Patent attributes
The present invention provides a variable valve timing device for an internal combustion engine having a double camshaft. A gas exchange valve control shaft is provided which has first and second concentrically arranged cam shafts that are adjustable in a rotatable manner with respect to each other, by which a cam of the first cam shaft is adjusted in terms of its angle towards a cam of the second cam shaft. A cam phasing device is provided which operates by rotatable vanes provoking a swivelling relative movement between a driven member and an output member. The cam phasing device comprises at least two pivotable vane adjusters. Each pivotable vane adjuster is assigned to one of the two cam shafts. The pivotable vane adjusters are arranged axially one after the other in a direction of a valve control shaft. Each pivotable vane adjuster may be designed as a rotor-type vane adjuster.
