Patent ID: 8147370
Filing Date: 2012-04-03
Classification: F16H,Y10T

Abstract:
1. A power unit for a motorcycle equipped with a continuously variable transmission including a drive pulley provided on a drive pulley shaft, to which a torque is transmitted from a crankshaft, a driven pulley provided on a driven pulley shaft with an axis that is parallel to the drive pulley shaft and a belt looped between the drive pulley and the driven pulley, the continuously variable transmission being housed in a transmission chamber within an engine body, and the continuously variable transmission changing steplessly the power transmitted from the drive pulley shaft to the driven pulley shaft by changing the effective diameter with which the belt actually wraps around each of the drive pulley and the driven pulley, the power unit comprising: an input clutch set between the crankshaft and the drive pulley shaft and being provided on the drive pulley shaft; and a starter clutch set between the driven pulley shaft and a rear wheel and being provided on the driven pulley shaft; wherein a switching between the engagement and disengagement of a first one of the input clutch and the starter clutch is hydraulically controlled, and a switching between the engagement and disengagement of a second one of the input clutch and the starter clutch is non-hydraulically controlled, wherein the continuously variable transmission includes a drive-side hydraulic drive mechanism and a driven-side hydraulic drive mechanism respectively annexed to the drive pulley and the driven pulley for changing a respective pulley groove width of the drive pulley and of the driven pulley, wherein the first one of the input clutch and the starter clutch is housed in the transmission chamber, wherein the first one of the input clutch and the starter clutch and a first one of the drive-side hydraulic drive mechanism and the driven-side hydraulic drive mechanism are disposed on a first one of the drive pulley shaft and the driven pulley shaft, wherein the second one of the input clutch and the starter clutch and a second one of the drive-side hydraulic drive mechanism and the driven-side hydraulic drive mechanism are disposed on a second one of the drive pulley shaft and the driven pulley shaft, wherein the drive-side hydraulic drive mechanism and the driven-side hydraulic drive mechanism are respectively located on opposites sides of the continuously variable transmission, and wherein the first one of the input clutch and the starter clutch and the second one of the drive-side hydraulic drive mechanism and the driven-side hydraulic drive mechanism are respectively located on the opposites sides of the continuously variable transmission.