US3209989A

US3209989A - Cross flow fan

Info

Publication number: US3209989A
Application number: US82885A
Authority: US
Inventors: Eck Bruno
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-01-18
Filing date: 1961-01-16
Publication date: 1965-10-05
Anticipated expiration: 1982-10-05
Also published as: GB974658A; DE1403545A1; CH399645A

Description

B. ECK

CROSS FLOW FAN Oct. 5, 1965 3 Sheets-Sheet 1 ll Filed Jan. 16, 1961 Fig.1

Oct. 5, 1965 B. ECK 3,209,989

CROSS FLOW FAN Filed Jan. 16. 1961 3 Sheets-Sheet 2 Oct. 5, 1965 B. EcK 3,209,989

CROSS FLOW FAN Filed Jan. 16, 1961 3 Sheets-Sheet 3 FIG. /0. F/G.

INVENTOR. w) [i F1 1 United States Patent 3,209,989 CROSS FLOW FAN Bruno Eek, Geisbergstr. 24, Cologne-Klettenberg,

11 Claims. 61. 230-125 The present invention relates to a cross flow fan, and more particularly to a cross flow fan of the type disclosed in my US. Patent 2,942,773, issued on June 28, 1960.

This patent discloses a cross flow fan including a cylindrical impeller surrounding an empty space through which the fluid is driven by the rotating impeller. A converging gap on one side of the impeller receives a part of the fluid flowing into the outlet of the stator casing, and deflects the returned fluid to form a whirling body of fluid in the cylindrical space surrounded by the impeller blades so that such whirling body of fluid forms a guide means for the fluid flowing through the apparatus eliminating the necessity of providing a fixed guide structure in the cylindrical space surrounded by the impeller.

The position and shape of the stator part which forms the converging gap together with the outer peripheral surface of the impeller have a substantial influence on the shape and position of the whirling body of fluid, and consequently on the function of the apparatus with dif ferent fluids, at different rotary impeller speeds, and for different impeller and stator constructions.

It is one object of the present invention to improve the known cross flow fans, and to provide a cross flow fan which can be adjusted to influence the shape and position of the whirling body of fluid which serves as a guide means for the main flow of the fluid through the apparatus.

Another object of the present invention is to provide movable flow control means in the region of the converging gap for influencing the position and shape of the whirling body of fluid.

Another object of the present invention is to provide in a converging gap of a cross flow fan, a flow control means which can be moved between a plurality of effective positions for producing whirling bodies of the fluid in different positions.

Another object of the present invention is to provide a cross flow fan including movable flow control means by which the output of the fan can be adjusted.

Another object of the present invention is to provide a cross flow fan with flow control means by which the apparatus can be adjusted to perfect operation at different rotary speeds of the impeller.

With these objects in view, one embodiment of the present invention comprises impeller means having a plurality of impeller blades disposed in a circle and defining a cylindrical outer surface concentric with the axis of rotation of the impeller means, and surrounding an inner cylindrical space within the impeller means; and a stator supporting the impeller means for rotation about its axis in one direction of rotation, and including two parts located adjacent the cylindrical surface of the impeller means and defining between each other a passage through the impeller means and through the inner space.

The passage has an inlet on one side of the two parts, and an outlet on the other side of the two parts so that, during rotation of the impeller means, a fluid admitted through the inlet flows through the passage and out of the outlet.

One of the two stator parts which form the passage, includes a movable flow control means and forms with the cylindrical surface of the impeller means an adjustable gap which converges in the direction of rotation from the outlet toward the inlet.

"ice

The converging gap receives from the impeller blades a portion of the fluid flowing into the outlet, whereby this portion of the fluid is deflected in the converging gap to form a whirling body of fluid in the gap and in the inner space Within the impeller means. This whirling body acts as a guide means and constricts the passage for the main flow of the fluid to an extent depending on the position of the movable flow control means so that by operation of the movable flow control means a whirling body having a shape and position as required for the particular operational conditions can be formed.

The movable flow control means is preferably movable between an ineffective position in which the whirling body is formed according to the shape of the gap, and an effective position in which it influences the shape and position of the whirling body of fluid.

The flow control means preferably extends into or across the converging gap when it is in its effective position, while it may extend in the direction of the flow or be completely retracted from the converging gap in its inelfective position.

Evidently, the flow control means can be moved to a plurality of positions in which it is effective to influence the whirling body of fluid, and also for producing the most stable whirling body of fluid under the prevailing operational conditions.

In the preferred embodiment of the invention, a guide member having a guide surface forms the converging gap with the cylindrical surface of the impeller means, and the flow control means is movable in, or into, the converging gap so as to have the effect of a variation of the shape of the guide member whereby the shape and position of the whirling body of fluid, and thereby the main flow of the fluid through the apparatus, is substantially influenced.

In one embodiment of the invention, the flow control means is a member which is pivotally mounted at the center of the converging gap for movement between a position extending in the direction of the gap, and a terminal effective position extending into the proximity of the guide surface of the guide member.

In another embodiment of the invention, the flow control means is slidably mounted on the guide member and is movable between a position completely retracted from the converging gap and a terminal effective position in which its end extends into close proximity with the cylindrical surface of the impeller means.

In a further embodiment, a flow control plate is pivotally mounted on the guide member and can be retracted to a position lying flat on the guide surface.

One surface of the flow control means, or parts of the surfaces of the flow control means and of the guide surface of the guide member may be used for forming the core of the whirling mass by which the main flow of the fluid is controlled.

The novel features which are considered as charac teristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a cross sectional view illustrating one em. bodiment of the invention in a first operation position;

FIG. 2 is a cross sectional view illustrating another operational position of the embodiment of FIG. 1;

FIG. 3 is a cross sectional View illustrating another embodiment;

FIG. 4 is a cross sectional view illustrating a third embodiment;

FIG. 5 is a cross sectional view illustrating a fourth embodiment;

FIG. 6 is a cross sectional view illustrating the em bodiment of FIG. 5 in another operational position;

FIG. 7 is a cross sectional view illustrating a fifth embodiment;

FIG. 8 is a cross sectional view illustrating the embodiment of FIG. 7 in another operational position;

FIG. 9 is a cross sectional view illustrating a sixth embodiment of the invention;

FIG. 10 is a side elevation of a cross flow fan according to one embodiment of the invention;

FIG. 11 is a front view of the embodiment of FIG. 10; and

FIG. 12 is a plan view of the embodiment of FIG. 10.

Referring now first to FIGS. 10 to 12, an impeller 4 is mounted on a shaft 4a which is journalled in corresponding bearings of a casing 16 and carries a pulley 13 driven by a belt 14 from the pulley of a motor 15 which is secured to casing 16. A guide member 1 and a wall 11 form the stator of the apparatus. A flow control means 2 is secured to a shaft 3 which is mounted on casing 16 and has a projecting portion 3a carrying a manually operated handle 12 by which flow control means 2 can be turned between the positions illustrated in FIG. 10, and also in FIG. 3.

Referring to the drawings, and more particularly to FIGS. 1 and 2, an impeller 4 has a set of curved impeller blades 4a arranged in a circle so that the impeller defines an inner cylindrical space 4b, and has an outer cylindrical surface 40. The ends of the elongated impeller blades 4a are secured to two end plates from which stub shafts project. The stub shafts 4d are mounted in bearings of a stator 11 so that the impeller means 4 is turnable about an axis of rotation coinciding with the center of the blade circle..

The stator 11 includes a guide member 1 having a curved guide surface 1a which defines a converging gap 13 with the cylindrical surface of the impeller means 4. A portion 1b of the guide member 1 extends into close proximity with the impeller means 4 forming a narrow gap with the same at the end of the converging gap 13.

Diametrically opposite portion 1b, a portion 11a of the stator 11 is located in close proximity with the cylindrical surface of the impeller means 4.

When the impeller means 4 is rotated in direction of the arrow B, a fluid will flow in direction of the arrows A through the impeller blades 4a, through the passage between portion 11a and portion 1b, and in direction of the arrows A. Consequently, it can be assumed that an inlet is located on one side of a plane passing through portions 11a and 1b, and that an outlet is located in the stator on the other side of this plane, and actually narrowed down by the guide member 1.

As explained in the US. Patent 2,942,773, part of the fluid passing toward the outlet will be driven by the impeller means 4 into the converging gap 13 so as to be deflected by the guide surface 1a whereby a whirling body 8 of fluid is formed. This whirling body 8 extends through the impeller blades and into the cylindrical space 4b and acts as a guide means for the main flow of fluid which consequently flows in the outlet between the stator wall 11b and the whirling body 8 of fluid. In this manner, the whirling body 8 performs the function of a rigid guide structure.

In accordance with the presentinvention, a flow control means 2 is mounted for turning movement on a pivot means 3 secured to the stator 11 and has a handle 12. In the position shown in FIG. 1, the flow control means 2 has no effect on the shape and position of the whirling body 8 which is substantially formed in the same way as if flow control means 2 were not provided. Therefore, the position of flow control means 2 in FIG. 1 can be referred to as ineffective position.

Flow control means 2 can be turned by manually operated means 12, located outside of stator 11 into the effective position shown in FIG. 2 in which the narrower end of the streamlined flow control means 2 is located in close proximity to the guide surface 1a, or even abuts the same. In this effective position, the concave surface 2a of the flow control means 2 forms a continuation of the guide surface 1a so that the position and shape of the whirling body 8 is influenced, resulting in a different shape of the passage for the main flow of the fluid which flows in direction of the arrow A.

It is evident that flow control means 2 is movable to intermediate positions in which the whirling body will be differently disposed, so that the adjustment of the flow control means 2 will have the effect of an adjustment of a guide means projecting into the space 4b within the impeller 4.

FIG. 3 illustrates a modified embodiment of the invention in which the pivot means 3 of the flow control means 2 is equidistant from the guide surface 1a and from the cylindrical surface 4c. The streamlined flow control means 2 extends in the direction of converging gap 13 in the ineffective position shown in solid lines in FIG. 3, and extends to the guide surface 1a in the effective position shown in chain lines in FIG. 3. The length of flow control means 2 is at least half the length of the converging gap 13 as shown in FIGS. 1 and 3 so that flow control means 2 in the ineffective position deeply projects into gap 13 toward the narrower end of the same. Concentric flow lines form along the concave inner face 2a of control means 2 and on the concave guide surface 1a. It will be understood that in accordance with the position of the flow control means 2, the whirling body will be adjusted to form different passages for the main flow of fluid into the outlet of the stator.

FIG. 4 illustrates another embodiment of the invention in which the flow control means is a slightly curved deflector plate 6 and is mounted on a pivot means 5 fixed to guide member 1. The deflector plate 6 can be turned between an ineffective position located flat on the guide surface 1a, and a plurality of effective positions, one of which is illustrated in FIG. 4. The shape and position of the whirling body 8 of fluid will be influenced by the position of the deflector plate 6 whereby the passage remaining open for the main flow of fluid is varied and adjusted in accordance with the prevailing operational conditions.

FIGS. 5 and 6 illustrate another embodiment similar to the embodiment of FIG. 4, but including a streamlined guide body 2 located in the converging gap 13. A deflector plate 6 can be turned between the position shown in FIG. 5, and .a position lying flat on the guide. surface 1a, as shown in FIG. 6, whereby the shape and position of the whirling body 8 of fluid can be adjusted and selected in accordance with the prevaling conditions.

In the embodiment illustrated in FIGS. 7 and 8, the flow control means is a deflector plate 9 which is shiftable between the ineffective position shown in FIG. 7 and the effective position shown in FIG. 8. In the position of FIG. 7, the main portion of deflector plate 9 lies flat on a convex surface 10 of guide member 1, while the curved free end of deflector plate 9 extends to the guide surface 1a, so that deflector plate 9 is completely retracted from the converging gap 13.

In the position of FIG. 8 the deflector plate 9 extends across the wider end of gap 13, and its free end is located in close proximity with the cylindrical surface of the impeller means 4. The position of the axis, and the shape of the whirling body 8 of fluid are influenced by the shifting of the deflector plates between the positions of FIG. 7 and FIG. 8, and consequently the passage for the main flow of fluid is adjusted and differently con stricted by the whirling body 8, and the adjustment can be selected in accordance with the prevailing operational conditions.

In the embodiment of FIG. 9, the flow control means has an effective position in which its free end 10a projects into close proximity with the cylindrical surface of the impeller means 4. The whirling body 8 of fluid, not shown in FIG. 9, will have substantially the same shape as shown in FIG. 8. When the flow control means 10 is retracted to the ineffective position 10 shown in chain lines, its free end forms a continuation of the guide surface 111 of guide member 1, so that the flow control means is ineffective, and the gap 13 functions as if no flow control means were provided so that the shape and position of the whirling body of fluid will correspond to the shape and position of the whirling body 8 of fluid shown in FIG. 7.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of cross flow fans differing from the types described above.

While the invention has been illustrated and described as embodied in a cross flow fan with measn for adjusting the shape and position of a whirling body of fluid forming a guide means for the main flow of fluid through the apparatus, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without deparing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt .it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A cross flow fan for moving a fluid comprising, in combination, impeller means having an axis and a plurality of impeller blades disposed in a circle and defining a cylindrical outer surface on said impeller means concentric with said axis and an inner cylindrical space within said impeller means, said blades defining channels between each other; a stator supporting said impeller means for rotation about said axis in one direction of rotation and including two parts located adjacent said cylindrical surface angularly spaced from each othe and defining between each other a passage through said channels of said impeller means and through said inner space, said passage having an inlet on one side of said two parts and an outlet on the other side of said two parts so that during rotation of said impeller means in said one direction a fluid admitted through said inlet flows through said passage and out of. said outlet, one of said parts including a guide member having a guide surface directly facing, and extending toward said cylindrical surface and forming with the same an unobstructed gap converging in said direction of rotation from said outlet toward said inlet, said gap communicating through said channels with said inner space and receiving from the impeller blades moving into said gap a portion of the fluid flowing into said outlet, and a flow control means including a substantially flat elongated deflector member mounted on said guide member at the wider end of said converging gap, and means for supporting said deflector member for movement between an ineffective fully retracted position lying flat on said guide member and at least one effective position extending transverse to said gap at said wider end of said gap, said deflector memberhaving a portion located in said effective position in close proximity to said cylindrical oute surface of said impeller means so as to substantially close said wider end whereby said portion of said fluid is deflected by said deflector member to form a whirling body of fluid in said gap, said channels, and in said inner space constricting said passage for the main means through said channels by said deflector member to an extent depending on the position of said movable deflector member.

2. A cross flow fan for moving a fluid comprising, in combination, impeller means having an axis and a plurality of impeller blades disposed in a circle and defining a cylindrical outer surface on said impeller means concentric with said axis and an inner cylindrical space within said impeller means, said blades defining channels between each other; a stator supporting said impeller means for rotation about said axis in one direction of rotation and including two parts located adjacent said cylindrical surface angularly spaced from each other and defining between each other a passage through said channels of said impeller means and through said inner space, said passage having an inlet on one side of said two parts and an outlet on the other side of said two parts so that during rotation of said impeller means in said one direction a fluid admitted through said inlet flows through said passag and out of said outlet, one of said parts including a guide member having a guide surface directly facing, and extending toward said cylindrical surface and forming with the same an unobstructed gap converging in said direction of rotation from said outlet toward said inlet, said gap communicating through said channels with said inner space and receiving from the impeller blades moving into said gap a portion of the fluid flowing into said outlet, and a flow control means including a substantially flat elongated deflector member mounted on said guide member at the wider end of said converging gap, and means for supporting said deflector member for sliding movement between an ineffective fully retracted position lying flat on said guide member and an effective position extending transverse to said gap at said wider end of said gap, said deflector member having a portion located in said effective position in close proximity to said cylindrical outer surface of said impeller means so as to substantially close said wider end whereby said portion of said fluid is deflected by said deflector member to form a whirling body of fluid in said gap, said channels, and in said inner space constricting said passage for the main flow of the fluid and being moved relative to said impeller means through said channels by said deflector member to an extent depending on the position of said movable deflector member.

3. An apparatus as set forth in claim 2 wherein said guide member has a face extending from the wider end of said converging gap transverse to said guide surface; and wherein said deflector member is located on said face in said ineffective position thereof.

4. An apparatus as set forth in claim 3 wherein said deflector member is a plate having a curved end portion extending in said ineffective position from said face onto said guide surface.

5. An apparatus as set forth in claim 3 wherein said deflector member has an end face forming a continuation of said guide surface in said ineffective position of said deflector member.

6. A cross flow fan for moving a fluid comprising, in combination, impeller means having an axis and a plurality of impeller blades disposed in a circle and defining a cylindrical outer surface on said impeller means concentric with said axis and an inner cylindrical space within said impeller means; a stator supporting said impeller means for rotation about said axis in one direction of rotation and including two parts located adjacent said cylindrical surface angularly spaced from each other and defining between each other a passage through said impeller means and through said inner space, said passage having an inlet on one side of said two parts and an outlet on the other side of said two parts so that during rotation of said impeller means in said one direction a fluid admitted through said inlet flows through said passage and out of said outlet, one of said parts including a flow of the fluid and being moved relative to said impeller guide member having a guide surface extending toward said cylindrical surface and forming with the same a gap converging in said direction of rotation from said outlet toward said inlet and receiving from the impeller blades moving into said gap a portion of the fluid flowing into said outlet and a streamlined elongated operator controlled flow control means located in said gap at the wider end thereof, said flow control means having a length at least half the length of said converging gap in said direction of rotation and being turnable about a pivot axis located in close proximity to said cylindrical surface at the wider end of said converging gap between an ineffective position extending deeply into said gap spaced from said guide surface and said cylindrical surface and in the direction of said cylindrical surface and an effective position extending transverse to the wider portion of said converging gap and substantially to said guide surface to substantially close said gap whereby said portion of said fluid is deflected to form a whirling body of fluid in said gap and in said inner space constricting said passage for the main flow of the fluid to an extent depending on the position of said movable flow control means.

7. An apparatus as set forth in claim 6 wherein said streamlined flow control means has a thicker end portion through which said pivot axis passes, and a thin end portion abutting said guide surface in said effective position.

8. An apparatus as set forth in claim 7 wherein said thin end portion in said effective position abuts the central portion of said guide surface.

9. An apparatus as set forth in claim 7 wherein said thin end portion in said effective position abuts the end of said guide surface located at the wide end of said converging gap.

10. A cross flow fan for moving a fluid comprising, in combination, impeller means having an axis and a plurality of impeller blades disposed in a circle and defining a cylindrical outer surface on said impeller means concentric with said axis and an inner cylindrical space within said impeller means, said blades defining channels between each other; a stator supporting said impeller means for rotation about said axis in one direction of rotation and including two parts located adjacent said cylindrical surface angularly spaced from each other and defining between each other a passage through said channels of said impeller means and through said inner space, said passage having an inlet on one side of said two parts and an outlet on the other side of said two parts so that during rotation of said impeller means in said one direction a fluid admitted through said inlet flows through said passage and out of said outlet, one of said parts including a guide member having a concave curved guide surface directly facing, and extending toward said cylindrical surface and forming with the same an unobstructed gap converging in said direction of rotation from said outlet toward said inlet, said gap communicating through said channels with said inner space and receiving from the impeller blades moving into said gap a portion of the fluid flowing into said outlet, and a flow control means including a substantially flat elongated deflector member mounted on said guide memher at the wider end of said converging gap, and means for supporting said deflector member for movement between an ineffective fully retracted position lying flat on said guide member and at least one effective position extending transverse to said gap at said wider end of said gap, said deflector member having a portion located in said effective position in close proximity to said cylindrical outer surface of said impeller means so as to substantially close said Wider end whereby said portion of said fluid is deflected by said deflector member to form a whirling body of fluid in said gap, said channels, and in said inner space constricting said passage for the main flow of the fluid and being moved relative to said impeller means through said channels by said deflector member to an extent depending on the position of said movable deflector member.

11. A cross flow fan for moving a fluid comprising, in combination, impeller means having an axis and a plurality of impeller blades disposed in a circle and defining a cylindrical outer surface on said impeller means concentric with said axis and an inner cylindrical space within said impeller means; a stator supporting said impeller means for rotation about said axis in one direction of rotation and including two parts located'adjacent said cylindrical surface angularly spaced from each other and defining between each other a passage through said impeller means and through said inner space, said passage having an inlet on one side of said two parts and an outlet on the other side of said two parts so that during rotation of said impeller means in said one direction a fluid admitted through said inlet flows through said passage and out of said outlet, one of said parts including a guide member having a concave curved guide surface extending toward said cylindrical surface and forming with the same a gap converging in said direction of rotation from said outlet toward said inlet and receiving from the impeller blades moving into said gap a portion of the fluid flowing into said outlet and a operator controlled flow control means of elongated substantially flat shape mounted adjacent to said impeller means in said gap at the wider end thereof, said flow control means having a length at least half the length of said converging gap in said direction of rotation, said flow' control means having a concave side and a convex side and being movable between an ineffective position extending deeply into said gap toward the narrower end of the same so that a flow line along said concave side is concentric with a flow line formed along said concave guide surface at the narrower end of said gap and an effective position extending transverse to the wider portion of said converging gap and substantially to said guide surface to substantially close said gap, said concave side of said flow control means confronting said cylindrical surface in said ineffective position whereby said portion of said fluid is deflected to form a whirling body of fluid in said gap and in said inner space constricting said passage for the main flow of the fluid to an extent depending on the position of said movable flow control means.

References Cited by the Examiner UNITED STATES PATENTS 507,445 10/93 Mortier 230 1,920,952 8/33 Anderson 230-125 2,658,700 11/53 Howell 230125 2,942,773 6/60 Eck 230125 2,944,786 7/60 Angell et al. 230114 2,965,284 12/60 Coester 230-125 2,968,436 1/61 Coester 230125 FOREIGN PATENTS 225,767 12/ 5 9 Australia.

559,024 1/58 Belgium.

291,007 8/28 Great Britain.

581,241 8/58 Italy.

KARL J. ALBRECHT, Primary Examiner. JOSEPH H. BRANSON, JR., Examiner,

Claims

1. A CROSS FLOW FAN FOR MOVING A FLUID COMPRISING, IN COMBINATION, IMPELLER MEANS HAVING AN AXIS AND A PLURALITY OF IMPELLER BLADES DISPOSED IN A CIRCLE AND DEFINING A CYLINDRICAL OUTER SURFACE ON SAID IMPELLER MEANS CONCENTRIC WITH SAID AXIS AND AN INNER CYLINDRICAL SPACE WITHIN SAID IMPELLER MEANS, SAID BLADES DEFINING CHANNELS BETWEEN EACH OTHER: A STATOR SUPPORTING SAID IMPELLER MEANS FOR ROTATION ABOUT SAID AXIS IN ONE DIRECTION OF ROTATION AND INCLUDING TWO PARTS LOCATED ADJACENT SAID CYLINDRICAL SURFACE ANGULARLY SPACED FROM EACH OTHER AND DEFINING BETWEEN EACH OTHER A PASSAGE THROUGH SAID CHANNELS OF SAID IMPELLER MEANS AND THROUGH SAID INNER SPACE, SAID PASSAGE HAVING AN INLET ON ONE SIDE OF SAID TWO PARTS AND AN OUTLET ON THE OTHER SIDE OF SAID TWO PARTS SO THAT DURING ROTATION OF SAID IMPELLER MEANS IN SAID ONE DIRECTION A FLUID ADMITTED THROUGH SAID INLET FLOWS THROUGH SAID PASSAGE AND OUT OF SAID OUTLET, ONE OF SAID PARTS INCLUDING A GUIDE MEMBER HAVING A GUIDE SURFACE DIRECTLY FACING, AND EXTENDING TOWARD SAID CYLINDRICAL SURFACE AND FORMING WITH THE SAME AN UNOBSTRUCTED GAP COVERGING IN SAID DIRECTION OF ROTATION FROM SAID OUTLET TOWARD SAID INLET, SAID GAP COMMUNICATING THROUGH SAID CHANNELS WITH SAID INNER SPACE AND RECEIVING FROM THE IMPELLER BLADES MOVING INTO SAID GAP A PORTION OF THE FLUID FLOWING INTO SAID OUTLET, AND A FLOW CONTROL MEANS INCLUDING A SUBSTANTIALLY FLAT ELONGATED DEFLECTOR MEMBER MOUNTED ON SAID GUIDE KMEMBER AT THE WIDER END OF SAID CONVERGING GAP, AND MEANS FOR SUPPORTING SAID DEFLECTOR MEMBER FOR MOVEMENT BETWEEN AN INEFFECTIVE FULLY RETRACTED POSITION LYING FLAT ON SAID GUIDE MEMBER AND AT LEAST ONE EFFECTIVE POSITION EXTENDING TRANSVERSE TO SAID GAP AT SAID WIDER END OF SAID GAP, SAID DEFLECTOR MEMBER HAVING A PORTION LOCATED IN SAID EFFECTIVE POSITION IN CLOSE PROXIMITY TO SAID CYLINDRICASL OUTER SURFACE OF SAID IMPELLER MEANS SO AS TO SUBSTANTIALLY CLOSED SAID WIDER END WHEREBY SAID PORTION OF SAID FLUID IS DEFELCTED BY SAID DEFLECTOR MEMBER TO FORM A WHIRLING BODY OF FLUID IN SAID GAP, SAID CHANNELS, AND IN SAID INNER SPACE CONSTRICTING SAID PASSAGE FOR THE MAN FLOW OF THE FLUID AND BEING MOVED RELATIVE TO SAID IMPELLER MEANS THROUGH SAID CHANNELS BY SAID DEFLECTOR MEMBER TO AN EXTENT DEPENDING ON THE POSITION OF SAID MOVABLE DEFLECTOR MEMBER.