Steuerbare Nockenwelle mit veränderlichem Ventilhub

摘要

A variable timing camshaft has concentric shafts for mechanically varying the valve timing of internal combustion engines and motors and air compressors and motors. By altering the rotational position of the cam lobes attached to each shaft (1, 2) relative to each other, the valve timing can be varied. This may be achieved by periodically changing the length of a timing chain or belt on one side of sprockets (7, 8). Alternatively, it may be achieved by a series of interconnected cogs which effectively rotate one shaft (1, 2) with respect to the other. The degree of valve lift may also be varied. Inverted cam lobes may act via pivoted rocker arms to open and close the valves. A cam follower spring maintains the tension which is kept to a minimum by means of a spring tensioning device, hydraulic piston lifter or air valve. Alternatively, the relative height of the rocker arm pivot shaft or camshaft can be varied.