| 摘要 |
<p>PURPOSE:To prevent a head and an electronic circuit disposed at the periphery of a motor from generating a noise by forming a magnetic path between a rotor magnet and a stator coil of a magnetic metal disc having a sufficient size, thereby reducing a leakage magnetic flux to the exterior of the motor. CONSTITUTION:A stator coil 14 is disposed on a substrate 13, and a rotor 15 secured integrally with a rotational shaft 6 is rotated oppositely to the coil 14. A magnetic metal disc 19 which rotates together with the rotor 15 is provided at the opposite side to the rotor 15 from the coil 14. When the width of the coil unit of the coil 14 is represented by A and the maximum distance between the outsides of air cores of the two opposite coils 14, 14 is represented by B, the diameter of the disc 19 is decided at least to the length of A+B, thereby effectively preventing the magnetic flux from the magnet or the rotor 15 and the coil 14 from leaking.</p> |
