An engine accessory with a wrap spring clutch, which is configured for selectively transmitting rotary power between a drive member and a shaft, and an actuator that is configured to selectively control the clutch. The actuator has first and second rotary flux elements, a clutch control ring and an electromagnet. The first rotary flux element is rotatably coupled to the drive member and has a plurality of first teeth that are spaced circumferentially about the rotary axis. The clutch control ring is rotatable about the rotary axis and is coupled to the tang of the wrap spring. The second rotary flux element is rotatably coupled to the clutch control ring. The second rotary flux element has a plurality of second teeth that are spaced circumferentially about the rotary axis. The electromagnet is selectively operable to generate a magnetic field that is transmitted between the first and second teeth.

Clutch assemblies and associated methods are disclosed herein. In an example, a clutch assembly comprise a first terminal, a second terminal, a clutch body enclosing a torque transfer fluid, and one or more electropermanent magnets (EPMs), each configured to generate a respective EPM magnetic field. The clutch assembly is configured to transmit a torque between the first terminal and the second terminal with a torque capacity that is at least partially based on the EPM magnetic fields. In an example, a method of operating a clutch assembly comprises transitioning each of one or more EPMs to a fully depolarized state, a fully polarized state, or an intermediate polarization state. In an example, a method of operating a clutch assembly comprises controlling each of one or more EPMs of the clutch assembly to vary a total EPM magnetic flux generated by the one or more EPMs.

An interrupter includes: an intermittent member having a meshing tooth meshing with a second rotary member, and moving in an axial direction between a coupled position and an uncoupled position; and an actuator making the intermittent member move in the axial direction. The actuator includes: a coil generating magnetic flux; and a plunger moving with the intermittent member in the axial direction. The plunger is disposed in a manner capable of making relative rotation to one of the first and second rotary members via first and second air gaps. When the coil is energized, the magnetic flux is introduced to the plunger from one of the first and second air gaps, the magnetic flux is led out of the plunger to the other air gap, and the plunger moves in the axial direction so as to reduce at least one air gap of the first and second air gaps.

An electromagnetic brake includes a hub disposed about a shaft and configured for rotation with the shaft about a rotational axis. An electromagnet assembly is fixed against rotation about the axis and includes a housing defining axially extending, radially spaced inner and outer poles and a brake plate extending radially therebetween. A conductor is disposed between the poles on one side of the brake plate. An armature is disposed on the other side of the brake plate and coupled to a body driven by the shaft. The electromagnet assembly, armature and hub form an electromagnetic circuit when the conductor is energized urging the armature towards the brake plate. A portion of the magnetic flux in the circuit travels radially inwardly across a first radial air gap from the inner pole to the hub and then radially outwardly across a second radial air gap from the hub to the brake plate.

The invention comprises a clutch device having an actuating device, wherein the actuating device has an electrical eddy current brake. The eddy current brake has a brake stator with at least one coil and a brake rotor with a brake region, wherein the brake region has a first layer which is electrically conductive and which has a first lateral face and a second lateral face, the first lateral face facing toward the coil and the second lateral face facing away from the coil. The brake region has a second layer which is magnetic and which is connected to the second lateral face. The invention further comprises a corresponding production method.

A clutch device is comprised of: an end wall rotatable about an axis; an extended wall elongated as a unitary body from a first face of the end wall along the axis to define a circular slot; a clutch including a clutch member movable along the axis and capable of resting on a second face of the end wall; and a solenoid configured to drive the clutch member along the axis, the solenoid including a core conducting a magnetic flux, the core including a fitting portion slidably fitting in the circular slot, an abutment portion projecting radially outward from the fitting portion to abut along the axis on the extended wall, and a back portion projecting outward along the axis from the circular slot and retracting radially inward from the contact portion.

An electromagnetic actuation assembly includes an actuator comprising a magnetic field frame provided with an annular housing extending circumferentially about a reference axis, a coil arranged in the annular housing of the magnetic field frame, and a plunger able to be moved axially between a first axial zone and a second axial zone with respect to the magnetic field frame as a function of the magnetic field produced by the coil when this coil is supplied with current. A first shock absorber is mounted either on the plunger or on the magnetic field frame or on an actuator support to which the actuator is fixed, the first shock absorber being arranged in such a way as to be deformed by the movement of the plunger when the plunger reaches the first axial zone.

The present teachings provide for a clutch including a hub, a rotor, and an electromagnet. The hub can be rotatable about a central axis. The rotor can be rotatable about the central axis and can be rotatable relative to the hub. The rotor can define an annular cavity that can be disposed about the central axis. A surface of the annular cavity can define at least one groove that can extend helically about the central axis. The electromagnet can be received in the annular cavity. When the electromagnet is energized, the hub can engage the rotor to transmit torque between the hub and rotor.

A rotor for an electromagnetic clutch assembly includes a substantially cylindrical main body extending from a first end to a second end. The first end of the main body is configured to engage an armature of the electromagnetic clutch assembly and includes a first flange formed around a circumference thereof. The second end of the main body includes a second flange formed around a circumference thereof. One of the first flange or the second flange has a non-uniform cross-sectional shape as the one of the first flange or the second flange extends circumferentially around the main body, wherein the cross-sectional shape of the one of the first flange or the second flange taken through a plane extending parallel to an axis of rotation of the main body.