SEAL FOR ROTATING SHAFT AND METHOD FOR MANUFACTURE THEREOF

摘要

A seal for a rotating shaft wherein a sealing element containing PTFE as a main component is housed in a metal case, characterized in that the sealing element is adhered to the metal case via a layer of a fluororesin having a hydroxyl group in its molecule so as to be integrated with the metal case; and a method for manufacturing the seal, wherein a laminate comprised of the sealing element, the metal case and, sandwiched between them, the fluororesin is subjected to heating and compression, and then the laminate is cooled under the application of a load. The seal has the sealing element fixed firmly to the metal case, and thus is extremely low in possibility of the occurrence of a critical path and highly reliable, without the use of a metal part or a rubbery elastomer specially made therefor and with a simple constitution. Further, the adhesion between a sealing element and a metal case has high durability also against the change of temperature, which results in the retention of good sealing performance capabilities against the temperature change in the circumstance for use. The manufacturing method, which is simple, allows the significant reduction of the time required for the manufacture relative to that in the case of a conventional seal of cramp type, does not need a heating operation for a long time which is required in the case wherein use is made of an epoxy resin based adhesive known as a heat-resistant adhesive usable also for a metal, and is free form complexities associated with the management of work conditions and facilities for application of an adhesive, which lead to the commercial production of a seal with good efficiency.