Installation structure of lip type seal

摘要

A lip type seal (3A) has an annular casing (31), a plurality of seal lips (32, 34) and a rear surface support ring (35) arranged at the rear side. The casing (31) is installed to an inner circumferential surface of a seal installation part (1a) of a shaft hole housing (1) of an equipment through a main gasket (36) made of rubber state elastic material. An inner circumferential part of the seal lips (32, 34) is closely contacted with an outer circumferential surface of a rotary shaft (2). A sub-gasket (41) made of a material having a CO2 transmission coefficient being smaller than that of rubber material is interposed between the rear surface support ring (35) and the shaft hole housing (1).