Patent ID: 6398493
Filing Date: 2002-06-04
Classification: F04D,F05D

Abstract:
A floatable impeller for multistage metal working pump, comprising:a plurality of pump shell units mounted in series on a shaft, each pump shell unit including an impeller and a diffuser shell made by metal working, the diffuser shell have diffusers located therein; the impeller having an inlet, a front wall, a rear wall, and including an impeller hub and an impeller thrust ring, the impeller hub having a metalic impeller metal working member integrally formed with an impeller plastic member, the impeller metal member being fixed to the rear wall of the impeller, the impeller plastic member having a shaft bore engaged with the shaft for transmitting shaft rotation power synchronously; the impeller thrust ring including a metallic thrust metal working member integrally formed with a thrust plastic member, the thrust metal working member being fixed to the front wall of the impeller around the inlet; a shaft sleeve having one end adjacent to the impeller plastic member and a shaft bore engaged with the shaft for rotating synchronously with the shaft; and a diffuser collar including a metallic metal working member integrally formed with a diffuser plastic member, the diffuser metal working being fixed to the diffuser, the diffuser plastic member having a center hole therein to house the shaft sleeve such that the diffuser plastic member acts as a bearing for the shaft and shaft sleeve to rotate therein; wherein the impeller is axially movable along the shaft a predetermined distance under thrust pressure of pumping fluid flowing from the inlet through the diffusers to an adjacent pump shell unit when the shaft drives and rotates the impeller for pumping operation such that the thrust plastic member facing and rotating against a side wall of the adjacent pump shell unit for providing a bearing function.