CIRCULAR SEAL WITH INTEGRAL BACKUP RINGS

摘要

A circular seal configuration is shown for sealing the annular clearance between an inner cylindrical member and an outer cylindrical member. A center portion of the seal is made of a compliant elastomer material and is adapted to seal both against the internal diameter of the outer cylindrical member and against the external diameter of the inner cylindrical member. A pair of external backup rings circumscribe the exterior surface of the elastomeric center portion and a pair of internal backup rings circumscribe the interior surface of the elastomeric center portion. The backup rings are of a relatively stiff material but expand independently upon the application of pressure to the elastomeric portion of the seal to provide a zero clearance fit with respect to the surrounding sealing surfaces and prevent extrusion of the elastomer which would cause a seal failure.