A compressor including a housing, a rotary shaft extending through the housing, and a sealing device arranged about the rotary shaft to seal the housing. A shaft bore extends through the housing for insertion of the rotary shaft. An elastomer lip ring seals the housing in cooperation with the rotary shaft, while contacting the peripheral surface of the rotary shaft in a slidable manner. A pressure resistant reinforcement arranged in the shaft includes a backup ring, which is arranged between the elastomer lip ring and the rotary shaft, and a stopper, which is fixed in the shaft bore. The backup ring contacts the elastomer lip ring. The stopper restricts movement of the backup ring in the axial direction relative to the rotary shaft and enables movement of the backup ring in a radial direction relative to the rotary shaft.