ROTATIONAL COUPLING DEVICE

摘要

A rotational coupling device for use as a clutch and/or brake is provided having a modular construction enabling relatively easy variation of braking torque and having improved magnetic efficiency during brake engagement and release. The device includes one or more brake modules attached to a mounting bracket to vary braking torque. The brake modules include brake poles axially aligned with one portion of an armature. Permanent magnets are contained in one of the brake pole and the armature and axially aligned with the other providing a strong magnetic circuit. The mounting bracket is axially aligned with another portion of the armature, radially outward of the portion aligned with the brake pole. At least one of the mounting bracket and the aligned portion of the armature has a high magnetic reluctance providing a flux busting gap in the magnetic circuit that allows easier release of the brake.