To provide an electromagnetic brake in which a spring for canceling braking force is omitted, reaction may not function when the braking force is generated, and there is no more requirement to flow an excessive current to a main coil, by arranging the main coil for generating the braking force and a subcoil for canceling the braking force.
A main coil 1 has a small energizing current by a part having no spring. Under a condition that a brake is applied, namely, a brake shoe 6 is pushed up, the inner circumference of a support yoke 3 and a plunger 7 are approached to each other, and the plunger 7 and a base 4 are separated from each other. When the brake shoe 6 is lowered, the energization of the main coil 1 is disconnected, and a subcoil 9 is energized. Then, a magnetic pass is formed by the bottom of the yoke 2, the base 4 and the plunger 7, and magnetic attraction is applied to a clearance between the base 4 and the plunger 7. Thusly, the plunger 7, a shaft 5 and the brake shoe 6 can be lowered without a spring.
JP6765271 | Tread brake device |
JP2004293643 | PARKING BRAKE PULLING CABLE PERPENDICULARLY |