A drive of mounting a rotating implement to a crane arm or similar, comprises a rotator located between the crane arm and the unit that at one end is pivot-mounted to the implement for rotating the same relative to the crane arm and slewing around a first pivot axis and at the other end is mounted to the crane arm via a hinged link for slewing around a second pivot axis, a swivel coupling arranged on the rotator for supplying the working chambers of a drive for the rotator and any other consumers included in the unit with a hydraulic medium and that to one end of the swivel coupling is arranged connecting unions, to which hydraulic medium lines leading from the crane arm are attached. For the flexible hydraulic lines between the crane and implement to be both well protected and cannot swing to and fro in an uncontrolled manner during the operational movement of the implement and/or crane arm, the hinged link between the crane arm and the rotator is designed as an open joint defined by two hinged points located at a distance from each other along the joint axis of pivot axis, that the connecting unions are arranged extending parallel to the first pivot axis and facing towards the second pivot axis, whereby the hydraulic medium lines connected to the connecting unions pass between the hinged points situated a distance from each other.