| 摘要 |
A travelling driving device for a bicycle capable of increasing rotational torque of a chain wheel (6) using pedalling cranks without elongating a crank arm is disclosed. This device is borne by a bearing (2) disposed on a frame (1) of the bicycle and has an eccentric plate (5) put on a rotating shaft (3) having cranks (4) with pedal (4a). This eccentric plate (5) is secured to a frame member (1) of the bicycle through a stay portion (8). The chain wheel (6) is put rotatably on the outer periphery of the eccentric plate (5) through a ball bearing and a working plate (9) secured to the rotating shaft (3) is linked to the chain wheel (6) by linking members (10, 11). When the rotating shaft (3) is rotated by pedalling action of the cranks (4), rotation is transmitted to the chain wheel (6) through the working plate (9) and the linking members (10, 11). Since the chain wheel (6) is rotated in an eccentric state with respect to the rotating shaft (3), it can be rotated with a rotation radius smaller than a chain wheel having no eccentric mechanism and as the result, rotational torque of the chain wheel (6) is increased, depending on eccentricity length. <IMAGE> |
