Abstract: An axial adjusting device includes two discs which are rotatable relative to one another and coaxially supported relative to one another, between which two discs balls are guided in pairs of ball grooves. The depth of the pairs of ball grooves is variable across the circumference of the discs. One of the discs is axially supported and one is axially displaceable against resilient returning forces of a first spring mechanism. At least one of the discs can be driven by a motor via a gear drive. A second spring mechanism is provided which—during the return motion of the discs, after the balls have reached their end positions in the ball grooves, which end positions are determined by the greatest groove depth—permit the drivable disc to overshoot against the resilient returning forces of the second spring mechanism.

Abstract: An axial adjusting device includes two discs which are rotatable relative to one another and coaxially supported relative to one another, between which two discs balls are guided in pairs of ball grooves. The depth of the pairs of ball grooves is variable across the circumference of the discs. One of the discs is axially supported and one is axially displaceable against resilient returning forces of a first spring mechanism. At least one of the discs can be driven by a motor via a gear drive. A second spring mechanism is provided which—during the return motion of the discs, after the balls have reached their end positions in the ball grooves, which end positions are determined by the greatest groove depth—permit the drivable disc to overshoot against the resilient returning forces of the second spring mechanism.

Abstract: A coupling assembly comprising a friction coupling a pressure-generating device comprising a pump body member, an axially-displaceable piston loading the friction coupling, and a pressure chamber formed by the pump body and by the piston and filled with a highly-viscous fluid, and with at least one conveying plate being provided in the pressure chamber; and a shear channel with a control member in the pressure chamber, the control member cooperating with at least one conveying plate. In a first embodiment, the shear channel with a control member forms two circumferential grooves of limited length and each covered by one of the two radial surfaces of the conveying plate, thereby forming two shear channels. Passages through the conveying plate connect the two shear channels. In a second embodiment, the shear channel with a control member forms a circumferential groove of limited length which is covered by one of the two radial surfaces of the conveying plate to form a first shear channel.