A clutch assembly includes a first clutch having a first translator and a friction pack and a second clutch having first and second coupling members, a locking element, and a second translator. The friction pack includes a first plate fixed to the first coupling member and a second plate fixed to the second coupling member. The first translator of the first clutch is movable to an actuated position in which the plates of the friction pack are engaged with one another thereby causing angular velocities of the first and second coupling members to be synchronized. The second translator of the second clutch is movable to an extended position in which the locking element engages the first and second coupling members with one another thereby causing a power flow path through the first and second coupling members.

An electromagnetic clutch assembly may include a first clutch plate, a second clutch plate, and a synchronizer. The second clutch plate may define an aperture. A portion of the synchronizer may be configured to extend through the aperture. In the absence of a magnetic field, the first clutch plate and the first surface of the second clutch plate may define an air gap and the portion of the synchronizer may extend into the air gap. In response to a first magnetic field, the portion of the synchronizer may contact the first clutch plate. In response to a second magnetic field, the portion of the synchronizer may translate in the aperture toward the second clutch plate and the first clutch plate and the second clutch plate may close the air gap.

A method for synchronizing a first drive element rotatable about an axis of rotation with a second drive element rotating about the axis of rotation at a target speed, of a powertrain of a motor vehicle, in which a synchronizing force is exerted on a synchronizing unit by an actuator. A speed, at which the first drive element rotates about the axis of rotation is adapted by the synchronizing unit to the target speed. The synchronizing force is increased during a first time span, so that the speed approaches the target speed. The synchronizing force is continuously reduced during a second time span following the first time span, before the speed corresponds to the target speed.

A method for synchronizing a first drive element rotatable about an axis of rotation with a second drive element rotating about the axis of rotation at a target speed, of a powertrain of a motor vehicle, in which a synchronizing force is exerted on a synchronizing unit by an actuator. A speed, at which the first drive element rotates about the axis of rotation is adapted by the synchronizing unit to the target speed. The synchronizing force is increased during a first time span, so that the speed approaches the target speed. The synchronizing force is continuously reduced during a second time span following the first time span, before the speed corresponds to the target speed.

A clutch assembly comprises an input shaft and an output shaft, co-axially arranged relative to the input shaft. The clutch assembly further comprises an input clutch drum, fixed to the input shaft, and an output clutch drum, translatable relative to the output shaft. The clutch assembly further comprises a clutch pack and a clutch piston that is translatable relative to the output shaft between, inclusively, a frictionally disengaged clutch-pack position and a frictionally engaged clutch-pack position. The clutch assembly additionally comprises a clutch-pack engagement spring. The output clutch drum is translatable between, inclusively, a fully disengaged position and, inclusively, a positively engaged position. When the clutch piston is in the frictionally disengaged clutch-pack position, the internal splines of the output clutch drum are not in mesh with the external splines of the input clutch drum.

A clutch assembly comprises an input shaft and an output shaft, co-axially arranged relative to the input shaft. The clutch assembly further comprises an input clutch drum, fixed to the input shaft, and an output clutch drum, translatable relative to the output shaft. The clutch assembly further comprises a clutch pack and a clutch piston that is translatable relative to the output shaft between, inclusively, a frictionally disengaged clutch-pack position and a frictionally engaged clutch-pack position. The clutch assembly additionally comprises a clutch-pack engagement spring. The output clutch drum is translatable between, inclusively, a fully disengaged position and, inclusively, a positively engaged position. When the clutch piston is in the frictionally disengaged clutch-pack position, the internal splines of the output clutch drum are not in mesh with the external splines of the input clutch drum.

A clutch device configured for a transmission may include a first body and a second coaxially mounted to the first body; a friction element mounted between the first body and the second body; a friction piston configured to axially press the friction element by use of hydraulic pressure; a retractable mechanism including a dog clutch, which is configured to restrict rotation between the first body and the second body, and repeatedly engaging and disengaging the dog clutch by repeatedly applying pressure in axial direction thereof; and an operation piston configured to provide pressure to the retractable mechanism in an axial direction of the retractable mechanism.

A clutch assembly includes a first clutch having a first translator and a friction pack and a second clutch having first and second coupling members, a locking element, and a second translator. The friction pack includes a first plate fixed to the first coupling member and a second plate fixed to the second coupling member. The first translator of the first clutch is movable to an actuated position in which the plates of the friction pack are engaged with one another thereby causing angular velocities of the first and second coupling members to be synchronized. The second translator of the second clutch is movable to an extended position in which the locking element engages the first and second coupling members with one another thereby causing a power flow path through the first and second coupling members.

An electromagnetic clutch assembly may include a first clutch plate, a second clutch plate, and a synchronizer. The second clutch plate may define an aperture. A portion of the synchronizer may be configured to extend through the aperture. In the absence of a magnetic field, the first clutch plate and the first surface of the second clutch plate may define an air gap and the portion of the synchronizer may extend into the air gap. In response to a first magnetic field, the portion of the synchronizer may contact the first clutch plate. In response to a second magnetic field, the portion of the synchronizer may translate in the aperture toward the second clutch plate and the first clutch plate and the second clutch plate may close the air gap.

A dog clutch of a vehicle power transmission device includes a sleeve, the dog clutch connecting/disconnecting a first rotating shaft to/from a first gear by moving the sleeve between a neutral position at which inner circumferential teeth formed on an inner circumferential side of the sleeve are not meshed with outer circumferential teeth on a side surface side of the first gear and an engagement position at which the inner circumferential teeth are meshed with the outer circumferential teeth, the inner circumferential teeth and the outer circumferential teeth having inclined surfaces tooth thicknesses of which become larger as the inner circumferential teeth and the outer circumferential teeth approach each other, and when the sleeve is moved to an engagement position by a shift fork, the sleeve being held in contact with a side surface of the first gear.