US3032317A - Jet turbine bucket wheel - Google Patents

Description

R. G. FRANK JET TURBINE BUCKET WHEEL Filed Oct. 24, 1958 FIG 5 FIG. 9

INVENTOR. ROBERT G. FRANK M/u. Ma

7 FIG. 0

A TTO ENE 75 3,032,317 JET TURBHNE BUQKET WHEEL Robert G. Frank, Cincinna @hio, assignor to the United States of America as represented by the Secretary of 3,032,3l7 Patented May 1, 1962 FIG. 3 is a view similar to FIG. 1 but showing additional means for supplying air to the airfoil body of the bucket;

FIG. 4 is a view similar to FIG. 1 but showing a diftion;

FIG. 2 is a view similar to FIG. 1 but showing a different type of wheel structure;

the Fame 5 terent type of turbine wheel;

Filed Oct. 24, 1958, Ser. No. 759,524 FIG. 5 is a fragmentary sectional view showing a thin I Ciaim. (Cl. 253-47) solid Wheel;

FIG. 6 is a transverse sectional view of any of the tur- The present invention relates generally to buckets for bine buckets shown in FIGS. 1 to 5, inclusive; use in jet turbines and as illustrated herein relates more FIG. 7 is a view, in section, showing th wires u et particularly to turbine buckets of the type wherein air is and b d t th h b f .th arrangements Shown i circulated through the bucket for reducing the tempera- FIGS. 1, 2 and 3; ture thereof. FIG. 8 is a view, in section, showing a modification of l engines and the like, an axial flow turbine P- the wheel shown in FIG. 3 wherein the bucket wires are erated by exhaust gases is usually provided which drives upset d b d to h inner i a blower for furnishing air under pressure to the burners. FIG, 9 is a view, in section, showing the bucket wires These turbines operate at very high temperatures and it upset d b d to h outer i d is desirable to provide suitable means for reducing the FIG, 10 i a fra me ta y sectional i Showing the temperature a Point Where damage to turbine PaYts is bucket wires upset and brazed to the rim of the wheel reduced substantially. Shawn i F G, 4,

It hefetefofe, been P p to form aXial how The drawings show turbine wheel designs of diiferent turbine buckets With radial Passages the Passage of types. The wheels shown in FIGS. 1, 2 and 3 disclose a suitable cooling fltlid- Such hllekets, however, have the bucket forming wires attached to the hubs of the been expensive, heavy and difiicult to manufacture. One h l d i G 4 5, 7 9 and 10 the bucket fo object of the present invention is to provide an inexpensive i Wires are attached to the rim of the Wheel. bucket which is relatively light and easily manufactured. h design shown in HQ 1 shows the bucket f r i T s end and in accordance with one feature, the wires 10, attached to the hub 12 by upsetting and brazing invention contemplates new and imPIOVed turbine buckets the ends of the wires it} after they have been inserted in wherein high temperature, high strength 3 Wire such holes formed in the hub 12. Spacer rings 14 are brazed as molybdenum could be attached as an integral part to to the wires f rigidity and as a heat Seal at the plat either the hub or the rim of a turbine wheel in any suitform, AS Shown i FIG 2 a h d 13 may he brazed able manner. Sheaths formed from oxidation resistant to the i f the buckets m fo thg purpose of maintainmaterial are attached to the Wires to form the airfoil surihg the Shape th of Thin Solid disks 1 are Welded f The g Weight of this Construction Permits the to the hub 12 and spacer rings 14 for torque conversion. use of a substantially lighter wheel. As illustrated, the Thg hub 12 and the Spacer rings 1 are Suitably mhigh temperature, high strength alloy wires may be serated to permit i li cured to either the rim or the hub of the turbine wheel Th wires 10 are formed of high temperature, high inserting the ends 0f the Wires through Openings, P- strength alloy. The wire and other parts of the turbine setting the ends of the Wire and then brazing the Upset structure may be fabricated from molybdenum or plated ends to the Wheel- This Provides not y an effective with an oxidation resistant material. Other high temmethod of anchoring the blades to the Wheel but properature high strength alloys may he used, Wires 10 vides also a blade which is hollow and thus may readily preferably are formed from molybdenum or a molybbe cooled. This enables the elimination of many of the denum alloy which is sufficiently ductile to be drawn. problems associted with separate turbine components and Sheet metal and other shaped, cast or molded parts may permits operation at exhaust gas temperatures as high be formed from other suitable alloys. as 2600 F, Suitable alloys include the following:

Carbon Manganese Silicon Chromium Nickel Cobalt Molyb- Tung- Colum- (O) (1 11 (Si) (Cr) (Ni) (Co) denum sten bium (M0) (W) 0.26 0.52 0.57 18.95 9.05 1.22 1.10 0. 29 0.11 0.60 0.42 18.87 8.63 0.40 1.36 0. 28 0.15 0.60 0.70 15.0 30.0 Timken:

16-25-6 0.08 1.35 0.69 16.72 25. 23 6.26 S495 0.41 0.68 0.34 13.92 19.71 4.28 N-155 0.14 1. 48 0.52 21.3 20.0 20.0 3.06 N-155- 0.32 1.54 0.59 21.08 20.80 20.54 3.0 S8l6 0. 30 0.72 0.19 18. 40 20. 23 45.63 4. 23 HastelloyB 0.05 0.59 0.19 65.1 28.63 Haynes (cast) Stellite No. 2L. 0.20 27. 51 Balance 5.63 Haynes Stellite No.30 422-19) 0. 40 0. 30 0. 51 24.75 15.92 Balance 6.08 Haynes Ste1liteNo.31(X-40)- 0.48 0. 64 0. 72 25.12 9. 69 55.23

With the above and other objects and features in view It is to be noted that the wire receiving openings are the invention will now be described with particular refarranged to form an airfoil surface of a type usual in erence to the accompanying drawings in which; turbine buckets for jet engines. The airfoil section of a FIG. 1 is a schematic View, partly in section, of a turturbine bucket 25 depicted in FIG. 6, shows clearly the bine bucket constructed according to the present invenspacing and positioning of the wires 10. It is evident that 70 closely spaced wires 10 form a relatively stiif shape about which a sheath 22 is wrapped. The inner surface of the sheath 2?. and the wires 10 are coated with a suitable brazing alloy and, after assembly, the sheath 22 and the wires 10 are welded together by any usual method. The outer surface of sheet 22 may be coated with an erosion and corrosion resistant material.

The construction shown in FIG. 3 is similar to that shown in FIG. 1 except that the sheath 22 of the bucket 20 shown in FIG. 3 extends down to the inner rings 14. In this construction the sheath 22 between the rings 14 could be formed of a lower temperature alloy material since it is not directly subjected to high temperatures to which the outer end portion of the sheath is subjected.

The wheel shown in FIG. 4 comprises a wheel fabricated from high strength alloy wire forming spokes 23 similar to a bicycle wheel fixed to the hub 12 and to the outer rim 30. The spokes 28 are covered by disks 32 which are also suitably fixed to the hub 12 and an inner ring 34.

The construction shown in FIG. 5 illustrates a solid forged wheel 38 on which are mounted turbine buckets similar to the ones shown in FIG. 4 and FIG. 10.

In FIGS. 7 to 10, inclusive, are disclosed various types of blade bases or supports to which the wires are secured. The construction shown in FIG. 7 is substantially the same as the embodiment shown in FIG. 1 wherein the wires 10 are secured to the hub 12. FIG. 8 shows a construction similar to that shown in FIG. 2, but wherein the wires 10 are secured to the inner ring 114 instead of to the hub 12. The construction shown in FIG. 9 is similar to that shown in FIG. 8 except that the ends of the wires 10 are secured to the outer ring 14. The FIG. 10 construction is substantially identical to that shown in FIG. 4 wherein the wires 10 are secured directly to the rim 39.

Regardless of how the wires 11) are secured to the blade base or supporting structure the procedure followed in forming the sheath 24} about the blade is substantially the same. Brazing alloy may be applied directly to the wires by dipping, flame spraying or other suitable means as hereinbefore stated.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

A turbine bucket arrangement for jet engines comprising a bucket of airfoil cross section and a support References Cited in the file of this patent UNITED STATES PATENTS 2,189,785 Fahrney Feb. 13, 1940 2,369,795 Planiol Feb. 20, 1945 2,780,435 Jackson Feb. 5, 1957 2,783,967 Scharf Mar. 5, 1957 2,866,618 Jackson Dec. 30, 1958,

FOREIGN PATENTS 235,304 Great Britain June 12, 1925 715,421 Germany Dec. 20, 1941 722.341 Great Britain Jan. 26. 1955

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