Locking system for a rotating joint

A locking system for a rotating joint, the rotating joint comprising a bearing to be connected between a first frame part and a second frame part in a working machine, to rotate the frame parts with respect to each other around an axial direction, and the locking system being arranged for locking and releasing the rotational motion between the frame parts, wherein the locking system comprises a rigid locking means arranged to be movable in the axial direction and being equipped with:

• a first cogging which can be transferred, for locking of the rotational motion, with the locking means to a first contact with a second cogging to transfer the rotational motion, the second cogging being arranged to rotate with the first frame part, wherein said coggings are, for releasing the locking of the rotational motion, designed in such a way that a force effect releasing the first contact is formed therebetween,
• a third cogging which is, at least during locking of the rotational motion, arranged in a second contact with a fourth cogging to transfer the rotational motion, the fourth cogging being arranged to rotate with the second frame part, wherein said third and fourth coggings are arranged to rotate the locking means with the second frame part around the axial direction, and
• a sealing element which is arranged to form at least one closed hydraulic space between the locking means and the sealing element, having a volume varying upon the movement of the locking means, wherein a pressurized medium can be conveyed into and from the hydraulic space, wherein the locking means is arranged to be, by the effect of the pressurized medium, transferred to a locking state and to be maintained in the locking state.