Rotary seal assembly comprising a first machine part and comprising a second machine part which is rotatable relative to the first machine part about an axis of rotation, wherein one of the two machine parts (12, 14) has a seal holding structure and the other of the two machine parts (12, 14) has a sealing surface, and comprising a rotary seal which is arranged on the seal holding structure of the one machine part (12, 14) in order to seal off a high pressure region H from a low pressure region N of the rotary seal assembly, comprising: - a mounting sleeve made of a rubber-elastic material; - at least one rotary seal element (38, 38') which can be activated by pressure and has a sealing edge which is arranged in or on the mounting sleeve and extends away from the mounting sleeve in the direction of the sealing surface; - a support body which abuts a support region (52, 52') of the rubber-elastically deformable mounting sleeve on the low pressure region side and against which the rotary seal element is directly supported on the low pressure region side such that, in a non-pressurized operating state, the sealing edge is arranged in a rest position in which the sealing edge is arranged spaced apart from the sealing surface or abuts the sealing surface without a contact surface pressure or substantially without a contact surface pressure, wherein, - when a predetermined differential pressure value P Diff between the high pressure region H and the low pressure region N is exceeded, a movement of the support body is effected by means of the rotary seal element (38, 38') under elastic deformation of the support region (52, 52') in the direction of the low-pressure region N such that the sealing edge of the rotary seal element (38, 38') is sealingly pressed against the sealing surface and wherein, - when the differential pressure falls below the predetermined differential pressure value P Diff, an elastic recovery of the support region (52, 52') and therefore an accompanying movement back of the support body in the direction of the high pressure region H is effected such that the sealing edge of the rotary seal element (38, 38') is moved back out of the sealing abutment of said edge against the sealing surface into the rest position thereof. - a mounting sleeve made of a rubber-elastic material; - at least one rotary seal element (38, 38') which can be activated by pressure and has a sealing edge which is arranged in or on the mounting sleeve and extends away from the mounting sleeve in the direction of the sealing surface; - a support body which abuts a support region (52, 52') of the rubber-elastically deformable mounting sleeve on the low pressure region side and against which the rotary seal element is directly supported on the low pressure region side such that, in a non-pressurized operating state, the sealing edge is arranged in a rest position in which the sealing edge is arranged spaced apart from the sealing surface or abuts the sealing surface without a contact surface pressure or substantially without a contact surface pressure, wherein, - when a predetermined differential pressure value P Diff between the high pressure region H and the low pressure region N is exceeded, a movement of the support body is effected by means of the rotary seal element (38, 38') under elastic deformation of the support region (52, 52') in the direction of the low-pressure region N such that the sealing edge of the rotary seal element (38, 38') is sealingly pressed against the sealing surface and wherein, - when the differential pressure falls below the predetermined differential pressure value P Diff, an elastic recovery of the support region (52, 52') and therefore an accompanying movement back of the support body in the direction of the high pressure region H is effected such that the sealing edge of the rotary seal element (38, 38') is moved back out of the sealing abutment of said edge against the sealing surface into the rest position thereof.