POWER TRANSMISSION DEVICE OF BICYCLE, WHICH IS CAPABLE OF INSTALLING SPEED CHANGE DRIVE PART AND SPEED CHANGE SLAVE SHAFT PART INSTEAD OF CHAIN

摘要

PURPOSE: A power transmission device of a bicycle is provided to easily run the bicycle with small pedal effort by installing a speed change drive part and a speed change slave shaft part instead of a chain. CONSTITUTION: A power transmission device(2) of a bicycle comprises a speed change drive part(4) and a speed change slave shaft part. The speed change drive part transmits power to a rear wheel through a crown sprocket gear(18) while changing the rotating force produced by pedal effort given a pedal shaft(10) with a sun gear, in operating a main speed change part(14) by a speed change lever(16) comprising a planetary gear part. The speed change slave shaft part is connected to a slave shaft(62) to transmit the speed change-rotating force increased through a rear roller gear part(60) by secondarily varying an auxiliary speed change part(58), to a hub crown sprocket gear of a rear wheel hub shaft through a front roller gear part(52) from the speed change drive part.