HEATER FOR SLIDING SEAL STRUCTURE

摘要

Canada F-2811(BBC) HEATER FOR SLIDING SEAL STRUCTURE A seal assembly for sealing the opening between the outer periphery of a movable shaft and an opening in the wall of a housing which permits entry of the movable shaft into the interior of the housing. The housing is filled with a fluid under positive pressure and the seal assembly includes a pliable annular seal which surrounds the shaft and slidably engages the outer surface of the shaft to permit relative movement between the pliable annular seal and the shaft. A heat conductive ring supports the pliable annular seal and presses the seal against the housing and fixes the seal against the interior of the opening in the housing. An electrically energizable heater is connected to the heat conductive ring at a location sically removed from the pliable annular seal and in thermal conduction relation with respect to the seal for heating the seal to prevent the seal from leaking under low temperature conditions which would make the seal ineffective in the absence of the thermal energy applied to the seal by the heater. A second seal ring is disposed on the heat conductive ring and concentric with the opening in said housing. The second seal ring is a static compressed seal and is heated by heat produced by the heater and conducted thereto by the heat conductive ring. The annular seal and the second seal ring are coaxial with one another and each is disposed in a common plane.