| 摘要 |
<p>PURPOSE:To permit an armature to be released promptly, by forming a ring- shaped groove by cutting on one of a magnetic flux passages of a field core and the armature and filling the groove with magnetic force shutting-off member of non-magnetic material. CONSTITUTION:An armature 11 is integrally constructed of a ring-shaped inner plate 11a and a ring-shaped outer plate 11b which is dividedly formed on its circumference through a magnetic force shutting-off plate 12. The magnetic force shutting-off member 12 disposed between the inner plate 11a and the outer plate 11b is accommodated in a ring-shaped groove 11e. When an exiting coil 4 of an electromagnetic brake 1 provided with the armature 11 is excited, the armature 11 is attracted toward the field core 2, whereby a magnetic force shutting-off portion 12 is made in a magnetic flux passage formed by the attraction. As a result, when power supply to the exciting coil 4 is interrupted, magnetic resistance in the magnetic force causes magnetic flux in the magnetic flux passage to reduce its magnetic attracting force, whereby the armature 11 leaves a friction surface 5 of the field core 2 promptly by a returning force of a leaf spring 6a.</p> |
