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 and a one-way clutch (8) disposed between the ring gear (2) and the crankshaft (4), including an inner ring (7) and an outer ring (84). The ring gear (2) comprises lubrication holes (224) adapted to allow lubricant to go from the internal combustion engine towards the one-way clutch (8), the torque transmission mechanism (A) comprising at least one sealing element (13) adapted to prevent lubricant from passing between an outer surface (848) of the outer ring (84) of the one-way clutch (8) and an inner surface (222) of the ring gear (2). The outer ring (84) of the one-way clutch (8) comprises a chamfered surface (852) inclined with respect to a central axis (X-X') of the torque transmission mechanism (A), the chamfered surface (852) diverging with respect to the central axis (X-X') of the torque transmission mechanism (A) from the lubrication holes (224) of the ring gear (2) towards the sealing element (13).