径向型超导轴承的计算和实验研究

针对应用于离心式氦气冷压机的径向型高温超导磁悬浮轴承,给出了永磁转子磁场计算和结构设计方法,并开展了轴承径向力和径向刚度的计算研究,搭建了超导轴承性能测量平台,开展了轴承转子空间磁场测量和轴承性能测试。计算和测试结果表明,磁场计算方法可行,且结果准确,在距离永磁转子外表面1 mm处的最大外磁场强度约为0.5 T。轴承径向力在场冷和零场冷条件下的计算结果均随转子偏心量的增大而增大,与测试结果在线性度和趋势上具有很好的一致性。本文实验轴承径向刚度测试值为362.4 N/mm,与场冷条件下的径向刚度计算结果334.594 N/mm接近。本文所述的径向轴承磁力计算方法可用于超导轴承径向刚度的定性计算和设计,对超导轴承的应用研究具有一定的指导意义。

Calculation and experimental study of radial high-temperature superconducting magnetic bearing

For the radial high-temperature superconducting magnetic bearing used in centrifugal helium cold compressor, the magnetic field calculation and structural design method of permanent magnet rotor are given, and the calculation of radial force and radial stiffness is carried out. A superconducting bearing performance measurement platform was built, and bearing rotor space magnetic field and bearing performance were measured. The calculation and measurement results show that the magnetic field calculation method is feasible and the result is accurate. The maximum external magnetic field at 1 mm from the outer surface of the permanent magnet rotor is about 0.5 T. The calculated radial force under field cooling and zero field cooling conditions both increase with the increase of the rotor eccentricity, which is in good agreement with the measurement results in linearity and trend. The measured radial stiffness value of the measured bearing in this paper is 362.4 N/mm, which is close to the calculated radial stiffness 334.594 N/mm, under field cooling conditions. The radial force calculation method described in this paper can be used for the qualitative radial stiffness calculation and design of high-temperature superconducting magnetic bearings, which has certain guiding significance for the application research of superconducting bearings.