both way power transmission apparatus of chainless type bicycle

摘要

PURPOSE: A bi-directional power train apparatus of a bicycle without chain is provided to relieve fatigue by moving forward in pedaling reversely, and to improve power transmission efficiency by reducing waste of driving force. CONSTITUTION: A power train device of a bicycle is composed of a pedal shaft(52) connected to a pedal to transmit rotational force of the pedal; a first bevel gear set(60) installed in the pedal to transmit rotational force of the pedal shaft; a driving shaft interlocking with the first bevel gear, and transmitting rotational force of the first bevel gear set to a rear wheel; a second bevel gear set installed in the rear wheel to transmit rotational force of the driving shaft; and a rear wheel shaft(56) transmitting rotational force from the second bevel gear set to the rear wheel. A first driving gear(62a) is installed in the pedal shaft with facing a second driving gear(62b), and a unidirectional power train unit is installed in first and second driving gears to transmit forward and reverse rotational force to the rear wheel. Fatigue is reduced, and power transmission efficiency is increased.