US 961328 A
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H. H. WAIT. TUBBINB BLADE. 4APPLIOATIQN FILED 1mm?. 1910.
Patented June 14, 1910.
`sectional area of the stock.
`HENBY H. WAIT, .0F
Application led March 17,
speciacaeon'of Imm Patent.
1ero. serial -110.5429368.
To all whom it may concern: U Be it known that I, HENRY H. WAIT, citizen of the United States, residing at Chicago, in the county of Cookv and State of Illinois, have invented a certain new and useful Improvement in Turbine-Blades, of which the following isa full, clear, concise and exact description.
My invention relates to rotary turbine wheels and more particularly to the structure of the blades or vanes and to the method of making Athe same, and to the manner 1n which said blades are attached to the lturbine The object of my invention -is to simplify and to render more economical the manufacture of turbine blades, and to provide a blade structure which has a strong rootN adapted t0 be flrmlyanchored to the turbine wheel.
The blade of my invention comprises a body portion havin the ,requisite strength and thickness and-o the usual shape, that is crescent in cross-section, the root of the blade being substantially of rectangular cross-section and having great thickness and breadth, thereby giving the blade the requisite strength to sustain thefsevere strain to which, as is well known, the blade is subjected'in use. The root of the blade preferably has on its front face va semi-circular groove or grooves adapted to register with a sinnlar groove or grooves in the wall of the bladereceiving slots in the rim of the wheel. The blades are then securely locked to the wheel by meansof pins inserted -in the vcircular holes thus provided between the rootsof the blades and the walls of the slots in which the blades are inserted.
Another feature of my invention consistsv in making the felly or rim of the wheel of increased thickness'gand making the root of the blade of correspondin width..
Stillanother featurev o the invention re lates to the stock from which the blades are made, and themanner in which the bladesv are shaped therefrom such stock consistingf-` of a drawn bar in the general form of a crescent in cross-section, but provided, preferably upon its convex side, with an angular projection or pr'ojections whereby a rectangle of increased width and thickness, correspondingto the desired cross-section of the blade root, can be inscribed'within'the'crossblade.
These and other features 'of my invention may be more readily understood by reference to the accompanying drawings, in which,
Figure 1 is a fragmentary view partly inv side elevation and partlypin section; Fi 2 is a section on the 11ne.2.-2 of Fig. 1. Fig. 3 is a fragmentary view partl in plan, partly in cross-sectionv and wit portions broken away; Fig. 4 4: of Fig. .5; Fig. 5 is a view, similar to that of Fig. 3, of the wheel and blades shown in Fig. 4; and Fig. 6 is -a perspective view of a from whichthe blades are manufactured.
Similar numerals of reference describe similar parts Athroughout the several views. The rotary wheel l is provided with a rim or felly 2 of increased axial thickness. Opening outwardly or radially from the periphery of the rim 2, are a series of slots 3 adapted to receive the roots of the turbine blades. The slots 3 are preferably mere channel slots havingparallel walls, since Said type of slot is more easily and economically provided.
Fittingin the transverse slots 3 are the roots 5 of the turbine blades. The said roots are of approximately rectangular crosssection. However, in order to lncrease the width and thickness of lthe blade root, which can be cutfrom `the stock, aslight cavity 5a may be left `in the front wall of the root corresponding to the concavity in the face of the corresponding'body portion 6 of the The back of the blade 'root thus Patented June 14, l1910.
4 is a section on the linepresents a plane surface, and the front face of the root likewise forms a plane bearing' surface for said root. thus of substantially rectangular cross-section and areV adapted to tit inthe channel slots in the rim of the turbine wheel or disk. In the preferred embodiment of my inven- .tion the root of the blade is provided with one or more semi-circular grooves T which are adapted, when the blade is in posit-ion, to register with the 'corresponding grooves i in the walls ofthe slots 3, thus forming #holes into which pins 8 are inserted for locking the blades in said slots. The bladesv Lare'preferably formed from the stock shown The blade roots are in Fig. v6 which consists of a: drawn metal bar of substantially crescent shape in crosssection, the convex surface of said bar being formed however, with angular, longi-` tudinally extending ribs 9, 10, the vertices of which are right angles. The inner faces of the ribs-9 and 10 are in the same plane,
and the-outer faces thereofl are in parallel plaie's.l rThese two ribs form' opposlte cormule stock shown in Fi of the blade is given 1s not necessary to give the upper contour, i 2
-'10'only, in the manufacture of the shorter blades, are milled off so as to give the en- IierS of-"a rectangle which may be inscribed 'within the cross-section of the blade, a's shown vin the dotted lines in Fig. 6. By providing such projections on theI convex side of .the -body of the stock, it is obvious that a ,rectangle can thus be inscribed, corresponding .to the desired cross-section ofthe blade root, having both' a greater width and a .greater thickness than could otherwise be obtained. In order that the thickness of the rectangle may be vmade somewhat greater, the front line to lie at its central portion somewhat outside the body of'the stock, thereby leaving 'a slight concavity 5a in the front surface of the .corresponding blade root, as hereinbefore described.
In the manufacture of the blades from 6, the body portion e desired conti ration by milling off so much of the stock as to the blade, as .for example, the ribs 9 and .tire thickness of "the stock, to such? short tangular ,blade root.
blades.- VThe structure'of such shorter blades is shown in Figs. 1 and 3.A In the longerblades illustrated in Fig. 4, the convexsurface of thel stock is milled down until the desired., s hape and thickness of the body f the bladfsgsecured. In both cases, however,
the ribs 9' and 10 forma portion of the rec- It is-'obvious that a blade canthus be.produced,having a very much larger and stronger root, and which nevertheless can be cheaply and quickly ma e.
'the' cover't plate 1 1, which 1s provided with -perforations 12 of a contour corespondin to the cross-sectional contour ofthe root o the blades. These perforations in the cover plate lie immediately over the 'slots 3,and encethe blades can readily be set in place.
The blades are thenv anchored'to the turbine a disk by the pinsA 8. Y
. .1 blade sa heilig .a b
It 'will be noted that I preferably make 'the creased axial thickness and also provide ribs upn theconvexsurfaceof the stock ,from
w of a widerV and thicker blade .rootthanf ch'theblades are made, thuspermitting could otherwise be secured v1It will 1 beunderstood, however, that.various modifications of my invention canbe made within the-scope of the appendedclaim's. a
l- Wha-t I claimis:
, 1, Ina t11 'rbi ne 'wheel, the combinationof i a wheel.- 'n iisk-f having fa of increased axial .thieknesasaid'rim being-provided with eriphery, turbine y portion of cres- Vaxial thickness,
thereof may be so drawn as 'said rim f andfprojecting The periphery of the any 21s veed'b'yfellyor rim ofthe turbine 'disk' of fin- 'plate surrounding the cent shape in crosssection anda rootiof 'approximately' rectangular `cross'- section, vsaid roots fitting in the slots of said rim,
the blade roots to the wheel,
pins locking plate overlying the periphery of said rim and projecting upon the opposite sides thereof to the tips of theb'o'dy. portion. of said blade. A.
v2. In a turbine wheel, the combination with a wheel disk having a rimofl increased said rim having in its 'eriphery a series of channel slots provi ed with parallel walls, of turbine blades each having a body portion of crescent shape in cross-section and'v a root vof approximately rectangular cross-section, said roots fitting in and appro 'xiniat'el'y,- filling the slots insaid' Irim, the walls of said slots and said v slots and of a contourfcorrespondlng tothe grooves, and a" the periphery of cross-sectional contour'of the roots of said 3. In a turbinev wheel, the Acombination with a wheel disk having a rim ofv increased axial thickness, said. rim' being provided in its periphery with a series of outwardly opening, transverse. slots, and. turbine. blades havinga body? portionof crescent shape in cross-section and a-rootv portion of approxi-- mately rectangular cross-section, the front 'surface of said root having a slight con'- cavity formingv a prolongatlonof the'- concave face of the body portion of the root, f
said4 blade groots fitting in and approximately 'filling said' slots lin A 'said' rini.-
4. In' a turbine wheel, vthe -combination with a wheel dislrhaving a rim of increased 'axial thickness, said rim being provided in its periphery with series of outwardly opening, transverse slots,-turbine blades havcrescent shape in cross-section and' a ropt'portion of approximately, rect-angular cross-section, the Afront' ing a body vportion 'of surfaceof'said' jroot having a slight conca vityforming a prolongation of theconcaveface of' the body portion of the root,
[said blade .roots fitting 1n and approximately filling said slots in said rim, and a cover periphery of said rim and projecting upon th opposite sides thereof, said coverplate being provided with pervforations overlying saidslots and of a contour corresponding to the cross-sectional contour of the roots of said blades.
5. As an article' of manufacture, a stock for turbine blades consisting of a drawn bar of approximately crescent shape in cross- `'section plio'vidledl witht a1iangular,' longitudi- '6. As an .article-'offnianufactura a' stocli for turbine blades consisting of a drawn bal; of. approximately crescent vshape in cross-l' section provided n, with angular, longitudi@ nally extending'ribs, the vertices of said ribs being right angles. p
7. As an article'of manufacture, a stock for turbine blades consisting of a drawn bar orf approximately .crescent shape in cross- 8; A turbine blade comprising a body por tion of crescent shape in crosssection and a root of ap roximately rectangular crosssectior'1, the ontl surface of saidv root having, at its central'p'guftiolny a slight concavty forming fa longitudinal prolongation of the front surface of saidfnbodylportion of the blade. z 1
9. A turbine' blade made lfrom drawn stock, provided with anula-IQ-'longiltudinally extending, ribs, said bla e portion of crescent Shape in"- cross-section and a root corresponding tofa rectangle in-l scribedin the said stock, .said ribs forming .two of the corners of said rectangle.
` I n Witness whereof, I hereunto subscribe my name this fifteenth day of March, A. D., 1910. p,
HENRY H. WAIT.
GEO. C. DAVIsoN, p MCCLELLANDYOUNG.
vcon'iprising a body