| 摘要 |
PROBLEM TO BE SOLVED: To achieve braking effect for a long time by restraining the temperature increase of a rotor. SOLUTION: Two support rings having a group of permanent magnets, where N and S poles are arranged alternately with the same interval as switch plates 4 along the peripheral direction counterposed to a rotor 2 are arranged via the group of switch plates 4 that are arranged between supports 3 at a prescribed interval in the inner- periphery surface side of the rotor 2 that is provided at a rotary shaft 1. The switching plates 4 of this eddy current brake device that is composed so that permanent magnets 5b and 5a can select the position, where the permanent magnet 5b and the adjacent permanent magnet 5a of a fixed support ring 6a are of the same pole by the turning movement of the other movable support ring 6b, and the positions where the permanent magnet 5b and the permanent magnet 5a of different polarity are set to a magnetic shunt material 4a. As the temperature rises, the reluctance of a magnetic circuit increases, and braking is inhibited in continuous braking for suppressing the temperature increase of the rotor, thus preventing thermal deformation of the rotor and thermal cracks from being generated. Also, the temperature increase in the permanent magnet due to the thermal influence of the rotor is inhibited, and stable braking effect can be maintained over a long time, while the temperature of the permanent magnet does not exceed the maximum temperature.
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