高精度球面洛伦兹力磁轴承设计与分析

针对柱面洛伦兹力磁轴承(LFMB)偏角有限导致磁悬浮控制敏感陀螺(MSCSG)力矩输出持续时间短和气隙磁密均匀度低影响控制敏感精度的突出问题, 提出了一种高精度球面LFMB设计与分析方法。所设计的LFMB转子球面导磁套和定子球面绕组均与双球面陀螺转子同球心, 气隙呈球壳状, 保证转子偏转时定子绕组两侧气隙宽度不变, 相较于柱面LFMB, 转子可偏转角度由±0.6°扩大到±2°。利用等效磁路法推导了柱面与球面LFMB气隙磁密的数学解析模型, 并基于ANSYS命令流构建了柱面与球面LFMB的有限元仿真模型。仿真结果表明:在转子可偏转范围内, 沿偏转中心线, 球面LFMB最大磁密较柱面下降了34.1%；当转子不偏转时, 球面LFMB绕组截面内的磁密均匀度较柱面提高了11.6%；当转子偏转时, 球面LFMB绕组截面内的磁密均匀度较柱面提高了17.7%。所提方法为磁悬浮控制敏感陀螺控制与敏感性能的提升奠定了基础。 

Design and analysis of high precision for spherical Lorentz force magnetic bearing

Aim at solving following problems. Firstly, the limited deflection angle of the cylindrical Lorentz force magnetic bearing (LFMB) can leads to the short duration of torque output of magnetically suspended control and sensing gyroscope (MSCSG). Secondly, the low uniformity of magnetic density between the LFMB's air gap will also affect the control sensitivity of the MSCSG. A high-precision spherical design and analysis of LFMB are proposed. The spherical LFMB's rotor spherical magnetic sleeve and stator spherical winding are both concentric with the double spherical gyroscope rotor, and the air gap is spherical shell shape, which ensures that the width of the air gap on both sides of the winding coil remains unchanged during deflection. Compared to the cylindrical LFMB, the deflection angle of the spherical LFMB is increased from ±0.6° to ±2°. The mathematical analysis model of the air gap magnetic density of the cylindrical and spherical LFMB is derived by the equivalent magnetic circuit method, and the finite element simulation model of the cylindrical and spherical LFMB is constructed based on the ANSYS command stream. The simulation analysis shows that the maximum magnetic density of the spherical LFMB decreases by 34.1% compared to the cylindrical LFMB within the deflection range of the rotor along the deflection centerline. When the rotor is not deflected, the uniformity of the magnetic density at the cross-section of the spherical LFMB coil increases by 11.6% compared to the cylindrical. When the rotor is deflected, the uniformity of the magnetic density at the cross-section of the spherical LFMB coil increases by 17.7% compared to the cylindrical. The proposed method lays the foundation for the improvement of the control and sensitivity of the magnetically suspended control and sensing gyroscope.