高温超导轴承转子系统在不同场冷偏心距下的动力学分析

Dynamic analysis of high temperature superconducting bearing rotor system with different field cooling eccentricity

高温超导轴承用超导材料在冷却过程中处于场冷状态,俘获磁通的存在使高温超导轴承具有自稳定性。场冷高度影响轴承的钉扎力,从而产生不同的刚度,最终导致整个轴系的转子动力学变化。本文以冷压缩机为应用背景,基于实验测量得到YBCO在不同场冷高度下的刚度值,利用有限元分析软件Ansys,得到设计轴系的模态频率和主轴振幅。结果表明,由于场冷偏心距的存在,导致高温超导轴承合力比不偏心时大,从而改善了转子的动力学特性。

The superconducting materials used in high temperature superconducting(HTS)bearings are in the magnetic field during the cooling process,and the trapped flux makes HTS bearings self-stable.The field cooling height affects the pinning force of the bearings,resulting in different stiffness,and finally leads to the rotor dynamics change of the whole shaft system.Based on the application of cold compressors,the stiffness values of YBCO at different field cooling heights were obtained by testing.Using Ansys,a finite element analysis software,the modal frequency and axis track amplitude of the designed shaft system were further obtained.The results show that because of the field cooling eccentricity,the resultant force of HTS superconducting bearings is larger than that without eccentricity,thus improving the dynamic characteristics of the rotor.