Patent ID: 7926461

Claim:
A system for controlling fluid flow to or from a cylinder of an internal combustion engine, the system comprising: first and second drive shafts having rotary valves mounted thereon; a cylinder head accommodating the rotary valves and at least part of the drive shafts therein, the rotary valves being arranged to selectively open or close flow openings in the cylinder head; a source of rotation; and a mechanical drive train rotatably coupling the source of rotation to the drive shafts, the mechanical drive train including a first non-circular element rotatably coupled to the source of rotation; a second non-circular element rotatably coupled to the first drive shaft; and a third non-circular element rotatably coupled to the second drive shaft; the first non-circular element being rotatably coupled to the second and third non-circular elements to cause a speed variation in the second and third non-circular elements upon a constant rotation of the first non-circular element; wherein the first, second, and third non-circular elements are elliptical gears.