一种新型径向磁浮轴承结构设计与磁场计算

在传统径向电磁轴承中,由于各电磁铁之间磁路相通而使磁场存在相互耦合,这将影响转轴的控制精度和动态响应,为此,提出一种新型的磁铁结构,解决了磁路耦合问题,并缩短了磁路长度.此外,当转子旋转时,磁场极性变化将使转子中产生涡流,此涡流将改变电磁轴承气隙回路中的磁场.利用ANSYS有限元分析软件,以实验样机系统为例,进行了相应的分析和计算.结果表明,随着转速的增加,涡流场将向磁极的后缘和表面集中,电磁吸力减小,而磁阻力增加.实际应用中应尽量选择相对磁导率较大而电导率较小的转子材料.

Structure Design and Magnetic Field Calculation of a Novel Radial Magnetic Bearing

In traditional radial active magnetic bearing(AMB),the control precision and dynamic responses of rotor are affected by the coupling between the magnets because of its interlinked magnetic circuit.A novel structure of radial AMB is proposed in this paper to eliminate this coupling and to shorten the length of magnetic circuit.Furthermore,the eddy current in the rotor is produced to change the air-gap magnetic field for the change of polarity of magnetic field while the rotor is rotated.Analysis and calculations to the test AMB motor are performed with ANSYS software.The results show eddy field is centralized to the rear fringe of magnetic pole and rotor surface with rotation speed increasing.The attractive force decreases and magnetic drag force increases.So a rotor material with high magnetic permeability and low conductivity is selected in the application.