Internal combustion engine

An internal combustion engine comprising:

• an engine block having a compression cylinder, an expansion cylinder, a combustion chamber, and means providing fluid communication among the combustion chamber, the compression cylinder, and the expansion cylinder;
• compression piston means for ingesting and compressing a gas, axially moveable in the compression cylinder;
• expansion piston means for expanding and exhausting combustion products, axially moveable in the expansion cylinder;
• rotary valve means for regulating gas ingestion, gas transfer to and from the combustion chamber, and gas exhaust, defining at least a partial closure for the compression cylinder and the expansion cylinder, and operable to selectively control the fluid communication means, wherein the rotary valve means includes
• a rotationally symmetric inlet valve defining an end closure of the compression cylinder, and having an inlet port therein,
• a first transfer valve including a first valve disc with a first transfer port operably positioned with respect to the fluid communication means to control flow from the compression cylinder to the combustion chamber,
• a second transfer valve including a second valve disc with a second transfer port operably positioned with respect to the fluid communication means to control flow from the combustion chamber to the expansion cylinder, and
• a rotationally symmetric exhaust valve defining an end closure of the expansion cylinder, and having an exhaust port therein;
• means for supplying fuel to the gas compressed by compression piston means to create a combustible mixture;
• means for igniting the combustible mixture;
• and
• means for synchronizing movement of the compression piston means, the expansion piston means and the rotary valve means.