异步电机永磁悬浮轴承结构设计与动力学计算

Structural Design and Rotor Dynamics Calculation of Permanent Magnet Levitation Bearings for Asynchronous Motors

为保证异步电机转子在永磁悬浮状态下仅有微摩擦特性,必须保证永磁轴承具有稳定的高势能状态。采用一个机械调心滚子轴承限定其转子轴向位移。基于气隙磁导及等效磁荷法计算出转子所受不平衡磁拉力,并给出永磁轴承定转子气隙、转子偏移、永磁轴承环数划分、气隙位置与径向刚度之间的关系,对上述参数进行优化以获得永磁轴承的最佳径向刚度,使永磁轴承能有效平衡电机转子所受的不平衡磁拉力。通过对转子涡动轨迹及临界转速进行分析,验证了异步电机永磁轴承悬浮结构可实现微摩擦悬浮。

To ensure that the rotor of an asynchronous motor has only micro-friction characteristics in the state of permanent magnetic levitation,it is necessary to ensure that the permanent magnet bearings have a stable high potential energy state.A mechanical spherical roller bearing was used to limit the axial displacement of its rotor.The unbalanced magnetic pul on the rotor was calculated based on the air-gap permeability and equivalent magnetic charge method,and the relationship between the stator-rotor air-gap of the permanent magnet bearing,the rotor offset,the division of the number of rings of the permanent magnet bearing,the position of the air-gap and the radial stiffness were given,and the above parameters were optimized in order to get the optimal radial stiffness of the permanent magnet bearing,so that the permanent magnet bearing could effectively balance the unbalanced magnetic pul on the motor rotor.The permanent magnet bearing levitation structure of asynchronous motor was verified to realize micro-friction levitation by analyzing rotor vortex trajectory and critical speed.