Patent ID: 8136498

Claim:
An engine, comprising: a crankshaft including a crankshaft body and a first gear mounted on the crankshaft body, wherein the crankshaft includes first, second, third, and fourth crank web pairs each having a pair of crank webs and sequentially disposed from one axial end side of the crankshaft to the other axial end side thereof, a first crank pin interconnecting the pair of crank webs of the first crank web pair, a second crank pin interconnecting the pair of crank webs of the second crank web pair and different in phase by about 90 degrees from the first crank pin, a third crank pin interconnecting the pair of crank webs of the third crank web pair and different in phase by about 180 degrees from the second crank pin, and a fourth crank pin interconnecting the pair of crank webs of the fourth crank web pair and different in phase by about 180 degrees from the first crank pin; and a balancer shaft for reducing a primary couple of the crankshaft, the balancer shaft including a second gear engaged with the first gear, wherein the first gear is disposed at one axial end side of the first crank web pair.