Belt pulley decoupler

A belt pulley decoupler for transmitting drive torque from a belt of an auxiliary unit belt drive to a shaft of an auxiliary unit, the belt pulley decoupler comprising:

• a belt pulley,
• a hub adapted to be mounted on the shaft,
• a first sleeve rotationally locked in the belt pulley,
• a second sleeve that engages the first sleeve and is rotatable in the belt pulley, and
• a decoupler spring and a wrap-around band arranged between the belt pulley and the hub that carry a flow of drive torque from the belt pulley to the hub, the wrap-around band extends in a direction of a rotational axis of the belt pulley decoupler and is arranged radially between the first and second sleeves and the decoupler spring,
• the wrap-around band includes ends that are adapted to widen the wrap-around band radially during drive torque transmission, such that the first and second sleeves are coupled with each other in a rotationally locked manner,
• one of the two sleeves has a slot extending circumferentially and the wrap-around band end coupled with said one of the two sleeves is constructed as a leg that is engaged with a positive-locking connection in a rotationally locked manner in the slot in a direction of rotation of the drive torque.