| 摘要 |
Durable pumps for abrasives are provided. In one implementation, an example centrifugal pump or pump stage for subsurface operation has a thrust washer located inside the circumference of a close-fitting clearance seal between an impeller shroud and the diffuser. The relocation of the thrust washer allows the clearance seal to protect the thrust washer from abrasives while the thrust washer supports the impeller against the reaction forces of axial fluid flow. In one implementation, the radius or size of a thrust washer or other seal-like feature is reduced in order to increase exposure of the bottom impeller shroud to pressured fluid, thus balancing pressure at the top and bottom of the impeller to decrease friction between the impeller and the thrust washer. Reducing the radius of the thrust washer also reduces surface area of the washer subject to friction and reduces the moment arm of a braking torque on the rotating impeller, thereby reducing power loss in the pump. |
