Torque transmission mechanism

This torque transmission mechanism (A) for an internal combustion engine, adapted to transmit a starting torque from a starter motor to a crankshaft (4) of the internal combustion engine, comprises a ring gear (2) that transmits the starting torque, a one-way clutch (8) disposed between the ring gear (2) and the crankshaft (4), including an outer ring (84) and an inner ring (7), a bearing (6) including an outer ring (7) fast in rotation with the gear ring (2) and an inner ring (62) fast in rotation with the crankshaft (4). The inner ring of the one-way clutch (8) and the outer ring of the bearing (6) are formed by a single tubular part (7).