| 摘要 |
A seal assembly 50 comprises a seal ring 64 having a sealing surface 80 and an opposing engaging surface 82. It also includes a cushion ring 66 comprising a base portion (90, fig 4) and an annular flange portion (92, fig 4). The base portion mates with the engaging surface of the seal ring, and the flange portion extends axially along the outside surface 86 of the seal ring. The cushion ring is made of a material softer than the first, preferably an elastomer. The cushioning effect of the ring absorbs vibration, and provides auxiliary energisation of the seal tending to bias the seal assembly together. The L-shape provided by the flange of the cushion ring also allows tolerances to be relaxed on the first ring. A further energising ring 60 may also be provided. The first ring may include a bevelled shoulder 85 forming a relief void 100 for deformation of the cushion ring. Also disclosed is a roller cone drill bit incorporating the seal assembly. |
