大位移角振动台的气隙磁场动静态特性分析

Dynamic and static characteristics analysis of air-gap magnetic field of a large displacement angular vibrator

针对电机驱动式角振动台气隙磁场不均匀和输出大位移时波形失真大的问题,提出了一种径向磁通磁路结构的大位移角振动台,对其气隙磁场动静态特性进行优化分析。基于等效磁化强度法,在极坐标系下建立气隙磁感应强度的解析表达式,通过有限元法验证该方法的有效性,进一步分析了永磁体厚度、永磁体扇形角及气隙厚度对静态气隙磁场的影响规律;通过瞬态有限元法仿真分析了0.01、0.1和1 Hz 3个频率点上外磁环固定不动而永磁体和内磁芯转动的气隙磁场动态特性,定量分析了相对运动对气隙磁感应强度的影响规律;将优化后的磁路参数用于大位移角振动台样机中,测试结果表明,气隙平均磁感应强度及其分布规律和理论计算结果相吻合;研究方法对角振动台径向磁通磁路的理论分析与优化设计具有重要意义。

Aiming at the issues of the uneven air-gap magnetic field and the high wave distortion under the condition of a large angular displacement output of the motor-driven angular vibrator,a novel large displacement angular vibrator with the magnetic circuit of the radial magnetic flux is proposed. The dynamic and static characteristics in the air-gap magnetic field are analyzed and optimized. Based on the equivalent magnetization intensity method（ EMIM）,an analytical expression of the air-gap magnetic flux density（ MFD） is established in the polar coordinate system,and the effectiveness of the method is verified by the finite element method（ FEM）. The effects of the thickness of permanent magnet（ PM）,the sector angle of PM and the thickness of the air-gap on the static air-gap magnetic field are also analyzed. The dynamic characteristics of the air-gap magnetic field are simulated by the transient finite element method at different frequencies such as 0.01,0.1 and 1 Hz when the outer magnet ring is fixed but the PM and inner magnet core are rotated. The influence of the relative movement between the magnetic circuits on air-gap MFD is quantitatively investigated. Finally,the optimized parameters of the magnetic circuit are applied to the large displacement angular vibrator,and the test results show that the actual average MFD and its distribution are consistent with the theoretical results. The method has great significances to the theoretical analysis and optimization design of the radial magnetic flux magnetic circuit of angular vibrators.