US3171357A

US3171357A - Pump

Info

Publication number: US3171357A
Application number: US174165A
Authority: US
Inventors: Egger Emile
Original assignee: EMILE EGGER AND CO AG
Current assignee: EMILE EGGER AND CO AG
Priority date: 1961-02-27
Filing date: 1962-02-19
Publication date: 1965-03-02
Anticipated expiration: 1982-03-02
Also published as: GB987452A; ES274969A1; DE1910853U; DK124277B; FI45596B; LU41283A1; CH390687A; SE334293B; FI45596C

Description

E. EGGER PUIIP 6 Sheets-Sheet 1 Filed Feb. 19, 1962 me 2w WW ME 6 y 0 ,M N -UMHM m m m 8 G. I \vN v 9 W 3 is Q r P I I Y a H WM U 3 E. EGGER March 2, 1965 PUMP 6 Sheets-Sheet 2 Filed Feb. .19, 1962 E. EGGER March 2, 1965 PUMP 6 Sheets-Sheet 3 Filed Feb. 19, 1962 7 ill/[III] [1a.

INVENTOR. EMILE/Essa BY Array/vars March 2, 1965 E. EGGER 3,171,357.

PUMP

Filed Feb. 19, 1962 e Sheets-Sheet 5 March 2, 1965 E. EGGER 3, 7 ,3 7.

PUMP

Filed Feb. 19, 1962 6 Sheets-Sheet 6 ".5; Tmllnmln" INVENTOR. 5 1w [GGE of the impeller.

United States Patent Office 3,171,353 ?a.tented Mar. 2, 1965 ,349/61 se Claims. (Cl. ins-103 The present invention relates generally to a pump device and more particularly to an improved apparatus for pumping a fluid containing foreign material or bodies of an appreciable size.

In the pumping of fluids such as the liquids encountered in industrial processes and the liquids encountered in municipal sewerage systems, the problem arises of handling such fluids without clogging or damaging the pumping apparatus due to the quantity of foreign substances which are contained in the fluids. processes the need arises for a pump which can handle liquids which are made up of solid substances entrained in a liquid. In other applications fluid used as a vehicle to carry solid substances must be pumped. In certain applications where a fluid is used as a vehicle to carry other substances, clogging may not be the only problem but in addition there may be the problem of preventing the substances from being damaged or destroyed by passing into contact with moving portions of the pumping apparatus. 7

In connection with these problems centrifugal pumps have been designed which are provided with a substantially open passage from the inlet to the outlet of the pump so that large solid substances can pass through the pump without causing clogging. In pumps of this type the centrifugal impeller is located at the side of the pump casing opposite to the pump inlet so that the flow passage is unobstructed and the substances in the fluid are less likely to strike the impeller. Pumps of this type operate along the conventional centrifugal pump principles wherein fluid passes toward the center of rotation of the impeller and then is accelerated radially outwardly along the impeller and finally hurled from the periphery of the impeller into the outer regions of the pump casing. The fluid being thrown from the impeller enters the outer portions of the casing and moves toward the pump outlet. This flow of fluid toward the outer portion of the pump casing engages fluid in that region of the casing and carries it toward the outlet. The large clearances in such a pump which are necessary to prevent clogging have a detrimental effect upon the efliciency of the pump and the maximum head which the pump can produce since the large clearance between the fluid in the casing and the impeller prevents effective control of the fluid by the impeller. Thus only the fluid which passes through the inlet to the center of the impeller and is subsequently hurled from the rim of the impeller into the outer regions of the casing is effectively under control The remainder of the fluid in the casing is engaged adjacent its periphery by the flow moving outwardly in a conical pattern from the impeller and is moved toward the outlet. Since the outward flow from the impeller is at a high velocity and meets the low velocity fluid adjacent the periphery of the chamber, it causes turbulence which results in energy losses and inefliciency. Because of the appreciable flow of fluid passing along the impeller in the prior non-clog pumps, the impeller is not protected from wear or damage by foreign substances. The flow into the center of the impeller results in impact of the foreign substances directly upon the impeller before they are swept toward the pump outlet. The overall result of previous eflorts In some industrial to provide a non-clog pump have been to prevent clogging at the expense of the operating characteristics of the pump.

Accordingly it is the primary object of the present invention to provide a pump which is capable of handling fluids containing foreign substances without clogging and which at the same time is capable of operating in an eflicient manner and capable of producing high flow at high pressure heads.

More particularly it is an object of the invention to provide a pump including large clearances within the pump passage and further including an impeller capable of forming a circulation of fluid with respect thereto which is adapted to engage or couple the remaining portion of the fiuid in the casing and to urge it to the outlet of the pump.

Furthermore it is an object of the invention to provide a pump in which the flow of fluid from the impeller is diverted back toward the impeller in order to form an effective coupling with the fluid passing through the pump.

Another object of the invention is to provide a pump having a substantially open passage in order to prevent clogging.

Also an object of the invention is to provide a pump sealing arrangement which is conditioned to prevent leakage whether there is a substantial positive or negative pressure within the pump casing adjacent to the shaft connected to the pump impeller.

A still further object of the invention is to provide a sealing arrangement in which the magnitude of closure forces between the sealing members are related to the pressure conditions adjacent to the sealing arrangement and to the rotational speed of the impeller.

It is also an object of the invention to provide a pump which minimizes the contact of foreign substances in the fluid from striking the impeller.

In addition it is an object of the invention to provide a pump with an open passage and adapted to provide a high head with high efficiency.

In accordance with the principles of our invention, the device comprises a rotary impeller having an axis about which it rotates and forming a wall rotating about the axis and extending radially therefrom. Blades extend laterally from the wall at an angle with respect to its rotating direction and rotate therewith. The device further includes structure forming a chamber laterally offset from the wall and entirely open thereto and to all of its blades and to full circumferential flow. The chamber is adapted to confine fluid with the wall and the blades immersed therein. Rotation of the impeller normally causes the blades to force the fluid to flow in the radially extending direction of the wall lengthwise with respect to the blades while rotating in their rotating direction. Rotation of the impeller further causes fluid to be discharged from the blades ends. Means are located adjacent to the ends of the blades for diverting the fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of the blades in paths oifset from the flow in the radially extending direction of the wall between the latter flow and the fluid in the chamber. In this Way there is formed a toruslike flow of fluid rotating about the axis while flowing recirculatingly, continuously and laterally with respect to its rotation. Thus there is formed in effect a fluid impeller engaging the fluid in the chamber. The structure forms a fluid inlet and outlet for the chamber which are respectively located to permit fluid to feed from outside of the chamber to the flow established by the fluid torus and to permit this flow to discharge to the outside.

In one embodiment of the invention the chamber is substantially cylindrical in form. The rotary impeller which is substantially in the form of a disc is disposed adjacent the inner surface of the chamber. The impeller includes a plurality of blades which extend towards its periphery. About the periphery of the impeller is disposed a shroud member which substantially diverts the movement of fluid with respect to the blades and reverses it toward the central portion of the impeller. The diverting of the fluid causes recirculation of the fluid with respect to the blades which forms a close coupling to the remainder of the fluid in the chamber and urges the fluid to passfrom the chamber. The shroud member for reversing the movement of the fluid may be mounted upon the impeller itself or may be mounted upon the chamber adjacent to the periphery of the impeller.

In another embodiment of the invention the pumping chamber as well as the impeller are in a substantially tapered form. This form reduces the turning of the solid substances in the fluid when the fluid is passing through the pumping chamber. The tapered impeller has a plurality of vanes for causing movement of the fluid with respect to the impeller. A shroud member either on the impeller or on the chamber adjacent to the periphery of the impeller diverts the movement of fluid so that circulation is established with respect to the impeller. The circulation forms a close coupling to fluid in the tapered chamber and urges it to pass through the chamber.

In still a further embodiment of the invention the pump includes an impeller having a substantially elongated form. The elongated impeller may be in the form of a hollow cylinder having a plurality of blades disposed along its inner surface. The vanes which can be arranged in an axial manner with respect to the axis of rotation of the impeller move the fluid adjacent the vanes toward one of the end portions. Adjacent the end portion either on the impeller or on the chamber adjacent to the impeller is a shroud member which diverts the movement of the fluid with respect to the impeller. The diverting of the fluid establishes recirculation with respect to the blades which in turn couples with the fluid in the chamber and the interior of the impeller. The coupling of the circulating fluid drives the fluid axially through the device.

In still another embodiment of the invention the device includes a sealing arrangement for the impeller shaft which is responsive to the pressure adjacent to it for determining the sealing pressure.

In a further embodiment of the invention the device includes a sealing arrangement for the impeller shaft which is responsive to the rotational speed of the impeller for determining the sealing pressure.

Prior pumps operating under centrifugal conditions and adapted to prevent clogging have employed impellers offset from the main flow passage and adapted to hurl the fluid from the periphery of the impeller outwardly toward the outer peripheral portion of the chamber. This arrangement results in only a portion of the fluid in the chamber being engaged by the fluid passing from the periphery of the impeller and is also accompanied by turbulence due to the intersection of the high velocity fluid from the impeller with the lower velocity fluid within the chamber. As opposed to these prior art constructions the device of the invention diverts the flow from the impeller to move in a direction opposite to that of the prior art pumps, that is to be diverted toward the axis of rotation of the impeller in order to establish recirculation of the fluid with respect to the impeller. The recirculation forms a torus-like body of fluid adjacent the impeller and having fluid blades which form an excellent coupling to the fluid in the passage adjacent to the impeller. The fluid blades engage the fluid in the passage substantially across the portion of the passage adjacent to the impeller so that the fluid in the passage can be rotated with high efficiency. The coupling of the fluid in this manner enables the pump of the invention to produce higher pressure heads than those obtained with the prior pumps having the same impeller diameter.

Furthermore the establishment of the recirculating fluid adjacent the impeller forms a barrier of flow which can deflect foreign substances in the fluid from contacting the impeller. Thus the pump of the invention is adapted to handle fluids such as wood pulp suspended in a liquid, mixtures of water and gravel or sand in dredging operations, sewerage containing solids, fragile articles such as fruit, vegetables and the like suspended in liquids, and solid articles such as coal suspended in liquids. The pump of the invention is also adapted to handle gases such as a flow of air for conveying substances suspended therein.

Other objects and features of the invention will become apparent in the following specification and claims and in the drawings in which;

FIG. 1 is an axial section View of one embodiment of the invention;

FIG. 2 is a radial section view of one embodiment of the invention;

FIG. 3 is an enlarged section view taken along the lines 3-3 in FIG. 2;

FIG. 4 is a fragmentary view of the end portions of the pump blades;

FIG. 5A is a fragmentary axial section showing a stationary shroud adjacent the impeller;

FIG. 5B is a section view showing an impeller with curved blades;

FIG. 6A is a fragmentary axial section view showing an impeller provided with a rotating shroud;

FIG. 6B is a section view of an impeller having radial blades;

FIG. 7 is a section view taken along the line 7-7 in FIG. 8 showing an impeller with a rotating shroud and having a ring member intersecting the blades;

FIG. 8 is a section view showing the face of an impeller having a rotating shroud and a ring member intersecting the blades;

FIG. 9 is a section view of an impeller having curved blades disposed in a direction opposite to that of FIG. 5B;

FIG. 10 is a section view of an embodiment of the invention in which the chamber and the impeller are of a substantially tapered shape;

FIG. 11A is an axial section view of an embodiment of the invention in which the pump contains a hollow cylindrical impeller;

FIG. 11B is a radial section view of an embodiment of the invention in which the pump has a hollow cylindrical impeller;

FIG. 12 is a fragmentary axial section view showing a membrane seal for an impeller;

FIG. 13 is a fragmentary axial section view showing a diaphragm seal for an impeller;

FIG. 14 is a fragmentary section view showing a further embodiment of an impeller seal;

FIG. 15A is a fragmentary axial section view of an impeller having a rotating shroud;

FIG. 15B is a radial section view of an impeller having radially disposed blades;

FIG. 16A shows another embodiment of an impeller seal of the diaphragm type;

FIG. 16B is a section view of the diaphragm spring of the impeller seal of the invention;

FIG. 17A is a fragmentary section view showing the blades inclined to an impeller in the direction of movement;

FIG. 17B is a fragmentary sectional view showing the blades inclined with respect to an impeller opposite to the direction of movement;

FIG. 18 is a fragmentary axial section view showing a rotating diaphragm seal.

FIGS. 19 and 20 are axial section views showing the impeller blades extending adjacent to a stationary wall.

Referring to FIG. 1 an embodiment of the invention is shown and is referred to generally by the reference numeral 20. Pump 20 comprises a pump casing 21 providing chamber 21a having an inlet 22 and outlet 23. Chamber 21a provides an open passage from inlet 22 to outlet 23. Impeller 24 is disposed adjacent side 21b of casing 21 facing toward chamber 21a and inlet 22. Impeller 24 comprises a plurality of radially disposed blades 25 extending from hub 26 in an outward direction (FIG. 2). Blades 25 extend at substantially right angles to disc portion 24:: of the impeller (FIG. 3). The side of impeller disc 24a opposite that to which the blades are attached is provided with a plurality of back blades 27 which are adapted to control the pressure at the back side of impeller 24 in order to minimize thrust loading of the impeller as well as leakage at the impeller shaft. As shown in FIG. 1 the profile of hub 26 and impeller disc 24a is a curved section extending across the impeller between vanes 25. In addition the depth of the blades increases as the blades extend from the center. Casing 21 further includes stationary shroud ring 28 which surrounds the periphery of the impeller adjacent the free ends of blades 25.

When fluid is admitted into pump 2! and impeller 24 is set into rotary motion, the fluid between blades 25 is accelerated outwardly in a radial direction between the blades toward stationary shroud ring 28 which is of a substantially cylindrical form surrounding the free ends of the blades. Since shroud ring 28 intersects the outward radial path of flow of the fluid between blades 25, the shroud ring serves as a means for diverting the movement of the outwardly flowing fluid thereby reversing it so that it is deflected inwardly toward the axis of impeller 24. The outward flow of the fluid between the blades and the subsequent returning flow of the fluid results in a recirculation of the fluid being established with respect to the impeller. The velocity of the fluid circulating adjacent to the impeller forms effectively a fluid barrier in front of the impeller which reduces the possibility of foreign substances in the fluid from striking the impeller. The higher pressure accompanying the diverting of the flow by shroud ring 28 serves to assist the fluid to flow back toward the axis of the impeller so that a major portion of the outward flow between the blades is subsequently returned toward the axis of the impeller.

Once the recirculation has been established about the impeller, the flow pattern of the recirculation eifectively forms a torus-like flow of fluid having fluid blades or lobes of moving fluid as the toroidal flow passes over the edges of the blades. The fluid blades or lobes formed by the recirculation couple to the remaining portion of the fluid in chamber 21a of the casing and drive it in a rotary motion so that flow is maintained from inlet 22, through chamber 21a and to outlet 23. The fluid blades or lobes formed by the recirculation with respect to the blades of the impeller provide an intensive coupling to the volume of fluid within chamber 210 of the casing. As a result of the coupling, the volume of fluid within the passage formed by chamber 210 becomes accelerated in a rotary direction. The rotating fluid in the chamber flows outwardly through outlet 23.

The flow passing from the inlet to the outlet is driven by the recirculation of fluid with respect to the impeller so that the flow through the pump need not intersect the blades of the impeller with the exception of the fluid involved in the recirculation. This flow arrangement is of great advantage when foreign material is carried in the fluid since it tends to prevent contact of the foreign material with the impeller. The pump produces a vortex which extends from inlet 22 back along pipe 29 due to the whirl of the fluid in chamber 21a. Inlet 22 may be pro vided with contraction 22b extending from location 22a to 22b which serves to increase the relative velocity of the fluid passing through the contraction and causes foreign substances to be thrown outwardly within chamber In so that the impeller is not contacted. The diffusing section between locations 22b and 220 facilitates the outward flow as the fluid enters chamber 21a. The relative velocity of the fluid through the pump can be maintained substantially constant until the fluid approaches outlet 23. In the transition from rotary flow to flow in the direction of the outlet, the relative velocity can increase as the flow advances from the interior of the casing into outlet 23.

The rotation of the impeller within the confines of shroud ring 28 serves to center the impeller'with respect to the shroud ring due to the cushioning elfect of the layer of fluid between the end portions 25a of blades 25 and the inside surface of the shroud ring. This arrangement and the fact that the impeller is substantially in the wall of the casing which reduces the degree of overhang of the impeller shaft results in only moderate loading upon th shaft bearings.

In order to reduce frictional eifects of the circulating fluid adjacent impeller blades 25, edges 25b of the blades which face the interior of casing 21 can be provided with sharpened edges. In FIG. 3 the arrow indicates the direction of motion of the blades. Similarly, to reduce the fluid friction at free ends 25a of the blades, this portion of the blades can also be provided with sharpened edges as shown in FIG. 4 Where the arrow also indicates the direction of rotation of the vanes.

In the embodiment of FIG. 5A, to facilitate the return of the fluid moving radially outwardly along the impeller between blades 25, casing 30 and support 31, are provided with curved recess or shroud ring 32 adjacent to curved ends 33a of blades 33. On the other hand as shown in FIG. 6A, impeller 34 is provided with a rotating shroud 35 having a curved recess 35:: adjacent to curved ends 36a of blades 36. In this arrangement stationary shroud ring 28 attached to casing 21 surrounds the periphery of rotating shroud ring 35. Similarly as in the arrangement in FIG. 5A curved recess 35a facilitates the return flow of the recirculating fluid adjacent to blades 36 of impeller 34.

In a further embodiment of the pump shown in FIG. 7, impeller 37 is provided with rotating shroud 38 similar to that of FIG. 6A and blade ring 39 which intersects each of the blades 40. The toroidal-like blade ring 39 forms curved passages 41 shown in FIGS. 7 and 8 which positively direct the flow of fluid from the axis of impeller 37 into a curved path which results in the fluid being returned toward the center of the impeller as it leaves the passage adjacent the periphery of the impeller.

Impeller 42 can be located in a portion of chamber 43a Within casing 43 (FIG. 15A). In this arrangement impeller 42 is provided with rotating shroud ring 44 which includes a curved recess 44a adjacent to curved ends 45a of blades 4-5. In this construction in order to provide the fluid centering-eifect for impeller 42 and to prevent excessive leakage past the impeller, the periphery 42a of the impeller is disposed within the cylindrical section of stationary shroud ring 43a adjacent to the casing.

In FIG. 2 blades 25 extend in a substantially radial direction. In a pump having low specific rotary speeds forward-curved blades 46 of impeller 45 can be used (FIG. 9). At high specific rotary speeds backwardcurved blades 33b can be used (FIG. 5B).

By way of example a pump of the type shown in FIGS. 1 and 2 can include chamber 21a with an axial dimension of approximately 3 inches. In such an example stationary shroud 25a surrounding the impeller would have an inside diameter of approximately 5 /2 inches. The axial dimension of the shroud would be approximately 2 inches. The inside diameter of casing 21 of such a pump would be approximately 8 /2 inches and its axial width approximately 3 inches. The axial dimension of blade 25 between its radial free edge and the surface of disc 24a would be approximately 1 /2 inches. The inside diameters of contraction 22b and the pipe at inlet 22 are approximately 3, 2, and 4 inches, respectively. In the pump of the example the impeller has 8 blades.

To obtain the improved coupling of the recirculating fluid adjacent the impeller with the fluid in chamber 210, it is necessary that the fluid blades extend adjacent to the free radial edges of blades 25. When pumps smaller than the example set forth are to be provided and the axial dimension of chamber 21a is reduced, the impeller may be provided with a greater number of blades so that the recirculating fluid does not extend across the entire passage of chamber 21a but instead extends in a manner suiticient only to engage the portion of the fluid in the passage adjacent to the impeller. To decrease the extent to which the recirculating fluid projects beyond the impeller, a greater number of impeller blades can be employed thereby reducing the width of the passage between them and at the same time reducing the size of the recirculating torus-like flow of fluid adjacent the impeller. Similarly the axial dimension of blades 25 with respect to disc 24a can be varied dependent upon the size of the impeller and its rotary speed to insure that the recirculating fluid extends adjacent to the free radial edges of the blades and is conditioned to engage or couple the fluid within the passage of chamber 21a.

During operation the fluid adjacent the free ends of blades 25 and the stationary shroud ring 25a experiences a build-up of pressure due to the diverting action of the shroud ring which directs the outward radial flow to return toward the axis of the impeller. At the same time the fluid in the clearance area provides the fluid centering effect previously discussed.

In a modification of the pump shown in FIGS. 1 and 2, outlet 23 is disposed in a radial direction with respect to casing 21. In an additional modification of the pump, outlet 23 is inclined with respect to the axis of rotation of impeller 24.

In FIG. there is shown an embodiment of the pump having a substantially tapered casing 48 and tapered impeller 49. Blades 50 extend from hub 52 of the impeller adjacent to its axis of rotation to curved ends 500 which are adjacent the stationary shroud ring formed by portion 48:: of the casing and portion 51a of support 51. The tapered form of casing 48 results in passage 48b having a tapered form which simplifies, reduces the angularity of the flow pattern from inlet 53 and past impeller 49 with the result that the tendency of foreign substances in the fluid to strike the impeller is substantially eliminated.

As previously discussed, the curved form of shroud rings 48a and 51a provides means for reversing the movement of fluid between blades 50 so that it returns toward hub 52 of impeller 49. This arrangement insures that the proper degree of circulation is established adjacent to the impeller so that the fluid passing into casing 48 is sufliciently coupled by the fluid blades or lobes formed during the process of recirculation with respect to the impeller.

In FIG. 3 blades 25 are shown disposed at substantially right angles to the plane of impeller disc 24a while in FIG. 17A, blades 54 are inclined at an angle in the direction of motion with respect to impeller disc 55. On the other hand as shown in FIG. 17B, vanes 66 can be inclined at an angle opposite to that of the direction of motion with respect to disc 57. In each form the tapered section adjacent to the edge blade reduces fluid friction and cavitation effects.

In FIG. 11A another embodiment of the invention is shown in which the casing and the impeller are of a substantially hollow cylindrical form. The casing of pump 58 includes sleeves 59 attached at each end to cylindrical impeller 60. Sleeves 59 are supported in rotation by bushings 61 at each end of the impeller and the bushings in turn are supported by housing 62. In the embodiment shown in FIG. 11A, impeller 60 also serves as the rotor of the electrical motor for driving the pump. The motor includes stator windings 63 disposed about stator 64. Windings 65 can be applied about cylindrical impeller or rotor 60. Along the inner surface of rotor 66 there are disposed in a radial manner with respect to the axis of rotation, a plurality of blades 66. Each of the blades has a curved end portion 660. The portion of the rotor adjacent to the curved end portions of the blades is formed into rotating shroud 67 having a curved recess. Upon rotation of the cylindrical impeller 60, the fluid is accelerated along the radially extending Wall between blades 66 in the direction of their curved end portions 66a. At this point rotating shroud 67 serves as a means for diverting the movement of the fluid so that it is substantially returned to the location from which its motion initiated. The result of the reversing flow is to institute a recirculation of the fluid with respect to blades 66 similarly as discussed with respect to the other embodiments of the pump. The recirculation causes the formation of fluid blades or lobes which couple to the fluid passing through the chamber. The coupling to the fluid causes it to rotate and advance so that the fluid moves from'inlet 68 through the chamber to outlet 69 with a screw-like motion.

Various embodiments of the pump of the present invention can be employed as a fluid motor by supplying a flow of fluid to the pump inlet. The movement of the fluid through the casing initiates movement of the impeller after which the rotation of the impeller establishes the recirculation of fluid with respect to the impeller. The fluid blades of the recirculation then form an eflective coupling with the flow of fluid through the passage with the result that efficient operation is obtained.

In industrial processes it may be necessary to pump a fluid or to agitate a fluid in a substantially closed system. For example in removing foreign substances from a fluid or in separating a given material from a fluid, it is customary to centrifuge the fluid in a closed chamber. The apparatus of the present invention is adaptable to serve as a means for rotating or agitating the fluid in such an apparatus. Here the impeller and the means for diverting the flow of fluid from the impeller to establish recirculation are disposed within a closed chamber and operated in order to establish the coupling with the fluid in the chamber. With this arrangement the fluid in the chamber is rotated by the coupling action and the resulting angular velocity accelerates the particles suspended in the fluid so that they can be separated from the fluid in the radial direction. For these purposes the chamber can be formed in the manner that is normally used for cyclone separators.

In FIG. 12 there is shown one embodiment of a seal arrangement adapted for the pump of the invention. Impeller 70 is mounted upon stepped shaft 71 which in turn is supported by roller bearing 72. The roller bearing is mounted within housing 74. Sealing ring 73 is secured to shaft 71 between the impeller and the roller bearing. About inner hub 25% of the impeller there is mounted sealing collar 79. Seal 78 which is formed from known material suited for this purpose such as rubber, plastic material, carbon, ceramic material, hard metal and the like, is supported by membrane 77 which is attached to support ring 76 mounted in housing 74. Membrane 77 which can be fabricated from material such as rubber, plastic, thin metal, etc., is corrugated so that it is free to deflect in both a radial and axial direction when subjected to fluid pressure along its surface. Back blades 31 disposed along the rear surface of impeller 76 are employed to control the pressure level within chamber 32 adjacent to the membrane seal. With a positive pressure on the impeller side of membrane 77, the membrane urges seal 78 radially in the direction of shaft 71 when the seal can be radially deformed and axially in the direction of bearing 72. The result of these combined forces is to urge seal 7 8 against surface 79a of the sealing collar and surface 73a of the sealing ring. Upon an in crease in pressure within chamber 82, the seal is urged with greater force against the adjacent surfaces so that the increase contact pressure provides more effective sealing.

Another embodiment of a seal adapted for the pump of the invention is shown in FIG. 16A. Impeller 83 is mounted upon shaft 84 which is supported by ball bearing 85, mounted in housing 86. Oil seal 87 mounted in housing 36 engages sleeve 88 and thereby prevents the escape of lubricant from the bearing. Support 89 for rotating seal 91) is mounted upon shaft 84 between sleeve 83 and sleeve 91 which is adjacent to impeller 83. Stationary seal 92 is supported in engagement with the face of rotating seal 90 by means of diaphragm support 93 which is attached at its outer periphery to housing 86. Diaphragm support 93 comprises diaphragm spring 94 (FIG. 1613) with covering 95 of a flexible material such as natural rubber, synthetic rubber, plastic and the like, vulcanized or molded about the diaphragm spring.

If impeller 83 is provided with relief openings 83a, the pressure in cavity 96 behind impeller 83 can be below atmospheric pressure. With this condition the reduced pressure causes diaphragm assembly 93 to be urged toward the impeller thereby reducing the pressure upon the seal during operation. The effect of this condition can be minimized by employing diaphragm assembly 93 in which diaphragm spring 94 in its rest position before assembly into the pump extends or deflects toward bearing 85. The deflection of the spring urges the diaphragm assembly into a cone-like shape. During assembly of the pump, the diaphragm is preloaded to take substantially the form shown in FIG. 16A. In this manner stationary seal 92 is preloaded against rotating seal 91). During operation a negative pressure condition within cavity 96 merely reduces the degree of preload but does not reduce it below a value at which an effective seal is still maintained.

For the case where the pressure in cavity 96 increases during operation, the diaphragm is urged in the direction of bearing 85 with the result that stationary seal 92 is urged with increasing force against rotating seal 90. With such an arrangement the sealing pressure increases as the pressure in cavity 96 increases so that leakage can be prevented or held to a satisfactory level for all pressure conditions of the pump.

In FIG. 13 diaphragm seal assembly 97 is initially deflected in a conical manner toward bearing 98 which supports shaft 99 upon which impeller is mounted. It is therefore possible upon assembly of the pump to preload stationary seal 101 against rotating seal 10?; mounted within seal support 103 which is secured to shaft 99. During operation if a reduced pressure exists within cavity 104 behind impeller 10%, the diaphragm seal assembly is urged toward the impeller. Under such a condition diaphragm spring 105 within assembly 97 offers an increasing resistance to the movement toward the impeller. Consequently this arrangement enables the pressure between the stationary and rotating seals to be confined to a predetermined range.

In FIG. 18 another seal arrangement suitable for the pump of the present invention is shown. Here diaphragm seal assembly 105 is attached by means of support ring 107 to rotate with shaft 1138 upon which impeller 1119 is mounted. At the periphery of the assembly there is attached rotating seal 119 which engages stationary seal 111 supported by housing 112. The assembly contains diaphragm spring 113 similar to that shown in FIG. 1613. The effect of pressure in cavity 114 is similar to that previously discussed. However since the seal assembly rotates, it is also subjected to the effects of centrifugal force during operation. Centrifugal force applied to diaphragm assembly 196 causes rotating seal 110 to be urged with increasing force against stationary force 111 as the shaft speed increases. Consequently the greater the pump speed, the greater the force at the seals so that increasing pressures in cavity 114 are prevented from causing excessive leakage.

For the case where it is desirable to reduce the sealing pressure during operation, for example, to prevent excessive wear of the seals at high surface speeds accompanying high rotational speeds, the stationary seal can be placed on side 110a of the rotating seal as seen in FIG. '18 with the result that as the diaphragm assembly is subjected to increasing rotating speeds and increasing centrifugal force, the pressure between the seals reduces.

Still another seal adapted for the pump of the present invention is shown in FIG. 14. Impeller 115 is mounted upon shaft 116 and secured by nut 117. At the side of the impeller 115 adjacent cavity 113 behind the impeller there is mounted sealing ring 119 which rotates with the impeller. Seal 120 is mounted in seal housing 121 which is supported within sleeve 122 engaged with housing 123. Pin 124 prevents any rotation of seal housing 121. Washer-type springs 125 disposed adjacent to seal housing 121 urge it toward the impeller thereby preloading seal 121) against sealing ring 119. Slot 126 in seal housing 121 enables the axial motion of the seal housing to take place with respect to pin 124.

The seal arrangement shown in FIG. 16A is especially suitable to the pump of the invention. The pressure changes within cavity 96 accompanying changes in pump flow are relatively small as compared with those of a centrifugal pump. This characteristic in conjunction with the function of the impeller back blades enables the pressure in cavity 96 to be maintained within a limited range. Therefore the load applied by diaphragm assembly 93 to stationary seal 92 and transmitted to rotating seal 91 can also be maintained within a limited range. Thus leakage can be prevented without undue seal Wear.

It should be understood that the various embodiments of the seals are also adaptable for rotating machinery other than pumps. These shafts which are subjected to an adjacent pressure condition or leakage problem of either the working fluid or of lubricating material can be provided with one or more of such seals.

While there has been disclosed what at present are considered to be preferred embodiments of the invention, it is to be understood that many changes and modifications may be made therein without departing from the essential spirit of the invention. It is intended therefore in the appended claims to cover all such changes and modifications within the true scope of the invention.

An example of a change or modification to the invention is shown in FIGS. 19 and 20. Impeller 131} includes a plurality of blades 131 radially extending from hub 132. The impeller does not include an impeller disc or rotating wall adjacent the blades but instead the blades extend radially free of one another. At the peripheral portion of the impeller there is disposed rotating shroud 127 which is mounted along the tips of blades 131. Stationary wall 128 extends radially from the axis of rotation of impeller shaft 129 and is disposed adjacent blades 131 of the impeller. During operation the fluid flows radially and in an outward direction along wall 128 and between blades 131. Shroud 127 diverts the flow so that recirculation takes place.

In FIG. 20, blades 133 of impeller 134 extend radially from hub 135 and again there is no impeller disc or rotating wall adjacent the blades. Instead, stationary wall 136 extends radially from the axis of rotation of the impeller and adjacent to the blades. Stationary shroud 137 is disposed about the periphery of the impeller. During operation the flow passes in a radial outward direction along stationary wall 136 and between the blades. Stationary shroud 137 diverts the outward flow and causes the flow to recirculate with respect to the impeller.

I claim:

1. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spacedfrom the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

2. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom at substantially a right angle and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths oflset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

3. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom with a substantially tapered form and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and means located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

4. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom with an elongated form and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally oifset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and means located contiguous to and sub stantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely toward the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

5. A device including a rotary impeller having an axis about which it rotates and forming a disc-shaped wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally olfset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths olfset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from out- 13 side of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

6. A device including a rotary impeller having an axis about which it rotates and forming a substantially conically-shaped wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wa l lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and means located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

7. A device including a rotary impeller having an aixs about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and substantially radially with respect to said axis, said blades rotating with said wall, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a toruslike flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

8. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and substantially radially with respect to said axis, said blades rotating with said wall and being curved along their length, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades While rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and means located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

9. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, said blades being curved along their length, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and means located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to perrnit this flow to discharge to said outside.

10. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending perpendicularly from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing 1 at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally wth respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

11. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to from a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, each of said blade ends having edge portions disposed at substantially right angles to the length of the blade, and stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

12. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, said blade ends being curved in the direction of said wall, and means located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

p 13. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a substantially cylindrical chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and stationary means, extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a toruslike flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in eflect a fluid impeller engaging the fluid in said chamber, said structureforming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

14. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a substantially tapered chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and means located contiguously to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respecttively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

15. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming an elongated chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and means located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in eflect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

16. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, the dimension of the outer portions of said chamber being greater than the dimension of the outer portions of said impeller, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending'direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and stationary means extending in a substantially lateral di ection about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid im peller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

17. A device including a rotary impeller having'an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance'extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rot-ating in their rotating direction and'to be discharged from the blades ends extending in said directiomand stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely to wards the other ends of said blades in paths offset from the flow in said radially extending direction of said Wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and'forming in effect a fluid impeller engaging the fluid in said chamber, said diverting means comprising a shroud member, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside. 7

18. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the por tion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous' to and substa'ntially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely to- Wards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, tofor m a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterallywith respect to'its rotation and forming in eflect a fluid impeller engaging the fluid in said chamber, said diverting means comprising a shroud member, the surface portion of said shroud member contiguous to and substantially enclosing each of said blades ends being substantially perpendicular thereto, said structure forming a fluid inlet and out let for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow estab lished by said fluid torus and to permit this flow to discharge to said outside.

19. A device including a rotary impeller having an axis about which'it rotates and forming a wall rotating about said axis and extending radiallytherefrom and blades extending laterally from said wall and at an angle with re} spect to its rotating direction" and rotating therewith; structure forming a chamber laterally offset from said wall and entirely open theerto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said'wall and blades immersed therein, rota tion of said impeller norm-ally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwisewith respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and means located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades'in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said diverting means comprising a shroud member disposed contiguous to said blades ends and having a continuous channel adjacent thereto, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

20. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure dis posed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a toruslike flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside, and means for accelerating the flow of fluid adjacent said fluid inlet.

21. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said Wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades -to force said fluid flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside, and means for accelerating the flow of fluid adjacent said fluid inlet, said accelerating means comprising a flow constriction disposed adjacent to said inlet.

22. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally oflset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, said wall and said blades forming a plurality of channels through which said flow in the radially extending direction lengthwise with respect to said blades passes, the depth of each of said Wall channels increasing along the length thereof in the direction of said blades ends, and stationary means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a toruslike flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

23. A device including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom, said impeller having a central hub and blades extending laterally from said wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, said wall and said blades forming a plurality of channels through which said flow in the radially extending direction lengthwise with respect to said blades passes, the depth of each of said channels increasing along the length thereof in a direction extending outwardly from adjacent said hubto a predetermined depth, and means located contiguous to and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the low in said radially extending direction or" said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said' axis while flowing recircuitin ly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

24. A device including a rotary impeller having an axis about which it rotates and a substantially tapered body portion rotating about said axis and extending angularly therefrom and blades extending laterally from said body portion at an angle with respect to its rotating direction and rotating therewith, structure forming a substantially tapered chamber laterally offset from said body portion and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine fluid with said body portion and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the angularly extending direction of said body portion lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends ex tending in said direction, and means located contiguous to'and substantially enclosing said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths oflset from the flow in said angularly extending direction of said body portion between the latter flow and fluid in said chamber, to form a torus-like fl w or" fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

25. A pump comprising a pumping chamber adapted to receive fluid to be pumped, a rotary impeller disposed adjacent to the inner surface of said chamber, the portion of said impeller facing said chamber being laterally spaced from the portion of said chamber disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said chamber, said impeller having a means for moving with respect to said impeller the portion of fluid in said chamber adjacent said impeller, said moving means substantially facing the interior portion of said chamber, and stationary means extending in a substantially lateral direction about the entire periphery of said impeller and contiguous to and substantially enclosing said moving means for substantially reversing said movement of said portion of fluid in a direction between said moving means and the other portion of said fluid in said chamber, said reversing means causing circulation of said portion of fluid with respect to said moving means, whereby said circulation couples with and rotates said other portion of fluid to urge said other portion from said chamber.

26. A pump comprising a pumping chamber adapted to receive fluid to be pumped, a rotary impeller disposed adjacent to the inner surface of said chamber, said impeller having a plurality of blades for causing movement toward an end portion of each of said blades of the portion of fluid in said chamber adjacent said blades, said blades substantially facing the interior portion of said chamber, the portion of said impeller facing said chamber being laterally spaced from the portion of said chamber disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said chamber, and stationary means extending in a substantially lateral direction about the entire periphery of said impeller and contiguous to and substantially enclosing said end portion of said blades for substantially reversing said movement of said portion of fluid in a direction between said i'm peller and the other portion of said fluid in said chamber, said reversing means causing recirculation of said portion of fluid with respect to said blades, whereby said recircu lation couples with and rotates said other portion of fluid to urge said other portion from said chamber.

27. A device including a rotary impeller having an axis about which it rotates, a stationary wall extending radially from said axis, said impeller having blades rotating therewith adjacent said wall, said blades extending laterally with respect to said wall and at an angle with re spect to the rotating direction of said impeller, structure forming a chamber laterally offset from said Wall and entirely open thereto and to all of said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the. blades ends extending in said direction, and means located contiguous to said ends of the blades for diverting said fluid in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths offset from the flow in said radially extend ing direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly con-' tinuously laterally with respect to its rotation and forming in eifect a fluid impeller engaging the fluid in said chamher, said structure forming a fluid inlet and outlet for said' chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by saidfluid torus and to permit this flow to discharge to said outside.

28. A device including a rotary impeller having an axis about which it rotates, a wall disposed about said axis and extending radially therefrom, said impeller hav-' ing blades extending laterally with respect to said wall and at an angle with respect to the rotating direction of said impeller and rotating therewith, structure forming a chamber laterally offset from said wall and entirely" open thereto and to all of said blades and to full circum-' ferential flow and adapted to confine fluid with said wall and blades exposed thereto, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, and means extending in a substantially lateral direction about the entire periphery of said impeller and located contiguous to and substantially enclosing said ends of the blades for increasing the pressure of said fluid adjacent thereto, the increase of pressure diverting said fluid in a direction extending toward the decrease in pressure of said fluid adjacent the central portion of said impeller and causing at least a substantial portion thereof to flow reversely towards the other ends of said blades in paths oflset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said 23 chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

29. A pump including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom at substantially a right angle and blades extending laterally from said Wall and at an angle with respect to its rotating direction and rotating therewith, structure forming a chamber laterally offset from said wall and entirely open thereto and to all' of its said blades and to full circumferential flow and adapted to confine fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, each of said ends of the blades having an edge portion extending substantially parallel to said axis, and stationary means located contiguous to and substantially enclosing the edge portion of each of said ends of the blades for diverting said fluid to increase the pressure thereof, the diverting being in a direction causing at least a substantial portion thereof to flow reversely towards the other ends of said blades and the lower pressure adjacent thereto in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said charn er, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in effect a fluid impeller engaging the fluid in said chamher, said diverting means comprising a circumferential shroud member having its surface contiguous to and substantially enclosing the edge portion of each of said ends of the blades, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torous and to permit this flow to discharge to said outside.

30. A pump including a rotary impeller having an axis about which it rotates and forming a wall rotating about said axis and extending radially therefrom at substantially a right angle and blades connected adjacent one of their longitudinal edge portions to said wall and extending laterally therefrom at an angle with respect to its rotating direction and rotating therewith, structure forming a substantially cylindrical chamber having spaced apart side portions and a central body portion, the longitudinal axis of said chamber being substantially coextensive with said axis, said chamber being laterally offset from said wall and entirely open thereto and to all of its said blades and to full circumferential flow and adapted to confine, fluid with said wall and blades immersed therein, the portion of said impeller facing said chamber being laterally spaced from the plane of the portion of said structure disposed opposite thereto to form a lateral clearance extending between all of said portion of the impeller and said plane of said portion of the structure, rotation of said impeller normally causing said blades to force said fluid to flow in the radially extending direction of said wall lengthwise with respect to said blades while rotating in their rotating direction and to be discharged from the blades ends extending in said direction, one of said side portions containing a recess havlng a longitudinal axis coextensive with said axis, said recess being adapted to receive said impeller and having a substantially cylindrical wall disposed about said axis, said wall being contiguous to and substantially enclosing said ends of the blades, said cylindrical Wall diverting said fluid to increase the pressure thereof, the diverting being in a direction causing at least a substantial portion thereof to flow rcversely towards the other ends of said blades and the lower pressure adjacent thereto in paths offset from the flow in said radially extending direction of said wall between the latter flow and fluid in said chamber, to form a torus-like flow of fluid rotating about said axis while flowing recircuitingly continuously laterally with respect to its rotation and forming in elfect a fluid impeller engaging the fluid in said chamber, said structure forming a fluid inlet and outlet for said chamber respectively located to permit fluid to feed from outside of said chamber to the flow established by said fluid torus and to permit this flow to discharge to said outside.

References Cited by the Examiner UNITED STATES PATENTS Re. 24,803 3/60 Burnside 103-115 X 1,627,294 5/27 Nydqvist l03-97 X 2,635,548 4/53 Brawley 103103 2,724,338 11/55 Roth 103-103 2,824,520 2/58 Bartels 103- 103 2,958,293 11/60 Pray 103 -103 FOREIGN PATENTS 719,353 4/42 Germany. 808,796 7/51 Germany. 1,046,502 12/58 Germany.

420,324 4/47 Italy.

ROBERT M. WALKER, Primary Examiner.

LAURENCE V. EFNER, Examiner.

Claims

1. A DEVICE INCLUDING A ROTARY IMPELLER HAVING AN AXIS ABOUT WHICH IT ROTATES AND FORMING A WALL ROTATING ABOUT SAID AXIS AND EXTENDING RADIALY THEREFROM AND BLADES EXTENDING LATERALLY FROM SAID WALL AND AT AN ANGLE WITH RESPECT TO ITS ROTATING DIRECTION AND ROTATING THEREWITH, STRUCTURE FORMING A CHAMBER LATERALLY OFFSET FROM SAID WALL AND ENTIRELY OPEN THERETO AND TO ALL OF ITS SAID BLADES AND TO FULL CIRCUMFERENTIAL FLOW AND ADAPTED TO CONFINE FLUID WITH SAID WALL AND BLADES IMMERSED THEREIN, THE PORTION OF SAID IMPELLER FACING SAID CHAMBER BEING LATERALLY SPACED FROM THE PLANE OF THE PORTION OF SAID STRUCTURE DISPOSED OPPOSITE THERETO TO FORM A LATERAL CLEARANCE EXTENDING BETWEEN ALL OF SAID PORTION OF THE IMPELLER AND SAID PLANE OF SAID PORTION OF THE STRUCTURE, ROTATION OF SAID IMPELLER NORMALLY CAUSING SAID BLADES WHILE FORCE SAID FLUID TO FLOW IN THE RADIALLY EXTENDING DIRECTION OF SAID WALL LENGTHWISE WITH RESPECT TO SAID BLADES WHILE ROTATING IN THEIR ROTATING DIRECTION AND TO BE DISCHARGED FROM THE BLADES'' ENDS EXTENDING IN SAID DIRECTION, AND STATIONARY MEANS EXTENDING IN A SUBSTANTIALLY LATERAL DIRECTION ABOUT THE ENTIRE PERIPHERY OF SAID IMPELLER AND LOCATED CONTIGUOUS TO AND SUBSTANTIALLY ENCLOSING SAID ENDS OF THE BLADES FOR DIVERTING SAID FLUID IN A DIRECTION CAUSING AT LEAST A SUBSTANTIAL PORTION THEREOF TO FLOW REVERSELY TOWARDS THE OTHER ENDS OF SAID BLADES IN PATHS OFFSET FROM THE FLOW IN SAID RADIALLY EXTENDING DIRECTION OF SAID WALL BETWEEN THE LATTER FLOW AND FLUID IN SAID CHAMBER, TO FORM A TORUS-LIKE FLOW OF FLUID ROTATING ABOUT SAID AXIS WHILE FORMING RECIRCUITINGLY CONTINUOUSLY LATERALLY WITH RESPECT TO ITS ROTATION AND FORMING IN EFFECT A FLUID IMPELLER ENGAGING THE FLUID IN SAID CHAMBER, SAID STRUCTURE FORMING A FLUID INLET AND OUTLET FOR SAID CHAMBER RESPECTIVELY LOCATED TO PERMIT FLUID TO FEED FROM OUTSIDE OF SAID CHAMBER TO THE FLOW ESTABLISHED BY SAID FLUID TORUS AND TO PERMIT THIS FLOW TO DISCHARGE TO SAID OUTSIDE.