Patent ID: 7533639

Claim:
A dual crankshaft internal combustion engine for a vehicle comprising: a cylinder block; a first series of cooperating pistons and cylinders mounted in the cylinder block; a second series of cooperating pistons and cylinders mounted in the cylinder block; a first crankshaft having a first end, a second end, a torsional flexibility and a shape, the first crankshaft being housed within the cylinder block and connected to the first series of cooperating pistons and cylinders, such that movement of the pistons of the first series within the cylinders of the first series causes the first crankshaft to rotate; a second crankshaft having a first end, a second end, a torsional flexibility and a shape substantially identical to the shape of the first crankshaft, the second crankshaft being housed within the cylinder block, connected to the second series of cooperating pistons and cylinders and positioned parallel to the first crankshaft, with the first end of the first crankshaft being positioned adjacent to the second end of the second crankshaft; a first gearset mounted in the internal combustion engine and connecting the first end of the first crankshaft to the second end of the second crankshaft; a second gearset mounted in the internal combustion engine and connecting the second end of the first crankshaft to the first end of the second crankshaft; a first mass having an inertia connected to the first end of the first crankshaft; a second mass having substantially the same inertia as the first mass connected to the first end of the second crankshaft; whereby the first and second crankshafts counter rotate and various forces and moments produced by the pistons and rotating crankshafts are balanced.