| 摘要 |
PURPOSE:To prevent dragging brake by opposing the magnet of fixed stator and the magnet of adjacent movable stator entirely to a ferromagnetic body thereby blocking flux leakage to the rotor side and achieving perfect magnetic shielding. CONSTITUTION:A rotor 4 is formed into drum shape and provided with radiation fins 6 on the outside. A fixed stator 7 is disposed oppositely to the inside of the rotor 4 and comprises an annular fixed yoke 8 and a first group 9 of permanent magnets. A movable stator 10 is disposed rotatably with respect to the fixed stator 7 while opposing to the inner circumferential face of the rotor 4 in adjacent to the fixed stator 7. The movable stator 10 comprises a movable yoke 11 and a second group 12 of permanent magnets. The section between the permanent magnet groups 9, 12 and the rotor 4 is composed of a ferromagnetic body 20 and a nonmagnetic body 21. Consequently, dragging brake due to flux leakage can be prevented at the time of releasing of brake. |
