Pressure-activatable rotary seal and rotary seal assembly

A rotary seal assembly, comprising:

• a first machine part and a second machine part rotatable about an axis of rotation relative to the first machine part, wherein one of the two machine parts comprises a seal retaining structure, and the other of the two machine parts comprises a sealing surface, and having a rotary seal arranged on the seal retaining structure of one machine part in order to seal a high-pressure region H from a low-pressure region N of the rotary seal assembly;
• an installation sleeve made of a rubber-elastic material;
• at least one pressure-activatable rotary seal element, which has a sealing edge, is arranged in or on the installation sleeve and extends away from the installation sleeve towards the sealing surface;
• a support body, which rests, on the low-pressure-region side, against a support region of the rubber-elastically deformable installation sleeve and on which the rotary seal element is directly supported on the low-pressure-region side such that the sealing edge is arranged, in a non-pressurized operating state, in an inactive position in which the sealing edge is spaced apart from the sealing surface or rests against the sealing surface without contact surface pressure or substantially without contact surface pressure;
• wherein when a specified differential pressure value PDiff between the high-pressure region H and the low-pressure region N is exceeded, the rotary seal element causes the support body to move towards the low-pressure region N, the support region thereby elastically deforming, such that the sealing edge of the rotary seal element is sealingly pressed against the sealing surface;
• and
• wherein when the specified differential pressure value PDiff is fallen below, the support region elastically recovers its shape, the support body thereby moving back towards the high-pressure region H such that the sealing edge of the rotary seal element moves out of the sealingly resting position of said sealing edge against the sealing surface, back into the inactive position of said sealing edge.