Patent ID: 11904981
Assignee: SUN RACE STURMEY-ARCHER INC.
Field: Transport (Mechanical engineering)
Classification: CPC B  F | IPC B  F

Claim 0:
1. A bicycle gear hub, comprising:
an axle;
at least two planetary gear modules, sequentially disposed at the axle, the at least two planetary gear modules being connected in series, each of the at least two planetary gear modules including a planet carrier, a ring gear and a sun gear, the planet carrier being furnished thereinside with the sun gear, the ring gear being meshed with a planet gear in the planet carrier;
at least two one-way clutches, connected correspondingly the planet carrier and the ring gear;
a shift mechanism, including a shift actuator and at least two control pawls, the shift actuator being disposed at the axle, the at least two control pawls being movably disposed at different positions of the axle, each of the at least two control pawls including a control protrusion, the shift actuator including thereinside a plurality of recess portions corresponding to the control protrusions, the shift actuator rotating to provide a plurality of speed-up ratios according to a number of the at least two planetary gear modules, gearshift between a low gear and a high gear being performed according to the plurality of speed-up ratios, the plurality of recess portions being used to control opening and closing of the control protrusion of one of the at least two control pawls so as to control the sun gear corresponding to one of the at least two planetary gear modules to be fixed to the axle while in each the gearshift; wherein, when the high gear is shifted to the low gear, a rotational direction of the shift actuator is identical to a close direction of the corresponding one of the at least two control pawls; and
a transmission part, the shift actuator being connected between the transmission part and the at least two planetary gear modules; wherein, when the high gear is shifted to the low gear, sequentially from one of the at least two planetary gear modules the furthest to the transmission part to another one of the at least two planetary gear modules the closest to the transmission part, the plurality of recess portions are utilized to close the at least two control pawls corresponding to the at least two planetary gear modules so as to have the sun gear of the corresponding one of the at least two planetary gear modules not to be fixed to the axle; wherein, while in shifting to a next gear, only the control protrusion of one of the at least two control pawls is controlled to perform the opening and closing.