Rotary feed-through with - a rotatably mounted machine part and a machine part that forms a bearing for the rotatably mounted machine part, wherein a first of the machine parts forms a seal-accommodating structure, and the second of the machine parts has a surface forming a sealing surface, and - at least one rotary seal arranged in the seal-accommodating structure, for sealing off a high-pressure area, configured as a rotary feed-through area, from a low-pressure area between the machine parts (2,3), wherein, through the rotary feed-through area, a fluid that is under a positive pressure relative to the low-pressure area can be introduced from one of the machine parts (2,3) through the sealing surface into the other of the machine parts (2,3), wherein the rotary seal has - a support element that is essentially rigid and positionally stable with respect to the first machine part, - a rubber-elastically deformable contact body in contact with the support element on the high-pressure area side, and - a sealing ring made from PTFE and preferably loosely in contact with the contact body and having a sealing edge, wherein the sealing ring has a wide side on each side of the sealing edge and a seal seat edge area facing away from a sealing edge and the wide sides are interconnected via the seal seat edge area, wherein the contact body is at least partially disposed between at least one of the wide sides of the sealing ring and the support element and wherein the support element extends, at least in a supporting area, obliquely with respect to the axial direction of the rotatably mounted machine part and the contact body is shaped in such a manner that, in the supporting area, the sealing ring is pressed away from the sealing surface by the contact body, such that, in the event of a pressure lying below a threshold pressure, the sealing edge of the sealing ring seats in the rotary feed-through area without exerting a pressing load on the sealing surface or such that the sealing edge is separated from the sealing surface and, in the event of a pressure exceeding the threshold pressure, the sealing ring with the sealing edge are pressed, in opposition to internal elastic forces of the contact body, towards the sealing surface and the sealing edge seats in a sealing manner thereon. - a rotatably mounted machine part and a machine part that forms a bearing for the rotatably mounted machine part, wherein a first of the machine parts forms a seal-accommodating structure, and the second of the machine parts has a surface forming a sealing surface, and - at least one rotary seal arranged in the seal-accommodating structure, for sealing off a high-pressure area, configured as a rotary feed-through area, from a low-pressure area between the machine parts (2,3), wherein, through the rotary feed-through area, a fluid that is under a positive pressure relative to the low-pressure area can be introduced from one of the machine parts (2,3) through the sealing surface into the other of the machine parts (2,3), wherein the rotary seal has - a support element that is essentially rigid and positionally stable with respect to the first machine part, - a rubber-elastically deformable contact body in contact with the support element on the high-pressure area side, and - a sealing ring made from PTFE and preferably loosely in contact with the contact body and having a sealing edge, wherein the sealing ring has a wide side on each side of the sealing edge and a seal seat edge area facing away from a sealing edge and the wide sides are interconnected via the seal seat edge area, wherein the contact body is at least partially disposed between at least one of the wide sides of the sealing ring and the support element and wherein the support element extends, at least in a supporting area, obliquely with respect to the axial direction of the rotatably mounted machine part and the contact body is shaped in such a manner that, in the supporting area, the sealing ring is pressed away from the sealing surface by the contact body, such that, in the event of a pressure lying below a threshold pressure, the sealing edge of the sealing ring seats in the rotary feed-through area without exerting a pressing load on the sealing surface or such that the sealing edge is separated from the sealing surface and, in the event of a pressure exceeding the threshold pressure, the sealing ring with the sealing edge are pressed, in opposition to internal elastic forces of the contact body, towards the sealing surface and the sealing edge seats in a sealing manner thereon.