A device for effecting an axial shift of a rotary shaft for use in a variable camshaft drive mechanism

摘要

A device for effecting an axial shift of a rotary shaft such as the camshaft of a vehicle comprising a first component having a shaft and a head, a second component having a first end and second end and a bore extending longitudinally there through, the shaft of the first component being inserted into the bore of the second component, a detent couples the first component to the second component such that rotation of the second component causes the first component to rotate wherein the first end of the second component is countersunk so as to define inclined ramps in walls of the second component and one or more rollers are disposed between the head of the first component and the first end of the second component in rolling contact with the inclined ramps, wherein as the second component is rotated about a longitudinal axis the rollers move along the inclined ramps and act upon the first component to move it axially with respect to the second component which may be arranged to rotate the first component with respect to the second component. In this way the timing of the valves of a combustion engine can be varied with rotational speed of the crankshaft of the engine.