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Publication numberUS2501038 A
Publication typeGrant
Publication dateMar 21, 1950
Filing dateMar 29, 1947
Priority dateMar 29, 1947
Publication numberUS 2501038 A, US 2501038A, US-A-2501038, US2501038 A, US2501038A
InventorsKarl E Fransson
Original AssigneeUnited Aircraft Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Mounting for hollow turbine blades
US 2501038 A
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Description  (OCR text may contain errors)

March 21, 1950 K. E. FRANSSON MOUNTING FOR HOLLOW TURBINE BLADES Filed March 29, 1947 m ay/Z INVENTOR la 1/ 4" It. I vzzz s14 41 ad I ATTORNEY Patented Mar. 21, 1950 UNITED STATES PATENT OFFICE MOUNTING FOR HOLLOW TURBINE BLADES Application March 29, 1941, Serial No. 738,023

Claims. (Cl. 253-77) This invention relates to an arrangement for mounting a hollow turbine blade on a turbine rotor. In the co-pending application of Buck, Serial No. 738,062, filed March 29, 1947, the turbine blade is positioned over a supporting post and is welded to the post at a point between its ends with the blade otherwise free from connection to the post. A feature of this application is an arrangement for mounting the hollow blade over a supporting post so that it will be free to expand radially with respect to the post but is supported against axial movement at spaced points. Another feature is an arrangement for positioning the turbine blade on the supporting post in such a manner that the loads on the blade, when the turbine is operating, will be compressive loads rather than tensile loads.

A feature of the invention is an arrangement of the rotor such that the blade-supporting post with the blade mounted thereon may be attached to the rotor without the necessity for mounting the blades on the posts while the latter are on the remainder of the rotor. Another feature is an arrangement for coolingthe posts to retain the necessary strength on the post in spite of the high temperature of the gas flowing over the blade.

Other objects and advantages will be apparent from the specification and claims and from the accompanying drawings which illustrate an embodiment of the invention.

Fig. l is a sectional view through a turbine rotor showing the blade mounting.

Fig. 2 is a sectional view along the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary sectional view similar to Fig. 1, showing a modification.

As shown in Figs. 1 and 2, the turbine rotor which may be a single or multistage axial flow turbine rotor, may be so constructed that each stage consists of a pair of discs 6 having lateral grooves 8 therein facing each other and in a position to engage with the root ID of the post I! which supports the hollow blade [4. The blade H which may be substantially airfoil shape in cross-section, as shown in Fig. 2, has a substantially uniform wall thickness to assure uniform heating and cooling of the blade. In the arrangement shown, the blade is fastened, as by a weld IE, to the outer end of the post I2 so that during rotation of the turbine rotor, the blade will be loaded substantially in compression as a result of the centrifugal forces acting on the blade. AdJacent the inner end of the blade, the post l2 carries a laterally projecting flange I8 2 which pilots the blade, holding it in predetermined relation to the post without interfering with free radial movement of the blade to accommodate thermal expansion. The blade Il may have a projecting rib l9 adjacent the flange I8, the elements of the inner surface of which are radial for engagement with the periphery of the flange regardless of relative thermal expansions.

Since the blade is loaded in compression, it will be apparent that it can withstand extremely high temperatures before failure; and since it is arranged so that it is out of contact with the post except at the weld l6, thereby providing an air space 20 surrounding the post, the latter is kept at a much cooler temperature than the blade itself. In addition, the blade may be cooled by providing a central passage 22 within the post which may be filled with sodium 23 or other material of high conductivity which preferably will be a liquid at the normal operating temperatures of the turbine. To increase the rate of heat transfer from the post l2 which carries the load of the blade, the space between the discs 6 may be supplied with a blast of cooling air which will engage the inner surfaces of the roots of the posts.

With reference to Fig. 3, the post 26, comparable to the post l2, has in this arrangement a flange 28 adjacent its inner end which engages with a cooperating inwardly extending flange 30 on the blade 32 to support the blade against radial outward movement and thereby maintain the blade in predetermined relation to the post. At the outer end of the post, the blade 32 is supported by a ring 34 integral with the post which guides the blade in such a manner as to maintain its predetermined relation to the axis of the post but to permit radial movement of the outer end of the blade. The outer end of the blade may have an inwardly projecting rib 38 with the elements of its inner surface radial to assure contact between the ring 34 and the blade regardless of relative thermal expansions. In this arrangement the blade is spaced from the post except at its points of attachment to form an insulating air space 36.

It is to be understood that. the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as defined by the following claims.

I claim:

1. A turbine rotor having a number of radiallyextending blade-supporting posts and a hollow blade positioned o er each post, each blade havin: means for attaching it directly to the post at only one radial point, and means for piloting the blade on said post at another radial point spaced from the point of attachment, said blade being otherwise spaced from said post by an airchamber completely surrounding said post.

2. A turbine rotor having a number 01 radiallyextending blade-supporting posts and a hollow blade positioned over each post, each blade having means for attaching it directly to the post at only one radial point, and means for piloting the blade on said post adjacent its inner end, said blade being otherwise spaced from said post by an airchamber completely surrounding said post.

3. A turbine rotor having a number of radiallyextending blade-supporting posts and a hollow blade positioned over each post, each blade having means for attaching it directly to the post at only one radial point, and means for piloting the blade on said post adjacent the outer end thereby providing for free radial expansion of the blade with regard to the post, said blade being otherwise spaced from airchamber completely surrounding said post.

4. A turbine rotor having a number of radiallyextending blade-supporting posts all in substantially the same plane, and a hollow blade positioned over each post, said blade having walls of substantially uniform thickness throughout and being substantially airfoil shape in cross-section, each blade having means for attaching it disaid post by an rectly to the post at only one radial point, and

means for piloting the blade for radial movement on said post at another radial point spaced from the point of attachment, said blade being otherwise spaced from said post by an airchamber completely surrounding said post.

5. In a turbine rotor, a disk, a number 01 radially-extending blade-supporting posts having pieces positioned and held by said disk, and hollow blade elements mounted over each post, each of said blade elements having a relatively thin wall of substantially uniform thickness, each of said blade elements being directly attached to a post adjacent one end, and means on the post adjacent the other end of the blade element for guiding the blade element on the post without restricting radial movement of the blade relative to the post, said blade being otherwise spaced from said post by an airchamber completely surrounding said post.

KARL E. FRANSSON.

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

UNITED STATES PATENTS Number Name Date 1,362,853 Darling Dec. 21, 1920 1,657,192 Belluzzo Jan. 24, 1928 1,966,104 Noack July 10, 1934 2,256,479 Holzwarth Sept. 23, 1941

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1362853 *Mar 4, 1919Dec 21, 1920Electric Service Supplies CoTurbine-wheel and bucket-mounting
US1657192 *Mar 12, 1924Jan 24, 1928Belluzzo GiuseppeWheel for internal-combustion turbines
US1966104 *Jan 18, 1932Jul 10, 1934Bbc Brown Boveri & CieTurbine rotor construction
US2256479 *Mar 17, 1939Sep 23, 1941Holzwarth Gas Turbine CoBlade for rotary machines operated by high temperature media
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2696364 *Jul 8, 1948Dec 7, 1954Thompson Prod IncTurbine bucket
US2708564 *Feb 29, 1952May 17, 1955Westinghouse Electric CorpTurbine apparatus
US2744723 *Dec 6, 1949May 8, 1956Thompson Prod IncControlled temperature fluid flow directing member
US2772851 *Jun 14, 1950Dec 4, 1956Stalker Dev CompanyRotor construction
US2772852 *Aug 3, 1950Dec 4, 1956Stalker Dev CompanyRotor construction for fluid machines
US2774566 *Dec 12, 1947Dec 18, 1956Richardson Edward AdamsFluid cooled permeable turbine blade
US2786646 *Jul 10, 1950Mar 26, 1957Power Jets Res & Dev LtdBladed rotors for axial flow turbines and similarly bladed fluid flow machines
US2802619 *Sep 16, 1950Aug 13, 1957Stalker Dev CompanyAxial flow rotors for fluid machines
US2839268 *Jan 18, 1950Jun 17, 1958Allis Chalmers Mfg CoGas turbine
US2858102 *Sep 3, 1954Oct 28, 1958Gen ElectricTurbomachine wheels and methods of making the same
US2866616 *Mar 2, 1951Dec 30, 1958Stalker Dev CompanyFabricated bladed structures for axial flow machines
US2891719 *Mar 2, 1951Jun 23, 1959Stalker CorpFabricated axial flow bladed structures
US3055633 *Apr 14, 1958Sep 25, 1962Robert PouitHot gas turbines
US3059901 *Apr 1, 1958Oct 23, 1962Carrier CorpRotor construction
US3314649 *Apr 15, 1963Apr 18, 1967Gen ElectricTurbomachine cooling system
US3314650 *Jul 20, 1965Apr 18, 1967Gen Motors CorpCooled blade
US3330474 *Dec 8, 1965Jul 11, 1967Lister & Co Ltd R AAxial-flow blowers
US4473336 *Sep 14, 1982Sep 25, 1984Rolls-Royce LimitedTurbine blades
US4854374 *Feb 2, 1988Aug 8, 1989Frank HarrisonTemperature controlling apparatus
US4879880 *Jan 17, 1989Nov 14, 1989Frank HarrisonAir temperature regulator
Classifications
U.S. Classification416/95, 416/214.00R, 415/114, 416/96.00R, 416/233, 416/214.00A
International ClassificationF01D5/18, F01D5/30
Cooperative ClassificationF01D5/3069, F01D5/3084, F01D5/30, Y02T50/676, F01D5/181
European ClassificationF01D5/18B, F01D5/30K, F01D5/30, F01D5/30G