| 摘要 |
PROBLEM TO BE SOLVED: To provide a structure capable of effectively preventing generation of cracking caused by ozone deterioration, in a weir portion 22a disposed on a part often exposed to ozone in a use state, in a seal material 18a constituting a seal ring 14b.SOLUTION: A plurality of radial recessed grooves 26 are formed on an axial outer side face of a weir portion 22a, at equal intervals in the circumferential direction. Each recessed groove 26 has a circular arc-shaped cross-section. A deformation portion 27 formed on a part between the recessed grooves 26 adjacent in the circumferential direction, of an axial outer part of the weir portion 22a, can be easily contracted in the circumferential direction. Thus tensile stress in the circumferential direction generated on a surface side part of the weir portion 22a can be reduced, and the problem can be solved. |
