US2641040A - Means for cooling turbine blades by air - Google Patents

Description

J1me 1953 R. H. GODDARD 2,641,040

MEANS FOR COOLING TURBINE BLADES BY AIR Filed Ja'n. 2, 1948 j- 24 jozfcfllfl. emammwa. Btfiez G. Goddazd, wom 'x.

- ATTORNEY INVENTOR.

Patented June 9, 1953 UNITEDL F"STATES PATENT OFFICE" MEANS FOR cootifi fioncmanmnus Robert H. Goddard, deceased; late of Annapolis,

Md., by Esther C. Goddard, ei'recutrix, Worcester, Mass, assignor of one-half to The Daniel and Florence Guggenheim Foundation, New York, N. Y., a corporation of New York Application January 2, 1948, Serial No. 75

1 Claim. 1

This invention relates to turbin blades which are exposed to high temperatures, as in certain types of rocket apparatus Where turbines are operated by blasts of combustion gases.

It is the general object of this invention to provide improved means for cooling such turbine blades by making the blades hollow and by causing a stream of air to flow outward therethrough.

A further object is to provide an air-collecting guide for each blade by which substantial outward air ilow through each hollow blade is assured. Specific provision is also made for exposing an increased area of metal surface to the air stream in each blade.

The invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claim.

A preferred form of the invention is shown in the drawings, in which Fig. 1 is a partial front elevation of a turbine rotor having an annular series of turbine blades mounted thereon;

Fig. 2 is a detail perspective view of one of the blades, together with portions of associated shroud rings;

Fig. 3 is a bottom view, looking in the direction of the arrow 3 in Fig. 1;

Fig. 4 is a sectional side elevation of one of the turbine blades and its associated air-collecting guide; and

Fig. 5 is a sectional perspective view of one of the hollow blades.

Referring to Fig. 1, a portion of a turbine rotor is shown, comprising a propeller l0 mounted on a shaft H. The outer ends of the propeller blades l2 are secured to and support an inner shroud ring I4. A plurality of turbine blades B have their inner ends secured in the shroud ring l4 and have their outer ends similarly secured in an outer shroud ring 16. A blast of combustion gases at high temperature is delivered against the blade B from a nozzle N which may be associated with a combustion chamber C.

Each blade B is hollow or tubular and has an air passage 20 extending lengthwise therethrough and freely open through the shroud rings at both ends.

Lengthwise partitions 22 in each blade B act to reenforce the blades. preferably metallic and are welded or otherwise secured to the side walls of the blade B in such manner that they provide additional metallic surface area from which heat may be transferred to the air stream.

These partitions are r An air-collecting guide is associated with each blade B and is mounted within the inner shroud ring [4 adjacent to said blade, as clearly shown in Figs. 3 and 4. These air-collecting guides are curved oppositely to the direction of rotation and with their ends or wings projecting forward. They are thus well adapted to direct a substantial flow of air radially outward through each blade as indicated by the arrows in Fig. 4.

As the air channels 32 in each blade B are reduced in cross section near the narrow edges of the blade, the width of each air-collecting guide 30 is increased near its outer and forward edges as indicated at 30a, so that relatively more air will be directed into and through the end channels 32a, thus equalizing the cooling effect over the entire blade.

With this construction, a substantial flow of air is developed through each turbine blade and the blades are thus sufficiently cooled to withstand the high temperature of the combustion gases by which the turbine is rotated.

Having thus described the invention and the advantages thereof, it will be understood that the invention is not to be limited to the details herein disclosed, otherwise than as set forth in the claim, but what is claimed is:

A turbine rotor comprising inner and outer shroud rings, and a plurality of hollow turbine blades which are crescent-shaped in cross section and which are mounted between said rings and freely open at both ends through said rings, and each blade having a separate air guide associated with said blade and defining an air passage along which substantial air stream is directed radially outward through said blade, each air guide comprising a separate air-collecting and air-directing member mounted radiallyinward with respect to said inner shroud ring and secured to the inner face of said shroud ring and entirely supported thereby, each air-directing guide over-hanging the inner open end of its associated blade in the direction of rotation and having end portions extending forwardly in said direction, and the air passage in each air-directing guide increasing in width circumferentially of said rotor from the middle diametral plane of said rotor toward each side edge of the supporting inner shroud ring and thereby equalizing the air flow in the associated crescent-shaped blade.

ESTHER C. GODDARD, Executrzzc of the last will and testament of Robert H. Goddard, deceased.

(References on following page) 3 References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Lorenzen Sept. 28, 1926 Lorenzen Feb. 19, 1929 Schaper Sept. 26, 1933 Goddard Oct. 10, 1933 Gordon May 29, 1934 Darrieus Mar. '7, 1939 Allen Mar. 11, 1941 Hageman Mar. 18, 1947 Bloomberg Apr. 20, 1948 Number 4 FOREIGN PATENTS Country Date Great Britain Dec. 18, 1930 Germany Nov. 8, 1922 Great Britain Mar. 3, 1932 Great Britain 1936 Germany Feb. 12, 1930 Germany Mar. 23, 1924 Great Britain Apr. 19, 1950

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