To provide a low-cost transmission mechanism for a bicycle, which enables smooth transmission with less resistance during transmission operation.SOLUTION: A follower-side rotary body 3 is rotatably and integrally mounted on a rear wheel of a bicycle 10. The rotary body 3 comprises a drive transmission unit 8 composed of annular non-eccentric transmission parts 5 and eccentric transmission parts 6, and an endless belt 2 is wound around the drive transmission unit 8. On the endless belt 2, multiple engagement claws 2a projecting inwards from the endless belt 2 are formed at equal intervals in a revolving direction. The plurality of non-eccentric transmission parts 5 and the plurality of eccentric transmission parts 6 are disposed one alternate the other along a rotation axis C1. Engagement recesses 3a respectively engageable with the engagement claws 2a are formed at equal intervals in a circumferential direction of an outer peripheral surface. In the non-eccentric transmission parts 5, a center axis 5a thereof coincides with the rotation axis C1. In the eccentric transmission parts 6, a center axis 6a thereof is deviated from the rotation axis C1 such that one of the engagement recesses 3a thereof matches one of the respective engagement recesses 3a of the non-eccentric transmission parts 5 adjacent to a side close to the rear wheel.SELECTED DRAWING: Figure 1
【課題】変速作動時における抵抗が少なくなってスムーズに変速を行うことができる低コストな自転車用変速機構を提供する。【解決手段】自転車10の後輪に従動側回転体3が回転一体に取り付けられる。回転体3は、環状の非偏心伝達部5及び偏心伝達部6からなる駆動伝達部8を備え、駆動伝達部8には、無端状ベルト2が巻き掛けられる。無端状ベルト2には、無端状ベルト2の内方に突出する多数の係合爪2aが周回方向に等間隔に形成される。非偏心伝達部5及び偏心伝達部6は、回転軸心C1に沿って交互に複数配設され、それぞれ係合爪2aに係合可能な係合凹部3aが外周面の周方向に等間隔に形成される。非偏心伝達部5は、中心軸5aが回転軸心C1に一致している。偏心伝達部6は、その各係合凹部3aのうちの1つが後輪に近い側に隣り合う非偏心伝達部5の各係合凹部3aのうちの1つと一致するように中心軸6aが回転軸心C1から偏心している。【選択図】図1
TRANSMISSION MECHANISM FOR BICYCLE
自転車用変速機構
2020-09-03
Patent
Elektronische Ressource
Japanisch
IPC: | B62M RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES , Antrieb von Radfahrzeugen oder Schlitten durch den Fahrer |