Abstract: An electric braking or clutching device includes a housing; an armature having an axis and disposed at the housing, the armature and the housing defining a radial air gap therebetween; and a coil configured to generate, when energized, a magnetic field at the housing and armature, a flux path of the field extending from the coil into the armature, from the armature into the housing, and from the housing back to the coil, with the direction of the flux path from the armature into the housing being substantially radial in orientation.

Abstract: A selective braking or clutching device includes a housing, an armature partially received within the housing and defining a radial air gap between the armature and the housing, and a coil productive of a magnetic field, a flux thereof being radially directed through the air gap. A method for extending the life of a selective braking or clutching device including positioning an armature relative to a housing such that a radial air gap is created between the housing and armature causing a magnetic flux to pass through the air gap in a radial direction.

Abstract: A wrap spring torque transfer device including a housing, a shaft rotatably positioned at the housing, a hub rotatably positioned at the housing, a wrap spring disposed about the hub and the shaft; and capable of selectively facilitating or defeating torque transfer between the hub and the sleeve, a coil in magnetic flux communication with the housing, shaft and hub, such that the magnetic flux passes the hub and sleeve to draw the hub and sleeve together. A method for improving service life of a wrap spring torque transfer device including passing a magnetic flux radially between a housing and a flange mounted to a shaft, passing the flux axially between the flange and a collar, passing the flux radially between the collar and a sleeve at the shaft, substantially avoiding flux passage directly between the collar and the housing.