US3791757A

US3791757A - New type of rotary pump for liquids

Info

Publication number: US3791757A
Application number: US00179983A
Authority: US
Inventors: C Tarifa; J Pedrosa
Original assignee: Sener Tecnica Industrial y Naval SA
Current assignee: Sener Tecnica Industrial y Naval SA
Priority date: 1970-09-11
Filing date: 1971-09-13
Publication date: 1974-02-12
Anticipated expiration: 1991-02-12
Also published as: BR7105349D0; ES383567A1

Abstract

The invention herein described refers to the introduction of improvements, development of new components, new types and new arrangements of the high pressure rotary hydraulic pumps according to the original Spanish Pat. No. 256,654, U.S. Pat. No. 3,093,080 and the Spanish ''''Certificado de Adicion'''' Pat. No, 272,092. These improvements have been registered in Spain in accordance with U.S. Pat. No. 383,567 and ''''Certificado de Adicion'''' Pat. No. 389,338.

Description

United States Patent Tarifa et a].

[ Feb. 12, 1974 3,093,080 6/1963 Tarifa et a1. 415/89 X NEW TYPE OF ROTARY PUMP FOR LIQUIDS 2,376,071 5/1945 Miess 2,256,201 9/1941 I-Iintze ..4I7/68 X [75] Inventors: Carlos Sanchez Tarifa; Jacobo valdes pedmsa, h f Madrid, FOREIGN PATENTS OR APPLICATIONS Spain 492,854 9/1938 Great Britain 415/89 179,877 7 1962 S d [731 Assign! Tecnica Y Naval 338,03l 6/1921 0:111: 1 415/89 S.A., Las Arenas, Bllbdo, V1zcaya, Spam Primary ExaminerC. J. I-Iusar [22] Filed: Sept. 13, 1971 Assistant ExaminerLeonard Smith pp 179 983 Attorney, Agent, or Firm-Stevens, Davis, Miller & U I Mosher I [30] Forelgn Application Prlorlty Data ABSTRACT Sept. 11, 1970 Spain 383567 The mventlon hereln descnbed refers to the 1ntroduc- 52 us. 01 415/89, 415/7, 415/88, of improvements development of new compo- 4|5/143,417/61, 417/2115 417/423 417/424 nents, new types and new arrangements of the high [51 Int. Cl. F04d 1/14 Pressure rotary hydraulic Pumps according to the orig 58 Field 01 Search. 415/88, 89, 24; 417/240, 241, I Spamsh Pat 256,654,

417/68 3,093,080 and theSpamsh Certlficado de Ad1c1on Pat. No, 272,092. These improvements have been reg- [56] Refere'nces Cited istered in Spain in accordance with US. Pat. No. UNITED STATES PATENTS 383,567 and Certificado de Adicion Pat. No.

' 389,338. 1,722,289 7/1929 Gurley 415/89 2,124,914 7/1938 Fottinger 415/89 5 Claims, 37 Drawing Figures 6O 20 73 7 4 2 75 76 l 1 I I T i 119 i I I 1 -1 i 1 1 i' 1 i 53 i 16 i 1 1 3e a .r" T: N I

71 I O I 7 PATENIEBFEB 1 21914 sneer 010E n FIGJ FIGLA PATENTEBFEBIZISH 3791,75? sum OZUF 11 FIGS r-- 6 mimtu im m 3,791,757

SHEET QJUF 11 FIG.18

PAIENIEHH 3.791.757

SHEET UHF 11 PATENTEBIEB 1 21974 sum as or 11 III-IIIIIIIII PAIENIEB FEB] 2:914

SHEET USUF 11 PAIENTEBFEB I 2 I974 I saw 10 0F 11 FIG.35

FIG.36

INVENTUR.

7 I 5 3 I 3 A l /6 3 NEW TYPE OF ROTARY PUMP FOR LIQUIDS The manner in which pressure is generated in the pumps to be described below is much the same as that claimed in the aforementioned Spanish Pat. No. 256,654 and US. Pat. No. 3,093,080. However, important improvements in design and the introduction of new components hitherto unclaimed in the aforementioned Patents have made the pumps to differ considerably from those initially patented.

The improvements mainly deal with the regulation system for amounts of liquid contained in the pump, and with modifications introduced in pressure generation areas and in the pump rotary casing which have rendered the pumps more efficient and simple while at the same time broadening their applications.

The introduction of new components, especially in the liquid feed system, has made the pumps selfpriming in various applications and has allowed for the complete elimination of all types of high or low pressure seals in several versions.

Finally, new types of pumps along with new arrangements of the same have been developed which were not claimed in the original Patent. These pumps are more efficient, simple and economical to manufacture thus making them capable of performing new and various tasks.

The pumps according to Spanish Pat. No. 256,654, allowed the attainment of high working pressures in an efficient form with only one stage. The newly introduced modifications and components, along with new types of pumps, have considerably widened their applications so as to permit them to compete favorably with centrifugal or reciprocating pumps, not only at high pressure but also for many applications at medium or low pressures.

DESCRIPTION The improvements shall be described with the aid of thirty-seven drawings outlined below:

FIG. 1 Longitudinal schematic section of the basic conception of a pump having only one power shaft and a fixed nozzle feeding system.

FIG. 2 Transversal schematic section of the pump shown in FIG. 1.

FIG. 3 Longitudinal schematic section of the basic conception of a pump with two power shafts and a feeding system consisting of rotary tubular arms.

FIG. 4 Transversal schematic section of the pump shown in FIG. 3.

FIG. 5 Longitudinal schematic section of'a variation of the pump shown in FIGS. 3 and 4.

FIG. 6 Transversal schematic section of the pump shown in FIG. 5.

FIG. 7 Longitudinal schematic view of a curved scoop diffuser tube with a circular intake section.

FIG. 8 Front schematic view of the scoop diffuser tube shown in FIG. 7.

FIG. 9 Front schematic view of a scoop diffuser.

tube with a rectangular intake section.

FIG. 10 Longitudinal schematic view of a conical scoop diffuser tube with intake section positioned on a radial plane.

FIG. 11 Longitudinal schematic view of a conical scoop diffuser tube with intake section perpendicular to the cone axis.

FIG. 12 Side schematic view of an ejection nozzle of the rotary tubular arms with circular outlet section.

FIG. 13 Front schematic view of the ejection nozzle shown in FIG. 12.

FIG. 14 Front schematic view of an ejection nozzle of the rotary tubular arms with rectangular outlet section.

FIG. 15 Side schematic view of an ejection nozzle of the rotary tubular arms screwed laterally onto the outer end of these arms.

FIG. 16 Longitudinal schematic section of a feeding system of the liquid into the rotary tubular arms by means of a jet impinging and collected on a bellshaped element.

FIG. 17 Transverse schematic section of the feeding system shown in FIG. 16.

FIG. 18 Longitudinal schematic section of a feeding system of the liquid into the rotary tubular arms by means of a suction axial tube, priming and feeding duct and a tank with constant level liquid.

FIG. 19 Longitudinal section of a feeding system of the liquid into the rotary tubular arms by means of a feeding axial tube, priming micropump and constant level liquid.

FIG. 20 Side schematic view of a micropump with blades for pump priming.

FIG. 21 Side schematic view of a micropump with a helicoidal shaped blade.

FIG. 22 Longitudinal schematic section ofa pump showing over flow orifices positioned along the rim of the rotary casing.

FIG. 23 Transverse section of the pump with overflow orifices shown in FIG. 22.

FIG. 24 Longitudinal schematic section of a pump showing a partition wall with slots placed within the rotary casing.

FIG. 25 Transverse section of the pump with a partition wall with slots shown in FIG. 24.

FIG. 26 Transverse schematic section of a rotary casing outer ring in which the intake section of a scoop diffuser tube penetrates.

FIG. 27 Longitudinal section of a pump with one single power shaft driven by electric motor and gearbox; having a feeding system of the liquid into the rotary tubular arms of the type of a jet impinging on a bell shaped element.

FIG. 28 Transverse section of the pump shown in FIG. 27.

FIG. 29 Longitudinal section of a single power shaft pump driven by an electric motor, belts and pulleys; with a feeding system of the liquid into the rotary tubular arms through a constant level tank, suction axial tube and priming and feeding duct.

FIG. 30 .'Transverse section of the pump shown in FIG. 29.

FIG. 31 Longitudinal section of a floating pump mounted directly on the shaft of an electric motor, and provided with a feeding system of the liquid into the rotary arms of the type of feeding axial tube and priming micropump.

FIG. 32 Transverse section of the pump shown in FIG. 31,

FIG. 33 Longitudinal semi-schematic section of a pump with two coaxial power shafts having an open rotary casing.

FIG. 34 Longitudinal section of a pump with two coaxial power shafts, having a closed rotary casing.

FIG. 35 Overhead view of a longitudinal section of a pump with two power shaft positioned one behind the other along the same geometrical axis; having an open rotary casing.

FIG. 36 Longitudinal semi-schematic section of a pump with the rotary tubular arms shaft driven mecanically and the rotary casing driven hydraulically with the pump; axis being in vertical position.

FIG. 37 Longitudinal section of a pump with two coaxial power shafts, with the shaft of the open rotary casing mounted on the central portion of the rotary tubular arms shaft.

The improvements shall be described below with references to the aforementioned drawings.

The basic operational principle which applies to the pumps described herein, and according to the schematics of FIGS. 1 and 2, consists in the use of the dynamic pressure of a thin film of liquid 1, maintained within the rotary casing 2 (defined open annular duct in the original Spanish Pat. No. 256,654, US. Pat. No. 3,093,080) by means of centrifugal force. The rotary casing must be shaped so as to maintain the liquid film within it. A transverse section, such as that indicated in FIG. 1, is acceptable; i.e., the rotary casing 2 is made up of a flat, or slightly curved, outer ring 3, a disc 4 and a rim 5. The rotary casing is driven and supported by a shaft 6, which is powered by a conventional electric motor or by means of other type of a suitable motor either directly or by means of belts and pulleys or through a gear box.

Liquid dynamic pressure is converted into static pressure by means of a scoop diffuser tube 7 whose intake section 8 is inserted into the liquid film. (This scoop diffuser tube was called stationary-dynamic intake in its initial version of a constant area according to the original Spanish Pat. No. 256,654 and US. Pat. No. 3,093,080). The scoop diffuser tube penetrates the liquid film 1 in the direction opposite to that of the local film peripheral speed. The outer border 9 of the intake section 8 of the scoop diffuser tube is placed near the inner surface 10 of the outer ring 3. The scoop diffuser tube 7 gradually curves and widens so that upon penetrating the liquid into it its velocity gradually decreases while its pressure increases. This scoop diffuser tube is fixed and its outlet tube 1 1 is attached to a stationary component on the outside of the rotary casing. The amount of liquid flow reaching the rotary casing is controlled in relation with the maximum flow capable of being ingested by the scoop diffuser tube in order to have a small thickness of the film of liquid 1 contained in the rotary casing. This thickness is of the same order of magnitude than the distance from the inner border 12 of the inlet section 8 of the scoop diffuser tube to the surface 10 of the outer ring 3. In this way the hydrodynamic drag of the scoop diffuser tube is low, thereby perturbing as little as possible the liquid film 1. Furthermore, since the liquid film is thin the rotary casing only holds a small amount of liquid.

' Liquid may be brought to the rotary casing by various procedures. In FIGS. 1 and 2 the liquid is directly ejected at low speed into the rotary casing through a fixed feeding tube 13 and a nozzle 14. This feeding liquid may be supplied by means of either an auxiliary pump or simply by gravity.

A pump constructed in this manner works perfectly and is extremely simple.

However, the liquid which is ejected into the casing must be accelerated up to the casing peripheral speed through a frictional process which is inefficient. For this reason the pumping process is improved if the liquid is carried into the rotary casing by means of a rotary tubular system, coaxial with the casing as is shown in FIGS. 3 and 4.

The liquid enters through an axial duct or tubular member portion 15 in a plurality of feeding rotary tubular arms 16 within which the liquid increases its pressure due to centrifugal force. At the extremities of the arms ejections nozzles 17 are placed, which expand the liquid down to ambient pressure and eject it tangentially and in the same direction as the local peripheral velocity of the rotary casing 2. With this arrange ment the liquid circulates at low velocity inside the tubular arms, minimizing frictional losses.

These nozzles 17 are positioned near the free surface 18 of the liquid film but without coming into contact with it.

The feeding rotary tubular arms 16 are supported and driven by the shaft 19 which is concentric with the shaft 20 which supports and power the rotary casing 2.

Hydrodynamic theory of pumps shows, and experience confirms that if the ratio between the angular velocities of the rotary casing 2 and the feeding rotary tubular arms 16 varies, pumping efficiency is optimum when said turning ratio has a value slightly less than two. Energy consumption is minimal under these conditions for given pressure and pump flow rates values,

This is due to the fact that under these conditions the relative velocity of liquid ejected through the nozzles 17 in relation to that of the liquid film 1 is null, or very slight; and in this way the liquid reaches the rotary casing 2 with small shock or friction losses.

Supporting of

power shafts

19 and 20, and driving them separately is easily accomplished by means of simple system of pulleys or gears to be described later If the ratio of angular velocities equals unity, only one power shaft 6, as shown in FIG. 1, is necessary, thereby directly connecting the feeding rotary tubular arms 16 to the rotary casing 2. These single drive pumps are more simple and economical than pumps having two drive shafts. These qualities may compensate its lower efficiency in several applications.

This single power shaft may be driven by pulleys or gears. In low pressure applications this single shaft may be the same as the motor power shaft so that the pump would not have any bearings.

There is also the possibility that the rotary casing would not be mechanically driven, but driven by the hydraulic force of the jet ejected by the nozzles 17 of the feeding rotary tubular arms 16. In this case the rotary casing 2 would rotate at a velocity between that of the rotary tubular arms and twice the same value.

' Theory shows, and experience confirms that the efficiency of a pump having hydraulically driven rotary casing, is also between the efficiencies of the other two types of pumps described above.

The rotary casing 2 need not necessarily have the form shown in FIGS. 1; 2; 3 and 4. Its function is to maintain the liquid film l by which its outer ring 3 could also have a curved form as indicated in FIG. 5. Likewise, the plane of the disc supporting the rotary casing outer ring need not necessarily be perpendicular to the drive shaft. Conical plated forms are also acceptable and it may be formed with a plurality of radial bars 21 which holds the outer ring containing the liquid film as shown in FIGS. 5 and 6.

The feeding rotary tubular arms 16 in which the liquid is centrifugated need not necessarily be radial. Forms such as those indicated in FIGS. 5 and 6 in which the tubes slope from an axial direction to a radial direction are completely acceptable, as are those in which the tubes gradually curve in the direction of pump revolution.

The scoop diffuser tube is not necessarily composed of one single element. Experience has shown that pumps also work with a plurality of scoop diffuser tubes. This arrangement may actually be more effi' cient when large amounts of flow are to be pumped. In this latter case the scoop diffuser tubes are positioned with their nozzles angularly equidistant around the circumference of the free surface 18 of the liquid contained in the rotary casing 2. The nozzles in this case would be placed on the same plane perpendicular to the drive shaft. Small deviations of these nozzles in respect to this plane may be permited. In FIGS. 5 and 6 an example of a pump with two scoop diffuser tubes 7 is shown. These scoop diffuser tubes may also be arranged one beside the other with their intake section placed on a line parallel to the shafts.

In FIGS. 5 and 6 the

shafts

19 and 20 which support and power the feeding rotary tubular arms 16 and of the rotary casing 2 respectively, have the same geometric axis. The drive shafts, however, are positioned one behind the other. In this case the liquid enters into the tubular arms through the inside of its power shaft. In some applications this arrangement would be convenient.

Following is a detailed description of the scoop diffuser tubes. The function of these scoop diffuser tubes is to capture the liquid in the rotary casing and transform its velocity into pressure.

One of the most efficient shapes of these tubes, as has been shown by experience, is that indicated in FIGS. 7 and 8.. The scoop diffuser tube has an interior duct 22 with the typical shape of a curved diffuser. The intake section 8 is positioned on a radial plane, i.e., it is perpendicular to the local average velocity of the liquid penetrating the tube. Its outer border 9 is located near the inner surface of the outer ring 3 of the rotary casing. Experience has shown that a circular shape for the intake section 8, and for the transverse section of the scoop diffuser tube, is the most simple and efficient. However, the scoop diffuser tube also functions efficiently with other shapes since the circular shape is not essential for its operation. Oval or rectangular 23 shapes with rounded corners for the intake section may be particularly advantageous. These would be positioned with their longer centerlines parallel to the inner surface 10 of the outer ring 3 of the rotary casing as shown in FIG. 9. This shape for the intake section reduces the thickness of the liquid film 1, thereby decreasing the stresses on the pump and disturbances of waves on the liquid film.

Experience has shown that scoop diffuser tubes also work efficiently when they are in the shape of a straight axis cone 24 such as shown in FIG. 10. This is especially so when the intake section 8 is cut so as to be situated on a radial plane 25. These scoop diffusers are simpler than those that are curved, but pump efficiency is slightly smaller. Even more simple than the preceeding case are scoop diffuser tubes in the shape of a straight axis cone with intake section situated on a plane 26 perpendicular to the cone centerline 27 as shown in FIG. 11. This type of scoop diffuser tube may be installed in any position with respect to the support attachment 28. These scoop diffuser tubes may be used to advantage in low pressure pumps at low cost.

The arrangements of liquid ejection nozzles 17 of the feeding rotary tubular arms are described below.

In FIGS. 12 and 13 the outer ends of the feeding rotary tubular arms 16 are provided withejection nozzles 17, whose function is to expand the liquid to ambient pressure and eject the liquid jets tangentially and in the same direction as that of the peripheral velocity of the pump. The liquid jet should strike the free surface 18 of the liquid film l with a small angle, and therefore the outlet section 29 should have its outer edge 30 very near the free surface 18 of the liquid film 1 and the ejection jet should have a peripheral direction. For these purposes the shapes shown in FIGS. 12 and 13 are applicable. In these cases the nozzles are screwed or welded on the outer ends 31 of the rotary arms 16. These nozzles have a curved centerline, its transverse section being reduced gradually up to the outlet section 29, located on a radial plane. This outlet section may be circular, although oval or rectangular shapes 32, as those indicated in FIG. 14, may be better when the liquid jet is to be ejected as close as possible onto the free surface 18 of the liquid film I.

On low power pumps the nozzles 33 can be screwed onto the sides of the rotary tubular arms 16 as shown in FIG. 15. This arrangement is extremely simple as they are easily replaced and acceptable from a functional point of view.

Liquid intake systems for the feeding rotary tubular arms shall following be described.

Between the stationary intake duct and the feeding rotary tubular arms a seal system of an already known type may be installed. But other systems of new invention have been developed which would offer special advantages owing to their lack of components working under friction conditions and which allow the pumps to be self-priming in several applications.

The systems shown in FIGS. 16 and 17 do nto contain any friction operated components. The feeding duct 34 ends in a calibrated nozzle 35 which determines the liquid flow rate in accordance with feed pressure. The liquid jet ejected by this nozzle is captured in a bell shaped tubular member portion or truncated cone 36 which is positioned at the junction of the feeding rotary tubular arms 16. This bell shaped element projects the liquid toward the rotary tubular arms 16 because of its conical shape. The feed duct 34 does not come into contact with the edge 37 of the inlet section of the bell shaped element; rather, there is an annular opening between them through which excess liquid is drained if the calibrated nozzles 35 supplied a flow rate somewhat greater than that determined by the ejection nozzles 17 of the feeding rotary tubular arms.

. This feeding system would last almost indefinitely due to its lack of friction operating components. Practical use of this system requires that the pressure in the intake duct vary only slightly so that the feeding flow through the calibrated nozzle be maintained more or less constant.

This inconvenience is avoided in the new system to be described below. In this case a feeding system without contact is combined with a constant level tank.

Re. FIG. 18: Liquid is fed to the rotary tubular arms 16 by means of a tubular member portion, here suction axial tube 39 which is submerged in a liquid maintained at constant level in a tank 40, and by means of a priming and feeding tube 41, whose extremety 42 is coaxially introduced into the suction axial tube 39 reaching the inlets of the rotary tubular arms 16.

This priming and feeding tube 41 initially primes the rotary tubular arms 16 and subsequently feeds them liquid. Liquid level is maintained constant in the tank by means of a valve 43 operated by a float 44 which throttles the feeding tube 41 when the level tends to rise, and also by the suction of the axial tube 39, which through the annular opening 45 sucks out the excess of liquid deposited in the tank by the priming and feeding tube 41.

Another non-friction self-priming pump feeding system is described below.

As shown in FIG. v19 there is a feeding axial tube 46 penetrating the liquid 47 which is maintained at constant level in regards to the pump. This tube 46 sucks in liquid and feeds the feeding rotary tubular arms 16.

casing and for supressing waves or disturbances on the liquid surface shall following be described.

Re. FIG. 22: For a determined lenght and fixed velocity of the feeding rotary tubular arms 16, the liquid flow rate reaching the rotary casing through the rotary tubular arms is determined by the ejection nozzles 17 installed on the arms outer ends.

The scoop diffuser tube 7 taking out the liquid from the rotary casing 2 should be designed with an intake section 8 and a transverse passage section large enough to ingest all the liquid ejected by the rotary tubular arms.

If the liquid flow rate ejected by the rotary tubular msm q sa s t tbs. qujs l m lfih kas s also i creases,.thereby augmenting the hydrodynamic drag of the scoop diffuser tube and splashing out of the rotary casing the excess of liquid ejected into the casing, and keeping almost constant the flow rate ingested by the scoop diffuser tube. In this way, there is a self regulating mechanism of the amount of liquid contained in the rotary casing. However, if the liquid flow rate ejected by the rotary tubular arms-is kept increasing, or if this flow rate is kept constant and the outlet duct 11 is partially or fully closed, then the difference between the flow rate ejected by the rotary tubular arms and the one that can be injected by the scoop diffuser tube will flow over the rotary casing rim 5.

The pump can operate under the above overflowing conditions but it consum es'more power. To counteract this, the rim 5 height should be small. But, on the other hand, if rim goes below a certain value the amount of liquid splashed outside of the rotary casing may in crease excessively.

To avoid the above problems overflow orifices 51 may be installed on the rim 5 such as shown in FIGS. 22 and 23. These overflow orifices are arranged in such a way that their outer borders'52 have slightly smaller radius than the inner border 12 of the intake section 8 of the scoop diffuser tube 7. In this way if the flow ejected by the rotary arm nozzles is slightly higher than that ingested by the scoop diffuser tube, the excess would overflow through the orifices and would not considerably increase the power consumed by the The diameter of these overflow orifices is always small in relation to rim height and the distance between them should be larger than their diameters. The circular shape is not essential, although it is the simplest to manufacture. Other shapes may be used including slots.

The rim 5, with or without orifices, may be attached to the casing or may constitute as a separate detachable part to facilitate pump mounting.

Re. FIGS. 24 and 25: Experience has shown that pressure recovery in the scoop diffuser tube increases if a partition wall 53 with slots 54 is installed in the rotary casing 2. This would separate the areas of the liquid film 1 to which the liquid ejected by the rotary tubular arms 16 is deposited fromthat of where the scoop diffusers 7 take the liquid. These partition walls reduce waves produced by the jets ejected from rotary arm 16 and impinging on the liquid surface, these waves being damped by passing liquid through the slots 54 from one area to the other.

The height of the aforementioned partition wall should be considerably more than the liquid film thickness. The slots should be narrow in relation to this height and to the distance between the slots themselves.

The sloted partition wall may constitute part of the rotary casing or may be a separate part to be installed on it.

The slots may be substituted by small orifices equally spaced around the periphery of the partition wall. This partition wall improves pressure recovery in the scoop diffuser tube and eliminates the formation of bubbles at the pump outlet.

. Re. FIG. 26: Experience has shown that pressure recovery improves and bubbles are eliminated if a channel 55 is provided at the'bottom of the outer ring 3 of the rotary casing 2 where the scoop diffuser tube 7 intake section 8 penetrates. The width and depth of this channel must be somewhat greater than the diameter of the aforementioned intake section 8 of the scoop diffuser tube. In thisway the liquid film on the rotary casing has a very small thickness and the rotary tubular arms may extend near the inner surface 10 of the outer ring 3 of the rotary casing.

In order to greater clarify the explanation of this invention, several complete versions of pumps incroporating the new components subject of the below claims and new versions of pumps to be claimed in this document shall following be described.

In FIGS. 27 and 28 a single drive pump with a gearbox using a non-contact feeding system is shown in detail.

The electric motor 56 drives the pump by means of a multiplicating gearbox 57. The pumps single power shaft 6, which drives the rotary casing 2 and feeding rotary tubular arms 16 is supported by

ball bearings

58 and 59.

Liquid penetrates through the feeding duct 34 and the calibrated nozzles 35. Liquid leaves the pump through the scoop diffuser tube 7 and outlet duct 11. The pump is provided with an outer protective casing 60 which collects the liquid splashed by the scoop diffuser tube 7 and the possible overflow of liquid ejected through the calibrated nozzles 35 in respect to the flow ejected by the ejection nozzles 17 of the feeding rotary tubular arms 16. The liquid collected into the protective casing is drained to the outside or to the intake of the pump by a drain 61 situated on the lower part of the outer casing 60. It can be seen that in this pump the feeding rotary tubular arms 16 are formed by a solid bored element, onto which the ejection nozzles 17 are screwed. This assembly arrangement may be more economic in some applications.

In FIGS. 29 and 30 a single shaft pump driven by flat belts and pulleys is shown. This pump has a noncontact feeding system combined with a constant level tank.

The pump, in vertical position, is powered by an electric motor 56 by means of

pulleys

62 and 63 and a flat belt 64. The pump power shaft 6, which is supported by

ball bearings

58 and 59, drive the feeding rotary tubular arms 16 and the rotary casing 2. The liquid penetrates through the feeding tube 41, throttle valve 43 and the priming and feeding duct 42. Liquid level is maintained constant in the tank 40 due to float 44 and suction axial tube 39.

A floating version of a pump is shown in FIGS. 31 and 32. The single drive shaft 6 of the pump is directly mounted on the power shaft of an electric motor 56 in vertical position, and in this way powers the rotary tubular arms 16 and the rotary casing 2.

The pump is mounted on a toroidal float 65 by means of a flange 66 which, along with the annular flange 67 of the float enclose the pump thus avoiding any splashing onto the motor.

The pump is provided with a feeding system of the type ofa feeding axial tube 46 and priming micropump 48.

The rotary casing 2 is arranged with its opening and rim facing upward so as to facilitate the mounting of the outlet tube 11 which takes the liquid outside on the motor flange 66 supporting directly the scoop diffuser tube 7. The disc 4 of the rotary casing 2, may be provided with orifices 68 to drain any liquid remaining in the rotary casing when the pump has stopped.

The float 65 may have several shapes. Toroidal shapes, as those shown in FIG. 31, are adequated.

The above arrangements of a floating pump is particularly useful for pumping water in wells of variable levels, as it is provided with a flexible hose 69 at the pump outlet, which can be adjusted to variations in well level. For well utilization it may be helpful to install a screen 70 on the float opening.

The type of floating pump shown in FIG. 31 is single drive shaft powered pump directly mounted on the electric motor shaft. This is the simplest type. However, this float arrangement is not restricted to this type of pump only.

New arrangements of double shaft and double drive pumps shall be given below.

In FIG. 33 one of these pumps is shown. In this pump the

power shafts

19 and 20 of the rotary tubular arms 16 and the rotary casing 2 are coaxial.

Ball bearings

71 and 72 are placed between the two shafts and

ball bearings

73 and 74 support the outer shaft. The shafts are driven by

pulleys

75 and 76 installed side by side so that they in turn may be powered by belts and two other pulleys located at the free end of the motor shaft.

The rotary casing 2 is open allowing the liquid to enter the pump through this open side through the system comprised of a feeding duct 34, calibrated nozzle 35 and bell shaped element 36 described above. However, a conventional seal system or any other described in this document may also be used.

Alternatively, the liquid could penetrate in the rotary tubular arms 16 through its power shaft 19. A low pressure seal may be installed at the end of the shaft. This feeding arrangement is more useful when a conventional seal system is to be used.

A two shafts pump with a closed rotary casing is shown in FIG. 34. The power shaft 19 of the rotary tubular arms 16 and power shaft 20 of the rotary casing 2 are coaxial.

Bearings

71 and 72 secure the rotary tubular arms shaft, which is mounted in a cantilever position.

Bearings

73 and 74 secure the rotary casings shaft, being positioned this rotary casing between both bearings.

Liquid penetrates in the rotary tubular arms through its shaft 19 and leaves the scoop diffuser tube 7 through an axial duct 79 which is concentric with the power shaft 20. This axial duct 79 forms part of a piece 80 which secures the scoop diffuser tube 7 and which also, by means of another piece support 81 is secured to the pump base 78. This latter piece support also secures bearing 74.

Orifices 82 may be positioned around the cincumference of the rotary casing in order to avoid that an increase of liquid contained in the rotary casing might unduly cause an increase in energy consumed by the pump. This arrangement would allow liquid to overflow through the orifices when it reaches a radius less than that of the inner border 12 of the scoop diffuser tube intake section 8.

The Figure also shows the drive pulleys 75 and 76 positioned side by side, and seals 83 protects ball bearings from splashes of liquid.

Pumps of this type are compact and strong; being able to be utilized for high operational pressures.

FIG. 35 shows a double shaft pump in section. This pump is arranged with the

drive shafts

19 and 20 of the rotary tubular arms 16 and the rotary casing 2 respectively positioned one behind the other along the same geometrical axis. The casing is of the open type. Liquid enters the rotary tubular arms through its power shaft 19 and leaves the scoop diffuser tube through the open side of the rotary casing passing through an outlet tube 11 situated on the same side of the pump as where liquid enters. Drive pulleys 75 and 76 of the rotary tubular arms and rotary casing are located on the ends of

shafts

19 and 20 respectively. In this way the pump may be belt driven by only one motor by means of pulleys positioned on the two ends of the motor shaft.

FIG. 35 also shows: The arrangement of the

ball bearings

71 and 72 on the drive shaft of the rotary tubular arms; rotary casing power

shaft ball bearings

73 and 74, outer casing 60 and the partition wall with slots 53.

Double shaft pumps with a hydraulic powered rotary casing are described below.

The pump arrangements shown in FIGS. 33 and 35 are also applicable to pump with a hydraulic powered rotary casing, simply by eliminating the mechanical belt drive of said casing.

Specifically, the arrangement, shown in FIG. 36 is especially advantageous for the aforementioned type of rotary casing hydraulic drive.

The pump is arranged with its power shaft in vertical position while the rotary casing 2 is open on the side being downward. This arrangement facilitates liquid evacuation during pump start-ups until the rotary casing attains its equilibrium speed. The power shaft 19 of the rotary tubular arms 16 is supported by

ball bearings

71 and 72 and is motor-driven, either directly or by means of gears or pulleys, the latter being the case shown in the drawing. The rotary casing 2 is supported by its power shaft 20 and

ball bearings

73 and 74. It is driven by the liquid jet ejected by the ejection nozzles 17 of the feeding rotary tubular arms 16. The pump is protected with the outer casing 60, also serving as the pump base.

The rotary tubular arms feeding system, as shown in the Figure, 1 is composed of a feeding duct 34, a calibrated nozzle 35 and bell shaped element 36. However, any of the above described feeding systems may also be used.

The selection of single drive, hydraulic or double drive pumps, and the choice between the described variations of these three types shall depend on the use which is foreseen for the pumps. ln each case the most appropriate and economical type of pump, in accordance with the task it is to perform, is sought.

Finally, a new configuration of double shaft pumps, registered in the Spanish Certificado de Adicion Pat. No. 389,338, is shown in FIG. 37 and described in the following:

The shaft 20 f the rotary casing 2 is mounted on the central portion of the shaft 19 of the rotary tubular arms 16. The

ball bearings

71 and 72 of the shaft 19 of the rotary tubular arms 16 are positioned at the two ends of this shaft, the rotary casing 2 being situated between them. This rotary casing 2 is of the open type.

and its shaft is mounted coaxially on the shaft 19 of the rotary tubular arms 16, by means of

ball bearings

73 and 74. Both power shafts l9 and 20 are driven by means of

pulleys

75 and 76 and respective belts from two pulleys which may be positioned side by side at one end of the motor shaft. With this configuration this type of double shaft pumps are compact and robust, the bearings of the rotary casing are only subjected to the difference between the rotational speeds of both

power shafts

19 and 20; and pulleys of both shafts may be driven with pulleys placed at only one end of the motor.

In addition, the power shaft of the rotary tubular arms is supported from its ends, that is to say, it is not working in a cantilever position.

FlG. 37 shows the liquid feeding system also. Liquid enters the rotary tubular arms 16 through its drive shaft 19. The liquid inlet seal 77 and the supporting element 84 fixed at the pumps base 78 are shown as well. The scoop diffuser tube 7, its outlet tube 1 1, partition wall 53, outer casing 60, drain 61 are similar to those of the other types of double shaft pumps already described.

In connection with the description of all these examples of pumps, it should be well understood that the above described arrangements are by no means limiting. Specifically, the drive system using pulleys may be sustituted by a gear system, especially for high power pumps.

ADVANTAGES The pumps which have been described are endowed with the following advantages in respect to other types of pumps:

a. Possibility of obtaining very high pressures with one single stage, even up to Kg/cm and higher.

b. Absence of high pressure seals or stuffing boxes for all pumps variations; and absence of low pressure seals also for many applications of the pumps.

c. Self-priming in several applications.

(1. Economic and simple.

e. Minimal maintainance.

f. Satisfactory efficiencies.

g. Absence of pressure surges.

We claim:

1. A rotary hydraulic pump comprising:

a rotary casing adapted to be rotated in one direction for maintaining a film of liquid on the inner wall thereof by centrifugal force;

at least one rotary tubular arm rotatable coaxially with said rotary casing in the said one direction, the rotary tubular arm having a nozzle adjacent the inner wall of the rotary casing for directing liquid substantially tangentially to the surface of a film of liquid on said inner wall;

at least one scoop diffuser tube for scooping liquid and generating pressure from a liquid film formed on the inner wall of the rotary casing, the scoop diffuser tube having an inlet arranged adjacent to the inner wall of the housing to penetrate a film of liquid, the inlet being directed in the direction opposite to that of the direction of rotation of the rotary casing, said scoop diffuser tube having an inner cross-sectional area which gradually increases from the inlet;

and said rotary tubular arm comprising a tubular member portion coaxial with the rotary casing, intowhich portion liquid is fed, and a feeding tube projecting coaxially into said tubular member portion for feeding liquid into the rotary tubular arm, with clearance everywhere between said priming and feeding tube and said tubular member portion.

2. Therotary hydraulic pump of claim 1 wherein said tubular member portion extends vertically into a volume of liquid to be pumped, and the level of the surface of said volume of liquid is substantially constant with respect to said pump, said feeding tube also being a" priming tube for initially priming and subsequently feeding liquid to the rotary tubular arm.

3. The rotary hydraulic pump of claim 1 wherein said tubular member portion of the rotary tubular arm comprises a bell-shaped member into which projects said feeding tube.

4. The rotary pump of claim 1, additionally comprising a rim forming one side of the casing wherein a liquid film is maintained by centrifugal force, said rim having a plurality of overflow orifices distributed around the periphery thereof said orifices having diameters small with respect to the rim height and positioned so that their outer borders have a smaller radius, from the axis of rotation of the pump, than the inner border of the inlet of the scoop diffuser tube.

5. The rotary pump of claim 1, additionally comprising a partition wall within the rotary casing, said partition wall having a plurality of slots extending radially to the inner wall of the rotary casing and positioned between the area in which liquid ejected by the rotary tubular arm is collected, and the area of a liquid film from which the scoop diffuser tube scoops liquid; said wall for increasing the pump performance, and said wall is higher than the thickness of a liquid film contained in the rotary casing, said slots being narrow in relation to the height of said wall and narrow in relation to the circumferential distance between adjacent slots.

Claims

1. A rotary hydraulic pump comprising: a rotary casing adapted to be rotated in one direction for maintaining a film of liquid on the inner wall thereof by centrifugal force; at least one rotary tubular arm rotatable coaxially with said rotary casing in the said one direction, the rotary tubular arm having a nozzle adjacent the inner wall of the rotary casing for directing liquid substantially tangentially to the surface of a film of liquid on said inner wall; at least one scoop diffuser tube for scooping liquid and generating pressure from a liquid film formed on the inner wall of the rotary casing, the scoop diffuser tube having an inlet arranged adjacent to the inner wall of the housing to penetrate a film of liquid, the inlet being directed in the direction opposite to that of the direction of rotation of the rotary casing, said scoop diffuser tube having an inner crosssectional area which gradually increases from the inlet; and said rotary tubular arm comprising a tubular member portion coaxial with the rotary casing, into whicH portion liquid is fed, and a feeding tube projecting coaxially into said tubular member portion for feeding liquid into the rotary tubular arm, with clearance everywhere between said priming and feeding tube and said tubular member portion.

2. The rotary hydraulic pump of claim 1 wherein said tubular member portion extends vertically into a volume of liquid to be pumped, and the level of the surface of said volume of liquid is substantially constant with respect to said pump, said feeding tube also being a priming tube for initially priming and subsequently feeding liquid to the rotary tubular arm.