A rotary transmission device for transmitting control and/or working pressures to a wheel hub. The rotary transmission device has a housing structure in which a piston element is displaceable between a first and a second position relative to the housing structure and relative to a running body of the wheel hub which is mounted so as to rotate relative to the housing structure. To transmit the control and/or working pressures, at least one pressure medium channel is formed in the piston element. In the first position, an air gap is present between an end face of the piston element on the running body side and an end face of the running body on the piston element side, while in the second position, no air gap is present, and the at least one pressure medium channel opens in sealed fashion into at least one pressure medium channel formed in the running body.