Patent ID: 7546819

Claim:
An internal combustion engine, comprising: a frame including two bulkheads and beams attached to the bulkheads; at least one cylinder disposed between the bulkheads; a pair of opposed pistons in the at least one cylinder; each bulkhead including an I-beam section; a pair of side-mounted crankshafts supported by the I-beam sections for rotation; a plurality of rods linking each piston to both crankshafts and adapted to move in response to primarily tensile forces acting between the pistons and the crankshafts; the engine characterized by an engine cycle in which each piston is substantially withdrawn from the cylinder and then driven back into the cylinder; and a system to apply a liquid coolant to the external surface of each piston that is withdrawn from the at least one cylinder; wherein the crankshafts are adapted to rotate in opposite directions, the engine further including: a first gear on the first crankshaft; a second gear on the second crankshaft; and, a third gear supported on the frame, the third gear having an annulus with an outside circumference engaging the first gear at a first location and an inside circumference engaging the second gear at a second location opposite the first location.