The Development of Micro Brushless Slotless Motors with 4-Pole Rotor Design

In order to satisfy the demands of miniature and precision servo driving, this paper develops a DC brushless micro motor by the size of Φ 6.0mm × L 20.0mm. For the restricted space, the proposed motor is adapted with slotless structure and the rotor magnet is magnetized with four poles to enhance the torque property. The magnetic field analysis and winding number design are then performed to determine the detail design parameters. And FEA simulation is also used to check the design results. Afterward, the prototypes are fabricated and tested. Both simulated and experimental results show that the proposed motor can be a reliable solution for the small power drive applications.