| 摘要 |
PROBLEM TO BE SOLVED: To provide a simple and compact configuration and improve assembling ability by equipping the hub shaft of a wheel with a drive part with a built-in electric motor, a built-in transmission mechanism for transmitting the rotation of the electric motor to the wheel and a built-in transmission, and arranging the transmission and the transmission mechanism in order along a direction from the wheel shaft toward the external surface thereof. SOLUTION: In a motor-driven bicycle, human power applied via a pedal 5 is transmitted to a rear sprocket 27 with a chain 17 and shifted with a transmission 24. Then, the power is transmitted to a reduction mechanism 45 via a turning plate 34 and a spring 37, thereby rotating a rear wheel. In this case, when a control part outputs a drive signal, based on signals from a torque detection means and a speed sensor, the speed of an electric motor 48 is reduced through the second reduction mechanism 67 to rotate the rear wheel. At this time, the transmission 24, the reduction mechanism 45 and the second reduction mechanism are arranged in order along a direction from a wheel shaft toward the external surface thereof. According to this construction, a drive part is made compact and the use of many gears is ensured. |
