US2647467A

US2647467A - Screw pump

Info

Publication number: US2647467A
Application number: US672801A
Authority: US
Inventors: John H Davis
Original assignee: JESSIE A DAVIS FOUNDATION Inc
Current assignee: JESSIE A DAVIS FOUNDATION Inc
Priority date: 1946-05-28
Filing date: 1946-05-28
Publication date: 1953-08-04
Anticipated expiration: 1970-08-04

Description

3 Shees-Sheet l m. V. Y m. m. N HM. 0M N.

J. H. DAVIS SCREW PUMP Aug. 4, 1953 Filed May E28, 1946 J. H. DAVIS SCREW PUMP Aug. 4, 1953 3 Sheets-Sheefl 2 Filed May 28, 1946 J. H. DAVIS Aug. 4, 1953 SCREW PUMP 3 Sheets-Sheet 3 Filed May 28, 1946 @www 062ml. QW

Patented Aug. 4, 1953 SCREW PUMP John H. Davis, Detroit, Mich., assignor to Jessie A. Davis Foundation, Inc., Detroit, Mich., a corporation of Delaware Application May 28, 1946, Serial No. 672,801

(Cl. S-89) 8 Claims.

This invention is a novel pump, and the principal object thereof is to provide a pump radically differing in principle from the conventional type of pump, my pump having a conical shaped impeller carrying ns surrounded by a sleeve secured thereto and closely fitting the machined outer edges of the fins which are preferably spirally arranged so that the cone and fins and sleeve rotate as a unit and impart to a liquid medium a velocity longitudinally of the impeller axis while building up a pressure radially from intake to discharge by centrifugal force, such pressure and velocity being governed by the rotational speed and diameter of the impeller.

A further object of the invention is to provide a pump of the above type which would be simple, novel and eiiicient in operation, and will be capable of delivering .a wide range of fluid capacity by merely regulating the speed of the impeller or the area of the outlet.

Other minor objects of the invention will be hereinafter set forth.

I will explain the inventionwith reference to the accompanying drawings, which illustrate one practical embodiment thereof to enable others familiar with the art to adopt and use the same; and will summarize in the claims the novel features of construction, and novel combinations of parts, for which protection is desired.

In said drawings:

Figure l is a side elevation of my pump.

Fig. 2 is a longitudinal section through the impeller chamber of the pump, also through the impeller mounted therein.

Fig. 3 is an enlarged side elevation of the nose of the pump showing the arrangement of ns therein.

I Fig. 4 is an end View of the nose shown in Fig. 3 looking at the larger end.

Fig. 5 is an enlarged section through the outer roller bearing for the impeller shaft.

Fig. 6 is an enlarged section through the inner roller bearing of the impeller shaft.

As shown in the drawings, the pump comprises an impeller casing I having a base 2 adapted to be mounted on a xed support. Casing I is provided with an axial extension Ia at one end in which are mounted the anti-friction bearings of `an impeller shaft 3 carrying on its inner end Within the casing I a cone head 4, said cone having formed on its periphery spiral fins 5, each vof which as shown preferably extends through sired. The head 4 is of conical shape, and such shape is preferable, but the angularity of the cone may be any desired degree.

As shown, the height of the fins 5 is greater at the smaller end of the cone head 4 than at the large end so that the volume of fluid passing through the impeller will remain constant as the cross-sectional area at all points along the cone head axis is the same.

'Ihe conical head 4 is preferably hollow as indicated at 4a, Fig. 2, in order to save unnecessary weight. As shown, the shaft 3 is provided with splines 3a adapted to engage corresponding slots in the hub of the cone head. The inner end of the head 4 engages an external annular ange 3b on the shaft 3 and the cone head 4 is retained on the shaft 3 by means of a nut 3c engaging threads at the inner end of the shaft, a washer 3d being interposed between the nut 3c and the inner end of the hub of the cone head. Suitable locking means to prevent rotation of the nut may be provided, such as an Allen head screw 3e tapped into a threaded bore adjacent the periphery of the nut, the nut being split at right angles normal to the said screw 3e so that when the screw 3e is tightened the threaded bore of the nut 3c will be distorted. Other means, however, may be used.

Around the shaft 3 preferably opposite the enlarged shoulder 3b is an oil seal 6 of conventional type, and shaft 3 is journaled in the extension Ia, of casing I by means of roller bearings 1 and 8e respectively, the inner bearings 'I engaging the annular shoulder 3b (Fig. 6) of shaft 3, and a sleeve 9 being disposed on the shaft 3 between the inner races of the bearings 1 and 8e. The outer race of bearing 8e is mounted in an enlargement I f of bore la as shown in Fig. 5, and its outer face is engaged by a cap Il secured by studs, bolts or the like I8 to the end of casing Ia, a seal or packing I9 (Fig. 5) being provided I in the cap Il around shaft 3 to lseal the outer end of the bore Ia around shaft 3. The outer face of the inner race 82 is engaged by a lock nut I6 of conventional type mounted upon a threaded section of shaft 3. Thus the inner races of the bearings 'l and 8e are fixed with respect to the shaft 3 so as to prevent axial movement of the shaft within the casing.

Within the casing I around the cone head 4 is a sleeve 5a soldered, welded or brazed to the outer peripheries of the fins 5, said sleeve 5a following the peripheries of the ns throughout their lengths and terminating at the outer enlarged ends of the fins. Members 4, 5 and 5a together form the pump impeller. Thus the liquid which enters the intake end of the impeller will have its velocity and centrifugal force increased in its movement towards the discharge end of the impeller, and the liquid emerging from the outer larger end of the impeller will have a strong swirling motion, while at the same time it is forced axially away from the end of the impeller towards the nose chamber 8 at the discharge end of the pump casing.

The outer wall im (Fig. 2) of the cone head 4 should be slightly arcuate in form rather than a true conical surface, the flare being outward and greatest at the center of the length of nuns 5. This permits the cross-sectional area between the head i and the sleeve 5a, to remain constant.

rIhe casing l surrounds the .sleeve :5c vand .is spaced therefrom, and within the portion oppo site the inner end of the sleeve 5a is an annular ring lil which is substantially V-shaped in crosssectien with its apex disposed adjacent the :beveled .inner end "5b of `the sleeve ha, thus providing a very slight .clearance lea between the :ring m and the inner end 4of the sleeve. The clearance between the ape-X and the inner end .Eb of sleeve .5a is for the purpose of preventing .any .extraneous mattei' except the finest sand passing 'through the clearance space ida between the ring l0 and sleeve 5a. It will be noted however that the clearance between the casing l and :the inner .end .of the sleeve 5a progressively .decreases .towards :theouter end of the sleeve, said difference in clearance permitting sand, grit or other sediment which lmay be passed through the .clearance .lita to .be .carried out along with the 'liquid passing through said .clearance space lsb :at the outer .end .of thesleeve 15a, the movement .of liquid .axially .through the impeller creating .a suction in theclearance space .ith sufcient to maintain the same lclear of sediment, said suc- 'tionzpulling `the sedimenti/o and beyond the outer end .of sleeve 5a .and into Lthe nose chamber 8 hereinafter described.

Inthe :casing I .around the shaft 3 andopposite the inlet .end of the impeller is Aan inlet chamber H., the end .of which .communicates directly with the .space between the cone -head 4 and the sleeve 5a. Inlet chamber .ll is 4fed .by one, :two .or more yinlet pipes I2, two being indicated in Fig. :2, `.whereby .a substantial iiow of water is constantly maintained at :the "inlet .end Q the impeller to be passed `therethrough into the .nose chamber :8.

.As shown Fig. 1, the -nose member 8 is se- .cured :to the l.outlet end of casing I .by means vof `bolts 8a, fsaid .nose .chamber 8 .being substantially cylindrical ladjacent the impeller .and reducing in diameter towards the outlet `.end 8d. `Within ythe nose chamber 18 is .a `core Bb Isubstantially ipa-rallel with the .inner wallof the nose .chamber 8 throughout the major portion of .its length but contracting towards the -outlet end to sub.. -stantially a point '80, in order tokeep the amount 'of fluid passing through the nose chamber 3 substantially .constant throughout the length thereof due to the decrease in diameter towards the outlet Tend -tdof the nose chamber 8. `Said .core .-819 is designed to .'iill the otherwise vacuum cone which would be created by "the flow of whirling waterdischarged from the impeller into the `nose chamber '8. Between the core .3b and the inner wall ,of the nose chamber l8 is an an- ;nular.series :of fins 8c, three ybeing indicated .in iiigil` which as showniin Fig. v3 are ysubstar-ltially `coaxial.with1the;;nose chamber 8 :fremithe .outer 75 end 8c to approximately one-half the length back through the nose chamber, at which point the ns are formed arcuately to substantially the shape of the reverse curve of the outer ends of the fins 5, the purpose of the iins 8c being to stop whirling of the volume of water discharged into the nose chamber from the impeller and to cause the ilow of water in the nose chamber to be in a straight line direction.- "The fins 8e are an important part of my invention, for it has been found in practice that without the fins the volume of water delivered by the pump is substantially infinitesimal as the tendency of the water Adischarged from the impeller is to pass in a radial direction tangent to the outer end of the impel'ler. 'The volume of water, however, upon ,striking the fins 8e is caused to move in a straight line towards the outlet Sd of the nose chamber.

In operation, the pump shaft 3 is driven in the .direction of the arrows 3m, Fig. 2, by .any suitable prime mover. 'The liquid to be Dumped is supplied through the inlet pipes t2 to .the inlet .chamber il, .the pump being previously primed. As the l.shaft s rotates, the impeller 1.6, 5 and .5a rotates therewith. The rapid. increase diameter of .the impeller .-cone 4, combined @with the high pitch of the spiral ns `5 will .cause the pressure .of the liquid rwithin the vimpelfler to gradually build :up parallel to .the impelier axis, forcing the liquid r'along vthe impeller .4, 5, r5ga through Ithe fins .5 .while .building :up a high pressure radially due to centrifugal force, which pressure reacts upon the conical sleeve 15a .to exert an axialcomponent whereby assthe liquid .emerges vvarying :the speed of .rotation of :the impeller,

or by valve means (not shown) :applied to Ytglie .discharge .end 8d. My pump 'will ,have la .wide

range of capacity depending 11110.11 :the adjustment of `the :valve Ameans,:whereby the pumpmay be continued to be run at full :Speed rwhile delivering ,only .-a ,small Qapaty Withoill? zlillly thereto asno fback pressure built up therein to injlile fthe ,pump. 1This feature is van -i-mportant improvement .over conventional ,pumps .designed for only one 'capacity and which `must he driven .at the 'designed speed to deliver such capacity, for in my pump as the valve means is closedthe .power to rotate the dispel-1er at the same speed becomes "les rather l.than greater, as in Lconventional pumps.

I do not limit :my invention to-the .exact forms shown inthe drawings, for obviously changesfmay be made therein `-within the :scopeof the claims.

I claim: p

1. A liquidpump, comprising an impeller chamber contracting towards one end into an inlet; a nose chamber of greater length than the -impeller chamber connected to thelarger end offthe impeller chamber yand contracting :towards its outer end into an outlet; `a driven .shaft entering :the inlet -end of the f-impellerfchamber coaxially thereof; kan impeller :on .said shaft within .the

Vimpeller chamber land comprising a ,substantially cone-shaped .head enlarging itQWaIds 'the nose chamber, a series l.of spirally arranged dus on -said vcone head having aV 'steep pitch, said fins fbeing spaced from the walls of the impeller chamber, and a' sleeve` surmounting the fins and rotatable with the head, said sleeve having a slight posed core therein whose outer surface is substantially parallel with the inner wall of the nose v chamber throughout -the major portion of its length thereby maintaining the area between the Score and nose chamber substantially constant throughout its length, and said nose chamber having fixed axially disposed ns between its innerwall and the surface of the core adapted to convert the rotary motion of the liquid emerging from the impeller into rectilinear motion 'within the nose chamber before emerging from -the outlet, the area between adjacent fins and "the head and sleeve of the impeller remaining substantially constant throughout the `length of the head, to maintain a constant volume of liquid rpassing through the impeller.

2. A liquid pump, comprising an impeller chamber contracting towards one end into an inlet; a nose chamber 0f greater length than the impeller chamberV connected to the larger end of the impeller chamber and contracting towards its outer end into an outlet; a driven shaft entering the inlet end of the impeller chamber coaxially thereof; an impeller on said shaft within the impeller chamber and comprising a substantially coneshaped head enlarging towards the nose chamber, ai series of spirally arranged fins on said cone head having a steep pitch, said fins being spaced from the walls of the impeller chamber, and a lsleeve surmounting the fins and rotatable with the head, said sleeve having a slight'clearance from the walls of the impeller chamber; the space 'between the head and sleeve progressively decreasing toward the larger end 0f the impeller; an inlet port at the inlet communicating with "the smaller end of the impeller and having a feed opening communicating therewith; and said no se chamber having an axially disposed core therein whose outer surface is substantially parallel with `the inner wall of the nose chamberthroughout the major portion of its length thereby maintaining the area between the core and nose chamber substantially constant throughout its length, and

said nose chamber having fixed axially disposed 'fins between its inner wall and the surface of the core adapted to convert the rotary motion of the liquid emerging from the impeller into rec- -tilinear motion within the nose chamber before emerging from the outlet, said impeller fins each making a half turn throughout the length of the head; and the area 'between adjacent fins and lthe head and sleeve of the impeller remaining substantially constant throughout the length of the head, to maintain aconstant volume of liquid `passing through the impeller.

3. A liquid pump, comprising an impeller cham- Lvber contracting towards one end into an inlet; a nose chamber of greater length than the impeller i chamber connected to the larger end of the irnpell'er chamber and contracting towards its outer 'end into an outlet; a driven shaft entering the inlet end of the impeller chamber coaxially thereof;` an impeller on said shaft within the impeller chamber and comprising a substantially 'coneshaped head enlarging towards the nose chamber, `a series of spirally arranged fins on said cone head having a steep pitch, said fins being spaced from the walls of the impeller chamber, and a sleeve surmounting the fins and rotatable with the head, said sleeve having a slight clearance from the walls of the impeller chamber; the space between the head and sleeve progressively decreasing toward the larger end of the impeller; an inlet port at the inlet communicating with the smaller end of the impeller and having a feed opening communicating therewith; and said nose chamber `having an axially disposed core therein whose outer surface is substantially parallel with the inner wall of the nose chamber throughout the major portion of its length thereby maintaining the area between the core and nose chamber substantially constant throughout its length, and said nose chamber having xed axially disposed fins between its inner wall and the surface of the core adapted to convert the rotary motion of the liquid emerging from the impeller into rectilinear motion within the nose chamber before emerging from the outlet, the inner end of the sleeve being beveled; and a ring of substantially correspondingly shaped cross-section disposed in the impeller chamber with its apex adjacent the beveled end of the sleeve while providing a slight clearance between the sleeve and ring; and the vclearance between the sleeve and walls of the rimpeller chamber progressively decreasing towards the outer end of the sleeve, whereby during op-eration of the pump suction created between the outer end of the sleeve and wall of the impeller chamber will maintain the space between the sleeve and wall of the impeller chamber free from sediment.

4. A liquid pump, comprising an impeller chamber contracting towards one end into an inlet; a

ynose chamber of greater length than the impeller chamber connected to the larger end of the impeller chamber and contracting towards its outer Vend into an outlet; a driven shaft entering the inlet end of the impeller chamber coaxially thereof; an impeller on said shaft within the impeller chamber and comprising a substantially coneshaped head enlarging towards the nose chamber,

-a series of spirally arranged ns on said cone Shead having a steep pitch, said fins being spaced .from the walls of the impeller chamber, and a sleeve surmounting the fins and rotatable with the head, said sleeve having a slight clearance from the walls of the .impeller chamber; the space between the head and sleeve progressively decreasing toward the larger end of the impeller; an inlet port at the inlet communicating with the smaller end of the impeller and having a feed opening communicating therewith; and said nose chamber having an axially disposed core therein whose outer surface is substantially parallel with the inner wall of the nose chamber throughout the major portion of its length thereby maintaining the area between the core and nose chamber substantially constant throughout its length, and said nose chamber having fixed axially disposed ns between its inner wall and the surface of the core adapted to convert the rotary motion of the liquid emerging from the impeller into rectilinear motion within the nose chamber before emerging from the outlet, the walls of said head being flared outwardly, and said fiare being greatest at Athe center of its length.

5. A liquid pump, comprising an impeller chamber contracting towards one end into an inlet; a nose chamber of greater length than the impeller chamber connected to the larger end of the impeller chamber and contracting towards its outer end into an outlet; a driven shaft entering the inlet end of the impeller chamber coaxiall'y thereof; an impeller on said shaft within the impeller chamber and comprising a substantially coneshaped head enlarging towards the nose chamber and terminating adjacent the outer end of said impeller chamber, a series of spirally arranged iins on said cone head having a steep pitch, said ns being spaced from the wallsk of the impeller chamber, Iand a sleeve surmounting the ns and rotatable with the head, said sleeve embracing the length of the head, said sleeve having a slight clearance trom the walls of the impeller chamber;

the space between the head and sleeve progressively decreasing toward the larger end, of the impeller; an inlet port disposed around the sh ft and communicating with the smaller end of the impeller and hav-ing an inlet opening communieating therewith; and said nose chamber having an axially disposed core therein whose outer surface is substantially parallel with. the inner wall of the nose chamber throughout the major portion of its length thereby maintaining the area between the core and nose chamber substantially constant throughout its length, and said nose chamber having xed axially disposed iins between its inner wall and the surface of the core adapted to convert the rotary motion of the liquid emerging from the impeller into rectilinear motion within the nose chamber before emerging from the outlet, the areal between adjacent ns and the head and sleeve or" the impeller remaining substantially constant throughout the length of the head, to maintain a constant volume of liquid pass-ing through the impeller.

6; A liquid pump, comprising an impeller chamber contracting towards one end into an inlet; a

nose chamber of greater length than the impeller' L chamber connected to the larger end of the impeller chamber and contracting towards its outer end into an outlet; a driven shaft entering the inlet end of the impeller chamber coaXially thereci; an impeller on said shaft within the impeller chamber and comprising a substantially coneshaped head enlarging towards thev nose chamber and terminating adjacent the outer end of said impeller chamber, a series of spirally arranged fins on said cone head having a steep pitch, said fins being spaced from the walls of the impeller chamber, 'and a sleeve surmounting the ns and rotatable with the head, said sleeve embracing the length of the head, sairl sleeve having a slight clearance from the walls of the impeller chamber; the space between the head and sleeve progressively decreasing toward the larger end ci' the impeller; an inlet port disposed around the shaft and communicating with the smaller end of the impeller and having an inlet opening communieating therewith; and said nose chamber having an axially disposed core therein whose outer surface is substantially yparallel with the inner wall of the nose chamber throughout the major portion of its length thereby maintaining the area between the core and nose chamber substantially constant throughout its length, and said nose chamber having fixed axially disposed fins between its inner wall and the surface of the core adapted to convert the rotary motion of the liquid emerging from the impeller into rectilinear motion within the nose chamber before emerging from the outlet, said impeller hns each making a half turn throughout the length of the head; and 'the area between adjacent ns and the head and sleeve of the impeller remaining substantially constant throughout thelength of the head, to maintain a constant volume of liquid passing through the impeller.

'7. A liquid pump, comprising animpeller chamber contracting towards one end into an inlet; a nose chamber of greater length than the impeller chamber connected to the larger end of the imheller chamber and contracting towards its outer end into an outlet; a drivenishaft entering the inlet end of the impeller chamber coaxially thereof; an impeller on said shaft within the impeller chamber and comprising: a substantially coneshaped head enlarging towards the nose chamber and terminating adjacent the outer. end of said impeller chamber, a series of spirally arranged uns on said cone head having a steep pitch, said ns being spaced from the walls of the impeller chamber, and a sleeve surmounting the iins and rotatable with the head, said sleeve embracing the length of the head, said sleeve having a slight clearance from the walls of the impeller chamber; the space between the head and sleeve progressively decreasing toward the larger end of the impeller; an inlet port disposed around theshaft and communicating with the smaller end of the impeller and having an inlet opening communieating therewith; and saidnose chamber having an axially disposed core therein whose outer surface is substantially parallel with the inner wall of the nose chamber throughout the major portion o its length thereby maintaining thearea between the core and nose chamber substantially constant throughout its length, and said nose chamber having fixed axially disposed fins between its inner wall and the surface of the core adapted to convert the rotary motion of the liquid emerging from the impeller into rectilinear motion within the nose chamber before emerging from ther outlet, the inner end of the sleeve being beveled; and a ringof substantially correspondingly shaped cross-section disposed in the impeller chamber with its apex adjacent the beveled end yof the sleeve while providing a slight clearance between the sleeve and ring; and the clearance between thesleeve and walls of. the impeller chamber progressively decreasing towards the .outer end ofthe sleeve, whereby during operation of the pump suction createdv between the vouter end of the sleeve and wall of the impeller chamber will maintain the space between the sleeve and. wall ci the impeller chamber free from sediment.

8. A liuuid pump, comprising an impeller chamber contracting towards one end into an inlet; a nose chamber of greater length than the impeller chamber connected to. the larger end of the impeller chamber and contracting towards its outer end into an outlet; a driven shaft entering the inlet end of the impeller chamber coaXially thereof; an impeller on said shaft within the impeller chamber and comprising a substantially coneshaped head enlarging towards the nose chamber and terminating adjacent the outer end of said impeller chamber, a series of spirally arranged hns on said cone head vhaving a steep pitch, said ns being spaced from the walls of the impeller chamber, and a sleeve surmounting the hns and rotatable with the head, said sleeve embracing thelength of the head, said sleeve having a slight clearance from the walls of the impeller chamber; the space between the head and sleeve progressively decreasing toward the larger end of the impeller; an inlet port disposed around the shaft and communicating with the smaller end of the impeller and hav-ing an inlet opening communieating therewith; and said nose chamber having an axially disposed core therein Whose outer surface is substantially parallel with the inner wall of the nose chamber throughout the major portion of its length thereby maintaining the area between the core and nose chamber substantially constant throughout its length, and said nose chamber having fixed axially disposed ns between its inner wall and the surface of the core adapted to convert the rotary motion of the liquid emerging from the -mpeller into rectilinear motion Within the nose chamber before emerging from the outlet, the walls of said head being flared outwardly, and said are -being greatest at the center of its length.

JOHN H. DAVIS.

References Cited in the le of this patent UNITED STATES PATENTS Number Number Name Date Magnot June 21, 1898 Freid Jan. 10, 1905 Angus Sept. 26, 1922 Lawaczeck Dec. 16, 1930 FOREIGN PATENTS Country Date Germany 1906 Great Britain Aug. 26, 1926 Great Britain Feb. 8, 1939