| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power-assisted bicycle in which a device is made compact in a structure including a reduction gear, an electric motor, and a transmission mechanism arranged in parallel along an axle. <P>SOLUTION: In a rear hub, a transmission mechanism 11, a deceleration mechanism 10 and a driving motor 8 are arranged in parallel in the shaft direction of the axle 14. The transmission mechanism 11 includes a sun gear 11a for transmission, a planetary gear 11b for transmission and a planetary carrier 11c for transmission, and transmits pedalling force to driving wheels. The deceleration mechanism 10 includes a sun gear 10a for deceleration and a planetary gear 10b for deceleration, and transmits driving force from the motor output shaft 8a of the driving motor 8 to the driving wheels. The transmission control mechanism 15 performs gear shift by switching the sun gear 11a for transmission so as to be rotatable or non-rotatable around an axle 14 via a clutch member 16a disposed between the transmission sun gear 11a for transmission and the axle 14. The planetary carrier 11c for transmission and the motor output shaft 8a are rotatably supported by a bearing 25. <P>COPYRIGHT: (C)2012,JPO&INPIT |
