US1972865A - Centrifugal pump - Google Patents

Description

Sept- 11, 1934. H. E. BRoUGH'oN Er AL 1,972,865

GENTRIFUGAL PUMP Filed June 15.` 1931 IIIIIIIII Zhwentors Patented Sept.,11, 1934 i l UNITED STATES PATENT OFFICE CENTRIFUGAL PUMP Harold E. Broughton and William F. Lamoreaux,

,. Isabella, Tenn.

Application June 15, 1931, Serial No. 544,640 y Claims. (Cl. ID3-103) Our invention relates to improvements in cenof the cylindrical body of the supporting section trifugal' pumps, and more particularly to cen- 10, we provide a radially extending flange 12 trifugal pumps designed to handle liquids which which has an outer -face 13 normal to the axis possess densities and/or viscosities greater than of the cylindrical portion. that of water. The casing assembly further comprises a bear- 60 It is a primary object of the present invention ing section or member 14 having a substantially to provide a centrifugal pump casing assembly cylindrical sleeve disposed in the interior of the which is extremely simple, compact, and eflicient, cylindrical portion of the supporting section 10, and which may be easily taken down or assembled. and it also has an outwardly extending radial l It is a further object to provide a centrifugal flange 15 which may be secured to and carried 65 pump in which the sectional area. of the passage by the flange 12 of the supporting section. The for the liquid travelling through the pump desleeve of the bearing member'may conveniently creases in a predetermined proportion to the inbe provided with a replaceable bushing 16, which crease in the velocity imparted to the liquid by is shown as extending the full length thereof.

15 a centrifugal impeller during its flow through the A volute section, represented generally by refer- 70 pump. A ence character 17, constitutes the third principal It is a further object of the invention to provide element or section of our casing assembly. This an open-sided impeller having a desirable rela.- section has certain desirable characteristics which tion between curved surfaces and vanes so that Will now be described.

a, pump is produced which is unusually eflcient A central inlet opening 18 communicates di- 75 with liquids of high viscosity and/or density. rectly with an interior substantially cylindrical f A further object is to provide, with such an impeller Chamber 19 in WhiCh the impeller 20, impeller, a casing of peculiar form which has described in vdetail below, is mounted for rotaparts cooperating with the impeller in a novel tion. The central inlet yopening 18 communicates' 3 way to produce new results. with an inlet conduit 21, which is of frusto- 80 Another object of the invention is to counteract conical shape and ares outwardly, havingr an end thrust which results from the weight of the enlarged opening 22. A discharge chamber 23 parts and from suction during the operation of is disposed in the peripheral portion of the volute the pump. This object is accomplished by curved section 17, and this chamber may be in substanl surfaces on the impeller, 'as will be pointed out tially the form of a volute,` or any other con- 85 below. ventional discharge chamber used with centrifu- In carrying out our invention, we provide acasgal pumps may be employed. The discharge ing assembly for a centrifugal pump, said aschamber communicates with a discharge passage semby comprising three principal'elements,which 24 in a conventional manner. Above the dis-- may be simply bolted together. Eachof the parts charge chamber we provide a thickened wall 25 90 is constructed of peculiar form in order to atto ourvolute section, and on the upper surface tain the objects of our invention. thereof a plane annular attaching surface 26 is In .the accompanying drawing, an illustrative located. As is clearly shown in the drawing, embodiment of the invention is shown, in which: this surface 26 is bolted to the outer portion of Figure 1 is a vertical elevation of a pump emange 12 on supporting section 10. An appro- 95 bodying our invention, the pump being submerged .priate gasket 27 should be interposed between in a tank, and the tank being shown in section. the surface 26 and flange 12 to prevent leakage 4 Figure 2 is a vertical sectional view of our imof uid along this joint.

proved Centrifugal Dump- Another important feature of the volute sec- Figure 3 iS a bottom plan view. tion resides in the fact that the impeller chamber 100 It iS t0 be UIIdeIStOOd that the apparatus ShOWIl thereof is provided with a substantially plane in the accompanying drawing is an illustrative interior surface 28 normal to the axis of the embodiment only of our invention, and that the pump and extending from the imei; opening 18 invention is not to be limited to the specific con outwardly to the discharge chamber 23. l struction shown, but'is to be given a scope equal The impeller of our invention is entirely open 105 to that dened by the accompanying'claims. on one side and closed on the other side by a In the device of the drawing, we have shown backing member 29. This backing member, or a pump casing assembly comprising a supporting body portion of the impeller, has on its front section 10 having a cylindrical body and secured face a plurality of vanes or blades 30 which may i at its upper end to a. stand 11. At the lower end be radial with respect to the impeller or may be curved rearwardly in accordance with well known centrifugal pump practice, asvshown in dotted lines in Figure 3. The blades 30 project from the front face of the impeller body, as aforesaid, and their front edges terminate in 4a plane which is normal to the plane of the terior surface 28 of the casing 17 and is parallelthereto. The front surface of the impeller curves from the point 31 away from the plane .surface 28 throughout the central portion of the impeller and then, approximately at point 32, commences to curve toward said plane and continues to do so throughout the remaining peripheral portion of the impeller.

The impeller described above is shown in the drawing as being secured to an axial driving shaft 33 connected to a suitable electric motor 34. The rear face of the impeller is provided with a shoulder 35 which extends across the end of bushing 16 and has a thrust t with an annular depression 36 in bearing member 14.

It will be seen that this construction of the impeller with respect to the casing in which it rotates provides a passage for the liquid being pumped, which passage gradually decreases in sectional area from the inlet to the outlet, and in a predetermined proportion to the increase in the velocity of \the liquid being worked onbyI entire path of the liquid into variel through the\ impeller is stream-lined and of suitably decreasing area., the efllciency of the pump is greatly improved.

'Ihe curvature of the impeller surface is so proportioned as to develop the desired velocity of liquid flow with respect to the peripheral speed of the impeller varies. Furthermore, the centrifugal flow of the liquid against the curved front surface of the impeller exerts an upward lift thereupon more than sufficient to balance the downward .thrust due to the weight of the impeller and shaft, and consequently there is maintained a constant contact between the shoulder 35 and the vbearing member at point 36, thereby preventing any vertical movement of these parts. This upward thrust causes the floating impeller to rotate in a fixed horizontal plane and prevents end play during the operation of the device.

From a manufacturing point of view, the pump casing assembly Y shown in the accompanying drawing and described above, presents many advantages. The meeting surfaces of the various parts are all exposed during the manufacturing process, and consequently may be conveniently and accurately machined on standard lathes so that an accurate fit between the various parts may readily be accomplished. The threepart assembly of the casing is extremely simple and may be taken down or assembled for installation,'removal or repair with ease by merely removing the bolts 3'?.

It will be seen by one skilled in the art that all of the objects of our invention are accomplished by a device made in accordance with the description given above when considered with the accompanying drawing, and that `an exceeding novel,

simple, and efficient centrifugal pump is provided..

.We claim:

1. In a centrifugal pump, a casing having .a

central inlet opening and an outwardly projecting inlet conduit adjacent said opening, said conduit being frusto-conical in form and having its smaller end adjacent said opening in said casing, said casing having a peripheraldischarge chamber and a plane interior surface extending radially from said opening to said discharge chamber, said pump having an open-sided impeller in said casing coaxial with said inlet opening and having its open side facing said plane interiory surface y of said casing and a plurality of rearwardly curved blades projecting from the open side and extending continuously from substantially the center of the impeller to the periphery thereof, said frontloo said impeller as said surface approaches said peripheral discharge chamber. f

2. An opensided impeller for use with a centrifugal pump having a fixed axis on which said impeller rotates, said pump having an axial inlet and a peripheral discharge, said impeller comprising a backing member having a curved front surface facing said inlet and a plurality of rearwardly curved blades -projecting from said curved surface and each extending from a point substantially adjacent the axis of the pump to the periphery thereof, the front edges of said blades being disposed to lie in a plane normal to the axis of said pump substantiallythroughout their lengths, said curved front surface of said impeller being disposed to intersect said normal plane adjacent the axis of said pump and at the inner ends of said blades and to form a substantially conical point projecting through said normal plane of said blade edges.

3. A casing assembly for a centrifugal pump having an impeller and an axial driving shaft, said assembly comprising a substantially cylindrical supporting section having means adjacent one end for attachment to a stand and having a radial outwardly extending flange at the other end, a bearing section having an elongated bearing sleeve for said driving shaft and extending into the cylindrical portion of the supporting section in spaced relationthereto, and an outwardly extending flange secured to the radial ange on the supporting section and constituting a backing 146 radial outwardly extending ange at the other 150 end, a bearing section having an elongated bearing sleeve for said driving shaft and extending into the cylindrical portion of the supporting section in spaced relation thereto and an outwardly extending ange secured in face to face relation to the radial ange on the supporting section and constituting a backing member for the impeller and dening one Wall of an impeller chamber, said flange on said bearing section having a diameter substantially equal to the diameter of said impeller, and a volute section secured to the rstmentioned ange in concentric relation to the bearing section ange and dening another wall of said impeller chamber. 1

5. A three part casing assembly for a centrifugal pump having an impeller and an axial driving shaft, the three parts of said assembly'serving to dene an impeller chamber and a discharge chamber and comprising a substantially cylindrical supporting section having a radial outwardly extending ange at one end, a bearing section for said shaft having an elongated bearing sleeve extending into the cylindrical supporting section in spaced relation thereto and having an outwardly extending radial iiange of gradually increasing cross-sectional thickness toward its periphery secured in face to face relation to the radial flange on the supporting section, said bearing section flange constituting a backing member for the impeller and having a surface constituting a truste-conical wall for said impeller chamber behind the impeller, and a volute flange in concentric relation to the bearing section flange and having surfaces dening another wall of said impeller chamber and the walls of said discharge chamber. y

HAROLD E. BROUGHTON. WILLIAM F. LAMOREAUX.

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