| 摘要 |
PURPOSE:To improve the torque of a starting motor by combining magnets of different types and considering the ratio in length of the magnets to armature core, thereby effectively utilizing the magnetic flux. CONSTITUTION:A magnet unit 2 is composed of a magnet 21 having high coercive force and high strength against a reducing magnetic field and a magnet 22 having high residual magnet flux density and high output performance. This unit 2 is formed to be longer in axial direction than the core 4 of an armature 3, the magnet 21 is disposed at the part opposed to the core 4 of the circumferential end having strong reducing magnetic field of an armature reaction, and the magnet 22 is disposed at the part not opposed to the core 4. In this manner, since the magnetic flux of the end part is effectively acted even if larger armature reaction is operated on the magnet, high torque is generated. |
