| 摘要 |
A spherical annular seal 10 having a through hole 11 in a center thereof and a partially convex spherical surface portion 12 on an outer surface thereof, wherein a surface of the partially convex spherical surface portion 12 is formed into a smooth surface 15 in which a lubricating sliding layer of a lubricating composition containing 70 to 90 wt.% of boron nitride and 10 to 30 wt.% of alumina and/or silica and a reinforcing material constituted by a metal wire net covering the lubricating sliding layer and integrated with the lubricating sliding layer are integrated in mixed form. The sliding layer may also contain polytetrafluoroethylene in a proportion ranging from 50 to 150 parts by weight. The seal also includes heat resistant material 14 comprising expanded graphite, mica or asbestos. A process for forming the seal is also disclosed Figs 2 - 7 (not shown). <IMAGE> |
