Patent ID: 8794200

Claim:
An engine assembly comprising: an engine block defining a cylinder; a crankshaft having a first axis of rotation and a crankpin offset from the first axis of rotation; a second shaft offset from the crankshaft and having a second axis of rotation and an eccentric portion offset from the second axis of rotation; a piston operatively connected to the crankshaft and movable in the cylinder to drive the crankshaft; wherein the piston is pivotably connected to the connecting rod to pivot at a pivot axis; and wherein the cylinder is configured so that the pivot axis is aligned with the first axis of rotation along a center axis of the cylinder; a connecting rod extending from the piston; a four jointed linkage assembly pivotably connected to the connecting rod, the crankpin, and the eccentric portion; a drive system operatively connecting the crankshaft and the second shaft to drive the second shaft via the crankshaft; and a phasing mechanism operatively connected to the second shaft and controllable to vary the rotational position of the second shaft relative to the crankshaft to thereby vary the operation of the piston within the cylinder between an Otto cycle and an Atkinson cycle.