US2386154A - Propeller - Google Patents

Description

Oct, 2, 194.5. M. WEBER PROPELLER Filed Nov: 6, 1942 5 Sheets-Sheet l Max Web;

I I I v v p 9 Oct. 2, 1945.

M. WEBER PROPELLER 7 Filed Nov. 6, 1942 5 Sheets-Sheet 2 .Max, WZ?

NEUTRAL zoA/E Oct. 2, 1945. WEBER A v k 2,386,154 I Y I PROPELLER I Filed Nov. 6, 1942 5 Sheet s-Sheet 4 Patented Oct. 2, 1945 zsse sc This invention relates to, air screws 1 or 1 proe pellersm An uobie'ct offihis invention ;-i.s;t.o provide ;a J KQ-r pellert structure; is .so constructediasitm provide a substantially filia'tihefitruriture where-'1 intend ..th'r.ust isrsubstantiallylelimiriated;

Another. object Lot-this -inrentidnisitd. provide, airpropellerestructure which 'the-tip portion of reach blade.is.lprovidediwitlLaipitchjeverse to theipitchion thesremai ifigapprtionmf1the..:b1ad, the. reverse pitch effecting to.eli'rh'iriate:enfi;thi:ust.- causedloythelremainingtnontion oi theblade and. alsoenlarging,theesuctionzonefiorthelaladsev A further object uofjthls invention .is impro-- vide ,a, pr-opener; structure .in nwhicmlthe central. portion thereofmis. formedlof ailengthsequalltor substantially? one=haltthe .length .of .eachibladd. the-central portionbeing pitched .toitheterrninal end thereof and.providingganaxialspiralwcyclonict air stream. M t j A further .objectsof lthisrimzentionis' tosprouide; aapropeller structureh-whichlis so iconstruCtedlaa toreducethe noisetnormallysformed-by propellers: now. .in usew A further ;-ob;iect sof tthis. inventionaisntorproe.

vide a propeller structure iivhiehwwill pcrniit grrately increased propeller speeds without causing fatiguer-inri-the tip ,portionsetofa-ttheablades f astis new -the case =withmpropellersaat epresent. email-1, able. t

A further :object =:of-sthisainventionsissto genocide? a. propeller structure in-twhich ,the suctiomcausedt by-ipartialvacuum on the rearsides ofi-thev-blades ,1 iscounterbalanoed by the forward thrust elfectedabyreversingtthe-pitoh at=the1tip;ends ofithe blades,-

V the efiect. of the-reversedpitch ain-ltheaouter-lends" being 3110 provide-:fordnward. movement .of the airradially lof int-heepropellerestuucture sinsteadrofiacev relented mane "iuiisnateenntneiaceompmymgl constnucteduacccrdingsto an emhodimenttofz-ithis'.

intrentiomt, l Figure 2eista plan,viewaofisthatprcpcllen; V .Figunet3tisaa .detaiLsidemlerationtoft-onelof propeller bladesp,

. Figure: 24:125 iassectional @viewataken LOU-{$11G dinez :4-4 of Figure 3;

1Figuree9 sisraesectinnal tviewy-takens on the dines SESwfHFEigm'eE-fi Figureil0 -lissaisectronale wiew takeniontthe 511116; Ills-art!ofrI "1'-gi;11-ie=-(13,1

Figured-1 :is arseotienalwiew takensron that-lines +4 1 -rofdliigure: 3;.

figure112t-israxseetionalviewwtakeirvonv-the liner I2+LIlZ T fQFIigHRe Figure 5'13 :18 ta:magrammaticwiew showingsthesaimcnrrents: generatedsbyythissprmneller anctithee movement-chair pausedtbylthe ,generatedrair 201.11

rents; and

axially "as -is at fpresent-tthewcase with propellers:

now Win 1156;"

A: further "Objects of Lithisfinyention'aissto-apron vide a propeller structureincludingir maimori inner-idriwzinggzone, a neutral intermediate zone, and an outer or rearward driving zone, the latter zone being of such width as to counterbalance the thrust of the main zone and effect a substantial floating of the propeller.

A further object of this invention is to provide a propeller structure in which the air circulating efiiciency thereof is increased without increase in power or size of the structure.

To the foregoing objects and to others which may hereinafter appear, the invention consists of the novel construction, combination, and arrangement of parts, as will be more specifically figureflais amend elevationpfithesairizcurrents showin sthe snmnementathereofficausedsby thisr propellers;

Re fe'nmrpto tnemeawingsanemmnemmstaess -'ignates generally azehnmstmcmlremnd tHe?'.-n11:f:=

meraL dfiides'ignates ronesolitaisseriesioi :bladesecarried 533ml; sfdrmedfintegral with :thekhub structure? tie. fllhesd'iubE-strnctur "ilirisadaptedrtoebetsee cimediiin ;-anycsuitableemarmemmamowemslmftir sucin'asia ranmmter shaitiirtosefiectirotatiomofithe I:

' propeller at the desired speed.

The hub structure I5 has projecting forwardly therefrom, a plurality of radially arranged blades l1, which'have a relatively deep pitch and the blades I! terminate in an apex g n-axially disposed point l8 which is coaxial with the axis of the hub IS. The lblades l1 being disposed on a relatively deep pitch, are adapted, as shown in Figure 13, to produce a centrally disposedspirally rotating column of air indicated by the arrows l9 a straight leading edge 2| and'a'lon'gitudinally' curved following edge 22. The forward or thrust side 23 of the blades I6 are substantially flat whereas the rear or-trailing sides 24 of the blades [6 are curved, as shown in Figures 5 to 12 inclu Referring now to Figures 13 and 14 the hub blades ll produce the central spiral column of air or fluid is which travels at a relatively high speed and also produce the spiral colurrm of air 29 which is produced .by the outer portions of the blades I! where they merge with the inner or root portions of the blades 16. The blades l6 produce a spiral column of air, indicated by the arrows?!) in Figure 13, this column of air moving at a slower speed than the column of air or fluid 29 'or'the column of air or fluid 19. The air enters between the blades 16 from the rear sides thereof, as shown by the arrows 3l, and also enters, as shown by the arrows 28, from the outer sive. The pitch of the blades l6 gradually re duces toward the outer ends. of these blades, in such a manner that the thrust of the forward sides 23 of the blades will be substantially equalized from the root orinner portion 20 thereof to a point designated by theline 25. The line 25 in-' dicates,fas shown in Figure 6 ,]a neutral zone wherein thepitch of eachbl'ade I6 is zero,',or in other words the front face 23, of eachlblade '25 at the point 25, is parallel with the plane of rota.-

tion of the blades 56. The blades l6, outwardly from the neutral zone 25, is formed with a reverse pitch,- as shown in Figures 4 and 5'. The reversely'pitched zone 26 is relatively shallow and constitutes a means for counter-balancing the thrust of theblade efiected'by the inner 'zone'2'l.'

This rev'erse' pitch 26 eliminates in great part the endwisethrust on the hub l5 so'as'to causea substantially'fioating of the blade 16 Within the plane of rotation. The rever'se'pitch also provides a means whereby the air or fluid, outwardlyfro'm the outer circle of the blades I6, is drawn inwardly, as shown by the arrows 28 in Figure 13. In other words, the reverselypitched zoneor portion 25fcauses the air or fluid stream to move radially inwardly of the blades l6 from the outer ends thereof in addition to stabilizing. or counter-balancing the endwis'e thrust on the propeller blades; The length of the reversely pitched portion 26 issubstantially'one-fourth the radius of each blade l6,

and provides a means for eliminating the objectionable hum or sound normally produced by high speed propeller blades at' the tips thereof. Reverse pitching of the blades by eliminating the thrust on the forward sides thereof also provides a' means-whereby thefatigue caused at'the tips of the blades is substantially reduced, if not entirely eliminated, when the propeller is operated at a" very high speed.

' The hub blades I! are of a length substantially equal to one-half the radius of each'blade l6 and these blades ll provide a means whereby the centrally disposed vacuum normally produced. by propeller blades, is eliminated.

'The combination ofthe centrallydisposed hub blades l1, and the reversely pitched blades or portions 26 of each propeller blade I6, provides a propeller blade structure-which is more eiflcient in operation, than" propeller blades at present available. f

ends of the blades, the latter mentioned air or fluid'moving radially inwardly along the sides of the bladesit. This blade structure has been tested under a fluoroscope with smoke or colored vapor, and the spiral movements of the air, as

shown, inFigures 13 and 14, have been clearly discerned under these'tests.

The inner stream or column of air or fluid 29, andalso the central column or stream of air or fluid l9, appears to expand, as indicated at 32, at

a point some distance forwardly from the blades and substantial portions of 'the air or fluid streams continue forwardly in an'expanded conditiomas'shown at 33, until the air streams strike an 'abutment or wallfacing the propeller blades.

The propeller structure, as herein shown, embodies flve blades but it will, of course, be understood thatthe propeller structure may have any desired numberof blades depending in great part uponthe speed of the blades and the force of air or. fluid which is to be generated by'the blades. The provision of the forwardly projecting central or hub blades I! produce what may be termed a cyclonic effect due to the high speed of movement This cyclonic action causes a. greater movement of air withinthe several air streams as the outer air streams'ten'd to be drawn inwardly as they move forwardly. The propeller structure herein dis- ,closed is an improvement over the propeller structure einbodied in my prior Patent No. 1,933,948, issri edjNovember'l; 1933.

A propeller comprising a hub',fand a plurality of blades carried by'said hub, said blades at their inner ends extending forwardly of said hub and terminating at substantially the axial center of said hub, the pitch of each blade gradually clecreasingfrom the hub axis toward theouter end thereof, each blade comprising a forwardly pitched forward thrust area for the major length thereof, a'reversely pitched tip areaand an intermediate neutral area defining a neutral zone between the forward thrust area and the reversely pitched tip area, the pitch of saidtip being substantially less than the average forward pitch of the blade whereby to provide a substantially balanced thrust. I

' MAX WEBER.

Images