Mechanical sealing structure for rotating shafts

Claim 1

IN A SEALING STRUCTURE, IN COMBINATION: A CASING HAVING A STATIONARY WALL MEMBER OF HARD SEAL-FACE MATERIAL TO PROVIDE A PLANAR ANNULAR SEAL FACE IN CONCENTRIC ENCIRCLING RELATION TO A ROTATABLE SHAFT ADAPTED TO EXTEND THROUGH SAID MEMBER, A SEAL ASSEMBLY ADAPTED FOR MOUNTING ON THE SHAFT AND INCLUDING A GRAPHITE RING MEMBER PROVIDING A PLANAR ANNULAR SEAL FACE IN CONCENTRIC ENCIRCLING RELATION TO THE SHAFT AND IN AXIAL ENGAGEMENT WITH THE SEAL FACE OF SAID WALL MEMBER, ONE OF SAID MEMBERS HAVING A CONCENTRIC ANNULAR RECESS OPENING AXIALLY THROUGH THE SEAL FACE THEREOF IN ENCIRCLING RELATION WITH AT LEAST A PART OF SAID LAST-MENTIONED SEAL FACE, AND A ONE-PIECE RING OF POLYTETRAFLUOROETHYLENE IN SAID RECESS IN AXIAL ENGAGEMENT BETWEEN SAID MEMBERS, TO PROVIDE PERMANENT LUBRICATION BETWEEN SAID SEAL FACES FOR ELIMINATING SQUEAKING SAID ONE MEMBER HAVING AN ANNULAR WALL BORDERING THE OUTER RADIAL PERIPHERY OF SAID RECESS TO CONFINE AND RESTRAIN SAID POLYTETRAFLUOROETHYLENE RING AGAINST RADIAL OUTWARD FLOW THEREOF.