US 3531214 A
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Sept. 29, 1970 F. w. ABRAMSON RADIAL-DRIVEN, MULTISIAGE JET PUMP 2 Sheets-Sheet 1 Filed Dec. 9, 1968 A o t m O m Q W ,Y/ N 2 3 A ww mm 4 I H mm mm m MN. HQ
F. W ABRAMSON RADIALDRIVEN, MULTISTAGE JET PUMP Sept. 29, 1910 2 Sheets$heet 2 Filed 'Dec. 9, 1968 INVENTOR.
fiawz W 452444500 United States Patent 3,531,214 RADIAL-DRIVEN, MULTISTAGE JET PUMP Franz W. Abramson, Los Angeles, Calif. (4523 N. Lone Pine Lane, La Canada, Calif. 91011) Filed Dec. 9, 1968, Ser. No. 782,339 Int. Cl. F04d 3/02; B63h 11 /00, 1/40 US. Cl. 41568 19 Claims ABSTRACT OF THE DISCLOSURE An axial pump is disclosed herein having a tubular, tapered housing in which a plurality of impeller stages are installed capable of rotating at high speed to induce high velocity fluid flow through a passageway defined by the housing. Each impeller stage includes an annular ring having peripheral gear teeth projecting exteriorly of the passageway and a plurality of impeller vanes radially dis-v posed across the inner diameter of the ring. Drive gears, carried on a common drive shaft, mesh with the peripheral ring gear teeth to rotate all impeller stages simultaneously. Suitable bearings and seals are placed between the ring gear and the housing to reduce rotational friction and restrict fluid flow therebetween.
BACKGROUND OF THE INVENTION Field of the invention Description of the prior art In the field of axial flow pumps, it is a common practice to employ a rotating impeller assembly carried in a fluid passageway defined by an enclosed housing. The impeller asembly includes a plurality of vanes adapted to engage with a fluid substance in the passageway in order to move the substance through the passageway. Conventionally, the impeller assembly is driven by a centrally located shaft lying on the central axis of the passageway and the vanes of the impeller assembly are fixed on the shaft so as to radiate outwardly therefrom so that the impeller assembly rotates in a plane normal to the direction of fluid flow. By so locating the shaft on the exact central axis of the fluid stream, an offset intake opening to the passageway is necessitated and the smooth flow of the fluid substance through the passageway is substantially inhibited.
Furthermore, conventional axial flow pumps encounter adverse ingestion difliculties when the fluid substance includes foreign matter such as weeds, debris or the like. Such matter or material has a tendency to entwine or wrap about the vanes of the impeller and about the drive shaft so that the passageway eventually becomes clogged, which greatly restricts the flow 0f fluid therethrough.
Still furthef problems and difliculties are encountered with conventional axial flow pumps in that the volume of fluid substance driven through the passageway is restricted and the velocity of the fluid substance relatively uncontrolled which results in undesired cavitation immediately behind the impeller assembly. Such cavitation again restricts the flow of the fluid substance through the passageway. Therefore, it can be seen that conventional pumps are limited with respect to flow velocity and flow volume.
3,531,214 Patented Sept. 29, 1970 SUMMARY OF THE INVENTION Accordingly, the problems and difliculties encountered with conventional axial flow jet pumps are obviated by the present invention which provides an elongated tapered housing defining an enclosed passageway in which multiple impeller assemblies are rotatably carried in spaced apart relationship. Each impeller stage is in reduced diameter following the general taper of the housing graduated downwardly from the intake portion of the housing to the exhaust portion. Each impeller assembly includes a ring gear having a plurality of vanes extending across its inner diameter and a plurality of gear teeth integrally formed about its peripheral edge marginal region that extend beyond the passageway defined by the housing. Drive means are provided which are external of the passageway and include pinion gears enmeshed with the peripheral gear teeth of each ring gear so that the impeller assemblies are rotated simultaneously. The pinion gears carried by the drive shaft are of different diameters so as to drive the various stages of impeller assemblies at different speeds.
By employing several stages of impeller assembly diameters and speeds, the inventive concept permits a minimum volume pump which satisfies the flow rate and pressure requirements for a given application. The first stage, having the largest diameter, operates at a low r.p.m. consistent with cavitation-free operation. Each successive stage can operate at a higher r.p.m. with a smaller diameter because of the increase in suction head created by the pressure rise of the previous impeller assembly stage. Therefore, the present invention permits a pump design to better control both the pressure rise and the fluid flow rate from the exhaust portion of the pump which elimi nates basic problems encountered with conventional axial flow pumps.
Additionally, when the axial pump of the present invention is used in connection with marine vehicles as a propulsion system therefor, the pump elements can be physically located lower in the marine vehicle hull than the power plant, thus assisting in the submergence level and hence, the priming of the pump. Also, since a central shaft extending between impeller elements within the housing is eliminated, the problems encountered with ingestion of weeds and debris is greatly reduced if not eliminated.
Therefore, it is among the primary objects of the present invention to provide a novel axial flow pump employing a plurality of impeller assembly stages for controlling the fluid substance pressure rise and fluid flow rate through the pump whereby a constant flow of liquid through the pump is induced.
Another object of the present invention is to provide a novel axial flow pump having a plurality of impeller stages adapted to rotate at high speed so as to induce a high velocity flow of liquid through the pump.
Another object of the present invention is to provide a novel radial drive hydrojet pump having a common drive shaft coupled to directly drive the periphery of each impeller assembly so as to avoid placement and location of the drive shaft on the central axis of the impeller assembly.
'Yet another object of the present invention is to provide a novel axial flow pump having peripherally driven impeller assemblages wherein the impeller assemblages are graduated in reduced diameters from an intake portion to an exhaust portion whereby impeller rpm. and impeller diameter are consistent with cavitation-free operation.
Still a further object of the present invention is to provide a novel radial drive multistage axial pump permitting the impeller stages to be counter-rotated so as to eliminate stators or flow straighteners normally used in connection with conventional axial fiow pumps.
Yet another object of the present invention is to provide a novel axial pump having multiple impeller stages adapted to reduce or eliminate weed ingestion problem BRIEF DESCRIPTION OF THE DRAWINGS The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a side elevational view of a marine vehicle showing a power plant and the novel axial flow pump of the present invention in broken lines;
FIG. 2 is an enlarged longitudinal sectional view of the jet pump incorporated into the marine vehicle of FIG. 1;
FIG. 3 is a transverse cross-sectional view of the first impeller stage of the multistage jet pump as taken in the direction of arrows 33 of FIG. 2;
FIG. 4 is a transverse cross-sectional view of the second impeller stage of the jet pump shown in FIG. 2 as taken in the direction of arrows 4-4 thereof;
FIG. 5 is a transverse cross-sectional view of the third impeller stage of the jet pump as taken in the direction of arrows 5-5 of FIG. 2;
FIG. 6 is a cross-sectional view of a dual axial flow pump driven by a common drive source;
FIG. 7 is a longitudinal view of another embodiment of the present invention eliminating axial stator supports for the impeller stages; and
FIG. 8 is a transverse cross-sectional view of one of the impeller stages of the modified embodiment of the invention shown in FIG. 7 as taken in the direction of arrows 8-8 thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the novel axial flow jet pump of the present invention is indicated in the general direction of arrow 10 carried on a hull 11 of a marine vehicle, for example. The marine vehicle may be of any conventional hull type such as a hydro-foil, hydroski or other planing or non-planing vehicle. The pump 10 is driven by a power plant '12 via a drive shaft 13 and multistage impeller assemblies, such as indicated by numeral 14. Although the present invention is shown in conjunction with a marine vehicle so as to serve as a propulsion system therefor in the form of a water jet pump, it is to be understood that the present invention may have other applications such as for use in petroleum fields for transferring oil under pressure over long distances. In fact, the present invention may be used as a sump or sludge pump in applications where a relatively thick and heavy fluid is to be transferred or forcibly urged therethrough.
Referring now in detail to FIG. 2, the radial drive, multistage pump 10 includes a tapered housing 15 coupled at one end to an inlet duct 16 taking the form of an elbow duct defining an intake opening 17 through which water is introduced to the pump. The housing 15 defines a passageway leading from opening 17 to an exhaust outlet 18 having an opening which is substantially smaller in diameter than the intake opening 17. The contour of housing 15 tapers from its joinder with elbow duct 16 progressively in reduced diameter to the outlet 18. However, it is to be understood that for applications other than marine vehicles, the intake opening need not be offset from the central longitudinal axis of the passageway so that fiuid fiow is introduced directly into the pump without the necessity of an offset inta-ke opening.
Located within the passageway defined by the interior wall surface of housing 15, there is provided a plurality of impeller assembly stages indicated in general by the reference characters 20, 21 and 22 which are arranged in spaced apart relationship with respect to each other. Impeller assemblage 21, for example, includes a plurality of vanes or blades 24 which are radially carried on a bearing 25 so as to outwardly extend from the outer race of the bearing to terminate in securement at the inner diameter of an annular ring 26. Therefore, the ring 26 is carried on the outwardly terminating ends of the plurality of blades 24 which substantially extend across the diameter of the fluid flow passageway. The outer periphery of the ring 26 includes a plurality of continuous teeth 27 exposed exteriorly of the housing passageway. The exposed annular gear teeth carried by the ring 26 are meshed in driving relationship with a pinion gear 28 carried on the rotating drive shaft 13. Preferably, the pinion gear 28 is enclosed within a water tight enclosure 30 which includes bearing assemblies 31 and 32 for rotatably supporting shaft 13. The enclosure 30 is carried on the external wall of the housing 15 and includes an annular carbon seal 33 for sealing the housing and the enclosure against the ring 26 to prevent or restrict the flow of fluid therethrough. A suitable carbon seal for use in this connection is manufactured by Koppers Company, Los Angeles, Calif.
Although the impeller assembly 14 will readily rotate in response to the driving engagement of pinion 28 with ring gear 26, the impeller assembly may be supported by providing a stator assembly taking the form of three blades 34 located on one side of the assembly and three blades 35, as shown in FIG. 3, located on the opposite side of the assembly. Each of the stator blades in assemblies 34 and 35 radiate outwardly from a pair of spaced apart bases 36 and 37, respectively, that lie on the central axis of the passageway and the blades terminate at their respective opposite ends in securement with the inside wall surface of the enclosure. Bases 36 and 37 of the stator mount a shaft 38 therebetween which extends through the inner race of bearing 25 in rotatable mounting relationship.
In the configuration of the invention employing the stator blade assemblies 34 and 35, the blades may serve as flow straighteners for the fluid substance passing through the passageway. However, it is to be understood that the stator assembly is substantially different from conventional flow straighteners in that the number of blades is greatly reduced and is sufiicient only to support the bases 36 and 37 and bearing 25 as well as shaft 38. Therefore, the blades 34 and 35 will not impede the fiow of fluid through the passageway nor will these blades become major stoppage points in the event weeds or other foreign debris tend to collect thereon.
Power plant 12 may be operatively coupled to drive shaft 13 by any suitable drive arrangement. Also, power plant 12 may be coupled to a second propulsion system 40 substantially identical to the propulsion system shown in FIG. 2. By this means, the pair of propulsion systems are driven in common by power plant 12.
The embodiment of the invention shown in FIG. 2 represents an axial flow pump in a typical marine vehicle application employing a radial drive, multistage concept. For this application, the speed of shaft 13 may be 4,000 r.p.m. and the impeller assemblies 21, 22 and 23 may turn at 875 r.p.m., 2,000 r.p.m. and 4,000 r.p.m., respectively. The impeller diameters are graduated in size so that impeller 21 may be 12 inches in diameter, impeller 22 may be 9 inches in diameter and impeller 23 may be 6 inches in diameter. The use of several stages of impeller diameters and speeds permits the design of a minimum volume pump which satisfies the flow rate and pressure requirements for propulsion of a marine vehicle. The first stage represented by impeller assembly 21 operates at low r.p.m. and has a large diameter so that cavitation-free operation is produced. Each successive stage can operate at a higher r.p.m. with a smaller impeller assembly diameter because of the increase in suction head created by the pressure rise of the previous impeller assembly.
Another feature of the present invention is that the pump permits counter-rotation of the multiple impeller stages through gearing so that flow straighteners, which generally create a problem of weed ingestion, may be eliminated. The counter-rotating impellers also have the effect of grinding up weeds and foreign matter which may be inadvertently drawn into the pump intake.
Referring now to FIGS. 3, 4 and 5, it can be seen that the stator blades 34 and 35 total no more than three in number and radiate outwardly from the bases 36 and 37 to the inside surface of enclosure wall 15. Also, it can be seen that each of the plurality of impeller blades or vanes 24 extend outwardly from the center axis of the passageway to terminate on the inside surface of ring gear 26. Preferably, each of the respective blades or vanes 24 are angularly disposed with respect to the transverse plane in which they reside in fixed space apart relationship so that fluid flow between the vanes is permitted as the ring gear 26 rotates. Y
The annular seal 33 is disposed between the portion of the enclosure adjacent the ring gear to impede the flow of fluid therebetween. Also, the relative diameters of the pinion gears 28, 28 and 28" are illustrated as well as the varying ring gear diameters represented by numerals 26, 26 and 26". Furthermore, it can be seen that each of the pinion gears associated with each of the impeller assemblies is secured in driving relationship to the common drive shaft 13 so that all of the pinion gears are driven to simultaneously drive each of the respective ring gears.
Referring now in particular to FIG. 6 a single power source means for driving two or more multistage, multir.p.m. hydrojet pumps is illustrated. In addition to axial flow pump 10, pump 40 is illustrated wherein the same impeller stage of each pump is driven in common -by a drive gear 41 fixed on shaft 13 so as to rotate therewith. Each impeller stage is identical to the stages shown with respect to the embodiment shown in FIG. 2 with the exception that drive gear 41 intermeshes with the teeth of both ring gears 26 and 42 carried by respective pumps 10 and 40. By this means, the impeller assemblages of each pump are driven in common by the drive shaft 13 via the pinion drive gears 41 associated with each stage. A common power source or power plant 12 is therefore employed to drive the two or more multistage pumps via the drive gears 41.
Referring now to FIGS. 7 and 8, another embodiment of the present invention is shown wherein the impeller assembly indicated by numeral is rotata'bly mounted directly on the wall of the housing 51 so that flow straighteners or other impeller assembly supporting members are eliminated. In this embodiment, a single stage impeller assembly is shown which comprises an annular support 52 which lies coaxially on the central axis of the passageway between an intake opening 53 and an exhaust outlet 54. The mounting member 52 supports a plurality of blades or vanes 55 which radiate outwardly therefrom and terminate in securement with the inside diameter of a ring gear 56. The periphery of the ring gear 56 includes a plurality of continuous teeth 57 to provide a ring gear extending from the passageway and in driving engagement with a drive gear 58. The drive gear 58 is secured to a drive shaft 60 that may be suitably driven by a power plant. Immediately below the teeth 57, there are formed a pair of outwardly extending flanges 61 and 62 which serve as an outer race disposed in spaced apart relationship from housing portions 63 and 64 that serve as an inner race. Disposed between the inner and outer races, there is provided a plurality of bearings 65 on opposite sides of the ring gear teeth 57. By means of the bearings, the impeller assembly is rotatably carried on the annular wall of housing 51 and additional support for the assembly within the passageway is avoided. As the drive shaft 60 is rotated to rotate the drive gear, the ring gear 56 is rotated to move the impeller blades transversely across the passageway. It is to be understood that the impeller blades are angularly disposed with respect to the direction of rotation but are arranged in fixed spaced apart relationship so as to permit fluid flow between each of the respective plurality of blades.
The discharge or exhaust nozzle defining exhaust outlet 54 may be variable or fixed as desired. To vary the exhaust nozzle, the nozzle may be fabricated in a plurality of segments which pivot with respect to one another to open and close or otherwise modify the exhaust orifice 54.
Therefore, it can be seen that the novel axial flow pump of the present invention provides a pump capable of inducing high velocity to the flow of fluid transferred through the housing passageway. The flow of fluid is not impaired by the presence of flow straightening means having substantial volume and the passage of weeds or other debris will pass through the passageway in conjunction with its carrier stream. The pump may be single staged as shown in FIGS. 7 and 8 or multiple stages may be employed as illustrated by the embodiment shown in FIGS. 2-5. A plurality of pumps may be driven by a common power source as shown in FIG. 6 and it is to be understood that the pump may be used for propelling a marine vehicle or may have other uses in applications in the petroleum industry or in other fields where it is advantageous to move or transfer heavy viscous fluid from one place to another in a constant flow.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.
What is claimed is:
1. An axial flow pump for propelling a fluid at a constant rate therethrough comprising:
a housing having an open ended passageway extending between its opposite ends adapted to conduct fluid flow therethrough;
an impeller assembly rotatably carried within said passageway;
a drive means carried on said housing exteriorly of said passageway;
means operably coupled between said drive means and the periphery of said impeller assembly for rotating said impeller assembly in response to said drive means to forcibly conduct the fluid through said passageway; and
a plurality of impeller assembly stages coaxially related with said passageway in spaced apart relationship.
2. The invention as defined in claim 1 wherein said impeller assembly includes a ring adapted to rotate in close proximity to the inner wall surface of said housing;
an annular mounting member coaxially disposed with respect to said ring and lying on the central longitudinal axis of said passageway; and
a plurality of blades secured between said mounting member and said ring in fixed spaced apart relationship.
3. The invention as defined in claim 1 wherein said impeller assembly rotating means includes gear teeth carried on the periphery of said ring extending out of said passageway in driving engagement with said drive means.
4. The invention as defined in claim 3 including bearing means disposed between said ring and said housing for rotatably supporting said ring on said housing.
5. The invention as defined in claim 4 including sealing means disposed adjacent said bearing means between said ring and said housing.
6. The invention as defined in claim 1 wherein said impeller assembly rotating means includes a ring in close proximity to said housing and having gear teeth carried on its periphery extending out of said passageway in driven engagement with said drive means;
flange means carried on said ring;
housing portions disposed adjacent opposite sides of said ring in spaced apart relationship with respect to said flange means; and
bearing means rotatably carried between said flange means and said housing portions to rotatably support said impeller assembly.
7. The invention as defined in claim 1 including a stator assembly fixed on said housing and extending across said passageway; and
a shaft carried on said stator assembly for rotatably supporting said impeller assembly.
8. The invention as defined in claim 1 wherein said passageway is tapered from its intake opening at one end of said housing toward its exhaust opening at the other end of said housing.
9. The invention as defined in claim 8 wherein the diameter of each of said impeller assembly stages is different and said impeller assembly rotating means drives each of said stages at a dilierent speed.
10. The invention as defined in claim 9 including stator means mounted on said housing within said passageway for rotatably supporting each of said impeller assembly stages.
11. The invention as defined in claim 9 including means rotatably supporting each of said impeller assembly stages on said housing.
12. In an axial flow jet pump for use as a propulsion system for a marine vehicle adapted to be driven by a power plant carried in the hull of the vehicle, the combination comprising:
an elongated tapered housing defining an open-ended passageway between its opposite ends adapted to conduct a flow of fluid;
a plurality of circular impeller assemblies disposed in said passageway in spaced apart relationship;
means for rotatably supporting each of said impeller assemblies on said housing; and
drive means connected to said power plant and operably coupled to the periphery of each of said impeller assemblies for rotating said impeller assemblies on said supporting means to forcibly urge the flow of fluid through said passageway.
13. The invention as defined in claim 12 wherein each of said impeller assemblies includes a peripheral ring gear projecting through said housing out of said passageway; and
said drive means includes pinion gears in mesh with each of said impeller assembly ring gears.
14. The invention as defined in claim 13 including bearing means for rotatably supporting each of said impeller assemblies; and
sealing means disposed between each of said impeller assembly ring gears and said housing.
15. The invention as defined in claim 12 wherein said supporting means includes a stator assembly disposed on opposite sides of each of said impeller assemblies and a fixed shaft connected between said stator assemblies for rotatably mounting its associated impeller assembly.
16. The invention as defined in claim 12 wherein said supporting means includes bearing means movably supporting each of said impeller assemblies on said housing adjacent said peripheral coupling means.
17. The invention as defined in claim 13 including a second axial flow pump; and
means interconnectig said drive means with said pumps to provide a common drive by said power plant.
18. The invention as defined in claim 13 wherein the diameter of each of said ring gears is dilferent and the diameter of each of said pinion gears are different.
19. The invention as defined in claim 12 including means for driving each of said impeller assemblies at a different speed.
References Cited UNITED STATES PATENTS 952,969 3/1910 Whelen 10389 1,023,515 4/1912 Graves 103-89 1,090,322 3/ 1914 McLaughlin 201 1,326,730 12/1919 Helguera -34 1,805,597 5/1931 Pratt 60-222 2,153,055 4/1939 Weissmann 11534 2,343,711 3/ 1944 Rusteberg 103-89 2,470,794 5/ 1949 Snyder 10394 2,656,809 10/ 1953 Frasure 103-91 3,044,259 7/1962 Tuttle 10389 2,306,840 12/ 1942 Waterual 10394 FOREIGN PATENTS 16,232 10/ 1927 Netherlands. 18,689 12/ 1928 Netherlands. 1,500,976 10/1967 France.
HENRY F. RADUAZO, Primary Examiner US. Cl. X.R.