| 摘要 |
PURPOSE:To accurately control the rotation of a motor which rotates a magnetic disc by providing a plurality of permanent magnets at the prescribed angular interval in the circumferential direction at the rotor of the motor. CONSTITUTION:A motor has a rotor 27 which is formed in a flat cylindrical shape, and permanent magnets 28, 29 are secured at an equal angular interval on the inside. The magnets 28, 29 are formed of synthetic resin which is mixed with magnetic powder, with excellent mass productivity. An output shaft 8 is secured to the rotor 27, and rotatably journaled to upper and lower bearing retainers 32a, 32b which are secured to a bearing holder 31 secured to a yoke 30. In this manner, a plurality of permanent magnets which are divided into rotors of the motor and independent from each other are provided, thereby clarifying the magnetic field and accurately controlling the rotation of the motor. |
