| 摘要 |
A brake (30) includes a magnetically permeable body (38) having a pole face (40), an armature (42) axially movable toward and away from the pole face, an energization coil (44) energizable to magnetically attract the armature toward the pole face, biasing members (50) biasing the armature away from the pole face, a pressure plate (64) mounted to the body and axially spaced from the pole face, a friction disc (66) between the armature and the pressure plate and keyable to an axially extending rotary shaft (36), such that upon deenergization of the coil, the biasing members bias the armature to a braking position pushing the friction disc against the pressure plate to stop rotation of the disc and shaft, the armature in the braking position defining an air gap (80) between the pole face and the armature, and such that upon energization of the coil, the armature is pulled through the gap toward the pole face to a released position releasing the disc and permitting rotation of the shaft. The body includes a housing shell (82) having a plurality of magnetically permeable segments (84, 86, 88) breaking up eddy currents and enabling faster brake response. An air gap adjustment mechanism (180) is adjustable to vary the axial distance from the pressure plate to the pole face to take up and compensate friction disc wear and maintain the air gap within a given tolerance as the friction disc wears with use. A torque adjustment mechanism (250) is adjustable to vary the bias of the biasing members biasing the armature away from the pole face, to vary braking torque. A release mechanism (310) includes pivot-bases (316, 318) with radially inwardly extending tabs (320, 322) for engaging and pushing the armature toward the pole face and against the bias of the biasing members, for manual release of the brake.
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