轴向电磁轴承多自由度承载力理论与实验研究

The oretical and experimental research on axial and radial magnetic force of axial magnetic bearing

为了实现磁悬浮轴承系统的微型化,对轴向电磁轴承的多自由度承载力进行理论与实验研究。基于轴向磁轴承气隙磁通空间分布,利用分割磁场法建立磁路模型,由虚位移法得到轴向和径向承载力的数学表达式。借助有限元仿真软件,得到轴向磁轴承气隙磁感应强度与磁场空间分布。在搭建的磁轴承三维力学测量平台上,实验测量了轴向磁轴承的轴向与径向承载力,分析总结了多自由度承载力随电流、轴向位移和径向位移的变化规律,结合理论与仿真结果,分析了结构参数变化导致气隙磁场分布变化,进而改变轴向与径向承载力的物理机理,为轴向磁轴承实现多自由度悬浮研究提供了参考依据。

In order to simplify magnetic levitation system supported by axial magnetic bearings, axial and radial magnetic force of axial magnetic bearing is studied in this paper. Based on spatial distribution of magnetic flux in the gap, equivalent circuit model was created and the mathematic formula of axial and radial magnetic force in axial magnetic bearing was deduced by virtual work method. Magnetic flux densi- ty and field distribution in the gap of axial magnetic bearing were obtained by finite element method. On three-dimensional force measuring experimental platform, axial and radial magnetic force of axial magnet- ic bearing was measured. The change law of magnetic force in terms of exciting current i, axial gap g and radial displacement Ar was analyzed and physical mechanism was discussed based on theoretical and sim- ulation results. These results provide reference for research of magnetic suspension system in multi-de- gree-of-freedom supported by axial magnetic bearings.