y 1965 J. A. c. HYDE 3,182,955

CONSTRUCTION OF TURBOMACHINERY BLADE ELEMENTS Filed 001;. 12. 1961 INVENTOR fiale... BY m Y ATTORNEYS United States PatentO 3,182,955 CONSTRUCTION OF TURBOMACHINERY BLADE ELEMENTS John A. C. Hyde, Lincoln, England, assignor to Boston & Hornsby Limited, Lincoln, England, a corporation of Great Britain Filed Oct." 12, 1961, Ser. No. 144,740 7 Claims priority, application Great Britain, Get. 29, "1960, 37,254/ 60 3 Claims. (Cl. 253-391) This invention relates to axial flow turbomachinery such as turbines and compressors having a working fluid passing through annular rows or stages of rotor and stator blades or vanes, particularly gas turbines operating at high temperatures when thermal expansion and distortion may adversely affect working clearances and alignment of such blades or vanes and their associated structure. The invention more particularly relates to the improved construction and connecting and reconditioning of annular stages of rotor and stator blades and their associated structure.

-It isknown to construct annular stages of rotor and stator blades or vanes, hereinafter referred to as blades, in turbomachinery by manufacturing units consisting of at least one blade and at least one associated plate generally known in the art as a platform or a shroud according to its locationat either the root end or the tip of a rotor or stator blade. As the invention applies equally to platforms and shrouds, the said platforms and shrouds will be hereinafter referred to as plates. Each unit consisting of at least one blade and at least one associated plate will be hereinafter referred to as a segment. In the known art, an annular stage is built up of a plurality of segments with the substantially axial edges of each plate abutting the corresponding edges'of its neighbouring plates so that when the annular stage is complete the said plates form a continuous ring, ir if each segment has two plates, one at each end of the blade, the said plates form two continuous concentric rings; The manner of locating and connecting the said plates has been given much thought in view of the necessity of obtaining and maintaining accurate blade alignment against thermal expansion and contraction.

The invention consists in a plurality of segments as defined above and connected to form an annular row or stage by means of pairs of lugs spaced apart radially with respect to the stage by grooves formed on the substantially Y axial edges of each plate which abuts the corresponding edges of its neighbouring plates within the stage, the inner' lugs with respect to the flow of working fluid being in contiguous relationship with all the inner lugs in a com tinuous ring, and the outer lugs with respect to the flow of working fiuid being butt-welded to the neighbouring outer lugs.

The invention further consists in a plurality of segments constructed and connected as described wherein each pair of abutting lugs define between-them a channel for a flow of fluid coolant, which may also be conveyed to the interior of the blades by means of passages formed in the blades and communicating ducts formed in the plates between channel and blades.

The invention also consists in an annular stage ofseg ments constructed as described wherein the inner logs with respect to the flow of working fluid are located in contiguous relationship with each otherby means of cooperating flanges 'formed in theirabutting faces, the said flanges being secured against movement and distortion relative to each other by conventional securing means, for

' example, studs or dowels.

The plates may be provided with brackets, flanges, or other fixing means whereby the segments may be located and secured within the turbomachinery.

ice

The following description relates to the drawings accompanying the specification, which show by way of example the application of the invention to the construction of an annular stage of stator segments, FIGURE 1 is an isometric view of two. segments conj nected according to the invention, :and

FIGURE 2 is a partially sectioned detail of alternative constructions.

Referring to FIGURE 1, two segments are shown connected, each segment consisting of a blade 11 and two plates 12 and 13 defining between them a passage ;for the flow of working fluid. On the substantially axial edges of each plate 12, 13, which abuts the corresponding edges of neighbouring plates Within the stage are formed pairs of lugs; these are termed, with respect to their nearness or remoteness from the working fluid, inner lug 14 and outer lug 15. The lugs 14, 15, are spaced apart radially with respectto the stage by a groove 16. The outer lugs 15 are butt-welded to their neighbouring outer lugs 15 as at 17, and the inner lugs 14 are in contiguous butting relationship with their neighbouring inner lugs 14.

The advantages of this construction are: It enables a and contraction and the relative positions of the blades within the annular stage will be maintained within very fine limits. Another advantage is that if in the course of service one of the blades becomes unserviceable, it may be cut out and a new blade welded or otherwise secured into the segment, again without disturbing blade alignment, whereas with conventional segment assembly the whole segment would be rejected. A further advantage is that with the meeting of two lugs 14 and two lugs 15, the two grooves 16 form a channel 18 (see FIGURE 2) which may be used for a flow of coolant. If desired, ducts 19 may be formed in plates 12 to form communicating ducts, to convey coolant from channel 18 to ducts 29 formed in the interior of blades 11.

FIGURE 2 also shows an example of alternative construction for inner lugs 14 as a further safeguard against movement or distortion of 'the lugs 14 relative to each other. Flanges formed in their abutting faces may be secured together by a conventional dowel 21.

" FIGURE 1 also'shows an example of a bracket 22 by which the segment may be located and secured within the turbomachinery casing (not shown). The bracket 22 may be designed to prevent radial or other displacement relative to the rotor stages and the turbomachinery casing.

What I claim is:

l. A turbo machinery stator blade stage comprising: a plurality of blade segments each including at least one generally radial'blade and a plate which generally a'segment of an annulus on at least one end of said blade and said plate having a pair of axially opposed edges; and means for connecting said blade segments to form a stator blade stage, said means including inner and outer, radially spaced lugs on the axial edges of said plate, said outer lug being crank-shaped in cross-section and having a portion offset radially from said plate, the contiguous inner lugs of adjacent segments abutting each other and the contiguous outer lugs of adjacent segments being welded wherein said plates and said blades have communicating ducts formed therein and wherein said inner and outer lugs define between them a channel for the flow of fluid coolant conveyed to the interior of said blades through said communicating ducts. 5 3. The turbomachinery blade stage recited in claim 2, wherein said inner lugs include cooperating flanges formed in their abuttting faces for locating them in contiguous relationship with each other and means for securing said flanges against movement and distortion relative to each 10 other.

References Cited by the Examiner UNITED STATES PATENTS Hcppner 253-77 Bloomberg 253-77 Bodger 253-77 Sollinger 253-77 Greenwald 29-1568 Galliot 230-122 Wayne 25.3-39.15 Morley 253-78 Cutler 25.3-39.1 Klompas et a1 253-77 Hockert et a1. 253-77 Stark 253-3915 JOSEPH H. BRANSON, JR., Primary Examiner. 1,470,508 10 23 Steerstrup 253.47 15 WALTER BERLOWITZ, Emmi/wr- UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,182,955 May 11, 1965 John A. C. Hyde It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 36, for "ir" read or line 53, for "fiuid" read fluid column 2, line 24, for "criticial" read critical line 61, after "which" insert is Signed and sealed this 28th day of December 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents