A power transmission device includes a friction clutch, an actuator, and a controller configured to determine an approximated temperature change of the friction clutch. The controller is configured to determine a current power state of the friction clutch, determine a desired power state change based on the current power state and a previous power state, determine a plurality of thermal coefficients based on a thermal coefficient model, the desired power state change, and a set of operation variables, determine an approximated temperature change of the friction clutch based on the thermal coefficients and a friction clutch temperature model, determine an approximated clutch temperature based on the approximated temperature change and a contemporaneous value of an device ambient temperature, and control operation of the actuator based at least on the approximated clutch temperature.

Axial adjustment device (1), comprising a first disk (2) which is rotatable and axially displaceable both in a first circumferential direction (I) and in a second circumferential direction (II), namely a circumferential direction counter to the first circumferential direction (I), and a second disk (3) which is locked against rotation in the first circumferential direction (I) and is rotatable in the second circumferential direction, wherein the second disk (3) has an activating element (8) on its end side facing away from the first disk (2), and wherein the first disk (2) and the second disk (3) each have, on their mutually facing end surfaces, at least three identically formed depressions (4) which lie opposite one another in each case in pairs and thus form at least three pairs of depressions, wherein a rolling element (5) is arranged in each of the pairs of depressions, wherein the depressions (4) each have a slope in the first circumferential direction (I) from a lower dead centre (6) towards an upper dead centre (7), and an actuation arrangement, comprising such an axial adjustment device.

A magnetic clutch for actuating a disconnect clutch includes an axis of rotation, an axially fixed stator, an axially movable armature, a torque-axial force converter unit with an armature side and a bearing side, and a rotary brake. The axially movable armature is axially retainable on the stator by a magnetic force from a power supply. The torque-axial force converter unit acts in an antagonistic manner to the magnetic force to hold the armature at an axial distance from the stator. The rotary brake is for effecting a rotational speed difference between the armature side and the bearing side. Other aspects of the disclosure include a disconnect clutch for an internal combustion engine in a hybrid drive train, a hybrid drive train, and a method for controlled closing of the disconnect clutch.

A magnetic clutch for actuating a disconnect clutch includes an axis of rotation, an axially fixed stator, an axially movable armature, a torque-axial force converter unit with an armature side and a bearing side, and a rotary brake. The axially movable armature is axially retainable on the stator by a magnetic force from a power supply. The torque-axial force converter unit acts in an antagonistic manner to the magnetic force to hold the armature at an axial distance from the stator. The rotary brake is for effecting a rotational speed difference between the armature side and the bearing side. Other aspects of the disclosure include a disconnect clutch for an internal combustion engine in a hybrid drive train, a hybrid drive train, and a method for controlled closing of the disconnect clutch.

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.

A magnetic brake assembly for use with a wheel rim is described. The brake assembly includes a rotor secured to rotate with the rim and a stator secured to be rotationally stationary relative to the rotor. One of the rotor and stator has an electrically conductive body and the other of the rotor and stator has a magnetic array including a plurality of magnets configured to generate a magnetic flux. An actuator is connected to at least one of the electrically conductive body and magnetic array to selectively effect a brake mode and a non-brake mode. In the brake mode, the magnetic array induces eddy currents in the electrically conductive body to generate a magnetic braking force when the rim rotates above a threshold speed and in the non-brake mode, the induced eddy currents cause a negligible or no magnetic braking force as the rim rotates above the threshold speed.

A magnetic brake assembly for use with a wheel rim is described. The brake assembly includes a rotor secured to rotate with the rim and a stator secured to be rotationally stationary relative to the rotor. One of the rotor and stator has an electrically conductive body and the other of the rotor and stator has a magnetic array including a plurality of magnets configured to generate a magnetic flux. An actuator is connected to at least one of the electrically conductive body and magnetic array to selectively effect a brake mode and a non-brake mode. In the brake mode, the magnetic array induces eddy currents in the electrically conductive body to generate a magnetic braking force when the rim rotates above a threshold speed and in the non-brake mode, the induced eddy currents cause a negligible or no magnetic braking force as the rim rotates above the threshold speed.

The invention describes a switchable clutch for a motor vehicle with hybrid drive, wherein the hybrid drive has a voltage system with a voltage exceeding the 12-volt on-board electrical system voltage of the motor vehicle, composed of a friction disk clutch with an actuator, which can have electricity applied to it, for the actuation of the friction disk clutch in the sense of opening or closing, and wherein the actuator can be actuated with a voltage of the voltage system of the hybrid drive, said voltage exceeding the 12-volt on-board electrical system voltage of the motor vehicle.

The invention describes a switchable clutch for a motor vehicle with hybrid drive, wherein the hybrid drive has a voltage system with a voltage exceeding the 12-volt on-board electrical system voltage of the motor vehicle, composed of a friction disk clutch with an actuator, which can have electricity applied to it, for the actuation of the friction disk clutch in the sense of opening or closing, and wherein the actuator can be actuated with a voltage of the voltage system of the hybrid drive, said voltage exceeding the 12-volt on-board electrical system voltage of the motor vehicle.