| 摘要 |
<p>An impeller pump including a housing (12) defining a seal cavity (26) having a shaft (20) rotatably mounted therein and an expeller (46) to pump fluid from the seal cavity. A dynamic seal (58) provides a fluid tight seal between the housing and the shaft. The seal comprises an axially movable primary seal ring (76) which rotates with the shaft and a mating stationary seal ring (80). Biasing means (96) urge the primary seal ring into sealing engagement with the mating seal ring (80). The radial face of the mating seal ring defines a plurality of spiral grooves (114). When the pump is operating, the primary seal ring rotates with the shaft and the grooves create a pumping action to pump air between the faces causing the primary seal ring to lift away from the mating seal ring to prevent wear and avoid undue heat generation.</p> |
