Patent ID: 7000492

Claim:
An axial adjusting device comprising first and second discs which are rotatable and coaxially supported relative to one another, and balls between said first and second discs guided in pairs of ball grooves, wherein the depth of said pairs of ball grooves is variable across a circumference of the first and second discs, and wherein one of the first or second discs is axially supported and one of the first or second discs is axially displaceable against resilient returning forces of a first spring mechanism, which spring mechanism is supported on a third part and wherein at least one of the first and second discs is directly rotatingly driven by an electric motor via a gear drive, and wherein said device comprises a second spring mechanism which, during a return motion of the first and second discs, after the balls have reached end positions in the ball grooves, corresponding to a greatest groove depth, permits the axially displaceable disc to overshoot against resilient returning forces of the second spring mechanism; and wherein the gear drive comprises gears and one of the gears comprises hub elements and gear rim elements which are separate from one another and which are resiliently supported relative to one another by the second spring mechanism.