US 3275223 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Sept. 27, 1966 A. J. FOWELL 3,275,223
FLUID MOVING MEANS Filed Aug. 5, 1964 INVENTOR Andrew J. Fowell ATTORNEY United States Patent 3,275,223 FLUID MOVING MEANS Andrew I. Fowell, South Bound Brook, N.J., assignor to American Radiator & Standard Sanitary Corporation, New York, N.Y., a corporation of Delaware Filed Aug. 3, 1964, Bar. No. 386,857 Claims. (Cl. 230125) This invention pertains to fluid moving means and more particularly to shear force crossflow fluid moving means.
Of the many uses of fluid moving means, one important application is a fan. Fans generally fall into two main types, the axial flow and the radial flow. While such fans are generally simple to fabricate and operate they are quite often bulky and noisy. Lately, a new type of fan has become available. It has a tangential intake and has become known as the crossflow type. The presently available crossflow type fans include a squirral-cage type rotary impeller with impeller blades aligned parallel to the axis of rotation of the impeller. With such a fan, air passes through the gaps between the blades of the rotary impeller to the central region thereof and is driven outward again through the blade gaps. Such fans require critical dimensioning of the various elements such as the blades. For example, if the air flow does not enter or leave the blade gaps at a critical angle, regions of flow separation are set up within the blade passages which results in a reduction in through-flow and efliciency. When such a fan operates at a point different from the point of maximum efficiency it becomes excessively noisy. Silencing of such a fan is complicated by the fact that the impeller blades intercept the air stream twice for each rotation of the impeller.
It is, accordingly, a general object of the invention to provide an improved fluid moving means which does not require critical dimensioning or geometry of its elements.
It is a further object of the invention to provide an improved fluid moving means whose efficiency is high over a broad range of operating characteristics.
It is another object of the invention to provide a crossflow fan which is relatively silent for a broad range of operating speeds.
It is yet another object of the invention to provide a fluid moving means which while satisfying all of the above stated objects operates reliably and is relatively simple and inexpensive to fabricate.
Briefly, the invention con-templates a fluid mover which has a plurality of annular members. Means are provided for rotating the annular members about a common axis. The rotation of the annular members exerts a shear force on the fluid between the members to cause the formation of at least one whirling body of fluid. The whirling body has an axis of rotation parallel to and displaced from the common axis of rotation of the annular members. Apparently, the whirling body or vortex enhances fluid flow from a region external to the outer edges of the annular members to another region external to the outer edges of the annular members.
Other objects, and the features and advantages of the invention will be apparent from the following detailed description when read with the accompanying drawing which shows, by way of example and not limitation, the now preferred embodiment of the invention.
In the drawing:
FIG. 1 is a top plan view of a fluid moving means in the form of a fan employing the principles of the invention;
FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1 and includes fluid flow streams;
FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2.
Referring now to the drawing a fan of the shear force crossflow type is shown including a housing 12, with end cover plates 14 and 16. As may be seen in FIG. 3
3,275,223 Patented Sept. 27, 1966 a rotor or fluid mover 23 is supported for rotation within housing 12. The fluid mover 23 is carried for rotation by end cover plates 14 and 16 of housing 12. The fluid mover includes a pair of circular end plates 33 and 35 respectively fixed to shafts 38 and 40 which extend outwardly through journals 42 and 44 of the end cover plates. An end of shaft 40 is connectced to motor 46 to rotatably drive the fluid mover 23. Although a direct motor drive is shown, conventional pulley and belt drives can be used with equal success.
The remainder of the fluid mover 23 will now be described. Basically, mover 23 includes a plurality of annular members or discs 24. Although discs 24 are shown with apertures continuous discs have been successfully employed. When apertured discs 24 are used the inner diameter of a typical disc 24:: is preferably onehalf of six-tenths of the outer diameter of disc 24e. Furthermore, it has been found that the separation s between the discs is from twice to eight times the thickness 1 of the discs and preferably four times. In a working embodiment wherein the fluid mover 23 rotated at about 4000 r.p.m. in air, the outer diameter of the discs was 5 inches and the inner diameter three inches. The disc thickness t was 0.016 inch and the spacing ranged from 0.050 to 0.100 inch. For the sake of clarity the disc thickness and separation are not shown true to scale in FIG. 3.
As may be seen from FIG. 2 the housing 12 is provided with an inlet 20 and an outlet 22 which diverges as it leaves fluid mover 23. The inlet 20 is angularly displaced from outlet 22 by between and as is evident from FIG. 2. Furthermore, it should be noted that the angle through which the inlet 20 extends about the axis 18 of the mover 23 is larger than the angle through which the outlet 22 extends about this axis.
The housing 12 includes a first wall portion 34 extending from inlet 20 in the direction of rotation clockwise of mover 23 to outlet 22 and a second wall portion 36 extending from outlet '22 in the direction of rotation of mover 23 to inlet 20. As can be seen in FIG. 2 the start of wall portion 34 adjacent inlet 20 includes a rolled-back lip portion 38 which it has been found enhances the intake of fluid. Wall portion 34 starting with the end of lip 38 gradually and continuously, in an increasing manner, can either diverge from the outer peripheral edges 26 of discs 24 or the wall .portion 34 can assume a shape which remains essentially parallel to the outer periphal edges 26 of the discs 24 for approximately 90 from the lip portion 38. Both embodiments have been found to provide good results. Second wall portion 36 between inlet 20 and outlet 22 tapers decreasingly in thickness in the direction away from mover 23. Furthermore, the separation of wall portion 36 from the outer periphery 26 of discs 24 increases in the direction from inlet 20 to outlet 22.
Fluid mover 23 will now be described in greater detail. Each of the discs 24 is mounted on tie rods 30. Initially, each disc 24in punched with undersize holes for accepting the tie rods 30. Each tie rod is pressed onto a stack of discs 24 with the holes aligned for passage of the tie rods 30. As the tie rods 30* enter the holes the edge defining material of the discs 24 is axially deformed to provide a raised lip 25 which grasps the rod and also acts as the spacer between adjacent discs 24. Instead of using separate discs it is possible to use a flat spiral array which when axially stretched resembles the discs. It should also be apparent that discs with holes having diameters which slidingly accommodate the tie rods could be used in conjunction with tubular spacers. The tie rods 30 are bolted or otherwise attached (Welded, brazed, soldered, peened, etc.) into circular end plates 33 and 35. Outwardly extending from the center of end plates 33 and 35 are journals 38 and 40 which are supported by bearings 42 and 44 in end cover plates 16 and 14, respectively. Accordingly, annular discs 24 are supported in axially spaced and parallel relationship and are rotatable about the central axis .18 of the housing 12.
As the discs 24 rotate, friction, between the faces of the discs 24 and the abutting fluids such as air, gas, water and the like exerts a shear force on the fluid which imparts a tangential component of motion to the fluid between the discs 24. This results in the creation of whirling body 50 or vortex of fluid whose center 52 is located inside the cylindrical cavity defined by the inner edges 28 of discs 24. The whirling body 50 has, in fact, been observed. There is a whirling body 50 between each pair of discs 24.
As long as the inlet 20 and the outlet 22 are not blocked, the whirling body 50 is substantially cylindrical with the axis 52 of the whirling body 50 displaced from the central axis 18. Accordingly, fluid drawn into inlet 20 passes between the discs 24 into the cylindrical cavity, moves around the whirling body 50, again passes between the discs 24 and is propelled from outlet 22. It should be noted that some of the fluid upon entering inlet 20 remains between the discs 24 and is driven therefrom to outlet 22. Accordingly, whirling body 50 urges the flow of fluid from inlet 20 to outlet 22 and enhances the movement of the fluid.
There has thus been shown an improved fluid mover which by using annular discs which exert a shear force on the fluid between the discs to create whirling bodies of air between the discs, enhances fluid movement from an inlet to an outlet wherein some of the fluid passes twice between the discs. Such a mover, since it does not intercept the fluid stream with blades, is extremely quiet and does not require the usual complicated aero-dynamic design for the blades.
While only a fan embodiment of the invention has been shown and described in detail, there will now be apparent to those skilled in the art many modifications and variations such as blowers, pumps and compressors which satisfy many or all of the objects of the invention but which do not depart from its spirit as defined in the appended claims.
What is claimed is:
1. A shear force crossflow gas mover comprising, end plates, a plurality of annular members including inner and outer edge portions positioned between said end plates, means for supporting said members in axially spaced relationship to form a rot-or having an elongated centrally located completely unobstructed cylindrical cavity defined by the inner edge portions of said annular members, said annular members being spaced from each other sufficiently close to exert a shear force on the gas between the surfaces of said members, a housing surrounding said rotor and forming for said rotor an inlet and an outlet, the cross-sectional area of said inlet being greater than the cross-sectional area of said outlet, said housing including a first wall portion smoothly diverging from said rotor in a direction from the inlet to the outlet, the portion of said first wall portion adjacent said inlet being a rolled back lip member, a second wall portion spaced from said rotor and extending from said outlet to said inlet in the direction of rotation of the rotor, said second wall portion including a portion smoothly and continuously converging toward said rotor in the direction from said outlet to said inlet and portions separating said inlet from said outlet comprising surface members which converge as the distance from said rotor increases, and means for rotating said supporting means in said housing so that all of said members rotate about a common axis of rotation aligned with said elongated cylindrical cavity to cause the shear force exerted on the gas to establish a whirling body of fluid having an axis of rotation parallel to and displaced from the axis of rotation of said annular members and angularly positioned between said inlet and said outlet in the direction of rotation of said rotor.
2. The structure of claim 1 wherein the annular displacement between said inlet and outlet is greater than ninety degrees and less than one hundred eighty degrees.
3. The structure of claim '1 wherein the region of said first wall portion starts from said inlet to about one hundred and twenty degrees angularly displaced from said inlet is substantially parallel to the periphery of said rotor.
4. The structure of claim 1 wherein the inner diameters of said annular members are between 50 and percent of the outer diameter of said annular members.
5. The structure of claim 1 wherein the separations between said annular members is two to eight times the thickness of said annular members.
References Cited by the Examiner UNITED STATES PATENTS 1,920,952 8/ 1933. Anderson 230 2,087,834 7/1937 Brown et a1. 103-84 2,339,575 1/1944 Lee 230125 2,626,135 1/i1953l Serner 1(l384 2,942,773 6/ 1960 Eck 230125 FOREIGN PATENTS 439,542 4/ 1912 France.
452,393 of 1913 France.
599,519 7/ 1934 Germany.
757,543 9/ 1956 Great Britain.
876,611 9/ 1961 Great Britain.
MARK NEWMAN, Primary Examiner.
HENRY F. RADUAZO, Examiner.