Patent ID: 6874458

Claim:
A balance system comprising: a crankshaft including a first crankshaft portion, a first crank arm portion, a crank pin portion, and a first eccentric portion, wherein the crank pin portion is coupled to the first crankshaft portion by the first crank arm portion, and is further configured to be coupled to a piston by a connecting rod; a counterbalance assembly having a first counterbalancing mass portion and a first coupling arm portion that are fixed with respect to one another, and a pin that protrudes from a side of the first counterbalancing mass portion, wherein the first coupling arm portion includes a first circular orifice by which the counterbalance assembly is supported by the first eccentric portion; and a groove that is capable of receiving the pin, wherein the pin is capable of moving longitudinally in relation to the groove and also rotating within the groove, so that the counterbalance assembly is capable of rotating while moving toward and away from the crankshaft.