| 摘要 |
The invention provides a motor-driven assist unit capable of conforming the rotational direction of a crank shaft to that of an output shaft with an inexpensive structure and also of accurately detecting a leg-power inputted to the crank shaft. A motor-driven assist unit contains an electric motor for generating an assist-power in response to a leg-power inputted to a crank shaft, wherein the assist-power and the leg-power are synthesized and a resultant power is transmitted to a drive wheel. The motor-driven assist unit is characterized by including a large-diameter gear 111 provided on a crank shaft 101; an output shaft 105 connected to the drive wheel; an idle shaft 102 disposed between the crank shaft 101 and the output shaft 105 in such a manner as to be in parallel thereto, the idle shaft 102 including a small-diameter gear 113 meshed with the large-diameter gear 111 of the crank shaft 101 and a second gear 102d meshed with the output shaft 105; and a leg-power detecting mechanism (102a, 102b, 102c, etc.), provided on the idle shaft 102, for detecting a leg-power inputted to the crank shaft 101. <IMAGE> |
