A study on magnetically-levitated micro PM motor using micro magnetic bearings

我们研制了一种毫米级圆柱转子磁悬浮微型永磁电机。在微型永磁电机中应用了两种类型的电磁铁。对微型永磁电机的动态特性进行了研究。从实验结果可以看出，这些微型永磁电机的驱动电流范围与其他普通尺寸的永磁电机相比较小。带有马蹄形电磁铁的微型永磁电机的速度高达每分钟30000转以上，速度非常快，令人惊叹。与采用马蹄形电磁铁的微型永磁电机相比，圆柱形电磁铁的微型永磁电机的驱动电流范围很小。采用圆柱形电磁铁的微型永磁电机的磁摩擦力比采用马蹄形电磁铁的电机小得多。结果表明，在高速旋转时，采用马蹄形电磁铁的微型永磁电机要优于采用圆柱形电磁铁的微型永磁电机。从功率消耗的角度来看，由于驱动电流范围很小，采用圆柱形电磁铁的微型永磁电机比采用马蹄形电磁铁的微型永磁电机要好。在快速响应方面，采用马蹄形电磁铁的微型永磁电机优于采用圆柱形电磁铁的微型永磁电机。利用这一特性，可以实现马蹄形电磁铁微型永磁电机的转速控制，可应用于微型陀螺仪、机械传感器等领域。它被认为是微型机电一体化的有前途的。

We have developed a magnetically levitated micro PM motor with a millimeter-sized cylindrical rotor. Two types of electromagnets are applied to the micro PM motors. And the dynamic characteristics of the micro PM motors were investigated. From the experimental results, it is found that the driving current ranges of these micro PM motors are small in comparison to other normal-sized PM motors. The micro PM motor with horseshoe-shaped electromagnets increases up to speeds higher than 【approximately equal】30000 rpm, which is very fast and marvelous. The driving current range for the micro PM motor with cylindrical electromagnets is very small compared to that for the motor with horseshoe-shaped electromagnets. The magnetic friction for the micro PM motor with cylindrical electromagnets is very smaller than that for the motor with horseshoe-shaped electromagnets. From these results, it is found that for high speed rotations the micro PM motor with horseshoe-shaped electromagnets is better than that with cylindrical electromagnets. From the standpoint of electric power consumption, the micro PM motor with cylindrical electromagnets is better than that with horseshoe-shaped electromagnets because of the very small driving current range. For quick responses, the micro PM motor with horseshoe-shaped electromagnets is better than that with cylindrical electromagnets. Using this characteristic, it is shown that the rotor speed of the micro PM motor with horseshoe-shaped electromagnets can be controlled.The micro PM motor may be applied to micro gyroscopes, mechanical sensors, and other applications. It is regarded as promising for micro mechatronics.