Variable compression ratio engine

Abstract

A variable compression ratio (VCR) internal combustion engine includes an engine block defining a cylinder and a cylinder head mounted to the engine block and defining at least a part of a combustion chamber. The engine also includes a reciprocating primary piston arranged inside the cylinder and configured to compress a mixture of air and fuel and a crankshaft arranged in the engine block and rotated by an application of a combustion force to the primary piston. The engine additionally includes a secondary piston mounted in the cylinder head, movably with respect to the combustion chamber and a mechanism configured to shift the secondary piston in the cylinder head and thereby vary a volume of the combustion chamber and a compression ratio of the engine. A vehicle employing such an engine is also disclosed.

Dependencies are inferred from the claim text.