Patent ID: 8894350

Claim:
A centrifugal pump comprising: a rotatably driven drive shaft; a diffuser having a bore through which the shaft passes, the diffuser having a generally concave receptacle surrounding the bore of the diffuser; a thrust bearing base having a generally convex side bonded to the receptacle of the diffuser, the thrust bearing base having a generally concave thrust face; a thrust runner having a generally convex side in rotating engagement with the thrust face of the thrust bearing base, the thrust runner being axially movable relative to the shaft and rotatable with the shaft; a downstream impeller rotated by the shaft downstream of the diffuser; a thrust sleeve surrounding and rotatable with the shaft and extending between the downstream impeller and the thrust runner for transmitting down thrust to the thrust bearing base; and wherein the thrust sleeve, the thrust runner, and the thrust bearing base are made of a harder material than the diffuser and the downstream impeller.