USRE24909E

USRE24909E - Submersible pump-motor

Info

Publication number: USRE24909E
Authority: US
Publication date: 1960-12-20

Description

Dec. 20, 1960 R. w. DOCHTERMAN Re- 24,909

suBMERsIBLE PUMP-MOTOR Original Filed Oct. 29, 1954 ,2 shams-sheet 1 Dec. 20, 1960 R, W DOCHTERMAN I Re. 24,909

SUBMERSIBLE PUMP-MOTOR Original Filed Oct. 29, 1954 2 Sheets-Sheet 2 United States Patent O SUBMERSIBLE PUMP-MOTOR Richard W. Dochterman, Fort Wayne, Ind., assignor to General Electric Company, a corporation of New York Original No. 2,782,720, `dated Feb. 26, 1957, Ser. No. 465,551, Get. 29, 1954. Application for reissue May 2, 1960, Ser. No. 26,389

15 Claims. (Cl. 103--'87) Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specilication; matter printed in italics indicates the additions made by reissue.

This invention relates to pump-motor assemblies, and more particularly to those pump-motor assemblies which are adapted to be immersed in the fluid to be pumped.

There are a variety of pumping applications where Iit `is preferable from an economical point of view to build the pump and the motor as a unit. In such instances it will be apparent that it is generally necessary to irnmerse the motor in the fluid to be pumped, which in many cases may be injurious to the motor parts because of corrosion, short-circuiting, etc. Many efforts have been made to solve the problem of protecting the motor from the uid in which it is immersed, most of the solutions being based on the idea of encasing the motor parts so that they were entirely isolated from the fluid; while many of the solutions have been relatively successful, it was, of course, always necessary to provide an eective seal between the motor and the pump so that the fluid would not leak in through the relatively moving parts, thereby considerably increasing the cost of production. It will be seen that it is desirable to eliminate the expense attendant upon the effective insulation of the movable motor parts from the pump. It is proposed in the subject invention that this expense be eliminated by deliberately leaving the movable parts of the motor open to the fluid, and enclosing only the stationary motor parts, which are generally the more sensitive insofar as corrosion and short-circuiting is concerned. Such a `structure permits a low cost pump-motor assembly which is simple to manufacture and which, by the omission of any seal, removes the diiculties occasioned by lea-lts therein.

yIt is an object of this invention to provide a pumpmotor assembly which will incorporate the improved features set forth above.

Further objects and advantages of this invention will become apparent and the invention will be better understood by reference to the following description and the accompanying drawings, and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

This invention, in its broadest aspects, provides a pumpmotor assembly wherein a housing of insulating material has a bore formed therein. A stator member is entirely encased within the insulating material of the housing and is so positioned that it surrounds the bore in relatively close proximity thereto. A rotor member is rotatably supported within the bore, and a pump impeller may be secured to the rotor so as to be rotatable therewith. The

yentire assembly may be immersed in a fluid, generally a liquid, and when electric power is supplied to the stator member, the rotor member will be caused to rotate whereupon the pump impeller will pump the fluid as desired.

In the drawing, Figure 1 is 'a side view, partly broken away and partly "ice in cross section, of the improved pump-motor assembly of this invention;

Figure 2 is a View along lines 2--2 of Figure l;

Figure 3 is a View along lines 3 3 of Figure 1;

Figure 4 is an exploded vie-w in perspective, partly broken away and partly in cross section, of the improved assembly of this invention; and

Figure 5 is a side view of the improved assembly in operation.

Referring now to the figures of the drawing, and in particular Figure 1, there is shown an improved pumpmotor assembly generally indicated by the numeral 1. The assembly is substantially enclosed by a housing 2, which is preferably formed of a stable insulating material having a low rate of fluid absorption. One such group of materials, for instance, includes the epoxy resins which incorporate the features set forth above and, in addition, provide a high degree of toughness for protective purposes. Housing 2 may be formed with a plurality of supporting members, such as 3, on which it will stand when in operation.

Before the housing is formed, preferably by casting or molding, the stationary parts of the motor are assembled, as will be explained below. A stationary shaft 4 is tightly fitted, as by press-fitting, into the central opening 5 of a spider member 6 which has a plurality of equispaced arms 7 extending radially outward. An annular member 8, preferably formed of some suitable metal, such as steel, is provided with a circular inner flange 9 and a similar, but longer, concentric outer ange 10. The assembly of shaft 4 and spider member 6 is tightly fitted within the inner flange 9 of member 8, and a dynamoelectric machine stator member 11, conventionally rnade up of thin laminations 12 of magnetic material, is tightly fitted into outer flange 10 of member 8. [Stator member 11 is provided with a plurality of inwardly opening] The illustrated stator member 11 is of the salient pole type having a pair of dametrically opposed pole pieces 13a which define a plurality of winding slots, such as 13, each of the slots preferably being provided with a sheet of insulating material 14 covering its inner surface so as to separate laminations 12 from the stator coil 15 which is wound in slots 13.

It will be seen from Figure 2 that two coils 15 are provided. It will be understood, however, that the number of coils used is dependent only upon the particular type of dynamoelectric machines utilized, and that this number may be varied without any effect whatsoever as to the improved structure constituting the invention.

It will be seen from the foregoing that the tight fitting of spider 6 into inner ange 9 and of stator member 11 into concentric outer flange 10 will provide a stator member which is maintained in exact concentricity with stationary shaft 4. Member 8 is provided with a plurality of openings 16; a cable 17 containing a pair of conductorsl 18 is passed through one of these openings to connection with the coils 15, the remainder of openings 16 being used for a purpose to be explained herebelow. Housing 2 may then be formed, for instance, by placing the assembly of the stator member 11, spider 6, and shaft 4 within a mold and pouring in the housing material. The mold (not shown) will preferably be of a shape to provide the outer conformation of the housing 2 without further effort being necessary. The insulating material will flow through the openings 16 and will completely encase stator member 11 and coils 15. The mold is so formed as to leave an opening 19 within the housing, and an eyelet member 20 is tightly fitted over shaft 4, as shown, to determine the entrance of insulation material to this cavity. Once the molding operation is complete, stator member 12 will be completely encased in the housing 2 with a thin coat 21 of insulation covering the inner surface of the stator. In the case of relatively small motors, coating 21 is preferably on the order of .0l inch at its narrowest part. This is suicient to insure protection of the inner surfaceof'the statorand is'small enough to avoid an unduly large air gap when the\rotor (to-be described herebelow) is. assembled within the stator.

It is deemed preferable, where the housing Ais cast or molded, to provide a mold of such a shape that cavity 19 wil-l be somewhat smaller than shown in Figure l and then to attach a tool to stationary shaft 4 and ream out cavity 19 to the desired size. This avoids the necessity of achieving the thin coating 21 in the mold, since coating 21 may bemade yrelatively thick and then teamed down to the desired size. The fact `that the tool (not shown) will be mounted von shaft 4 will insure perfect concentricity since, as explained above, shaft 4 is entirely concentric with'stator member 11.

Oncethe structure is completed to the extent set forth above, `a washer member 22'is secured againsteyelet member'20 and a bearing lmember 23 is secured over shaft 4,'in vrotatable relation thereto,-by the addition of a second washer 24 and a second eyelet member 25' at end 26 of shaft 4. A rotor member 27, generally formed of thin laminations of magnetic material, such as 28, is secured to bearing 23 so as to be rotatable therewith. Rotor 27 hasa plurality of slots (not shown) through which pass bars 29 of non-magnetic conductive material. Bars 29 are shorted together at their ends by

rings

30 and 31, thereby to form a squirrel-cage rotor. It will thus be seen that the electric motor used in the illustration ofthe invention is a two-pole induction motor. It wi11,-of course, be understood that other types of motors may be successfully used, and that this particular type has'been set forth in complete detail for purposes of illustration. The outer surface of rotor 27 is preferably coveredwith a thin coat 32 of insulation which may be, for example, either sprayed on, dipped, or brushed on. The assembly of the motor parts of the pump-motor unit is then complete. Rotor 27 is concentrically mounted on shaft 4 within stator member 11 which is entirely encased within housing 2.

A11-additional feature which may be added, if desired, to further insure the protection of stator member 11, is a knurled substantially tubular member 33 which is placed about cable 17 before the casting process. The material of housing 2 will adhere rmly to member 33 whichjin turn, has a pinched-in section 34 to cause it to maintain cable 17 securely in-place. This provision affords fa connectionwhich is-secured in place and which yvwilln'ot provide lan opening for the fluid to be pumped to` enter within ythe housing to the detriment of the stator member 11.

lIt will be observed that end ring 31 of rotor 27 is exftendedaway from the rotor, as at 35, and a member 36 is` tightly fitted over extension 35 so as to be rotatable 'with rotor 27. Member'36 has an outwardly extending peripheral Vflange 37 with a plurality of openings 38 formed therein. A circular piece 39 of sheet metal has a plurality of impeller blades 40 punched out of it. Impeller blades-40 vare each yformed with a pair of tabs 41 "and 42 extending respectively from each side. Tab 41 'ts within opening 38 in flange 37 to position the impeller plate -39 with respect to member 36. Each tab 42 ts y-into an opening 43 formed in amember 44 to position :member 44 with respect to impeller member 39. It will be seen that by means of the'foregoing an impeller as- `sembly is formed consisting of the three

parts

36, 39, and 44. -Member 44 is preferably formed with a U-shaped 'cross section, that is, having an outer circular ilange 45 and an inner circular flange 46.

In forming impeller blades V40fout`of plate 39, a preferred method is to use la plate having the same original'diameter fas 'members 36 an'd`44; the impeller blades `40 are stamped 4out and Ibent over as shown, and the remaining materialbetween the innen-'edge of the impeller blades Aand the original outer diameter of plate 39 is punched out and removed.

It will be seen from the foregoing that there has been provided a complete impeller unit integrally secured to rotor 27 so as to be rotatable therewith.

The bottom of housing 2 has a volute recess 47 formedy therein; recess 47 forms the pump chamber, as is best. seen in Figures 3 and 4, and terminates in an access 48 which leads to a passageway l49, which is preferably' formed in the-die mold during the casting of housing 2.. A pipe 50 is yplaced in connection with Vpassageway '49l so as to extend it all the Way from the volute pumping, chamber 47 at the bottom of the housing out through topf of the housing. It will be seen in vFigure l that pipe: 50 extends far enough above the top 51 of the housing: so that a coupling may be effected with a pipe or hose,. 52.by any desired means, such as clamp S3.

A plurality of relatively pliable strips of metal 55 are' cast into housing 2, when it isformed, with their ends- 56 extending into the volute chamber 47. Strips 55 extend respectively through openings 58 in a member S9.- Once parts 55 have respectively been fitted through openings 5S of member 59, their ends 56 may be bent over' so as to secure member 59 to the remainder of the assembly. Member 59 is seated on parts 60 and 61 formed in housing 2 surrounding volute chamber 47, and it will be seen in Figure 4 that member 59 is so shaped as to correspond substantially with the shape of the bottom of housing 2 so as to cover the bottom of the housing and substantially enclose the pumping chamber 47. Member 59 has an opening 62 located in a protruding portion 63 and formed by a re-entrant annular flange 69 thereof, as is best observed in Figure l. Portion 63 is also provided with a similar outer annular ange 68. When memer 59 is secured in place, opening 62 provides the entranceway to the pumping chamber through impeller blades 40. The protrusion of part 63 provides closerunning surfaces between flanges 45 and 46 and flanges 68 and 69 respectively to improve the pumping efficiency.

When electric conductors 18 are connected to a source of power, rotor 27 will be induced to turn and thereby cause the pump impeller assembly to turn with it. irnpeller blades `40 will d-raw in fluid through Vopening 62 and force the Huid into pump chamber 47. The volute shape which has been given to this chamber tends, as is well-known in the art, to convert velocity into static pressure so that by the time the uid is forced around to access 48 and passageway 49 a relatively high amount of pressure is available to force the fluid up the pipe. It will be observed at this point that volute chamber 47 and the impeller assembly are almost in contact at 64 (see Figure 3) so that practically all the uid pumped around in the chamber will tend to go through passageway 49 and pipe 50 rather than through the small clearance 64 to be pumped around again.

Referring particularly to Figure 5, there is illustrated one possible use of the improved submersible pumpmotor assembly of this invention, wherein the assembly 1 is submerged in a liquid 65, such as water, for instance, and is connected to a source of power through cable 17. Energization of coil'15 of stator member 11 through cable 17 Will cause the pump impeller assembly to rotate and force water through pipe 50 and hose 52 to be ejected as shown at 66. It'will be observed that no effort has been made to prevent the uid, such as water, from passing entirely around the rotorandy inthe air gap, indicated at 67 in Figure l. Whatever the properties of the fluid, no harm can come to the stator mem ber in view of the fact that it is completely encased within housing 2, even at the air gap where'it is ycovered by the thin coating 21. The part of rotor 27 most vulnerable to corrosion, that is, the outer periphery, has also been coated as shown at 32 so that no matter what fluid circulates Within the motor enclosure neither the stator nor the rotor will be harmed thereby. Thus, the

assembly may be entirely -immersed in the uidto be more, this is achieved without any necessity for sealing the motor cavity from the pumping apparatus, and it is possible to make the assembly more compact and to avoid the expense of additional parts while achieving the desired function in an efficient manner.

While exact structures have been set forth for illustrative purposes as to both the motor component and the pump component of the assembly, it will be understood that the construction of either or both may be varied considerably from that shown while still incorporating the essential features of this invention. Therefore, while the invention has been explained by describing a particular embodiment thereof, it will be apparent that improvements and modifications may be made without departing from the scope of the invention as defined in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A motor comprising a housing of insulating material having a bore formed therein, said bore being formed to be open at one end of said housing and closed at the other end thereof, a stator member entirely encased within said housing and positioned concentric with said bore and in relatively close proximately thereto, a shaft member secured within said housing and positioned to extend into said bore concentrically with said stator member, means independent of said housing encased therein and joining said stator member and said shaft member to ensure concentricity thereof, an eyelet member rigidly positioned on said shaft member, and a rotor member rotatably supported on said shaft and substantially axially aligned with said stator member, said eyelet member being arranged to determine the axial position of said rotor member on said shaft member.

2. A motor comprising a stator member; a coil positioned on said stator member; an annular member having a circular outer flange, a circular inner ilange substantially -concentric with said outer ilange, and an element connecting said flanges, said stator being tightly secured within said outer flange; a circular spider member having a central opening arranged within said inner flange in tight engagement therewith; a shaft firmly secured within said central opening; an eyelet member rigidly positioned on said shaft adjacent said spider member; a rotor member rotatably secured on said shaft and substantially axially aligned with said stator member, said eyelet being arranged to determine the axial position of said rotor member; said connecting element of said annular member having an opening formed therein, an electric conductor arranged to pass through said opening and to be connected to said coils, sai-d conductor being adapted to be connected to a source of power thereby to cause rotation of said rotor member; a housing composed of insulating nonabsorbent material arranged to encase completely said stator member and said coil, said housing having a bore formed therein so as to be lopen at one end thereof and closed at the other end thereof, said shaft being arranged to extend into said bore from said closed end thereby to position said rotor in said bore.

3. A motor comprising a housing of insulating material having a bore formed therein, said bore being formed to be open at one end of said housing and closed at the other end thereof, a stator member entirely encased within said housing and positioned concentric with said bore and in relatively close proximity thereto, a shaft member secured within said housing and positioned to extend into said bore concentrically with said stator member, means independent of said housing encased therein joining said stator members and said shaft to ensure concentricity thereof, and a rotor member rotatably supported on said shaft member and substantially axially aligned with said stator member.

4. A motor comprising a housing of insulating material having a bore formed therein, said bore being formed to be open at one end of said housing and closed at the other end thereof, a stator member entirely encased within said housing and positioned concentric with said bore and in relatively close proximately thereto, a shaft member secured Within said housing and positioned to extend into said bore concentrically with said stator member, metallic means encased in said housing joining said stator member and said shaft to ensure concentricity thereof, and a rotor member rotatably supported on said shaft member and substantially axially aligned with said stator member.

5. A motor comprising a stator member, a coil positioned on said stator member; an annular member having a circular outer ilange, a circular inner flange substantially concentric with said outer flange, and an element connecting said ilanges; said stator being tightly secured within said outer flange, a circular spider member having a central opening arranged within said inner flange in tight engagement therewith, a shaft firmly secured within said central opening, a rotor member rotatably secured on said shaft and substantially axially aligned with said stator member, said connecting element of said annular member having an `opening formed therein, an electric conductor arranged to pass through said opening and to be connected to said coil, said conductor being adapted to be connected to a source of power thereby to cause rotation of said rotor member, and a housing composed of insulating non-absorbent material arranged to encase completely said stator member and said coil, said housing having a bore formed therein so to be open at one end of said housing and closed at the other end thereof, said shaft being arranged to extend into said bore from said closed end thereby to position said rotor in said bore.

6. A motor comprising a stator member, a coil positioned on said stator member; an annular member having a circular outer flange, a circular inner flange substantially concentric with said outer flange, and an element connecting said flanges; said stator being tightly secured within said outer ilange, a circular spider member having a central opening arranged within said inner flange in tight engagement therewith, a shaft firmly secured wtihin said central opening, a rotor member rotatably secured on said shaft and substantially axially aligned with said stator member, said connecting element having an opening formed therein, an electric conductor arranged to pass through said opening and to be connected to said coil, said conductor being adapted to be connected to a source of power thereby to cause rotation of said rotor member; and a cast housing composed of an epoxy resin arranged to encase. completely said stator member, said coil, said annular member, said spider, and at least a portion of said electric conductor; said housing having a bore formed therein so as to be open at one end of said housing and closed at the other end thereof, said shaft being arranged to extend into said bore from said closed end thereby to position said rotor in said bore.

7. A pump-motor assembly comprising a housing of insulating material having a bore formed therein, said bore being formed to be open at one end of said housing and closed at the other end thereof, a stator member entirely encased within said housing and positioned encircling said bore and in relatively close proximity thereto, a rotor member rotatably supported within said bore, a pump impeller secured to Said rotor so as` to be rotatable therewith and being adapted to be immersed in a iluid and to pump the same when rotated, the end of said housing adjacent the open end of said bore being formed into a volute recess, and means for covering said recess thereby to form a pump chamber, said impeller being positioned substantially centrally in said recess thereby to pump fluid therethrough, said housing so having a passageway formed therein as to communicate with said recess and adapted to receive the pumped fluid.

8. A pump-motor assembly comprising a housing of afgana insulating material having a bore formed therein, said bore beingforrued.tobeopenat one end of said housingand closed at the other end" thereof, astator member entirely encased within saidrhousing and positioned encircling said bore and in relatively close` proximity thereto, a rotor member rotatably supported within said bore, a shaft arranged totextend-into said bore from said closed end, said rotor ,beingvrotatably mounted on said shaft thereby to position said rotor insaid bore, a` pump impeller secured to said rotor so as to be rotatable therewith, the end of said `housing adjacent the open end of said bore being formed into a volute recess, a member arranged to be secured to said housing and to cover said recess thereby to form a pumpchambensaid Vimpeller being positioned substantially centrally in lsaid recess, said member coveringV said recess having a substantially centrally located opening therein, said housing having a passageway formed therein so as to communicate with said recess wherebyupon rotation of said rotor member said impellerl is adapted to draw uid through said centrally located opening and pump thek same through said chamber into said passageway.

9. A pump-motor assembly comprising a housing of insulating material having a bore formed therein, said bore being formed to be open at one end of said housing and closedat the other end thereof, a stator member entirely encased within said housing and positioned encircling said bore and in relatively close proximity thereto, a rotor member rotatably supported within said bore, a pump impeller secured to said rotor so as to be rotatable therewith, a pump chamber formed at the end of said housing around said impeller, said housing having a passageway formed therein in communication with the outlet part of said chamber, and an inlet passageway arranged in communication with said impeller whereby when said assembly is submerged in a uid and said rotor member is caused to rotate said impeller is adapted to draw iluid through said inlet and pump the same through said chamber into said formed passageway.

10. A pump-motor assembly comprising a housing of insulating material having a bore formed therein,said bore being formed to be open at one end of said housing and closed at the other end thereof, a stator member entirely encased within said housing and positioned encircling said bore and in relatively close proximity thereto, a rotor member rotatably supported within said bore, said rotor having an end ring formed vat the end thereof toward the open end of said bore, and a .pump impeller rotatably positioned in the open end of said bore, vsaid impeller comprising a plurality of impeller bladesand an annular member secured thereto, said annular Vmember having an inner circular ilange extending around and in tight-engagement with said end ring, said housingl having a volute pump chamber formed at vthe openend of said bore about said impeller, a member arranged substantially to close said chamber, means extending from said housing to secure said chamber-closing member thereto, said chamber-closing member having an opening formed therein to provide an inlet to saidimpeller, said 4housing having an outlet passageway formed therein in communication with the outlet portion of said chamber whereby said impelleris adapted `to pump ,liquid` in through said inlet kand force the same lthrough said chamber and said passageway.

11. A pump-motor assembly comprising a housing` of insulating material having a bore formedv therein, said bore being formed yto be open at one endvof said `housing and closed at the other end thereof, a statormember entirely encased within said housing andpositioned concentric with said bore and in relatively close proximity thereto, a shaft member secured within said housing and positioned toextendinto said bore vconcentrically .with sadi stator member, metallic means encased A,in said heusing .joining said, stator member and Saidflshaft atuensure concentricity thereof, a rotor member rotatably supported on said shaft member and substantially axially aligned with said statormember, and a pump impeller positioned in the open en d of said bore and secured vto said rotor so as to be rotatable therewith, said impeller being adapted tobe immersed in a fluid and to pump the same when rotated, said housing having a pump chamber formed therein around said impeller,fsaid housing also having formed therein a passageway in communication with the outletpart of said chamber, and inlet means arranged in communication with said impeller whereby saidimpeller is adapted to draw uidbthroughsaid inlet means and pump the same through said chamber into said formed passageway upon rotation of said rotor member. 12. A pump-motor assembly comprising a stator member, a coil positioned on said stator member; annular member having a circular outer flange, a circular inner flange substantially concentric with said outer flange, and an element yconnecting said flanges; said stator being tightly secured within said outer ange, a circular'spider member having a central opening arranged within said inner ange in tight engagement therewith, a shaft rmly secured within said central opening, a rotor member rotatably secured on said shaft and substantially axially aligned with said stator member, said connecting element of said annular member having an opening formed therein, an electric conductor arranged to pass through said opening and to be connected to said coil, said` con-- ductor being adapted to be connected to a source of power thereby to cause rotation of said rotor member,A a housing composed of an insulating non-absorbent material arranged to encase completely said stator member and said coil, said housing having a bore formed therein to be openatoneend of said housing and closed at` the other end thereof, said shaft being arranged to extend into said borekfrom said closed end lthereby yto position said rotor in said bore, and a pump impeller positioned in the open endV of said bore and secured to said rotor so as to be rotatable therewith, said impeller being adapted to be immersed lin a fluid and to pump the same when rotated, the end of said housing adjacent the openL end of said bore, being formed into a` volute recess, means for covering said recess thereby to form `aApump chamber, said impeller being positioned `substantially centrally Vin said recess thereby to pump fluid therethrough, said housing having a passageway formed therein so Vas to communicate with saidrecess and adapted to receive the pump fluid. v'

13. A pump-motor assembly comprising a stator mm ber, a coil positioned on said stator member; Van annular member having a circular outer tlange, a circular inner flange substantially concentric with said outer ange, and an element connecting said flanges; -said statormbeing tightly secured within said outer ange, `a circular. spider member having a central opening` arranged .withins'aid inner ange in tight engagement therewith, a shaft firmly securedwithin said central opening, a rotor member rotatably ,secured on said shaft and ysubstantially axially aligned withsaid stator member, said connectingelement having an opening formed therein, an electric conductor vrarranged to pass through said opening and to be connected to said coil,` said conductor4 being adapted top be connected to a source of power thereby to cause rotation ofv` said rotor member; a cast housing composed oflran epoxy resin arranged to encase completely said stator member, said coil, ksaid annular member, said spider,` and at least a portion of said electric conductor; said housing having a bore formed therein so as to be open at one end of said housing and closed at the other end thereof, -said vshaft being arranged toextendnto said rbore from-said closedend thereby to position said rotor in saidfbore, said `rotorAhaving- Yan end ring formed at -fthe lend- `theret'if toward` the-openend, of said bore, and a pump `impeller positionedfinithe open-endet saidl bore, said yimpeller samprsinsra: plurality; ,of-i rt1pe11er-bladesA and a second annular member secured thereto, said second annular 9 member having an inner circular ange extending around and in tight engagement with said end ring, said housing having a volute pump chamber formed at the open end of said bore about said impeller, a member arranged substantially to close said chamber, means extending from said housing to secure said chamber-closing member thereto, said chamber-closing member having an opening formed therein to provide an inlet to said impeller, said housing having an outlet passageway formed therein in communication with the outlet portion of said chamber whereby said impeller is adapted to pump fluid in through said inlet and force the same through said chamber and said passageway.

14. In a pump-motor assembly, an electric motor comprising a housing of insulating material having a bore formed therein, said bore being formed to be open at one end of said housing and closed at the other end thereof, a stator member entirely encased within said housing and positioned concentric with said bore and in relatively close proximity thereto, a shaft member secured within said housing and positioned to extend into said bore concentrically with said stator member, a spider member secured about said shaft within said housing, an annular member having an outer circular flange in tight engagement with the outer surface of said stator member and an inner circular flange substantially concentric with said outer flange in tight engagement with the outer surface of said spider member thereby to ensure concentricity of said stator member and said shaft member, and a rotor member rotatably supported on said shaft member and substantially axially aligned with said stator member.

15. In a pumpmotor assembly, an electric motor comprising a stator member, a coil positioned on said stator member; an annular member having a circular outer flange, a circular inner ange substantially concentric with said outer ange, and an element connecting said flanges; said stator being tightly secured within said outer flange, a circular spider member having a central opening arranged within said inner ange in tight engagement therewith, a shaft firmly secured within said central opening, a rotor member rotatably secured on said shaft and substantially axially aligned with said stator member, said connecting element having an opening formed therein, an electric conductor arranged to pass through said opening and to be connected to a source of power thereby to cause rotation of said rotor member, a housing composed of an insulating non-absorbent material arranged to encase completely said stator member and said coil, said housing having a bore formed therein to be open at one end of said housing and closed at the other end thereof, said shaft being arranged to extend into said bore from said closed end thereby to position said rotor in said bore.

References Cited in the file of this patent or the origlnal patent UNITED STATES PATENTS 1,921,111 Apple Aug. 8, 1933 2,067,155 Levy et al Jan. 5, 1937 2,286,993 Naul June 16, 1942 2,318,786 Korte May 11, 1943 2,548,133 Treat Apr. l0, 1951 2,649,048 Pezzillo Aug. 18, 1953 2,685,658 Feiertag Aug. 3, 1954 2,695,969 Yates Nov. 30, 1954