US2524269A - Pump - Google Patents

Description

Oct. 3, 1950 G. A. PATTERSON PUMP- 2 Sheets-Sheet 1 Filed Oct. 14, 1946 Patented Oct. 3, 1950 PUMP Glenn A. Patterson, Delavan, Wis., assignor to Sta-Rite Products, Incorporated, Delavan, Wis., a corporation of Wisconsin Application October 14, 1946, Serial No. 703,207

6 Claims.

This invention relates an improved pump and particularly to an improved pump for liquids such as water for pressure pumping systems and the like. The invention relates primarily to a pump of improved compactness.

The principal object is the provision of a pump of improved compactness employin what may be termed a wet motor pump" in which the pumped fluid, usually a liquid such as water, is directed through the pump driving means whereby the latter is cooled by the pumped fluid to permit a much higher power rating for any given size of driving means. The driving means will usually be an electric motor but it will be obvious that the present invention is applicable advantageously with any other heat producing driving means, for example, gas or steam turbines and the like.

Another object is the provision of a pump in which the fluid pumped is directed through a passage in contact with the rotor of the pump driving means to act as a coolant therefor.

Another object is the provision of an electric motor powered pump in. which at least a portion of the fluid pumped is diverted through a passage in contact with a stator to act as a coolant therefor.

Another object in connection with the pump in which the pump driving means is in heat exchange relation with the fiuid being pumped is the provision of removable parts which may be replaced to adapt the basic structure to either deep well or shallow well pumping service.

Another object in conjunction with a pump having a hollow rotor driving an impeller and conducting fluid through a passage in the rotor to the impeller is the provision of means, such as vanes formed in the rotor passage, for imparting a pre-swirl to the fluid before it reaches the impeller, whereby the pumpin efliciency of the latter is substantially improved over conventional structures not having the pre-swirl feature.

Other objects and advantages will become apparent from the following description in connection with the drawings in which- Figure 1 is a longitudinal sectional view of one modification of the present invention as applied to an electric motor driven pump, the rotor Venturi tube or diffuser, jet nozzle, and casing plug being shown arranged for shallow well pumping service which may be employed for suction heads equivalent to'28 feet of water or less;

Fig. 2 is a view similar to Figure 1 of the same pump but showing the rotor Venturi tube, jet nozzle, and casing plug replaced by other parts to adapt the same basic structure to deep well pumping service in which the suction heads ordinarily exceed the equivalent of 28 feet of water, and

Fig. 3 is a reduced outside view of the pump as shown in Fig. 2, showing also the jet and Venturi tube which may be employed for deep well pumping service.

For illustrative purposes, the invention is shown in the drawings in one way which it may be applied to an electric motor driven pump. In Figure 1 where the parts are arranged for shallow well service the pump casing is formed in four separate parts-the central part generally designated I formed of a sheet metal cylinder 2 having gasket bearing rings 3 and 4 affixed as by welding;impeller frame 6 formed internally with pump volute chamber 1 and having outlet passage 8 providing communication between the volute outlets 9 and the outlet port I I and recycle outlets I2; outlet cover plate I3 providin access to the volute chamber 1 and inlet end frame I4 having recycle passage I6, jet nozzle Il threaded into opening I8, inlet port I9 and passage 2I, and a port 22 closed by threadedplug 23. The four casing parts I, 6, I3 and I4 in this instance are bolted together by a number of through bolts 24 (Fig. 3) and the joints therebetween are sealed by gaskets 26, 21 and 28.

The inlet port I9 is connected throughcheck valve 29 by pipe 3| to a well 63 or other source of fluid supply. The outlet port II is connected by pipe 32 to a pressure storage tank (not shown) or in some cases directly to a point of use such as a valve or faucet.

An important part of the present invention is that the pump driving means, in this case the electric motor generally designated 33, is mounted directly inside the pump and one or more parts are in heat exchange relationship with the fluid being pumped. The parts of themotor 33 are substantially the same as those of a conventional induction type motor and hence have been shown more or less diagrammatically. The rotor generally designated 34 has the usual laminations 36 mounted as by a shrink or press fit, on the hollow rotor shaft 38 which is formed interiorly with a venturi or diffuser bore or passage 39 and which is axially aligned with the jet nozzle H to receive recycling fluid. The inlet end of the rotor shaft 38 is journaled within wearing ring- 4I mounted in casing frame member I4. The outlet end of the rotor shaft carries a pumping element or impeller generally designated 42 threadedly engaged there t and rotatable to discharge fluid by centrifugal action into the volute chamber 1, the impeller hub being rotatably journaled within wearing ring 43 mounted in the casing frame or volutemember 6. The stator generally designated 45 comprises the usual laminations 44 and windings 46 mounted on a stationary frame 41. The entire stator 45 is contained in a waterproof enclosure 48 which will preferably be formed of heat conductive sheet metal. The enclosure member 48 is generally cylindrical and is carried on circularly extending shoulders 49 and formed on casing members i4 and 6, respectively. The windings 46 are energized in use from an electrical circuit not shown. The enclosure 48 has an inner cylindrical portion 52 which will preferably be as thin as the fluid pressure permits and of low magnetic permeability, such as "Monel metal" or nonmagnetic stainless steel. As can be seen in Figure 1, there is slight clearance between the cylindrical portion 52 and the exterior of the rotor to permit rotation of the latter. The outer portion 53 of the enclosure 48 is spaced from the casing cylindrical portion 2 sufliciently to leave an annular longitudinal passage 54 between casing 2 and enclosure 48 to convey the recycle stream back to the nozzle i1.

Figs. 2 and 3 illustrate how the basic structure of the Figure 1 pump may be employed for deep well operation, that is, where the suction head exceeds the equivalent of about 28 feet of water. The jet nozzle I! will be replaced by plug '56 and the recycle stream will be directed through pipe 51 (replacing plug 23) to the jet nozzle Ila indeep well 58. The rotor Venturi shaft 38 will, in effect, be replaced by the hollow rotor shaft or tube 59 and Venturitube 38a will be provided in the well to receive the discharge from jet nozzle Hi1 as well as the water drawn from the well throughfoot valve 6| (which replaces check valve 29).

A certain amount of leakage will occur between the ends of the rotor shaft and the wearing rings 4| and 43; in the usual case where the fluid pumped is a liquid a slight leakage at these points is actually beneficial to the operation of the pump in that it provides lubrication for the wearing rings and also provides for a certain amount of cooling of the rotor and stator.

Another feature of the present invention is the provision of means in the rotor passageway for imparting rotational movement to the fluid passing through it, before it reaches the impeller 42. One way of accomplishing this is by means of vanes 62 or 62a (Figs. 1 and 2 respectively) which may be spiral or helical as shown or may be straight and either longitudinally or diagonally extending. This feature contributes to improved pumping efficiency of the impeller by imparting a pre-swirl to the fluid thus eliminating the turbulence that would otherwise be present in the entrance portion of the impeller.

In describing the operation of the modification shown reference will first be made to the pump arranged for shallow well operation, as shown in Figure 1. On rotation of the impeller or pumping element 42 by the rotor, fluid will be thrown out ward from the impeller by centrifugal force and into the volute chamber 1. Assuming the source offluid 63 is a well containing water, flow of water from the well to storage or use is shown by the solid arrows and may be traced as follows: pipe 3Icheck valve 28-inlet passage 2 l-rotor Venturi passageway 39-impeller 42-outlet passage 8-pipe 32. The water flowing through the rotor passageway 39 will effectively cool the motor as well as the stator to a certain extent, thereby making it possible to use the motor at a higher power output than would be possible with the same motor used in conventional pumps in which the cooling efiect by the pumped liquid is not employed in this manner.

Referring further to Figure 1, another aspect of the invention, namely, the direct cooling of the stator 45 by the recycle or by-pass stream in passage 54 is shown. In the outlet passage 8 a portion of the pumped liquid is diverted through bypass port I! into the passage 54 and from there flows through the nozzle l1 and discharged into the Venturi passageway 39 along a course shown by the broken line arrows. The action of the jet and venturi serves to create a low pressure in the inlet passage 2| and lifts water from the well. With this construction the recycle stream thus serves both to perform the actual lifting of water from the well and the cooling of the stator through the conductive metal enclosing shell 48.

The operation of the pump adapted for deep well operation is shown in Figs. 2 and 3. The nozzle Fla and venturi or diffuser tube "a in this case are in the well rather than in the pump. However, the actual flow and recycle through the pump are the same as for the shallow well operation. The main flow of water is shown by the solid arrows, as before. The by-pass stream likewise is diverted out of the main stream in the same manner in outlet passage 8, flows backward over the stator shell 48 in heat exchange relation therewith and is directed through the pipe 51 to nozzle PM where its change from kinetic to static energy creates a low pressure inchamber 64 to draw water through foot valve 6i and up through pipe 3ia into the pump inlet passage 2|. The recycle stream in Figs. 2 and 3 is also shown by broken arrows.

While a particular form of the present invention has been shown it will be apparent that minor changes therein will readily suggest themselves to others skilled in the art without departing from the spirit and scope of the invention. Having thus described the invention, what is claimed as new is:

1. A pump having a casing with inlet and outlet passages, a movable pumping element for moving fluid between said passages, heat producing driving means having a. rotor operable to move said element to pump fluid, said rotor having a central longitudinal passageway for carrying fluid pumped by said element to cool said heat producing driving means by heat exchange through a wall of said rotor passageway, a Jet nozzle secured in said casing and axially aligned with the longitudinal passage through said rotor and a recycle conduit for diverting a portion of the pumped fluid through said nozzle at high speed into the inlet of said rotor passageway to create a vacuum in said casing inlet passage simultaneously with efl'ecting said heat exchange.

2. The combination of claim 1 in which the passageway in said rotor is in the form of a Venturi tube.

Walls Of s id rotor passageway, means for recycling a portion of the pumped fluid through a port in said casing and through said rotor passage, and a jet nozzle communicating with said port and adapted for supplying energy to the recirculating fluid to simultaneously increase the emciency of the pump and cool the heat producing means.

4. In a pump, a casing having an inlet and outlet for pumped fluid, an electric motor unit disposed in said casing and comprising a rotor provided with laminations assembled upon a shaft having a central longitudinal bore for passage of pumped fluid through the pump, an impeller secured to said hollow rotor shaft and rotated thereby to force fluid to enter said inlet and pass through the central bore of the shaft for discharge through said outlet, the flow of the pumped fluid in the bore of the rotor shaft increasing the efliciency or the motor by cooling thereof, a conduit by-passlng a portion of the discharge of said impeller in contact with said motor unit to cool the same and conveying said by-passed fluid into the lnletoi the rotor bore, and a jet pump in said conduit. to boost the velocity or the by-passed cooling fluid before passing through the rotor bore to improve the pumping emciency of the P mp.

5. A packaged pumping unit comprising a casing, an electric induction motor mounted in said casing upon a shaft driven thereby and having a central longitudinal bore through which the pumped fluid flows in passing through the pump to initially cool said motor, a pressure pump mounted on one side of said unit and driven by said shaft, a conduit connecting the discharge side or the pressure pump to the inlet of the central bore of the motor shaft to by-pass pumped fluid through the unit in contact with motor parts to cool the same, and a Jet pump in saidconduit 6 on the side of the unit opposite the pressure pump to supply energy to the lay-passed cooling fluid to utilize the same for increasing the efliciency of the pump.

6. A packaged pumping unit comprising a casing, an electric motor mounted in said casing and having a stator and a rotor mounted in the stator upon a. shaft having a central longitudinal bore through which pumped fluid flows in passing through the pump and cools the inside of the motor, a pressure pump mounted directly on said shaft on one side of said motor and driven thereby for forcing fluid through the unit, a jet pump mounted on the opposite side of said motor in axial alignment with the bore of the rotor shaft, and a by-pass conduit connecting said pressure pump and jet pump around the outside of the motor to circulate a. portion of the pumped fluid discharged by the pressure pump in contact with the outer parts of the motor to cool the same with said jet pump supplying energy thereto substantially simultaneously to increase the efllciency of the pump.

GLENN A. PATTERSON.

REFERENCES CITED The following references are 01' record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,347,732 Cooper July 27, 1920 1,405,959 Woock et al Feb. 7, 1922 2,181,677 Whittome et a1 Nov. 28, 1939 2,272,906 Da C01 Feb. 10, 1942 2,312,848 Pezzillo Mar. 2, 1943 2,319,730 Garraway May 18, 1943 2,335,109 Conery Nov. 23, 1943

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