US2484274A - Turbine wheel - Google Patents

Description

Oct. ll, 1949. D. P. EASTMAN I 294849274 TURBINE WHEEL Filed Sept. 16, 1946 SSI-leets-Sheet l I I :9 I 3 I I I I I I I I I I I I I y/Q M,

AFiled Sept. 16, 1946 oct. 11, 1949.I D, p, EAS-MAN 2,484,274

TURBINE WHEEL 5 Sheets-Sheet 5 Patented Oct. 11, 1949 TURBINE WHEEL David P. Eastman, Chicago, Ill., assigner to United Specialties Company, Chicago, Ill., a corporation of Delaware Application September 16, 1946, `Serial No. 697,362

This invention relates to a turbine Wheel and to the method of manufacturing such a Wheel. It has for one object to provide a method of manufacturing a turbine Wheel having a plurality of buckets.

Another object is to provide a turbine wheel construction in which the buckets are held in place by the construction of the wheel and by the other parts which make up the wheel.

Another object is to provide a turbine Wheel in which the buckets are held in place without being themselves welded, soldered, brazed or otherwise permanently secured to the wheel body.

Another object is to provide in a turbine wheel means eiective to prevent distortion of the parts and loosening or separation of the wheels as a result of centrifugal action.

Another object is to provide a turbine wheel body so arranged that under the inuence of centrifugal force, the buckets are eiectively gripped and the centrifugal tendency to separate the buckets from the body is eifectively counteracted.

Another object of the invention is to provide a turbine wheel having plates which may be formed radially of at sheet or strip stock.

Other objects will appear from time to time throughout the specification and claims.

The invention is illustrated moreor less diagrammatically in the accompanying drawings,` wherein:

Figure 1 is a section taken through a portion provide a plurality of curved portions 4. In the form of VFigure 2 the inwardly bent portions 3 lie substantially inwardly of the portions 2. In the form Aof Figure 4, however, the curved portions 4 are alternately positioned on opposite sides of the center line of the portions 2.

In the form shown in Figure 1 the wheel comprises a disc-like member 6 Which may be enlarged, as at l, the portions 6 and 1 being separated by shoulders 8. At its outer edge or periphery the portion 'I is provided with tapered surfaces S. The member 8 is also provided With annular grooves Il) and with annular shoulders I I which are of less depth than the grooves I0. When ,the wheel is assembled, the members 2 of the buckets I are shaped to provide the curved portions 3 which lie within the grooves I Il and the flattened portions I2 which lie on the shoulders II. The inner faces of the members 2 thus conform to the shape of the member I with which they are in contact.

Positioned on either side of the wheel member E are plates I3. These plates are shaped to conform to the shape of the members 6 and 'I and to contact the shoulder 8. Each of them is provided with a laterally bent edge member I4. Annuli I5 may be secured on the outer face of each of the members I3 and are held in place by rivets I'Ei which pass through them and the members I3 Aand 'I. Each annulus I5 is cut away, as at I1, and is provided with a peripheral eX- of a turbine Wheel with the bucket shown in tension I 8. Each peripheral extension I8 is in elevation; I y contact with the inner face of one of the mem- Figure 2 is a side elevation ofv one form of the bers I4. The cut away portion II provides clearbucket; L35 ance between the annulus I5 and the corre- Figure 3 is a transverse section taken at line 3 3 of Figure 2; f

Figure 4 is a section similar to Figure 1, show# ing a modified form of bucket-engaging means;

Figure 5 is a plan view of the turbine wheel of Figure 1.

Like parts are indicated by like characters throughout the specification and the drawings.

In the particular form here shown, the turbine wheel includes one or more body members shaped and assembled to engage the buckets. The buckets are generally alike in the two forms of the device.

Each bucket includes a blade portion I, curved as shown in Figure 1, and provided with attaching portions or extensions 2. In the form shown in Figure 1, the attaching portions 2 are shaped to provide inwardly bent members or portions 3. In the form shown in Figure 4 the lattaching members 2 are crimped Aor otherwise shaped -to 55' sponding portion I4.

I9, I9 are members which are annular in shape and may be continuous or discontinuous. Each of them lies within the annular groove defined by the curved portions 3 of its associated buckets and is held in place therein by the side plates I3 but need not be secured to those members and are merely held iirmly in position when the assembly -is riveted together by means of the rivets I6.

As above pointed out, the form of Figure 4 differs from that of Figure 1 primarily by the diierence in the shape of the extensions 2. The central plate is provided with a relatively small enlargement 20 and the portion 2| closest to its edge is provided with one or more annular grooves or depressions 2|, between each of which remains a raised portion 22. Plates 23 are positioned one on each side of the member 6 and each of them is provided with an internal groove 24` Within which the enlargement 24 fits. A clearance is provided between the periphery of the enlargement, as shown. Each of the plates 23 is provided with one or more annular grooves or depressions 25 between each pair of which a raised portion 26 remains. The grooves 25 of the plates 23 are formed or positioned with respect to the grooves 2| of .the member 20 to alternate so-that a crimped or sinuous passage remains between 'the member 20 and each of the members 23 within which the curved portions 4 of the members 2 o'f the buckets may be tightly received.

Each of the members 23 is provided with a lateral extension or flange 21 andzannuli'fmaybe positioned one adjacent each of 'the 'pl-.altes 23. The lannuli, if present, are each provided with a. peripheral extension 29 and a-'cutfawaymortion 130.

The wheel in the form of Figure 4 is nallysecured together by rivets 3 I.

Although Iihave shown an operative'formx'o'f my invention, it will lbe recognized that -many changes in Vthe lform, shape land arrangement :of parts Vcan be :made without departing from .the spiritfof theinventionfand'my showing is :therefore :to be takenas, in-a sense, diagrammatic.

11n particular, fthe invenltion is -not'limitedlto the exactfdetails-shown. The two 'forms ofthe invention hare gener-allythe same. Eachincludes wheel members shaped to grip parts ofthe buckets soithat when :the wheel is `assembled,lthebucket parts are'held in place on the wheel. The fbucket parts arecurved, bent or otherwise so shapedithat :theyfcannot bel'displaced from .fthe wheel during operation as a result'of centrifugal force. 'The members TIF and28 may or may'notbe used-:land if fused, they might Ibe welded or otherwise'permanently securedito theeparts 1113 and 23,\respe.c

tively. The exact curvature :or fcontour of the members2 Vin either-form ofthe device is optional and :the invention is not limiteditmthe particularrcurvature "or yshapes shown. The'fbuckets :are preferably 'made :from fiat -sheet or stripfstock. Theyare. cut tothe requiredplianeand theLfbucket portion is shaped to the contour Islrownrin Fig- Iure Sor .to any .desired contour. The attaching i portions .l2 are cut k'from :the body :of the sheet or strip stock and .rare integral with :the blade portion.

The use and `operationcfthis inventionareas I.

follows:

Whi-chever form ofthe 'inventionlis tobeused,

` the vwheel parts lare shaped as ,shown and ithe In the form `of Figure l, the bucketsgareifitted over the 'outer .ed-ge of '.thernember :1 and lare shaped .or bent ,to :lie in 7lclose :contact with `the inclined surfaces vE! y.and :to vrit :closely :into *the grooves II! :and to lie inclose vtcontactwith the grooves or :shoulders 'I I. The :members `I?) are then put in place, one in eachof'zthergrooves defined :by :the portions 13 of .the bucket members YNow theplates I3 :are :.put .in place -an-d `the annular mem-bers I5 may, if desired, beiputin place-and the f entire structureiis vrivetedatogether by :the rivets IE. Obviously otherrmeans might be' used zf'or :fastening the ivari'ous :parts .nf :the structure stogether.

ifIhe wheel Aofzthisgform of theizinventiomwhen put .in use, is .of icourse subjecteditoicentrifugal force, which'ha-s atendency tothrovvmhebuckets out of .place or fto separate them .entirely-trom the 'wheel body. @Obviously :this vcannot occur if the `parts .arefnotfseparated or :distortedgfromrthe the blades. :fluence of centrifugal force, tend somewhat to position and shape of Figure 1. One way in which separation might occur would be for the members I3 to spread slightly or Ito become distorted otherwise, `or to grow so as to provide some lclearance or at least some looseness which would 'permit Ithe members 2 to be pulled out of engagement with the wheel. The Wheel has, therefore, been lshapedto provide means for counteracting any'tendencyto distort under centrifugal force which might permit loosening of Thus the portions I4, under the intilt inwardly andin doing so they exert ian invlwardiforcein-thediiection .of the bucket members '2, ."3 #.andthus frforce'the members I9 increasingly the'members 2, 3. This effect counteracts farryfftendency to, distort in the direction of lloosening the -buckets and utilizes centrifugal forceto hold the buckets ever tighter during rotation. The mem-bers 144 might be considered counter-.weights forithis' purpose.

The plates il3, and `v`in particular .the portions M, .have -Ibeen .made ;unsymmetrical in order to create structures which, .under the .influence -of centrifugal force, will exert =an inwardfpressure inthe direction .tolholdflthe bucketmembers 2, 3 against; distortion: and against escape.

Obviously .thefareatof .thamembers I8 might :be increased .and .the ,clearance lor: cut away `portions I I might .bereliminatedsso that the ledgeofeach plate |25 would be lincontact '.with `the Iportion 1I4 throughout its entrearea.

The '.annuiar .members lIll, if present, serve to augment the counterweight select of the .members I4. vSince `they .are yin :contact -with vthose membersconly along the Alimited .area of the portion I8 which is positioned l:oni/the .outward side of .the members :I yfwhatever .effect the members I.5.impart under .thezinfluenceof centrifugalforce 1is. :exerted upon lthe outeriportion-of Y eachqmemf er I4.

:.Obviously, :although fthe "forces discussed may be veryflargethe -rellative movements of. the parts are-small. However, they :are vsuiticientfto hold the blades implace under all working conditions. It is importantzto realize :that the buckets vare neither welded, brazedinorzotherwise'fpermanentlyfastenedtorthe fwheel. '.TIThey-iaremerely engagedwith the lpartszof ithe wheeliandthose parts lare so shaped that centrifugal force is at `alltihies effective to fhold the :buckets firmly in place. .In the ,Aform f of :Figure l :fthe iload ,of :the buckets is carried entirely on the central member :6 and-on its enlargement 1.

The method of assembly of the form shownzin Eik-gureefi is :the same -.as :.thatpreviously: described, except that there are no memberscomparableto the members sISfof :Figure 1. Afteritheplate 6 has-been formed :and the. grooves 2l fformedin the 1portion2;,pthe rbuckets. are yput in placeand the curved portions 4 vare registered with =the grooves and raised portionslof-themember 20. Thereafter the outer "plates V-23 are l put vin position and ytheir Igrooves '-25 nand 4raised 4'portions 26 register vwith the corresponding grooves and depressions of'thebucketportionsf 2. 'The members 21 of the plates 23 correspond'to the members I4 of the plates I3 .and the annular members 28 correspond to Lthe annular members I5. Under the influence of centrifugal Mforce, .the members 25| tend to .move .inwardly =v andvthus exert va `pressure :inwardly y.against the v.bucket'members -2 and the V,cum/.ed l .por-ticms -4 'of jthose .members .The

,annular :members 28, through rtheir :reduced portions 29, augment this effect by exerting a force outwardly on the portions 21.

The form of Figure 4 differs further from the form of Figure 1 in that the load of the buckets is carried approximately one-half upon the portion 20 of the central member and approximately one quarter on each of the plates 23. It will be noticed that the center line of each of the members 2 contacts the peaks formed in the parts 20 and 23 by the alternate grooves and raised portions 2 I, 22 and 25, 26, respectively.

The rings or members I5 or 28 may be used to balance the turbine wheel as they are themselves not highly stressed. Thus the rings I5 or 28 may, after the wheel is assembled and tested for balance, be altered slightly to correct balancing. This may be done by boring out or otherwise removing parts of the metal. The anges I4 and 2'I might also be shaped or otherwise treated to accomplish balancing of the wheel.

In Figures 1 and 4, a clearance is shown between the inner or central plate and the outer plates. This clearance is exaggerated in the drawings, and it may in certain cases disappear entirely when the wheel is riveted together. The parts are shaped to provide this initial clearance prior to riveting or other permanent fastening. This is to insure a tight contact between the members 2 of the buckets and the parts which engage them. If this initial clearance, for example between the members 1 and I3, were not provided, the wheel when assembled might not grip the bucket parts 2 with sufcient tightness; therefore, the clearance is provided to make sure that in the assembled wheel an adequately tight grip is eected upon the bucket parts 2 by the members which contact them.

I claim:

1. In combination in a turbine wheel, a central wheel member, a plurality of buckets, said buckets provided with parts shaped to interfit with said wheel member, and a pair of holding members positioned one on each side of said wheel member, and each in engagement with a part of said buckets, said holding members provided with portions adapted, under the influence of centrifugal force, to move to exert an inward pressure upon said buckets to hold them in place, and additional counterweights positioned on each side of said wheel, and adapted, under the influence of centrifugal force, to effect through said holding member an inward pressure on said buckets. l

2. In combination in a turbine wheel, a central wheel member, a plurality of buckets, said buckets provided with parts shaped to intert with said wheel member, and a pair of holding members positioned one on each side of said wheel member, and each in engagement with a part of said buckets, said holding members provided with portions adapted, under the influence of centrifugal force, to move to exert an inward pressure upon said buckets, to hold them in place, and additional counterweights being shaped each to bear against an outer portion of its respective holding member, and adapted, under the inuence of centrifugal force, to effect through said holding member an inward pressure on said buckets.

3. In combination in a turbine wheel, a central wheel member, a plurality of buckets, said buckets provided with parts shaped to intert with said wheel member, and a pair of holding members positioned one on each side of said wheel member, and each in engagement with a part of said buckets, said holding members provided with unsymmetrical portions extending outwardly therefrom and adapted, under the influence of centrifugal force, to move to exert an inward pressure upon said buckets to hold them in place,

and additional counterweights positioned on each to bear against an outer portion of its respective holding member, and adapted, under the inuence of centrifugal force, to effect through said holding member an inward pressure on said buckets.

4. In combination in a turbine wheel, a central wheel member, a plurality of buckets, said buckets provided with parts shaped to intert with said wheel member, and a pair of holding members positioned one on each side of said wheel member, and each in engagement with a part of said buckets, said wheel member and holding members being secured together, said holding members provided with unsymmetrical portions extending outwardly therefrom and adapted, under the inuence of centrifugal force, to move to exert an inward pressure upon said buckets to hold them in place, and additional counterweights positioned on each side of said wheel, said counterweights being shaped each to bear against an outer portion of its respective holding member, and adapted, under the inuence of centrifugal force, to effect through said holding member an inward pressure on said buckets.

DAVID P. EASTMAN.

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

UNITED STATES PATENTS Number Name Date 770,207 Wilkinson Sept. 13, 1904 849,992 Frikart et al. Apr. 9, 1907 883,926 Alexander et al Apr. 7, 1908 1,035,543 Dake Aug. 13, 1912 1,345,678 Kasley July 6, 1920 1,415,266 Rice May 9, 1922 1,891,948 Rice Dec. 27, 1932 FOREIGN PATENTS Number Country Date 20,818 Great Britain Sept. 19, 1906 42,539 Austria 1910

Images