US2217746A - Submersible pump - Google Patents

Description

Oct. 15, 1940. J. B. HAwLEY, JR

vsummslm: PUMP` original Filed Feb. 22, 195'.'

2 Sheets-Sheet 1 l Saffi/1424343:

Oct. 15, 1940. J, B HAWLEY, JR 2,217,746

SUBMERSIBLE IUMP Original Filed Feb. 22, 1937 2 Sheets-Sheet 2 00000000000 Qq O 000000000000 w 000000000000 000000000000 OOOOOOOOOQO gwvemlfob OOOOOOOOOOOOOO- @0000000000000 r Jw//f//m/fr/Jff Patented Oct. 15, 1940 UNITED STATES 2,217,746 SUBMERSIBLE PUMP John B. Hawley, Jr., Minneapolis, Minn., assignor to Reconstruction Finance Corporation, Minneapolis, Minn., a. corporation o! the United States Application February 22, 1937, SerlaLNo. 127,674, which is a substitute for application Serial No.

91,484, July 20, 1936.

Divided and this appli-V cation July 23, 1938, Serial No. 220,932

y s claims. (ci. a-a7) This invention relates to a portable pump and particularly to such a pump which may be operated either submerged in the liquid to be pumped or outside of said liquid. The pump is further of the electric motor driven centrifugal l or rotary type. Such pumps are generally used for pumping liquid from the holds of vessels, from mines and other places where it is convement to lower a pump into the liquid to be pumped.

It is an object of the invention to provide a submersible pump having a novel and eiiicient impeller structure.

It is also an object of the invention to provide a pump comprising a casing having a minimum' of projecting parts.

It is still another object of the invention to provide a pump having a novel means for insuring drainage.

:0 It is still further an object of the invention to provide a pump of very compact structure so as to have as short length of impeller shaft projection as possible.

'I'hese and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings, in which like reference characters refer to similar parts throughout the several views and in which:

Fig. l is a central vertical section through the main portion of the pump;

Fig. 2 is a partial view similar to Fig. 1 shown on an enlarged scale;

Fig. 3 is-.raview in end elevation as seen from the left of Fig. 2;

Fig. 4 is a view in end elevation of some of the parts shown in Fig. 2;

Fig. 5 is a view in side elevation oi the suction end of the pump with the inlet valve and strainer secured thereto;

Fig. 6 is an inner end view of the inlet end member of the pump casing; and

Fig. 7 is a view partly in end elevation showing the inner side of the main impeller and partly in vertical section through the vanes of said impeller.

Referring to the drawings a pump is shown having a main or central casing portion I5. While this portion might be of various forms, in the embodiment of the invention illustrated it is shown as substantially cylindrical, the same having an outer wall I5a and an inner wall I5b, said walls forming an' annular chamber |50 therebetween and said inner Wall forming a central chamber I5d therein. An end member or suction nozzle I6 is secured to the inlet end of casing I5, said member being of tapering Io'rm toward its outer end and having a cylindrical exteriorly threaded inlet portion |60, at its outer end of much? less diameter than casing I5. plurality of recesses about the sides thereof forming short ange portions IBb apertured, to receive headed screws l1 threaded into the end of casing I5 and which secure member I6 to casing I5. Member I6 has on itseinner side helical distribut- 10 ing plates I6d cooperating with an impeller to be later described. Casing I5 is provided in its end and adjacent its outer side with an annular groove and member I6 has a projecting annular rib l6c tting into said annular groove and en- 15 gaging a gasket I8 seated in said groove. Gasket I8 is compressed in said groove by the rib I6c so that a fluid-tight joint is formed. A motor I5 is disposed in chamber 15d, the same comprising a stator I9a and a. rotor I9b. Said stator :dts against the wall I5d and is engaged at one end by a cup-shaped member 20 and at its other end by\ a cup-shaped member 2l. One or more keys 22 are fitted in the inner end of member 2,0 and also in the stator so that said members are keyed together. Casing I5 is provided with a plurality of recesses I5e at its outer side, there being only a thickened portion of wall between the bottom of these recesses and chamber I5d. Said portion of wall has an inwardly tapered threaded opening into chamber I5d and headed drain plugs 23 are threaded into said openings. one of said drain plugs having its end extending into an opening 20a. in member 20. Said latter drain plug therefore functions-to prevent rotation of member 20. It will be noted that the heads of drain plugs 23 are disposed in `recesses I5e and are thusprotected from being struck by any object when the pump is being suspended. Wall I5b is provided in its inner side with annular slots in which are disposed snap rings 24 and 25. Said rings are substantially cylindrical but open at one point so that they can be compressed and inserted into said slots and will remain therein by their cxpansive elasticity? or resiliency. It will be noted that member 2l has a reduced portion extendingalong the inner side of snap ring 24 and thus has a shoulder formed thereon engaging the inner side of snap ring 24. 4\Any' outward stress on member 2| is thus taken by snap ring 24 and transmitted to the casing wall I5b. Just at the outer side of snap ring 24 member 2I is soldered to the inner side of wall I5b `by solder 26, which is preferably silver solder. Member 2i has an inwardly projecting central portion bored to re- 55 Member I6 has a 5 ceive and havesecured therein a bearing 21 illustrated as of the ball bearing type. A shaft 28 is secured to the rotor I 9b by a long key 29, said shaft having a slightly enlarged portion between the end of rotor I9b and bearing 21 and having a reduced portion journaled in said Bearing so that a shoulder on said shaft engages the inner side of bearing 21 which thus takes the outward or downward thrust of said shaft. A cup-shaped member or housing 30 has an open inner end with a groove formed therein fitting over an annular outwardly projecting rib I5f on the outer end of casing I5 substantially alined with inner wall I5d. Member 30 forms an annular passage I6d with member I6 constituting in effect a continuation of annular passage I5c. Member 30 has a multiplicity of radially projecting lugs apertured to receive headed screws 3I threaded into the end of casing I5 for securing member 30 to said casing. A gasket 32 is disposed in the groove in the end of member 30 and engaged by the rib I5f so that a fluid-tight joint is formed. Member 30 has a central inwardly extending portion 30a having a cylindrical bore in its outer side to form a cup-shaped recess and portion 30a at its inner side has a centralhub bored to receive a member 33 tightlyi fitting therein and having parallel end faces perpendicular to the axis of shaft 28. Member 2| also has a shallow bore at its outer side in which is tightly fitted a disklike member 34 having an outer face perpendicular to the axis of shaft 28. A sealing disk 35 preferably made of carbon tightly surrounds shaft 28 and engages the outer face of disk 34. Another similar disk 36 also preferably made of carbon engages the inner face of member 33. Disk 36 has projections 36a, extending radially at right angles to each other as shown in Fig. 3 and disk 35 has similar projections. A cage member 31 is provided having a central portion with an inner bore 31a fitting on shaft 28. At either side of said central portion member 31 has an outwardly projecting cylindrical shell portion 31b and each of said shell portions has formed in its end slots 31e in which are partially disposed the projections 36a. Between bore 31a and its outer side the central portion of member 31 llas a plurality of cylindrical bores or holes 31d extending therethrough. Said central portion also has a threaded bore extending radially from the outer side of member 31 to bore 31a and said member is secured to shaft 28 by a set screw 38, a second set screw 39 also being disposed in said threaded bore and closing the outer end thereof. Cup washers 40 of thin sheet metal surround shaft 28 between disks 35 and 36, the same facing said disks respectively and having lugs 40a thereon extending into compression coiled springs 4I disposed in the holes 31d. Holes 31d are shown as nine in number and five of the springs 4I are preferably secured at their ends to one washer 40 while the remaining springs are secured at` their ends to the other washer 40. This facilitates handling of the springs. Each washer 40 has in its cupped side a flanged ring 40a which extends beyond the edge of washer 40 and engages the outer portion of a resilient ring 42. Ring 42 has a central portion fitting against shaft 28 and this portion is cylindrical at its inner end and is clamped against shaft 28 by a ferrule 40h. Ring 42 has a flange or projecting portion at its outer side which bears against disk 35 or 36. From the described construction it will be seen that springs 4I urge washers 4I! away from each other and through the rings 48a press on the outer portions of rings 42 which are in turn pressed against the disks 35 and 36 respectively. There is very little outward motion of members 42 against the disks 35 and 36 and what motion there is is permitted through the flexing of rings 42. The ferrules 40h have been found to be very important. Without these it was found that relative motion would occur between shaft 28 and rings 42 which would interfere with the proper functioning of the seal. With the present construction the central portion of ring 42 is held in fixed position relative to shaft 28 and any outward motion of the outer portion of the ring is accomplished by flexing of the ring. Members 33 and 34 in practice have been made of nickel and their faces which are engaged by the disks 35 and 36 are made of some extremely hard and noncorrosive metal. In practice these disks have been coated with stellite, a composition of cobalt, chromium and tungsten. Tungsten carbide has also been used. 'Ihe disks 35 and 36 may be made of metal but in practice it has been found very suitable to have these made of carbon. A tight seal is thus effected designed to prevent the passage of any liquid through member 2I or through member 30. Another disk 43 similar to disks 35 and 36 engages the outer face of member 33 at the outer side of member 30. Disk 43 is engaged by a ring 44. A cupped washer 45 receives rings 44a and is engaged at its outer side by a plurality of compression coiled spring 46 disposed in cylindrical sockets formed in the inner or upper side of an impeller member 41 having a hub secured to a slightly tapered portion of shaft 28 by a key 48. Said hub of impeller 41 has a cylindrical flange 41h extending inwardly about members 44 and 45, said flange having slots therein at right angles to each other and receiving projections on member 43 similar to the projections 36a '\n member 36. Member 43 is thus driven by member 41 just as member 36 is driven by member 31. Shaft 28 has a reduced threaded end beyond impeller 41 on which is threaded a closed nut 49 having an outer rounded end. A spring washer 50 is disposed between nut 49 and impeller 41. Impeller 41 has inner and outer Walls between which extend a plurality of spaced vanes 41a. The inner or upper wall of impeller 41 is concave and of `conical form. An auxiliary impeller 5I is disposed between member 30 and impeller 41, the same having a cylindrical hub of a size to be journaled in the bore of portion 30a. Said auxiliary impeller has a conical wall parallel to the inner surface of impeller 41 and has a plurality of radial blades 5Ia engaging impeller 41 by which it is driven. A pin 5Ib connects impellers 41 and 5I so that the latter is driven by impeller 41. It will be seen that a chamber is formed within member 30 between the impeller or pump chamber and the motor chainber I5d. Casing I5 has a recess I5g in the side thereof from the bottom of which' an opening extends into theichamber in member 30, the outer end of said opening being threaded and receiving a threaded plug 52. Said plug has a passage therethrough at its inner end having an enlargement outward thereof forming a valve seat with which a ball valve 53 cooperates. Ball 53 is pressed toward its seat by a coiled compression spring 54. Spring 54 is engaged at its outer end by plug 55 having a central passage therethrough and held in place by a transverse pin 56.

The upper end of casing I5 has secured thereto an upper end member 6I). The upper end of casin g I5 adjacent its outer side has an annular groove therein into which enters an annular rib 60a formed on the end of member 68. A gasket 6| is disposed in said groove and engaged by said rib. Member 50 has a plurality of recesses about the outer side thereof forming short flange porl tions 60h apertured to receive headed screws or bolts 62 threaded into the end of casing I5 for holding rib Iatightly against the gasket 8| to form a fluid-tight closure. Member SI1-is tapered toward its outer end and has a reduced exteriorly threaded cylindrical outlet portion 60e. As shown in Fig. 1 this portion is closed by a cap 63l threaded onto portion 60o and engaging a gasket 64 held between the same and the end of member 68. Cap 63 has secured to and projecting from its outer side a bail handle 63a. The member 28 previously referred to has an inwardly or downwardly extending central portion 20h bored at its inner side to receive a bearing 65 shown as of the ball bearing type in which is journaled a vreduced portion of shaft 28. Bearing 65 is engaged at its upper or outer side by a disk 65 having a central portion thinner than its peripheralportion. Disk 86 is engaged centrally by a screw 61 extending through portion 20h, said screw having a slotted outer end and carrying a jamb nut 68 engaging the outer side of portion 20h. Disk 66 has considerable resiliency and shaft 28 is thus held with some resiliency lengthwise thereof. An annular plate 69 extends about an inner side af wall I5b and at its upper or outer side engages the inner side of snap ring 25. A plurality of circumferentially spaced screws 10 are threaded through plate 69 and engage the outer end of member 20. Member 20 as already stated engages theupper end of stator I9a so that the latter is thus held longitudinally in place by screws 10. It will be noted that the snap ring 25 takes the outward or upward thrust caused by the action of screws 19. The endwise thrust or stress of the motor is thus taken at both ends by the snap rings 24 and 25. An end cover plate 1| has an annular groove adjacent its outer edge fitting over a projection or rib I5h at the upper end of wall I5b and a gasket 12 is disposed in said groove and engaged by said projection or rib. End cover plate 1I has a plurality of lugs at its periphery apertured to receive headed screws or bolts 13 which are threaded into the end of casing I5 and hold said cover plate in place compressing gasket 12 and forming a fluid-tight joint. A stuffing box cover 14 of conical cup-shaped form is provided having an annular groove at its inner end into which fits an annular rib or flange 1Ia on cover 1I, a gasket 15 being disposed in said groove and engaged by rib 1 Ia. Member 14 has a plurality of lugs at its periphery apertured to receive headed bolts or screws 16 threaded into cover plate 1I and holding member 14 in place with gasket 15 compressed to form a fluid-tight joint. Member 14 has a recess at one side thereof with an opening at its bottom leading to the interior of member 14, said recess being adapted to receive packing 11. The walls of said recess are interiorly threaded and a packing gland 18 is screwed therein compressing said packing about a cable cover or sleeve 19 passing through said gland and through said opening into member 14. Cable 19 covers a plurality of conductors 19a, one of which is shown as secured to the upper side of cover 1| by a screw 80 and another of which is shown clamped between nuts 8| threaded onto a rod 82 forming a binding post and extending through cover 1 I. Rod 82 has secured thereto at the inner side of cover plate 1| a plurality of conductors 83 held in place thereon by nuts 84 and passing through an insulating bushing 83a in member 20. An insulating bushing 85 surrounds rod 82 and is tightly fitted in cover 1I and passes therethrough, the same being enclosed at its outer side by another insulating plug or member 86. Rod or binding post 82 is thus insulated from cover 1I. Member 6I) has a cup-like projection 60d at its upper side adapted to receive packing 81. Member 19 passes outwardly through an opening in member 68 through the packing 81 and through a packing gland 88 threaded into portion 60d and compressing packing 81 about member 19. Gland 88 has an outer portion 88a threaded to receive a pair of headed screws 89 extending through a clamping cap 90 overlying cable sleeve 19 so that the latter is clamped in position by the clamping cap 90. Scr'ews 89 as well as screws I1, 3|, 62, 13 and 16 are shown as having split spring washers 9| beneath the heads thereof. Member 60 is shown as having a ring lug 60e at one side thereof. 1

In Fig. 5 the pump casing, particularly end member I6, is shown ashaving threaded thereon and secured thereto an inlet valve member 92. Said Valve member has secured at its outer or lower end a strainer member 93. Members 92 and 93 per se form no particular part of the invention and need not be further described.

The pump can be conveniently transported by using the handle 63a when cap 63 is in place and the pump is not in pumping operation. Whenthe pump is to be used cap 63 will be removed and the discharge hose or conduit will be connected to portion 60o. The pump can be lowered` into the hold of a vessel or other desired place by a cable secured in the lug 60e. When it is desired to operate the pump the motor I9 will be started by current supplied through the conductors 19a which will be controlled by a suitable switch. Rotor I9b rotates and shaft 28 is driven. Impeller 41 is rotated and water is drawn through the strainer 93, through the valve 92 which is a regular pump check valve and said water passes from impeller 41 into the annular chamber between members I6 and 39. The water is directed against the distributing vanes I8d on member I6 which assist the flow and distribution of the water and the water passes upwardly through annular chamber I5c, through the annular chamber between members 14 and 80 which alines with passage or chamber I5c and the water then passes out through the end of member 6'0 and is discharged in the desired place by the attached conduits. The auxiliary impeller 5I is driven by impeller 41 and discharges any liquid which may have passed into the cylindrical chamber in portion 30a. By having the discharge passages of the impellers directed upwardly the average effective diameter of the auxiliary impeller 5I is greater than the average diameter of the main impeller 41. The effective diameter of impeller 41 would be that at the lower outer edge or substantially along a line extending from said edge perpendicular to the center line of the discharge passage. The fluid pressure on the seal member 43 is thus either zero or less than zero or in other words, there is a partial vacuum in the chamber in portion 30a. This vacuum reaches about five pounds when the pump is operating at zero pressure and is at zero when the pump discharge is shut off. It will be seen from this that the auxiliary impeller 5| thus acts to draw out any liquid from portion 38a and will draw out and discharge any fine particles of dirt or foreign matter which might work through the running fit between the cylindrical portion of impeller 5| and the bore in portion 30a. When the pump is running, therefore, there is no tendency for the liquid to pass into the chamber in portion 30a and thus to work past the seal members 43 or 36. It will be seen that by having the auxiliary impeller 5| that the pressure on the sealing members 33 and 34 is substantially zero and that there is a negative pressure on these members at all times when the pump is operating or when the motor' i running. The seals are subjected to a maximum pressure equal to the submergence pressure'when the pump is not running. The auxiliary impeller thus constitutes means for limiting the pressure on the sealing members to a small percentage of the discharge pressure of ythe pump.

It will be noted that by having the springs 46 housed in the impeller 4,1 the structure is made quite compact lengthwise of shaft 28. 'I'his eliminates extra parts and saves space lengthwise of the pump. This is highly important since the shaft overhang from theglower bearing 21 must be kept as short as possible. It is also pointed out that members 30 and I6 each has one single annular sealing gasket. This results in a structure where both gaskets can be kept tight. It is quite diicult to have two parallel gaskets on one part and keep both tight. 'I'he inner gasket 32 is quite inaccessible and it is all the moreimportant' to have this gasket kept tight. Members 68, 1| and 'I4 also have only a single gasket and the above remarks apply to these members. Gaskets |6c, 32, 60, 'Ha and 12 are of resilient material, preferably containing cork. Members I6, 30, 60, 'Il and 14 are drawn down to a metal to metal contact at the sides of the gasket grooves, thus assuring concentric assembly, the engaging edges being disposed in planes perpendicular to the centralaxis of the parts. The member 'I4 encloses a terminal chamber independent of the chamber at the inner side of member 1|. This forms a convenient chamber for the distribution of the conductors 'and a convenient connection for a ground conductor for grounding the casing is made by the screw 8U. A tight andinsulating seal is made by the telescoping members 85 and 86 which are clamped on member 1| by the nuts 84 and 8|. The cable member 79 is flexible so that no strain is put on member 14 by any exterior stresses on the cable. Should any water leak into the chamber in member 14 about the cable, this water can be removed by removing member 14 Without removing member 'Il and thus breaking the seal into the motor chamber. By having the recesses |58 and |5g the plugs therein are protected from striking exterior objects in the handling of the pump. Should the pressure in the chamber between members 2| and 30 exceed the outside pressure and any water kbe in Said chamber it will lift ball valve 53 and pass out through plug 52. The pressure within member 30 therefore cannot exceed the exterior or submergence pressure plug the pressure of spring 54.

The motor unit is held by members and 2|. These members react against the snap rings 24 and 25 so that the end thrust is taken by the casing wall. No end thrust of the motor due to holding it in place or due to expansion and contraction of the parts due to temperature can place any pressure on member 1| and thus cannot affect the seal between member 1| and wall |5b of the casing. It should also be noted that no endwise pressure is exerted on the solder 26 since the end thrust of member 2| is taken by snap ring 24. The action of screw 81 on' resilient disk 66 holds shaft 28 under a slight reslliently yleldable pressure. This prevents any axial displacement of the shaft which might disturb the accurate positioning of the sealing disks 35, 36 and 43 or which might disturb the proper positioning and clearances of the impellers. The yielding pressure exerted on shaft 28 also acts to prevent any hammer eiect due to a shock to the pump due to dropping or other cause.

It is pointed out that since sealing members 36 and 43 are urged in opposite directions against member 33 that one of these members will be urged to sealing position by the pressure whether the pressure is positive or negative in the chamber within member 38. The springs of one of the sealing members will thus always act with the pressure. It is impossible to balance or adjust a spring pressure'for a wide range of positive and negative pressure With the described arrangement as above stated one seal always acts with the pressure whatever the pressure in the adjacent chamber. By having member 33 made with parallel sealing faces this part can be made with extrme accuracy. This results in a very eiicient seal.

By having gland member 88 constitute the cable clamp the necessity for a separate or auxiliary cable clamp is eliminated.

From the above description it is seen that applicant has provided a very simple and highly efficient pump. 'I'he pump is designed to withstand the rigorous use to which it is put when submerged at considerable depths. The motor is protected from the liquid to be pumped and is mounted in a very ecient manner. The parts are all contained within the outer wall of the casing. The pump has been amply demonstrated in actual practice, found to be very successful and efficient andlis being commercially made.

This application is a division of applicants copending application, S. N. 127,674, filed February 22, 1937, which was a substitute for applicants copending application S. N. 91,484, led July 20, 1936.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts, without departing from the scope of applicants invention, which generally stated, consists in a device capable of carrying out the objects above set forth in the parts and combinations of parts disclosed and defined inthe appended claims.

What is claimed is:

1. A pump of the submersible type having in combination, a casing having a chamber with an inlet at one end and a sealing chamber adjacent said chamber, a shaft extending longitudinally and centrally of said casing and through said chambers, means for driving said shaft, an impeller secured to said shaft adjacent said inlet and an auxiliary impeller disposed inwardly of said impeller to discharge any fluid which might pass inwardly thereof, said casing having a centrai hub at the lower end of said sealing chamber having a cylindrical bore closed at its upper end and forming an auxiliary` sealing chamber, said auxiliary impeller having a hub journaled in said bore.

2. A pump of the submersible type having in combination, a casing having an inlet at one end, a shaft extending longitudinally and centrally of said casing to a point adjacent said inlet, means for driving said shaft, an impeller secured to said shaft having an outwardly directed inlet opening and discharge passages flaring upwardly, means forming an auxiliary sealing cihamber above said impeller and an auxiliary impeller disposed inwardly of said impeller and having an inlet passage extending upwardly and having an open upper end communicating with said auxiliary sealing chamber and having discharge passages extending radially and upwardly.

3. A pump of the submersible, type having in combination, a casing having an inlet at one end, a shaft extending longitudinally and centrally of said casing to a point adjacent said inlet, means for driving said shaft, a main impeller secured to said shaft having a downwardly directed inlet opening with an upwardly and outwardly directed discharge passage, means forming an auxiliary sealing chamber above said impeller, an auxiliary impeller disposed inwardly of said impeller and having an inwardly directed inlet opening communicating with said auxiliary sealing chamber to maintain a negative pressure therein.

4. A pump of the submersible type having in combination, a casing having an inlet at its lower end, a shaft extending longitudinally and centrally of said casing to a point adjacent said inlet, means for driving said shaft, an. impeller secured to said shaft having discharge passages flaring upwardly and having a conical inner surface sloping downwardly toward the axis of said shaft, said casing having means forming an auxiliary sealing chamber above said impeller and an auxiliary impeller having blades fitting against said surface to form passages therewith, said auxiliary impeller thus having upwardly extending discharge passages and having an inlet opening communicating with said auxiliary sealing chamber.

5. A pump of the submersible type having in combination, a casing having an end chamber with inlet opening at one end, a shaft extending longitudinally of said casing, an impeller secured to said shaft adjacent said inlet opening, said casing having a sealing chamber inwardly of said chamber, a sealing means about said shaft inwardly of said impeller, an auxiliary sealing chamber between said impeller and rst mentioned sealing chamber and an auxiliary impeller between said impeller and sealing means for maintaining a low pressure on said sealing' means and in said auxiliary sealing chamber when said pump is operating.

6. A pump of the submersible type having in combination, a casing having a chamber with an inlet opening at one end, a second chamber for containing a driving means and a sealing chamber between said chambers, a shaft extending longitudinally of said casing, means in said second chamber for driving said shaft, an impeller secured to said shaft adjacent said inlet opening, a sealing means surrounding said shaft between said first mentioned chamber and sealing cham- 55 ber and a plurality of springs urging said means to sealing position, said impeller having recesses therein for receiving said spring.

'7. A pump of the submersible type having in combination, a casing having inner and outer walls forming an annular chamber therebetween, a shaft extending axially of said casing, a partition within said inner wall through which said shaft passes forming the bottom of a motor chamber in said casing, a second casing having an open-ended cylindrical portion of substantially the same diameter as said inner wall, means securing said second casing to said first mentioned casing, said inner casing having a chamber therein forming a sealing chamber between its lower end and said partition, said shaft extending through said second casing, sealing means about said shaft at said partition and lower end of said second casing, a propeller secured to said shaft below said second casing, a third casing having a cylindrical portion of substantially the` same diameter as said outer wall and forming a continuation thereof, .means securing said third casing to said rstmentioned casing, a 'gasket between said third casing and saidrst mentioned casing, said third casing tapering toward its lower end and having a cylindrical open' end forming an inlet passage for the iiuid moved by said impeller, which uid passes between said second and'third casings and between said innen-and outer walls, whereby said third casing may be removed and access had to said propeller Without breaking said sealing means.- A

L 8. A pump'of the submersible type having in combination, a casing' having inner and outer walls forming an annular chamber therebetween, a shaft extending axially of said casing, a partition within said inner wall through which said shaft passes and forming the bottom of a motor chamber, a bearing for said shaft in said partition, a second casing having an open-ended cylindrlcalportion of substantially the same diameter as said .inner wall, means securing said second casing to said first mentioned casing, a gasket between said casings, said second casing having a chamber therein. forming a sealing chamber and having1 a lower end through which said shaft passes,`means for sealing the openings for said shaft through said partition and second casing, a third casing having a cylindrical open end of substantially the same diameter as said outer wall and forming a continuation thereof, means securing said-thlrdcasing to said rst mentioned casing, a gasket between said third casing and said first .mentioned casing, said third casing tapering toward its lower. end and having a reduced cylindrical open-ended portion at its lower end, a propeller secured to said shaft b etween said secondand thirdcasings, said second and third casings forming a passage communicating with the passage through said inner and outer Walls through which the liquid is moved by said propeller, whereby said third casing may be removed and access had to said propeller without breaking said sealing means.

JOHN B. HAWLEY, Jl.

Images