| 摘要 |
A lip seal comprises resilient annular sealing means 2, 3 having a sealing lip (4 in Fig. 1) adapted for sealing engagement at its end (9 in Fig. 1) with a relatively movable shaft 5, and a valve lip (6 in Fig. 1). The lips 4, 6 are, in use, normally closed and means 11, 13 for injecting pressurised fluid into a space 7 between the closed lips 4, 6 causes the lips 4, 6 to open during use to allow the fluid to flow towards the end 9 of the sealing lip 4. |
