| 摘要 |
PURPOSE: A power transmission device powered by labor force is provided to enable a user to easily and stably pedal using the small amount of power, and to reduce manufacturing costs by simplifying the structure of the device. CONSTITUTION: A power transmission device powered by labor force comprises a frame(10), a crank gear shaft(21), a crank gear(23), a crank assembly(20), a crank driven gear(35), a crank sprocket(33), a drive sprocket(37), and a driving unit(30). The frame has a crank gear shaft joint. The crank gear shaft is rotatably coupled to the crank gear shaft joint. The crank assembly has a pair of pedals which rotate a crank gear. The crank driven gear is rotated with the crank gear. The crank sprocket is rotated with the crank driven gear. |
