US2471671A - Air circulating fan - Google Patents

Description

May 31, 1949.

J. H. BECKERT AiR CIRCULATING FAN 2 Shets-Sheet 1 Filed Sept. 30, 1946 g ll //////IIIIIIII/ lill INVENTOR. xam #6561527 y 1949- v J. H. BECKERT 2,471,671

AIR CIRCULATING FAN Filed Sept. 50, 1946 2 Sheets-Sheet 2 IN VEN TOR.

Max/1v 1% icm-ver BY Y Patented May 31, 1949 KIR CYRCULATING 'FAN -"John--H. Beckert, Iibshngeles, Galif.

. Application September 30,-1-94 6, Serial No."l00,306

"This invention rlates to-air circulating fan arid has its general object 'to provide a "fan-thatis adapted to circulate air in all directions.

A specific object of the invention is to..provide 'a 'fan adapted to deliver air from both the .pe-

ripheral and the sideareas thereof including the central or axial regions,

A further objectof'theinvention'is toprovide-a 'fan'having a doubleimpeller adapted to deliver air in substantially all -directions to..produce a movement of air generally similar moan expandingglobe.

Another object of the invention is toprovidea fan including an impeller and driving --'means therefor supported upon a base-that'lies beneath the impeller, which 'fan is adapted todliver air in all directions except directly downwardly '(the downward direction or dlivery'being obstructed by the base).

A particular object of 'the .pres'entinven'tion is to provide an air circulating 'fanofLthe type specifled above in which a power unit. thatdrives the impeller is disposed within the confineso'i the impeller.

Another'Obj ect'of the ihVel'itiOhfistOjDlOViHe an air circulating fan embodying a 'm'btor and an impeller "encompassingthe motor and including novel an'dimproved'ineans'for 'circurati'ngaportion of the'air thatis delivered bytheinipeller,

axially 'through'thembtor'so as to codi thesani'e. Other objects "will becomeappareritinfthe "ensuing specification "and "appended drawings, -iii which:

Fig. l is a "side 'view'of "awair circulating fan embodying "my "invention;

3 is "a sectionalviewtakenfon'the line B t of 'Fig. 2;

Fig. 4 is a sectional view taken on the line 4- 4 of Fig. 1;

Fig. 5 is a detailed sectional view taken on At its'upper end, "the uprightfl 'is 'form'ed'vvith'a "headw that has 'a "rear surface "'1 "and'aforward surfaces eacho'f which is-concave-anddefined a'sa surface of revolution of a curved -line. {For example, thef'surfa'ce's l" a'nd8 may beparabbl'oi'd. Where the surfaces "1 andt 'rrieet, the'y"d'efi'ne-a sharp edge "9. k

Supported upon the forward ridbf the head "6 is a'nel'ectric motor'which'is indicated generally fall H]. The motor I'llis receivedwithin the hub "sleeve "[3 "of an impeller Ill. 'The motor "ill includes a case I I that'is mounted upon a "collar 12 on the head 6, "and is separated from the sleeve ltbya'n annullarsliace! 5*that provides for circulation of air axially'theiethrou'gh, around the motor, for cooliri'gthe same. Mounted within "the collar 12 is a bearing 2| 'in'the'inner'race of"wliich is secured themot'or "shaft'fz.

The sleeve 13 is mounted upon"th'e"'shaft 22 through themedium ofa clutch'memberncom- "prising an integral collar on the shaft'22 "and "apair of pins 24 projecting from the collar, a 'hub member 25 joined to the sleeve 'lil'byblades 'ZB,'and a 'nutZ'I that isthreaded 'at28drito'fthe "endof the shaft 22. The hub member '25 l'ia'ls "recesses in which the pins 24 are clutched, and "the nut"2'lsecure's the part's in assembly. Byremoving th nut'zi, the hub 25 maybe slippedo'if "the "shaft 22. As ShOWn, the hub '25, blaid'esifi "and sleeve l3 are formed -iritegi a'lly, although i'twill be understood that they maybe'constructed separately and suitably secured together. The nut"'2"|, hub'24 and collar 23 form afaired core device which cooperates with the sleeve l3 'to' de- "fine'ithe annular air flow passage 15 which converges at its forward end, as tit 2 9, theffo'rwar d end ofthe sleeve I 3 beingcurved inwardly as at "'30.

"The bladesYZB constitute a ventilatingian in -thepassage I5. Referring now toF-ig.'5, the leading edges iii of the blades -26 are bluntly curved, while the .trailingedgesBZ-are feathered out, the blades thus being of air foil cross section. 'The direction of rotation of the impeller and ventilating Tfan isindicated by the arrows 33 in Figs. :2 .and' 5, and the direction of-ainflow through the duct 29 is indicated by the arrows in Fi'gs.- 5 .and6, respectively. 7 v 4 L Ihe impeller It includes a plurality. of double .blades which are shapedso as -to-deliver-air peripherallywand axially in both directions. Each of. these blades includes a pair of air-ducts 35, each of which is shaped generally similartq a gor-nu-copia and has an inletttand an outlet 31. The inlets 36 of one pair of ducts are located in the forward face of a respective blade, whereas the outlets 3'! of these same ducts are located ahead of the forward face of a succeeding blade. At its inlet end, each duct is flared outwardly to a maximum cross sectional area, and it gradually decreases in cross section area from the inlet 36 to the outlet 31. The axis of each duct 35 is spiral shaped, in a plane normal to the axis of the shaft 22, and gradually app-roaches the shaft 22 from the inlet 36 to the outlet 31. The spiral axes of the ducts of one blade lie in a common plane with the spiral axes of the ducts of the other blade. The inner end of each duct is extended into a space defined between the sleeve l3 and the outer, or inlet end, of an opposed duct.

Radiating in an arc of somewhat more than 180 degrees from each pair of duct inlets 33 is a fan blade including a pair of axially extending portions 38, a radially extending peripheral portion 39, and curved intermediate portions ill jointhe blade portions are inclined rearwardly and in directions intermediate the axial and radial. Consequently the air encountered by the inclined surfaces will be thrown on" the blades in all directions throughout a substantially peripheral surface of revolution of the fan impeller, axially toward the head 6 as indicated by the arrows 4|, radially outwardly as indicated by the arrows 42 and axially away from the head 6 as indicated by the arrows 43.

The air, moving in the direction il past the sharp edge 9 of the head 6, creates a turbulence that is indicated by the arrow it. This turbulence resists the air movement past the edge 9, tending to seal the exit in the direction 4! in the inner region of the impeller. Consequently, the air thrown axially from the innermost portions of the blade members 38 will be deflected inwardly into the sleeve I3 as indicated by the arrows 5. The inclined surface 8 of the head ti directs the air currents into the sleeve 13. The ventilating fan blades 26 at the other end of the sleeve l3 cooperate with the pressure head thus set up by the air currents 45, to create the circulation 34 through the sleeve l3 and through the motor l5.

The slope of the lateral portions 38 of the fan blades varies from the inner to the outer extremities of these lateral portions. At the outer extremities, there is a gradual slope from the mouth 36 of the duct 35 to the lateral edges of the blade portions 38, as indicated at 38 in Fig. 3. The inner extremities of the blade portions 33, lying between the mouth portions 35 of the ducts 35 and the sleeve I3, extend axially as indicated at 41, in Fig. 3, to points beneath the lateral walls of the discharge end 31 of the other duct, and then are sloped as at 48 to the web wall 49, so as to provide space for the discharge of air from the discharge ends 37 of the ducts.

In the operation of my improved air circulating fan, there will be an induction or inward movement of air into the center of the region swept by the impeller 14, along the periphery of the sleeve l3. A portion of the air thus brought to the center of the impeller will be scooped up by the inlets 36 and forced through the ducts 35 to the outlets 4 31 thereof, from which the air will be discharged circumferentially against the sloping surfaces 48 and thereby deflected axially outwardly as indicated by the arrows 58 in Fig. 3. The remainder of the air inducted to the center of the impeller will be engaged by the inclined blade portions 38, 39 and id and will thereby be thrown outwardly in all directions as indicated by the arrows ll, 42 and 23. Due to the reduction in cross sectional area of ducts 35 from the inlets to the outlets thereof, the air passing through these ducts will have its velocity accelerated. This tends to speed up the movement of air discharged from the central region of the fan and provides for substantially as much movement of air in the axial regions encompassed within the extended periphery of the sleeve i3, as in the outer regions of air discharged from the impeller. Thus the invention provides for a substantially uniform flow of air from the fan in all directions. This flow is comparatively gentle, since the i an is not designed for the proj ection of a high velocity concentrated air stream, but rather for a low velocity, defused air movement in all directions. This is a desirable characteristic in an air circulating fan for ventilating purposes.

The only direction in which the fan does not deliver air, is the downward direction, in which the air currents delivered from the fan are blocked and deflected outwardly by the base 5. This is an advantageous feature, since downward delivery of air from the fan is not desired.

In the modified form of the invention shown in Fig. '7, the impeller has three instead of two blades, and the ducts 35 are somewhat shorter. The three bladed impeller will deliver approximately 50% more air to the sleeve i3 and will circulate approximately 50% more air than the two bladed impeller.

I claim as my invention:

1. In an air circulating fan, a motor through which air may be circulated in an axial direction; an impeller having a hub sleeve open at one end and surrounding said motor and having a plurality of fan blades thereon shaped to deliver air both radially and axially; and a support for said motor and impeller including a head portion providing an annular barrier disposed adjacent the open end of said sleeve and extending radially beyond the open end of said sleeve and in the path of air currents discharged axially from said impeller adapted to deflect some of said air currents inwardly into said hub sleeve.

2. In an air circulating fan, a motor through which air may be circulated in an axial direction; an impeller having a hub sleeve open at one end and surrounding said motor and having a plurality of fan blades thereon shaped to deliver air both radially and axially; a support for said motor and impeller including a head portion providing an annular barrier disposed adjacent the open end of said sleeve and extending radially beyond the open end of said sleeve and in the path of air currents discharged axially from said impeller, adapted to deflect some of said air currents inwardly into said hub sleeve; and a ventilating fan within said hub sleeve at the opposite end of said motor from said head.

3. In a ventilating fan, an impeller including a hollow hub sleeve open at one end and having blades thereon, adapted to discharge air axially and radially, an electric motor within said hub sleeve, through which a ventilating current of air may pass axially, and a support having a head on which said motor is mounted, said head including an annular barrier that is disposed adjacent the open end of said sleeve and cooperating with the surface of revolution of the inner end extremities of the impeller blades to define an annular air passage extending inwardly and toward said motor and increasing in width toward its inner extremity, said annular barrier extending radially beyond said sleeve in order to deflect into said hub sleeve, currents of air delivered axially from said impeller blade.

4. In a ventilating fan, an impeller including a hollow hub sleeve open at one end and having blades thereon adapted to discharge air axially and radially, an electric motor within said hub sleeve through which a ventilating current of air may pass axially, a support having a head on which said motor is mounted, said head including an annular barrier that is disposed adjacent the open end of said sleeve and cooperating with the surface of revolution of the inner end extremities of the impeller blades to define an annular air passage extending inwardly and toward said motor and increasing in width toward its inner extremity, said annular barrier extending radially beyond said sleeve in order to deflect into said hub sleeve currents of air delivered axially from said impeller blade, and a ventilating fan in said hub sleeve on the opposite side of said motor from said barrier.

5. In an air circulating fan, an impeller having a hub sleeve open at one end, and blades adapted to discharge air axially and radially, an electric motor within said hub sleeve, connected to said impeller for driving the same, and a support having a head on which said motor is mounted, said head including an annular barrier having a sharp edged periphery disposed adjacent the open end of said sleeve and extending radially beyond the sleeve and in the path of some of the air currents delivered axially from said blades, said barrier deflecting some of said air currents inwardly into said hollow hub sleeve.

6. In an air circulating fan, an impeller having a plurality of blades shaped to deliver air in all directions from the center thereof and having corresponding air ducts, each having an inlet in the forward face of one blade and an outlet discharging ahead of and toward the forward face of a succeeding blade, the blades having inclined portions adapted to deflect in an axial direction the discharge from said outlets, said impeller having a hub sleeve open at one end, an electric motor Within said hub sleeve; and a support for said motor and impeller including a head portion providing an annular barrier disposed adjacent the open end. of said sleeve and extending radially beyond said sleeve and into the path of air currents discharged axially from said impeller to deflect some of said air currents inwardly into said hub sleeve.

7. In an air circulating fan, an impeller having a plurality of blades shaped to deliver air in all directions from the center thereof and having corresponding air ducts, each having an inlet in the forward face of one blade and an outlet discharging ahead of and toward the forward face of a succeeding blade, the blades having inclined portions adapted to deflect in an axial direction the discharge from said outlets, said impeller having a hub sleeve open at one end, an electric motor within said hub sleeve, through which a ventilating current of air may pass axially, and a support having a head on which said motor is mounted, said head including an annular barrier disposed adjacent the open end of said sleeve and extending radially beyond said sleeve and cooperating with the surface of revolution of the inner end extremities of the impeller blades to define an annular air passage extending inwardly and toward said motor and increasing in width toward its inner extremity, said annular barrier deflecting into said hub sleeve, currents of air delivered axially from said impeller blade.

JOHN H. BECKERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,797,455 Vose Mar. 24, 1931 1,870,342 Munk Aug. 9, 1932 2,397,171 Troller et al Mar. 26, 1946

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