A clutch system for a motor vehicle includes a friction clutch, a ramp system, a driver, and a magnetic clutch. The friction clutch includes a pressure plate, and is arranged for transmitting a torque between a torque admission element and a torque release element. The ramp system is for axially displacing the pressure plate. The ramp system has an input ramp and an output ramp, rotatable relative to the input ramp, for varying an axial extent of the ramp system as a result of a speed differential between the torque admission element and the torque release element. The driver is coupled to the input ramp and supported so as to allow relative rotation on the torque admission element. The magnetic clutch is for rotationally coupling the driver to the torque admission dement.

A driving force transmission control device includes a driving force transmission device configured to press a friction clutch by an actuator and a controller configured to control the driving force transmission device. The controller calculates a torque command value indicating a driving force to be transmitted from a rotating member on an input side to a rotating member on an output side based on information of a vehicle. The controller sets an electric current command value according to a magnitude and an amount of time change of the torque command value. The electric current command value is a target value of an electric current. The controller performs electric current feedback control such that an electric current corresponding to the calculated electric current command value is supplied to the actuator.

A driving force transmission control device includes a driving force transmission device configured to press a friction clutch by an actuator and a controller configured to control the driving force transmission device. The controller calculates a torque command value indicating a driving force to be transmitted from a rotating member on an input side to a rotating member on an output side based on information of a vehicle. The controller sets an electric current command value according to a magnitude and an amount of time change of the torque command value. The electric current command value is a target value of an electric current. The controller performs electric current feedback control such that an electric current corresponding to the calculated electric current command value is supplied to the actuator.

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.

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 differential can comprise a pilot clutch, a main clutch, a first ball ramp configured to act on the pilot clutch, and a second ball ramp configured to actuate the main clutch when the pilot clutch acts on the second ball ramp. An electromagnetic differential can comprise a carrier, a stator mounted on the carrier, a pilot clutch in the carrier, and a main clutch in the carrier. An electromagnetic differential can comprise a carrier and a first side gear and a second side gear in the carrier. A pilot clutch can be in the carrier surrounding a portion of the first side gear. A main clutch can be in the carrier surrounding a portion of the pilot clutch and surrounding a portion of the first side gear.

A clutch assembly includes a housing, a rotational member configured to rotate relative to the housing about an axis, and a clutch pack coupled between the housing and the rotational member. The clutch pack is configured to regulate movement of the rotational member relative to the housing. The clutch pack includes a speed sensor ring coupled to the rotational member such that the speed sensor ring is configured to rotate with the rotational member about the axis. The clutch assembly includes a sensor in communication with the speed sensor ring. The sensor is configured to measure an angular velocity of the rotational member relative to the housing.

A clutch assembly includes a housing, a rotational member configured to rotate relative to the housing about an axis, and a clutch pack coupled between the housing and the rotational member. The clutch pack is configured to regulate movement of the rotational member relative to the housing. The clutch pack includes a speed sensor ring coupled to the rotational member such that the speed sensor ring is configured to rotate with the rotational member about the axis. The clutch assembly includes a sensor in communication with the speed sensor ring. The sensor is configured to measure an angular velocity of the rotational member relative to the housing.

A driving force transmission device includes an input rotation member and output rotation member, a multiple-disc clutch, a pressing mechanism, and a control device that includes a current supply circuit. The control device is configured to compute a torque command value based on a state of a vehicle, the torque command value being a driving force that needs to be transmitted by the multiple-disc clutch, to compute a current command value, to correct the current command value, and to control the current supply circuit such that an electric current depending on the current command value is supplied to the pressing mechanism. The control device is configured to perform the correction so as to increase or decrease the current command value by a correction amount depending on a change rate of the torque command value.

A clutch system for coupling a drive shaft of a motor vehicle engine to a transmission input shaft of a motor vehicle transmission is disclosed. The clutch system includes a friction clutch for transmitting a torque between a torque-introducing element and a torque-discharging element. The system includes a ramp system for the axial displacement of a pressure plate of the friction clutch, wherein the ramp system has an input ramp and an output ramp, which can be turned in relation to the input ramp to change an axial extent of the ramp system. A pilot clutch for actuating the ramp system based on a differential speed between the torque-introducing element and the torque-discharging element is provided. The clutch system further includes an electromagnet for the magnetic actuation of the pilot clutch, wherein the pilot clutch is arranged between the friction clutch and the electromagnet in the axial direction and the ramp system is arranged radially on the inside in relation to the pilot clutch and/or in relation to the friction clutch.