| 摘要 |
PROBLEM TO BE SOLVED: To provide a disk-shaped electromagnetic brake preventing the whole braking force from working immediately at the time of simple de-energization of an electromagnetic coil, and preventing a braked instrument from being stopped suddenly because of the excessive speed reduction. SOLUTION: At the time of simple de-energization of the energized electromagnetic coil 16 of the disk-shaped electromagnetic brake, a main movable iron core 12 attracted to a fixed iron core 2 via a magnetic gap means 19 is separated from the fixed iron core 2 before a sub movable iron core 15 with the pressing force of a corresponding main braking spring 17. Accordingly, the time differential is generated between the pressing action of a brake board 3 in the main movable iron core 12 and that in the sub movable iron core 15, and the braking torque is generated in two steps at the time of de- energization of the electromagnetic coil 16. Therefore, the whole braking force by the pressing force of the main braking spring 17 and a sub braking spring 18 will not immediately work, so that failures caused by the impact from the sudden stop of a braked instrument can be prevented.
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