Title of Invention

A PUMP EXERTING A REDUCED AXIAL THRUST ON THE PUMP SHAFT

Abstract

A pump exerting a reduced axial thrust on the pump shaft comprising a pump housing accommodating a rotatable pump shaft on which the pump impellers are mounted; a rotatable disc mounted on the shaft above, or between, the impellers; a stationary sealing disc, with a central aperture therein. mounted in the housing. the rotatable disc being located snugly in the aperture in the sealing disc. such that the adjacent sides of the two discs are circumferentially in contact with each other. the space below the rotatable disc being exposed to pressure of the pumped fluid, while the space above the sealing disc communicates with the outside of the pump, through a passage in the housing, and is thus exposed to pressure less than the pressure of the pumped fluid, such pressure differential acting upwardly on the rotatable disc. to lift the shaft correspondingly and reduce the axial thrust thereon.

Full Text

This invention relates to a pump exerting a reduced axial thrust on the pump shaft This invention is especially useful in multistage pomps, such as, those used in bore-wells where the thrust load on the pump shaft can be very large. The pump proposed herein is so constructed that the normal thrust load on its shaft is substantially reduced. The pump exerting a reduced axial thrust on the pump shaft, according to this invention, comprises a pump housing accommodating a rotatable pump shaft on which the pump impellers are mounted! a 0 rotatable disc mounted on the shaft above, or between, the impellers; a stationary sealing disc, with a central aperture therein, mounted in the housing, the rotatable disc being located snugly in the aperture in the sealing disc, such that the adjacent sides of the two discs are cirumferentidly in contact with each other, the space below the rotatable disc being exposed to pressure of the pumped fluid, while the space above the sealing disc communicates with the outside of the pump, through a passage in the housing, and is thus exposed to pressure less than (he pressure of the pumped fluid, such pressure differential acting upwardly on the rotatable disc, to lift the shaft corresponding!* «id reduce the axial thrust thereon. The pump proposed herein will now be described with reference to die accompanying drawings, which illustrate by way of example, and not by way of limitation, one of various possible embodiments of this invention Fig. 1 illustrating the embodiment in sectional elevation Fig.2 illustrating the rotatable disc as fixed to or integral with the top portion of the impeller as a variation of the said embodiment. The pump-housing H accommodates a rotatable pump shaft S on which the pump impellers I are mounted. A rotatable disc Dl is mounted on the shaft S above the impellers (Fig. 1). Alternatively this disc can be mounted between the impellers; or fixed to or integral with the top portion of an impeller (Fig.2). A stationary Healing disc Dl with a central aperture Z therein, is mounted in the housing, the rotatable disc Dl being located snugly in the aperture in the sealing disc D2, such that the adjacent sides A and B of the two discs D2 and Dl are oirumferenttaUy in contact with each other. The disc D2 seals off the fluid in the pump in the space below the said disc from the outside of the pump. The space above the disc D2 communicates with the outside of the pump through the passage P. It will be seen from the foregoing description that the space below the rotatable disc Dl is exposed to pressure of the pumped fluid in the housing, while the space above the sealing disc D2 is exposed to the outside of the pump through the passage P above the disc D2 e.g. exposed to atmosphere or to the external water column, as in a bore well The pressure outside the pump being less than the pressure of the pumped fluid, the resulting pressure differential acts upwardly on the two discs, more importantly, on the disc Dl, thus lifting the shaft S correspondingly to reduce the axial thrust thereon. The terms and express ion 8 in this specification are of description, and not of limitation, having regard to the fact that various other embodiments of the pomp proposed herein are possible without departing from the scope and ambit of this invention. I Claim: 1. A pump exerting a reduced axial thrust on the pump shaft comprising a pump housing accommodating a rotatable pump shaft on which mounted on the shaft above, or between, the impellers; a stationary sealing disc, with a central aperture therein, mounted in the housing, the rotatable disc being located snugly in the aperture in the sealing disc, such mat the adjacent sides of die two discs are cirumferentially in contact with each other, the space below the rotatable disc being exposed to pressure of the pumped fluid, while the space above the sealing disc communicates with the outside of die pump, through a passage in the housing, and is thus exposed to pressure less than the pressure of the pumped fluid, such pressure differential acting upwardly on the rotatable disc, to lift the shaft correspondingly and reduce the axial thrust thereon. 2.A pump as claimed in Claim 1 wherein the rotatable disc is fixed to, or integral with, the top of an impeller. 3.A pump exerting a reduced axial on the pump shaft substantially as herein described and illustrated with reference to the accompanying drawings.

Documents:

653-che-2003-abstract.pdf

653-che-2003-claims.pdf

653-che-2003-correspondnece-others.pdf

653-che-2003-correspondnece-po.pdf

653-che-2003-description(complete).pdf

653-che-2003-drawings.pdf

653-che-2003-form 1.pdf

653-che-2003-form 19.pdf

653-che-2003-form 26.pdf