US1165005A - Blade construction for elastic-fluid turbines. - Google Patents

Description

H. T. HERR.

BLADE CONTRUCTION FOR ELASTIC FLUID TURBINES.

HIS ATTORNEY IN FACT HERBERT r. HERB, or rrrrsnonen', PENNSYLVANIA, ASSIGNOR TO THE wnsrrnenoUsE MACHINE COMPANY, A CORPORATION or PENNSYLVANIA.

BLADE CONSTRUCTION FOB, ELASTIC FLUI D TURBINES.

Taall whom it may concern:

Be it known that I, HERBERT T. HERB, a citizen of the United States, and a resident of Pittsburgh, in the county of ,Allegheny and State of Pennsylvania, have-made a new and useful Invention in Blade Construction for Elastic-Fluid Turbines,\of which the followingis a specification.

This invention relates construction and hasfor an object to produce new and improved means for shrouding and tying together the outer ends of the blades locatediin a row. This'and other objects I attain by means of a blade construction embodying the features herein described, and illustrated in the drawings accompanying and forming a part of this application.

In the drawings: Figure 1 is a fragmental, sectional view of a rotor element of a turbine equipped with blading. embodying my invention; Fig. 2 is a perspective view of a blade forming a detail of my invention, and discloses the tie memberreceiving slot formed across the outer end of the blade; Fig. 3 is a sectional view of a tie member, forming a detail of my invention, and discloses its shape before it is secured in place in the mounting slots formed inthe ends of the blades; Fig. 4 is a perspective view of several blades in the position they occupy when assembled on a blade-mounting element.; the blades are shown in connection with the tie member, which is shown crosssectioned at one end and broken away at the other; and Figs. 5 and 6 are each fragmental elevations of blades equipped with integrally formed spacing pieces (shown in section) and illustrate two separate embodiments of my invention. 7

It is desirable to provide a shroud for the outer or free ends of blades of the impulse type; that is, for the ends of the blades located farthest from the blade-mounting element. It is also desirable to tie the outer ends of turbine blades together, since during the operation of a turbine each blade is subjected to successive shocks due to the impact of the motive fluid and this tends to create vibrations in the blade. By tying together the outer ends of the blades located in a row, each blade-is caused to cooperate with the blades to which it issecured in resisting the vibration creating strains and the tendency for each blade to vibrate'is to turbine blade next adjacent blade,

Specification of Letters Patent. Patented Dec, 21 1915.

Application filed May 14, 1914. Serial No. 838,538.

thereby largely overcome. I

In the drawings I have, for convenience of illustratiom'disclosed a turbine rotor pro vided with a circumferentially extending undercut groove which is adapted to receive blades havlng specially formedbases or mounting portions. It will, however, be understood that my invention may be employed in connection with the stationary as Well as the rotating blades.

As illustrated in Figs. 1, 2, and 4:, each blade 7 consists of 'a substantially crescent shape body portion, which is provided on one side with a concave Working face 8 and on the other side with a convex forward face 9. The mounting portion 10 of each blade is adapted to fit into the blade-mount- -ing slot and also to provide means for spacing the blades. In other words the. base pieces 10 of the blades not only secure the blades in place, but also insure a proper spacing of the blades. Each base piece cor- .responds in cross-section to thecross-s'ection of the blade-mounting slot in which it is located, and, as illustrated in Fig. 4, is adaptany means may be employed for spacing the blades at their bases or mounting ends.

Each blade forming a detail of my in vention is provided at its outer or free end with a cover or spacing piece 11, which is adapted to cooperate with the spacing pieces J 11,01 adjacent blades, in maintaining the proper spacing for the outer ends of the blades, in forming a cover or shroud for the row of blades and 1n providing means bywhich the outer ends of the blades'are secured together. v

In the specific embodiment of my inven-' tion illustrated each spacing piece 11 1s of substantially the same width as the blade on which it is mounted; it extends substantially at right angles to the curved working faces of the blade, and its front and rear faces are -each curved to the same degree of curvature. With this arrangement the front face of each piece 1? engages and 'fits snugly against the rear face of the piece 11 on the it being understood that,

between the blades.

spend in degree to that of the concave working face 8 or to that of the convex forward face of the blade on which it is mounted. If desired, it may be of any other degree of curvature or may even be'providedwith straight or .angular.edges.. .In addition to this, the p1ece may be located. in any desi ed posi on with relation to the blade;

that is,--it*1fia'v overhang the forward face only, or it may overhang the concave work ing face only, or, as illustrated,it may be located in an intermediate 'positionon the blade, so thatitroverhan'gs'both theforward and the rear working faces. x

-The outer face of each blade spacing piece cated that its endsregister with the adjacent 5 ential'slot adapted to receive a tie member.

ends of the slots formed in' adjacent pieces 13 for the outer ends of the-blades.

As illustratedyin Fig- 3, the tie member is' initially arch-shapein cross section,.and.is

- each blade and consequentlytie -the'outer gently.

4 I such length 'as to merelyflsecure groups of provided with para'llel'lateral' sides.- In .-'ad-.

dition to this,'it'is of' su 'ch widththat it' is capable of beingfitted into the eircumfer-f; ential slot 'formedby' the cooperatingslots. in the outer face of'each of the pieces 11. After thestrip 13 is'in place,.i t is flattened out, as shownin Fig. I;v is therebyincreased .in width and its parallel lateral f'acesaremoved to inclined positions {corresponding to the inclination of the undercut wall of the slot with which they enga e. this way themember 13 is positively secured to ends of the blades together and eliminates the TJOSSlbilltY of their vibrating independan'annular row of blades, or it may -be of blades in an annular row together.

15 mayb ecured toitsenga 2,14: 5 by any suitable means,-such,f fi

. In Fig. have shownv an embodiment of; my inventlon in which the spacingTpiece 111? is provided on" its outer "face-"witlijfie .bv welding, and'by'weldin'g Imeanby the ap-: pllcationof heat either with or without pres It will be understoodthatthe member 15,1ike'the member-13, 6b. v faces. of adjacent bladesengages-the outer secured to'each' of the; blades engaged by it.

. In Fig. 7 I'have illustrated a still fur,-' .ther modification of myjinvention in ,vvhich the "spacing piece 11 formed at the outer iend of the blade-,i7is arranged so that it is fifiilicapable of 1bei ng "positively secured to :two

What I claim' is; 1. Incombination The strip 13 may extendfclear around ands positively welding.

For the purpose of' preventing the-blades.

v or pieces 11 from moving in a longitudinal direction, relatively to the "tie-member or strip, I preferably employ means for posi-.

tively. locking the strip and each spacing piece together. This may be accomplished by distorting one or both edges of the strip so that it is pressed into gripping e'ngage-* ment'with theadjacent edgesof the stripillustrated in Fig. 4, I have distortedthe strip by means of a center punch, or similar tool, by driving the punch between. each receiving slot formed in each piece; As

edge of the strip. 13 and the adjacent edges of the slot 12,so that-both the strip andthe (pieces 11' are distorted and are pressed into 11 illustrated, is provided with acircumferv entially extending undercut slot 12, so 10- looking or positive engagement' with-each While I have described several modifications of I ny invention, it 'willbe'; apparent forth. by the appended claims. 1

with a blade-mountin element, a""row 'ofblades mounted on said element, a 'spacing piec'e for the outer end y invention, as set of'eacl blade, said spaeing'pieces cooperatto form an organized shroud for the row of blades-and a .tie'ymember' mounted in a circumferentially ex'tndedgroove in the organi'zed shroud.

2. In combination"with -iaiblade mounting 1 element, aow of blades mounted on the ele-' ment, aspacing piece for; the outer end of 'each blade integrallyformed oneach blade,

said spacing pieces cooperating to form. an

organized shroud" forthe-zrow. of. blades, an'dk a circumferentially extending .tie. member n positixtelysecuredto each spacing piece-so. as'to prevent relative motion between the '--member and the piece. longitudinally of: the h 3. Inv combination with a turbine blade mounting element, a row of blades mounted on the element, a spacing pieceforthe outer v V ends of the-blades'integrally formedon' each. I

.' blade, said spacing. piecesfcooperatil?flto .form a' shroud for, the outer ends o blades, and a tie member locatedina'groove formed on the shroud and'poslt vely'locked to eachblade. J

' 4. In combination'with turbine, ablade i mounting element, a-row of blades mounted 2'5 formed onthe outer end of each bladefthe on (said. element, a: spacing piece integrally lit 3 blades in said row being 'so -located-'.on"said element that the spacing. pieces coiioperate to form a shroud for the row and a he memher for the outer ends of the b1ades extefid- 'formed on the outer end of each blade, the

blades being so located in each row that the spacing pieces cooperate to form a shroud for the row,- and a tie member for the outer ends of the blades extending along a circumferentially extending slot formed in the peripheral face-of the organized shroud and Welded to each spacing piece engaged there- 6. In combination with a turbine blade carrying element, a row of blades mounted on the element, spacing pieces for theouter ends of the blades cooperating to form an organized shroud for the row of blades, and a tie member mounted in a circumferentially extending groove formed in the shroud.

7 In combination with a turbine blade carrying element, a row of blades mounted on the element, spacing pieces for the outer ends ofthe blades cooperating to form an organized shroud for the row of blades, and a tie member mounted in a circumferentially extending groove formed in the shroud and positively secured to each of the blades of the row.

In testimony whereof, I have hereunto subscribed-my name this 12th day of May,

HERBERT T. HERB.

Witnesses:

C. W. MoGlmu,

E. W. MCCALLISTER.

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