| 摘要 |
PROBLEM TO BE SOLVED: To supply sealing fluid widely to a peripheral wall surface which moves relatively axially, and maintain good lubricating condition, by forming a recessed groove twisted against the axial direction which communicates a sealing fluid side with a opposite sealing fluid side on a sliding surface of a backup ring which restrains transformation of an annular seal member. SOLUTION: A sealing device 1 which is installed into an annular groove Ha of a housing H has a rubber ring 2 made of rubber-shaped elastic material, and a backup ring 3 which is placed on the atmospheric side O of the inner surface of the rubber ring 2. A recessed groove 3b spirally twisted against the axial direction so as to communicate a sealing fluid side M with the atmospheric side O is placed on a sliding surface 3a of backup ring 3 and a peripheral wall surface Sa of a shafts. Sealing fluid which enters into a gap 4 between a lip 2a and the backup ring 3 when the shaft S is stroked can be supplied to a wide region through a recessed groove 3b, and lubricating condition between the peripheral wall surface Sa and the sliding surface 3a of the backup ring 3 is maintained good. |
