| 摘要 |
PURPOSE:To easily regulate a rotor balance by integrating a field magnet with a rotary shaft directly by a plastic magnet. CONSTITUTION:A disklike magnet rotor 19 is so integrally molded by molding means of a plastic magnet under a rotary shaft 18 rotatably supported by a bearing 10 as to take in advance a dynamic balance. This rotor 19 is formed with main and FG poles 19, 19b. The inner periphery of the pole 19a is formed in a recess 19c, and a bearing holding ringlike protrusion 19d is integrally formed at a position opposite to the bearing 10 of the inner peripheral position of the recess 19c. The protrusion 19d is abutted on the lower section of the bearing 10 to prevent the bearing 10 from axially vibrating. Thus, since the rotor 19 is integrated with a rotary shaft 18, the rotor balance can be easily regulated to improve its assembling operability. |
