models,rotor drop simulations for various elastic ring support stiffness and damping range are carried out.Moreover,the simulation results with and without elastic ring are compared.The results show that appropriate elastic ring helps to reduce vibration amplitude and collision force after rotor drop.And the experimental results for various initial states are consistent with the theoretical analysis results.