US3269323A

US3269323A - Pumps

Info

Publication number: US3269323A
Application number: US422371A
Authority: US
Inventors: Kenneth R Lung
Original assignee: Tait Manufacturing Co
Current assignee: Tait Manufacturing Co
Priority date: 1964-12-30
Filing date: 1964-12-30
Publication date: 1966-08-30
Anticipated expiration: 1983-08-30

Description

United States Patent 3,269,323 PUMPS Kenneth R. Lung, Morehead City, N.C., assignor to The Tait Manufacturing Company, Dayton, Ohio, a corporation of Ohio Filed Dec. 30, 1964, Ser. No. 422,371 6 Claims. (Cl. 103-87) This invention relates to submersible pumps, and more particularly to a multi-stage submersible motor-pump assembly having an improved arrangement of the housing and impellers whereby the impellers are maintained in axial alignment without the need for a pump shaft.

Primarily, the apparatus of the present invention is directed to a submersible pump assembly which is intended for submerging into a well, within the well casing, and which operates in response to the pressure variances within a supply tank connected by a pipe line with the pump. The invention has particular reference to an improved motor-pump assembly which provides for economical construction and, in addition, may be easily assembled for economical production and easily disassembled for servicing.

Accordingly, it is a primary object of the present invention to provide a multi-stage submersible pump assembly having an improved impeller and housing structure which makes possible an aligned assembly of the impellers to the motor without requiring a pump shaft.

As another object, the present invention provides a submersible multi-stage pump having a plurality of impellers and a novel construction for interlocking successive impellers together for driving engagement in such manner as to maintain axial alignment therebetween while providing for relative axial movement between adjacent impellers to permit the upward end thrust developed by each impeller to be absorbed within its corresponding housing.

Still another object of the present invention is to provide a submersible pump as outlined above which has an improved construction for connecting the impellers to the motor shaft in order that the motor-pump assembly may be easily assembled for economical production and disassembled for servicing.

A further object of the invention is to provide a submersible pump as outlined above wherein a series of impellers are adapted to drive each other in a successive manner and to distribute equally the drive load around the periphery of the impeller hub so that the impellers may be constructed inexpensively from a plastic material which resists corrosion and provides a smooth unfinished surface for high pump efficiency.

Other objects and advantages will be apparent from the following description, the accompanying drawing and the appended claims.

In the drawing:

FIG. 1 is an elevational view illustrating a submersible pump assembly incorporating the improved impeller structure and positive drive arrangement between successive impellers and the motor shaft in accordance with the present invention;

FIG. 2 is an enlarged detail view in axial section of the motor portion of the motor-pump assembly shown in FIG. 1;

FIG. 3 is an enlarged fragmentary view in axial section through the pump portion of the motor-pump assembly of FIG. 1 showing details of construction in accordance with a preferred embodiment of the invention; and

FIG. 4 is an enlarged section on the line 44 of FIG. 3.

Referring to the drawing, which illustrates a preferred embodiment of the present invention, the submersible pump assembly includes a pump 12 of the mu-lti-stage centrifugal type and a motor 14 having electric leads 15 which are protected by the shield 16. The lower end of the pump 12 includes an intake housing 18 which serves to connect the pump rigidly to the motor 14. A cylindrically shaped perforated screen 19 is mounted around'the intake housing 18 and serves to filter the liquid flowing into the pump 12.

As shown in the enlarged detail view of FIG. 2, the motor 14 generally includes a motor shaft 20 and rotor 22 which are rotatably mounted within the sleeve type bearings 24 fitted within the

end brackets

26 and 27. The motor casing 30 serves to support the

end brackets

26 and 27 and also the stator 31, which is mounted within the cylindrically shaped yoke 33. Thrust washers are provided on each end of the rotor 22 and are adapted to rotate with the motor shaft 20 against the end of the sleeve bearings 24 in order to oppose the axial thrust which is transferred to the motor shaft 20 from the pump '12. It is to be understood, however, that other suitable bearing means, as for example, ball bearings, can be used to take both the radial and axial thrust produced on the motor shaft.

Referring to FIG. 3, the bottom of the intake housing 18 includes an annular mounting flange 40 which is secured rigidly to the end bracket 27 of the motor 14 by a series of cap screws 42. The upper end of the intake housing 18 includes a male threaded portion 43 which extends upwardly from the top plate 45. Integrally connecting the top plate 45 to the mounting flange 4%) are a series of four radially spaced ribs 47 which support the bearing retaining hub 49.

Connected to the-threaded portion '43 and extending upwardly from the top of the intake housing 1 8 are the stacked pump housing 50 and top support housing 5.1 which are preferably formed from a non-corrosive plastic material and have threaded connections '52 for removably coupling the housings together to delflne the separate stages of the pump. While only three stages are shown, it is to be understood that any number of stages can be employed depending upon the output pressure and flow rate desired. As shown, the top support housing 5'1 is provided with a series of suitable vanes 53 which serve to support the top support plate 54. Rigidly mounted within each of the pump housings 50 is a diffuser member 57 which cooperates with the top plate 59 of each pump housing 50 to direct a smooth [flow of liquidradially inwardly to the inlet portion of an impeller 60.

Each of the impellers 60 includes a top opening having an internal spline 61 formed therein which is adapted to receive slidably an external spline formed on the lower hub extension '62 of the above adjacent impeller to form a socket connection which provides both axial and radial alignment of the impellers. The lower hub extension 62 of the bottom impeller is similarly connected with a splined socket in the upper end portion of a coupling 65 which is attached by a spline connected 67 to the motor shaft 20 for positive driving thereby.

Surrounding the lowermost hub extension 62 and retained by the hub 4-9 is a bearing sleeve 72 preferably formed from a material having a low coeflicient of friction, as for example, a plastic such as a fluorinated hydrocarbon or similar material. Each of the hub extensions 62 of the impellers 60 includes a cylindrical portion 73 which is rotatably supported in a cylindrical bearing surface provided by a flange 74 formed as a part of the associated diffuser member 57. These

bearings

72 and 74 cooperate with the spline connection between the impellers 60 to hold the impellers in axial alignment with the motor shaft 20.

The downward axial thrust produced by the impellers 60 of the pump during operation is transferred to the motor shaft 20 and is opposed by the thrust washers 35 (FIG. 2) spaced on the opposite ends of the rotor 22. In some installations, however, the impellers 60 may produce an upward thrust. When this happens, the upward thrust produced by each impeller is carried by each corresponding stage housing by the thrust bearing or washer 80 spaced between the top surface of each impeller 60 and the bottom surface of the flange 74 formed as part of the diffuser member 57. The upward thrust produced by the top impeller 60 is carried by support plate 54 forming a part of the top housing 51 and provided with a central projection '81 which spaces the top thrust washer 80. Thus as a result of the axially floating spline connection between each impeller 60, the impellers are adapted to move relative to one another to distribute the combined upward thrust uniformly over the

housings

50 and 51. Furthermore, it can be seen that the axial spacing of the housings and impellers is not critical as a result of the axial floating provided for each impeller while maintaining the axial alignment.

One important feature which is provided by the successively connected impellers is the substantial cost of saving which results from eliminating the pump shaft. Commonly, the pump shaft is constructed from a corrosion resistant material such as stainless steel and thus adds significant cost to the pump portion of the submersible motor-pump assembly. On the other hand, the impellers formed in accordance with the present invention may be molded from a plastic material which offers corrosion resistance in addition to considerable cost savings. [Furthermore, the molded plastic impellers substantially eliminate the need for machining the impellers after the molding operation. In addition, the coupling 65 may be formed from a suitable plastic bearing material, in which case, all of the rotary components of the pump are formed of a corrosion resistant plastic material.

Another desirable feature which is provided by a pump formed according to the invention is the simple and convenient manner in which the pump can be assembled and disassembled. For example, by simply unthreading the housings 50, the pump may be separated at any stage for servicing or replacement without disturbing the next adjacent stage. For example, the upper housing 51 and enclosed impeller 60 may be removed without disturbing the adjacent pump stage housing 50 and its enclosed impeller 60. On the other hand, if it is desirable to remove only the motor 14 from the pump 12, the motor may be separated by simply removing the screen 19 and the screws 42, since the motor shaft 20 can slide out of engagement with the coupling 65.

It is to be understood that the term spline connection as used herein is intended to include any aligned socket arrangement whereby the loading transferred through the connection is distributed generally uniformly around the periphery of the hub extensions '62 and also provides for relative axial movement between adjacent impellers while maintaining axial and radial alignment of the impellers in the housings.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. An improved submersible multi-sta-ge pump adapted to be driven by a drive shaft extending from a motor, comprising a plurality of pump housings connected rigidly together in stacked relationship, a corresponding plurality of impellers arranged With one impeller positioned in each said housing, integral hub extension means projecting axially from one side of each of said impellers and having external spline means formed thereon, means defining an axial opening in the opposite side of each said impeller having corresponding internal spline means for receiving said hub extension means of the adjacent said impeller to form a positive drive socket connection therebetween and for maintaining said impellers in radial and axial alignment, means separably connecting adjacent said pump housings and corresponding impellers to provide for convenient servicing of the pump, and coupling means for connecting the end impeller to the motor drive shaft for rotating said impellers by transferring the torque successively fromo'ne said impeller to the adjacent said impeller through said socket connections.

2. An improved submersible multi-stage pump adapted to be driven by a drive shaft extending from a motor, comprising a plurality of pump housings connected rigidly together in stacked relationship, a corresponding plurality of impellers arranged with one impeller positioned in each said housing, integral hub extension means projecting axially from each of said impellers and having external spline means formed thereon, means defining an axial opening in each said impellers having corre sponding internal spline means for receiving said hub extension means of the adjacent said impeller to form a positive drive socket connection there'between and to provide for relative axial movement between adjacent said impellers while maintaining said impellers in radial and axial alignment, bearing means associated with each stage housing for opposing axial thrust produced by said impeller spaced Within, means for separably connecting adjacent said pump housings and corresponding impellers to provide for convenient servicing of the pump stages, and coupling means for connecting the end impeller to the motor drive shaft for rotating said impellers by transferring the torque successively from one said impeller to the adjacent said impeller through said socket connections.

3. An improved submersible motor-pump combination comprising a motor having a submersible casing and including an upwardly projecting motor shaft, a plurality of stage pump housings connected rigidly together in stacked relationship and connected to the top end of said motor casing, a corresponding plurality of impellers arranged with one impeller positioned in each said housing, coupling means for connecting said motor shaft to the bottom said impeller and adapted to provide axial. alignment therebetween, said impellers each having a hub extension on one side and means defining a central opening on the opposite side, corresponding spline means formed on said hub extension and in said opening for providing driving engagement between adjacent said impellers and to maintain axial alignment therebetween while providing for relative axial movement between adjacent said impellers, and bearing means associated with each stage housing for opposing axial thrust developed by said impeller spaced within.

4. An improved submersible motor-pump combination comprising a motor having a submersible casing and including a projecting motor shaft having an external spline formed thereon, pump housing means connected rigidly to one end of said motor casing and including a plurality of separable stage housings, a plurality of impellers spaced in stacked relationship within said housings and adapted to increase progressively the pressure of the liquid passing through said housing means, a coupling having an internal spline for providing a driving connection to said motor shaft and adapted to drive the adjacent said impeller and to provide axial alignment therebetween, said impellers each having an integral hub extension on one side and mean-s defining an opening on the opposite side to provide for a socket driving connection between the hub extension of one impeller and said opening formed within an adjacent impeller to maintain axial alignment therebetween and to provide for relative sliding movement, a cylindrical surface formed on said hub extension, bearing means carried by each said stage housings and engaging said cylindrical surface for rotatably supporting said impellers, and means on each said stage housings for opposing axial thrust developed by said corresponding impeller.

5. An improved submersible motor-pump combination comprising a motor having a submersible casing and including a projecting motor shaft, a multi-stage pump housing connected rigidly to one end of said motor casing, a plurality of impellers spaced in stacked relationship within said housing, coupling means forming a splined driving connection between said motor shaft and the adjacent said impeller, an integral hub extension projecting axially from each of said impellers having an external spline formed thereon, means defining an opening in each of said impellers and having a spline formed thereon to provide a driving connection between said impeller and said hub extension of the adjacent said impeller and cooperating with said hub extension to maintain adjacent said impellers in radial and axial alignment within said housing, bearing means can'ied by said housing for rotatably supporting the hub extension of said impellers, bearing means within said motor for opposing axial thrust transferred downwardly to said motor shaft from said impellers, and thrust bearing means within said housing to oppose the upward axial thrust developed by said impellers.

6. An improved submersible motor-pump combination comprising a motor having a submersible casing and including a projecting motor shaft, a multi-stage pump housing connected rigidly to the top end of said motor casing, a plurality of impellers positioned in stacked relationship within said housing, coupling means forming a driving connection between said motor shaft and the adjacent said impeller, an integral hub extension projecting axially from each of said impellers and having an external spline formed thereon, means defining an opening in each of said impellers having a spline formed therein to provide a driving connection between said impeller and said hub extension of the adjacent said impeller and cooperating with said hub extension to maintain adjacent said impellers in radial and axial alignment within said housing, a cylindrical bearing surface formed on each of said hub extensions, bearing means carried by said housing for rotatably supporting said bearing surface on said hub extensions of said impellers, thread means separably connecting adjacent said pump housings for axial separation of said impellers to provide for convenient servicing of the pump stages, bearing means within said motor for opposing axial thrust transferred downwardly to said motor shaft from said impellers, and thrust bearing means within said housing to oppose the upward axial thrust developed by said impellers.

References Cited by the Examiner UNITED STATES PATENTS 3,076,411 2/1963 Guillory 103-102 3,154,019 10/1964 Hoyt 103-87 3,188,967 6/ 1965 Glessner 103-408 ROBERT M. WALKER, Primary Examiner.

Claims

1. AN IMPROVED SUBMERSIBLE MULTI-STAGE PUMP ADAPTED TO BE DRIVEN BY A DRIVE SHAFT EXTENDING FROM A MOTOR, COMPRISING A PLURALITY OF PUMP HOUSINGS CONNECTED RIGIDLY TOGETHER IN STACKED RELATIONSHIP, A CORRESPONDING PLURALITY OF IMPELLERS ARRANGED WITH ONE IMPELLER POSITIONED IN EACH SAID HOUSING, INTEGRAL HUB EXTENSION MEANS PROJECTING AXIALLY FROM ONE SIDE OF EACH OF SAID IMPELLERS AND HAVING EXTERNAL SPLINE MEANS FROMED THEREON, MEANS DEFINING AN AXIAL OPENING IN THE OPPOSITE SIDE OF EACH SAID IMPELLER HAVING CORRESPONDING INTERNAL SPLINE MEANS FOR RECEIVING SAID HUB EXTENSION MEANS OF THE ADJACENT SAID IMPELLER TO FORM A POSITIVE DRIVE SOCKET CONNECTION THEREBETWEEN AND FOR MAINTAINING SAID IMPELLERS IN RADIAL AND AXIAL ALIGNMENT, MEANS SEPARABLY CONNECTING ADJACENT SAID PUMP HOUSINGS AND CORRESPONDING IMPELLERS TO PROVIDE FOR CONVENIENT SERVICING OF THE PUMP, AND COUPLING MEANS FOR CONNECTING THE END IMPELLER TO THE MOTOR DRIVE SHAFT FOR ROTATING SAID IMPELLERS BY TRANSFERING THE TORQUE SUCESSIVELY FROM ONE SAID IMPELLER TO THE ADJACENT SAID IMPELLER THROUGH SAID SOCKET CONNECTIONS.