A wet friction disc includes a lubrication groove and a plurality of lands defined by the lubrication groove. The lubrication groove has a plurality of circumferential groove portions that extends in a circumferential direction and has a predetermined groove width in a radial direction, and a plurality of intersecting groove portions that extends in directions intersecting the circumferential direction. At least some of the circumferential groove portions have an arc shape such that an end in the circumferential direction is located adjacent to one of the lands in the circumferential direction and that the groove width is entirely contained within a range in the radial direction spanned by that land.

An electrically controlled differential gear is disposed between a right front wheel and a left front wheel of a vehicle. The electrically controlled differential gear includes a clutch mechanism that limits a differential operation of the electrically controlled differential gear. A second ECU (control portion) obtains information as to failure associated with actuation of a right front electric brake mechanism. The second ECU obtains a physical amount relating to a required braking force which is applied to the left front wheel and the right front wheel. The second ECU outputs a differential limiting control command for limiting the differential operation of the electrically controlled differential gear to the clutch mechanism (or more specifically, a differential ECU that controls the clutch mechanism) based on the information as to the failure and the physical amount relating to the required braking force.

A disconnect mechanism comprises an input shaft defining a drive axis, a disconnect shaft selectively engaged with the input shaft to be driven about the drive axis by the input shaft, and a disconnect ramp operatively connected to the disconnect shaft to axially move the disconnect shaft between at least a first axial position and a second axial position. A disconnect pawl is selectively engaged with the disconnect ramp shaft, and a brake is selectively engaged with the disconnect shaft in the second axial position.

A parking brake for a wheel rotor having a brake pad associated therewith includes a housing defining first and second passages. First and second pistons are provided in the respective first and second passages. Spindles extend into and are connected with each piston. A clutch unit is connected to the spindles and includes a motor. The clutch unit has a first condition allowing for rotation of the spindles in response to hydraulic pressure applied to the pistons such that the pistons are axially movable within the passages and relative to the spindles into engagement with the brake pad. The clutch unit has a second condition for rotating the spindles to drive the pistons into the brake pad and apply the parking brake.

A method of controlling a brake system that includes a motor and an actuator. The method includes moving the actuator towards a retracted position; activating a timer; monitoring a motor characteristic of the motor and monitoring the timer; and determining the actuator has reached the retracted position after the timer meets or exceeds a predetermined time threshold before the motor characteristic has reached or exceeded a predetermined motor characteristic threshold.

A brake device for braking rotation of an input shaft includes a selectively operable trigger brake that includes: a static element; a trigger brake shaft mounted for rotational and axial movement relative to the static element and the input shaft; a preloaded torsion spring rotationally coupled to the input shaft but permitting a limited rotational movement between the trigger brake shaft and the input shaft; a roller jamming mechanism operable upon the relative rotation between the trigger brake shaft and the input shaft exceeding a predetermined amount to stop rotation of the input shaft upon operation of the trigger brake; and a brake actuator for selectively moving the trigger brake shaft into and out of engagement with a contact surface of the static element. Engagement of the contact surface of the static element and the trigger brake shaft overcomes the preload of the torsion spring.

An electromechanical brake apparatus includes a housing supporting an inboard brake pad and an oppositely facing outboard brake pad for selective frictional contact with a rotor interposed longitudinally therebetween. An adjuster ramp assembly indirectly receives torque from the motor unit. A spindle is provided for selectively moving the inboard brake pad longitudinally. The spindle is operatively connected with the adjuster ramp assembly to indirectly receive torque from the motor unit therethrough. A leading ramp assembly is configured to transmit applied torque from the motor unit to the adjuster ramp assembly via at least one ramp ball longitudinally interposed therebetween. A predetermined amount and direction of torque is applied to each of the adjuster ramp assembly and the leading ramp assembly to assist with a selected one of (1) service brake application and (2) service brake release functions. The electromechanical brake apparatus is operative, at different times, for both functions.

An electromechanical brake apparatus includes a housing supporting an inboard brake pad and an oppositely facing outboard brake pad for selective frictional contact with a rotor interposed longitudinally therebetween. The housing includes a mechanism cavity located longitudinally between the inboard pad and a motor having a motor output shaft. An adjuster ramp assembly indirectly receives torque from the motor. A spindle is operatively connected with the adjuster ramp assembly to indirectly receive torque from the motor therethrough. A leading ramp assembly is configured to transmit applied torque from the motor to the adjuster ramp assembly. The leading ramp assembly receives stepped-up torque from the motor via the motor output shaft and a ball thrust bearing at least partially located radially between the motor output shaft and an actuator ramp of the leading ramp assembly.

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.

An actuation system includes a power drive unit that drives a plurality of drive shafts that each has a first end individually connected to the power drive unit. The power drive unit includes a geartrain including a plurality of individual gears that are offset relative to each other along the gearbox, and a motor-driven rotation of one of the plurality of individual gears drives rotation of the other individual gears, and each of the plurality of individual gears rotates to drive rotation of a respective one of the plurality of drive shafts. A plurality of torque brakes is mounted to the gearbox, the torque brakes being mechanically coupled to respective individual gears and drive shafts. When the torque being passed through is above a predetermined threshold value, a locking of one of the torque brakes stops rotation of all gears simultaneously to maintain positional symmetry in the actuation system.