SHAFT SEALING STRUCTURE BY LIP-TYPE SEAL

PROBLEM TO BE SOLVED: To provide a shaft sealing structure by a lip type seal capable of preventing the permeation and leakage of the fluid of a small molecular diameter in a sealed space to a non-sealed space. SOLUTION: This lip type seal is provided with a first seal member 15 having a seal lip part 15d and a first backup ring 16 for controlling the deformation of the first seal member 15 on an inner periphery of a cylindrical case 14 fixed to an opening part 23 of a housing 11, successively from a sealed space A side, and an inner diameter edge 15c of the seal lip part 15d is slidably kept into contact with an outer peripheral face of a rotating shaft 12 to prevent the leakage of the fluid in the sealed space A to the non-sealed space B along the rotating shaft 12. A permeation preventing film 22 is mounted on a face at the sealed space A side, of the first seal member 15 to prevent the permeation of the fluid. COPYRIGHT: (C)2005,JPO&NCIPI