Patent ID: 7210434

Claim:
A hydraulic variable valve train apparatus, adapted for use in an engine having a combustion chamber, a hydraulic camshaft rotating in a timed relationship with a combustion sequence occurring in the combustion chamber, the hydraulic camshaft rotating along a circumferential axis of rotation of the hydraulic camshaft and comprising: (a) a first graduated cavity disposed on a first portion of a hydraulic camshaft lobe and a second graduated cavity disposed on a second portion of the hydraulic camshaft lobe, wherein the hydraulic camshaft lobe rotates concentrically with the circumferential axis of rotation of the hydraulic camshaft; (b) at least one valve operatively coupled to the hydraulic camshaft lobe; and (c) a hydraulic circuit adapted to actuate the at least one valve in the engine, the hydraulic circuit comprising: (1) a hydraulic fluid source operatively coupled to the hydraulic camshaft lobe via a first inlet portion disposed at a first inlet port on the hydraulic camshaft and a second inlet portion disposed at a second inlet port on the hydraulic camshaft; (2) a first control port operatively connected to a first control port side of the hydraulic camshaft lobe and a second control port operatively connected to a second control port side of the hydraulic camshaft lobe; and (3) a first exhaust port operatively connected to a first exhaust port side of the hydraulic camshaft lobe and a second exhaust port operatively connected to a second exhaust port side of the hydraulic camshaft lobe.