Single-Ended Barrel Engine with Double-Ended, Double Roller Pistons: 6,834,636

An internal combustion barrel engine includes an engine housing with a first and second end. An elongated power shaft is longitudinally disposed in the engine housing and defines a longitudinal axis. A combustion cylinder and a guide cylinder are spaced apart and disposed on a common cylinder axis that is generally parallel to the central axis. The cylinders each have an inner end and an outer end, with the inner ends being closer to each other. The outer end of the combustion cylinder is closed. An intake system is operable to introduce a mixture of air and/or fuel into the combustion cylinder. A track is supported between the inner ends of the cylinders and has an undulating cam surface. The track is moveable such that the portion of the cam surface most directly between the cylinders undulates toward and away from the inner end of the combustion cylinder. A double-ended piston includes a combustion end disposed in the combustion cylinder so as to define a combustion chamber between the combustion end and the closed end of the combustion cylinder. A guide end is disposed in the guide cylinder. A midportion extends between the combustion end and the guide end and is in mechanical communication with the guide surface of the track. A variable compression ratio device is operable to move the track axially towards and away from the inner end of the combustion cylinder so as to adjust the compression ratio. Combustion occurs only in the combustion cylinder and does not occur in the guide cylinder.