| 摘要 |
PROBLEM TO BE SOLVED: To restrain a rise in temperature, even at continuous braking over a long time, without causing losses of a braking effect at braking over a short time. SOLUTION: In an eddy-current reduction gear, which switches on/off braking by moving a permanent magnet 1 from a non-braking position to a braking position, an actuator 5 constituting an on/off switch is used, of which the stroke is set to be St2 longer than a stroke St1 required for switching on/off braking, and the permanent magnet 1 is moved to a position where a braking force becomes strongest immediately after the starting of braking, and the braking force is then restrained by moving the permanent magnet 1 in the forward or backward direction. Accordingly, the stable braking effect independent of an elapsed time can be obtained by restraining the generated braking force from lowering after long braking, without increasing the initial braking force to be more than required.
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