MULTI-STAGE TRANSMISSION

摘要

A multi-stage transmission having more stages using planetary gear sets and employing a forced return means for achieving smooth shifting in a forward operation by acceleration manipulation and a reverse operation by deceleration manipulation is provided. The multi-stage transmission includes a shaft with both ends fixed, a sprocket for receiving a rotational force and a hub shell for outputting the rotational force; a shifting unit comprising one-way clutches and planetary gear sets, each of planetary gear sets being composed of a sun gear, planetary gears, a carrier and a ring gear provided within the hub shell to change the rotational force input through the sprocket and to output the changed rotational force to the hub shell; and a control unit for controlling shifting by controlling pawls provided on the shaft according to manipulation of a shift lever to selectively restrict rotation of the sun gear.

主权项

1. A multi-stage transmission comprising:
a shaft (100) with both ends fixed, and a sprocket (200) for receiving a rotational force and a hub shell (300) for outputting the rotational force, the sprocket (200) and the hub shell (300) being rotatably located on an outer periphery of the shaft (100); a shifting unit (400) comprising one-way clutches and planetary gear sets, each of planetary gear sets being composed of a sun gear, planetary gears, a carrier and a ring gear provided within the hub shell (300) to change the rotational force input through the sprocket (200) and to output the changed rotational force to the hub shell (300); and a control unit (500) for controlling shifting by controlling pawls provided on the shaft (100) according to manipulation of a shift lever to selectively restrict rotation of the sun gear, wherein the manipulation for rotating the shift lever generates a displacement of a drive pawl clutch (620) in an axial direction of the shaft (100), so that the rotational force is selectively transferred with intervention of drive pawls (630) between a rotatable driver (610) and the non-rotatable drive pawl clutch (620), thereby achieving the shifting.