One-way overrunning belt pulley of power generator of automobile

The invention relates to a one-way overrunning belt pulley of a power generator of an automobile. The one-way overrunning belt pulley comprises a belt pulley shell (1), a mandrel (2), a one-way combination bearing (3), a deep groove ball bearing (4), a sealing end cover (5), a sealing ring (6) and a dust cover (7), and is characterized in that an outer ring of the one-way combination bearing (3) is in interference fit with the belt pulley shell, an inner ring (3-2) of the one-way combination bearing (3) is in close fit with the outer periphery of the mandrel (2), one end of the mandrel (2) is in close fit with the deep groove ball bearing (4), two ends of the mandrel (2) are respectively riveted and sealed by the sealing end cover (5) and the sealing ring (6), and the dust cover (7) is arranged at one end of the belt pulley shell. The one-way overrunning belt pulley has the advantages that the single one-way combination bearing and the single deep groove ball bearing are used as a one-way mechanism and a supp