Patent ID: 8573085

Claim:
A power unit for a vehicle, said power unit comprising: a crankcase; a crankshaft disposed in the crankcase; a first main shaft, a second main shaft and a single countershaft that are rotatably supported by said crankcase with their axes being parallel to each other; a plurality of multispeed gears that are selectively established and provided among the first main shaft, the second main shaft and the countershaft; a primary reduction gear mechanism; a single driving gear that makes up a part of said primary reduction gear used to transmit rotary power from the crankshaft to the first and second main shafts, said single driving gear being provided on the crankshaft; and first and second clutches that are operable to selectively transmit or interrupt a transfer of rotary power from the primary reduction gear mechanism to the first and second main shafts, said first and second clutches disposed at ends of the first and second main shafts, respectively, wherein the primary reduction gear mechanism comprises: the driving gear; a first driven gear that is supported by the first main shaft for relative rotation therewith at a position adjacent to the first clutch, and that meshes with the single driving gear; an intermediate driving gear arranged to rotate with the first driven gear; an idle gear that meshes with the intermediate driving gear and that is supported by the countershaft for relative rotation therewith; and a second driven gear that is supported by the second main shaft for relative rotation therewith, and that meshes with the idle gear, wherein the first clutch is provided between the first driven gear and first main shaft, and wherein the second clutch is provided between the second driven gear and the second main shaft.