Variable compression engine

Abstract

A diesel, gasoline or gas internal combustion engine adapted for operation on a two-cycle or four-cycle basis includes apparatus to vary the compression ratio of gases during operation of the engine. Two pistons, connected to separate crankshafts, communicate with each other in a single internal combustion chamber. One piston is reciprocated by a crankshaft in one cylinder portion to convert thermal energy into mechanical energy. The displacement of the one piston defines a fixed compression ratio and the displacement of a second piston by a second crankshaft in the other cylinder portion operates in the combustion chamber to a second fixed compression ratio. The two crankshafts are coupled together through timing means used to change the relative rotational phase relation between the crankshafts whereby a net compression ratio is formed as components of the compression ratios of both pistons. In one embodiment, differential gearing is coupled to the two crankshafts for changing the relative rotational phase relation between them; while in the second embodiment, sprocket wheels on the crankshafts are joined together by an endless chain. The lengths of the chain at the drive side and the slack side are adjusted by moving idler sprockets or shoes to thereby change the relative rotational phase relation between the two crankshafts. A servo control system responsive to the output of a supercharger is used to effect phase changes between the two crankshafts.

Dependencies are inferred from the claim text.