Self-priming centrifugal pump

Patent metadata

Field	Value
Publication number	US-2016245291-A1
Application number	US-201514625732-A
Country	US
Kind code	A1
Filing date	Feb 19, 2015
Priority date	Feb 19, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

A self-priming centrifugal pump has enhanced efficiency and performance characteristics and/or features which facilitate installation, inspection and maintenance of the pump. For efficiency and performance, the pump may include a smooth fluid flow path which enhances pump output for a given input power, including one or more of a specially shaped and directed volute discharge, a lack of internal stiffening ribs on the pump casing walls, a necked inlet and a rounded, flow-channeling outlet aperture. For maintenance and serviceability, the pump may include one or more of a coarse-threaded drive shaft and impeller with a concentricity feature, a combination port for both filling the casing and accessing the inlet flapper valve, and a drive disassembly system which facilitates attachment or removal of the drive system from the pump.

First claim

What is claimed is:

1 . A centrifugal pump comprising:
a drive mechanism; an impeller drivingly connected to the drive mechanism; a casing having an inlet and an outlet, the casing comprising:
an inlet-side wall having an inlet aperture formed therein;
an outlet-side wall joined to the inlet-side wall to form a cavity within the casing, the outlet-side wall having an outlet aperture;
a volute disposed in the casing and in fluid communication with the inlet aperture and the outlet aperture, the volute having a central opening sized to receive the impeller and a spiral-shaped fluid channel such that the fluid channel progresses radially outwardly toward a volute discharge opening, the volute discharge opening defining a longitudinal discharge axis which extends through the outlet aperture,
whereby the volute is adapted to receive fluid accelerated outwardly by the impeller, direct the fluid radially outwardly through the spiral-shaped fluid channel, and discharge the fluid along the longitudinal discharge axis toward the outlet aperture.

2 . The centrifugal pump of claim 1 , wherein the casing defines a vertical center plane containing an axis of rotation of the impeller, and the longitudinal discharge axis is oriented to cross the vertical center plane.

3 . The centrifugal pump of claim 1 , wherein the impeller defines a spin plane perpendicular to the axis of impeller rotation, the discharge axis is angled with respect to the spin plane.

4 . The centrifugal pump of claim 3 , wherein the casing further comprises a partition wall interposed between the inlet-side wall and the outlet-side wall to form an inlet pump chamber and an outlet pump chamber, the partition wall having an inner drive aperture positioned to allow fluid communication between the inlet pump chamber and the outlet pump chamber via the inner drive aperture.

5 . The centrifugal pump of claim 4 , wherein the discharge axis is angled away from the partition wall.

6 . The centrifugal pump of claim 4 , wherein the casing further comprises a plurality of fastener bosses disposed within the outlet pump chamber and adjacent the outlet aperture, the fastener bosses each having a smooth, rounded outer surface.

7 . The centrifugal pump of claim 6 , wherein the fastener bosses each have a convex distal surface and a concave surface at the junction between the convex distal surface and the adjacent inner surface of the outlet pump chamber.

8 . The centrifugal pump of claim 6 , wherein the fastener bosses define a tear drop shape with a pointed end of the tear drop shape pointing toward the outlet aperture, whereby the fastener bosses promote laminar flow of fluid discharged from the volute and advanced toward the outlet aperture.

9 . The centrifugal pump of claim 4 , wherein the casing of the pump comprises a sump region formed in a lower region of the outlet pump chamber, the sump region including a central portion in direct fluid communication with the impeller and a peripheral portion in indirect fluid communication with the impeller,
the casing further comprising at least one drain channel in direct fluid communication with the peripheral portion of the sump region and in indirect fluid communication with the central portion of the sump region, whereby the at least one drain channel does not form any part of the volute.

10 . The centrifugal pump of claim 9 , wherein the casing comprises a first drain channel and a second drain channel, the first and second drain channels positioned on opposite side of the volute.

11 . The centrifugal pump of claim 1 , wherein the pump further comprises an inlet adapter connected to the inlet aperture, the inlet adapter including a necked portion in which a flow area through the inlet adapter gradually increases along a flow direction toward the inlet aperture.

12 . The centrifugal pump of claim 11 , wherein:
the pump further comprises an outlet adapter connected to the outlet aperture, the outlet adapter having a substantially cylindrical fluid passage, and the inlet and outlet adapters configured to receive a common nominal size of fluid conduit and the necked portion of the inlet adapter leading to the inlet aperture having larger area than the outlet aperture.

13 . The centrifugal pump of claim 1 , wherein the outlet aperture comprises an outlet transition area having a radiused internal edge operable to facilitate smooth flow therethrough, the outlet transition area defining a nominal radius at least equal to a minimum thickness of the outlet-side wall.

14 . The centrifugal pump of claim 13 , wherein the nominal radius of the outlet transition area is at least 131% of the minimum thickness of the outlet-side wall.

15 . The centrifugal pump of claim 1 , further comprising a plurality of stiffening ribs extending along and integrally formed with the inlet-side wall and the outlet-side wall of the casing, the stiffening ribs disposed only on an exterior surface of the casing.

16 . The centrifugal pump of claim 15 , wherein a plurality of ribs on the outlet-side wall extend along a substantially vertical face of the outlet-side wall, round a corner at the junction between the vertical face a side face of the outlet-side wall, and extend along a front-to-back direction on the side face.

17 . The centrifugal pump of claim 16 , wherein the plurality of extend radially outwardly along the vertical face from a central area of the vertical face.

18 . The centrifugal pump of claim 1 , wherein the outlet-side wall of the casing comprises an outer drive aperture sized to receive the drive mechanism.

19 . A centrifugal pump comprising:
a drive mechanism; an impeller drivingly connected to the drive mechanism; a flapper valve; a casing having an inlet and an outlet, the casing comprising:
an inlet-side wall having an inlet aperture formed therein, the flapper valve positioned at the inlet aperture to admit a flow of fluid into the casing via the inlet aperture while preventing a flow of fluid out of the casing via the inlet aperture;
an outlet-side wall joined to the inlet-side wall to form a cavity within the casing, the outlet-side wall having an outlet aperture;
a partition wall interposed between the inlet-side wall and the outlet-side wall to form an inlet pump chamber and an outlet pump chamber, the partition wall having an inner drive aperture positioned to allow fluid communication between the inlet pump chamber and the outlet pump chamber via the inner drive aperture;
a combination port formed in the casing near the flapper valve, the combination port sized and positioned to allow access to the flapper valve by a maintenance person, and to allow fluid to be added to the inlet pump chamber; and
a fill vent formed through the casing on an opposite side of the partition wall as the combination port, such that the fill vent allows fluid communication between the outlet pump chamber and the ambient environment, whereby liquid added to the inlet pump chamber is allowed to flow to the outlet pump chamber via the inner drive aperture while air contained in the outlet pump chamber vents to atmosphere via the fill vent.

20 . The centrifugal pump of claim 19 , further comprising a combination port cover comprising:
a fill port cover portion sized to be received over the combination port to fluidly isolate the combination port from the ambient environment; and a fill vent cover portion sized to be received over the fill vent to fluidly isolate the fill vent from the ambient environm

Assignees

• Franklin Electric Co Inc

Inventors

• Carnes William M

Classifications

• F04D29/4206

  especially adapted for elastic fluid pumps · CPC title

• F04D29/624

  especially adapted for elastic fluid pumps · CPC title

• F04D17/10 Primary

  for compressing or evacuating · CPC title

• F04D25/02

  Units comprising pumps and their driving means · CPC title

• F04D9/06 Primary

  of jet type · CPC title