| 摘要 |
PURPOSE: A gearless transmission for a bicycle is provided to efficiently drive a bicycle on uphill and downhill roads by enabling the stable speed change of the bicycle through the width increase in a variable chain belt. CONSTITUTION: A gearless transmission for a bicycle comprises first and second pulleys (100, 200), a variable chain belt (300), and first and second belt width varying parts (400, 500). The first and second pulleys are fixed to a pedal shaft (P) and a rear wheel shaft (W), and first and second inclined belt grooves are formed thereon. The variable chain belt is fitted to the first and second inclined belt grooves to be rotated, and the rotation radius thereof in the first and second pulleys is changed to change the speed of a bicycle. The first and second belt width varying parts are formed on positions right before the first and second inclined belt grooves and increase and decrease the width of the variable chain belt. |
