Variable valve timing device for internal combustion engines utilizing hydraulic valve actuators
A variable valve timing device for an engine utilizing hydraulically actuated valves. A cam follower block, complete with radial bores, and cam followers within these bores, is pivotally mounted about a rotating camshaft. The rotating camshaft displaces the cam followers within the bores, causing the followers to displace hydraulic fluid, forcing movement of either, an intake or exhaust valve, by hydraulic force on a secondary hydraulic cylinder. The cam follower block angular position about the camshaft is mechanically adjustable during operation. Separate cam follower blocks are used for intake and exhaust valve operation such that the valve timing of the intake and exhaust valves can be changed independently.
1. A variable valve timing device for an engine having a crankshaft and a plurality of valves movable between open and closed positions, said variable valve timing device comprising:
a camshaft rotatably coupled to the crankshaft, said camshaft rotates in a fixed orientation relative to the crankshaft;
a plurality of cam lobes defining an eccentric profile and fixedly disposed on said camshaft;
a plurality of blocks each defining at least one bore and configured to independently rotate relative to one another;
means for actuating at least one said block for controlling independent rotation of at least one of said block relative to another one of said blocks;
at least one cam follower operably disposed within at least one said bores and configured to follow said eccentric profile of one of said cam lobes for selectively actuating the valves;
wherein each of said cam followers is adjusted relative to said camshaft independent of other cam followers.
2. The variable valve timing device of claim 1 , wherein independent adjustment of at least one said cam followers selectively manipulates timing of opening and closing of at least one said valves.
3. The variable valve timing device of claim 2 , wherein said timing of opening and closing of each of said valves is independent of at least one of valve lift and/or duration.
4. The variable valve timing device of claim 1 , further including hydraulic fluid or some other alternate liquid and a controller or other means of regulating pressure and flow of said hydraulic fluid for independently adjusting at least one said cam followers.
5. The variable valve timing device of claim 1 , wherein said valves are further defined as intake valves and exhaust valves.
6. The variable valve timing device of claim 1 , wherein said at least one cam followers further include lifters.
7. The variable valve timing device of claim 1 , wherein said at least one cam followers further include pistons.
8. The variable valve timing device of claim 1 , wherein said camshaft is further defined as a single-lobe camshaft.
9. The variable valve timing device of claim 1 , wherein said camshaft is further defined as a two-lobe camshaft.
10. The variable valve timing device of claim 1 , wherein said camshaft is further defined as a multi-intake, multi-exhaust lobe camshaft.