US2960305A - Fluid turning blades - Google Patents

Description

Nov. 15, 1960 E. A. STALKER 2,960,305

FLUID TURNING BLADES Original Filed Aug. 3, 1950 v 8 I .2 E15. 9 ulvu/flIINVENTOR.

F g 10 fl y/[ United States Patent FLUID TURNING BLADES Edward A. Stalker, Bay City, Mich., assignor to The Stalker Corporation, a corporation of Michigan Original application Aug. 3, 1950, Ser. No. 177,479,

now Patent No. 2,772,855, dated Dec. 4, 1956. Divided and this application Feb. 25, 1953, Ser. No.

Claims. (Cl. 253-39) "ice 2 a very important point since machining operations to produce faired surfaces at the leading and trailing edges are very expensive.

For succinctness in the claims I refer to one of the parts as a base part or wall. Either part may be regarded as a base part which carries the other or mating part. I also refer to the juxtaposed blade parts as complementary or mating parts. The front portions of either wall, especially the portions which are curved, are called nose portions.

The blade parts 14 are preferably stamped from a carrier strip of metal 40 inwardly of the strip leaving continuous margins along both longitudinal edges thereof. The blade parts are held integral with the marginal port-ions of the strip at both ends of the blade parts as shown in Fig. 5 by the small necks of metal 42 at each end of the blade parts which as shown in Fig. 5 are Still another object is to provide a blade formed from she'et metal which requires a minimum of finishing at it's joints.

- Other objects will appear from the description, drawings and claims.

In the drawing: Fig. 1 shows a blade in planform according to the present invention;

Fig.2 is a section along line 2-2 in Fig. l

Fig. 3 is a section of a blade part before being given 7 the airfoil contour;

Fig. 4 is a section of the blade upper part; Fig. 5 shows in plan form a gang of blade parts partly pressed to shape;

separated in the spanwise direction of the blade and located in areas intermediate the leading and trailing edges of the blade, thus constituting a gang or set of blade parts. The strip may be of any length and contain any number of blade parts.

In the next operation as shown in Fig. 6 the leading edge portion '24 is bent to the position shown in Fig. 2 and the general curvature in the chordwise direction is impressed on the part 14 as shown in the latter figure.

- Fig. 6 is a side elevation of a portion of the gang of Fig. 5;

Fig. 7 is a side elevation of a portion of the gang of blade upper parts;

Fig. 8 shows the upper gang superimposed on the lower gang 30 and supported on a fixture;

Fig. 9 is a plan view of an individual blade lower part;

and

Fig. 10 shows a gang of blade upper parts and individual blade lower parts placed in mating relation thereon rial No. 177,479, filed August 3, 1950, now Patent No. 2,772,855.

As shown particularly in Fig. 2 the blade 10 is formed in two parts, the upper part 12 and the lower part 14. The latter has the groove or recess 16 near the trailing edge into which the upper part nests to form the joint 18. The groove is just deep enough that the upper surface of the blade is fair across the joint 18.

At the leading edge there is the groove or recess 22 forming a portion of reduced thickness so that the narrow outer part 24 beyond the groove can be bent about the recess into the position shown in Figs. 2 and 6 with a. very small nose radius 26.

The lower blade part 14 with the grooves 16 and 22 is shown in Fig. 3 before the part is bent to the shape shown in Fig. 2.

The grooves 16 and 22 and the tapered parts 24 and 28 are preferably stamped or rolled to shape.

The upper blade part 12 has the groove 30 forming a contoured edge as shown in Figs. 2 and 4 into which the portion 24 fits.

It will be observed that both upper and lower parts can be rolled or pressed or milled and that when the two parts are assembled there are no further operations required to form the leading and trailing edges. This is The blade part is twisted at the neck 42 to an angle of about 45 relative to the plane of the strip at its margins 46 and 48 which remain continuous. The upper blade parts 12 are formed in a strip 50 in a manner similar to that of the lower parts 14. Suitable lengths of the two strips are imposed one on the other in overlying relation as shown in Fig. 8 and located by the pins 54 (of fixture 51) passing through the holes 52 in the strips 40 and 50 which thus form means formdexing the strips relative to each other. The complementary parts to form a blade are thus brought into registration or mating relation. The juxtaposed strips 40 and 50 held in place by the pins 54 on the fixture 51 are passed through a brazing furnace to braze the joints at the leading and trailing edges of each blade assembly. The brazing material may be inserted or painted on the parts at the joints just before the blade parts are brought into mating relation.

After removal firom the furnace the blade necks 42 may be sawed through to free the blades from the strips.

This application is a division of parent application Se- The blades are particularly adapted for stator blades in axial flow compressors and turbines where they may be inserted in suitable rings at either or both ends.

Instead of both upper and lower blade parts being carried in strips, just one strip of blade parts may be used and the mating parts may be individually made and placed in mating relation on the other part. Such an individual piece is shown in Fig. 9 as 14. Fig. 10 shows it placed on blade part 12.

The end portions 24 and 28 arer eferred to as being outside or outwardly of the grooves 22 and 16 respectively.

Although the carriers are shown in the figures as being straight, they may also be arcuaite or any other shape.

While I have illustrated a specific form of this invention it is to be understood that I do not intend to limit myself to this exact form but intend to claim my invention broadly as indicated by the appended claims.

I claim:

1. A hollow axial flow blade structure for compressors, turbines and the like comprising a continuous sheet metal carrier strip having longitudinal side edges, said strip having a series of spaced blade parts formed therein inwardly of said edges leaving continuous integral margins along both said edges thereof separated in the spanwise direction of the blades, said blade parts being 3 curved chordwise thereof to form the contour of one face of the blade and having leading and trailing edges, in tegral necks at each end of the blade parts joining said blade pants with said carrier strip along both of said mar! gins in areas intermediate said leading and-trailing .edges, and mating blade parts having the contour of the other face of the blade, said mating blade parts each over1ying and mating with one of said series of blade parts in assembled relation to form a continuous series of streanr line axial flow hollow blades having sharp trailing edges.

2. A hollow axial flow blade structurefor compressors, turbines and the like comprising a first continuous sheet metal carrier strip having longitudinal side edges, said strip having a series of spaced blade parts formed therein inwardly of said edges leaving continuous integral margins along both said edges thereof, said blade parts having the curved contour chordwise thereof of one face of the blade and having leading and trailing edges, integral necks at each end of the blade parts joining said blade parts with said carrier strip along both of said margins in areas intermediate said leading and trailing edges, 3. second continuous sheet metal carrier strip having a second series of mating blade parts formed therein each having the contour of the other face of said blade, said second series of blade parts each overlying and-mating with one of said first series of blade parts in assembled relation to form a series of streamline axial flow hollow blades having sharp trailing edges.

3. A hollow axial flow blade structure for compressors, turbines and the like comprising a'first continuous sheet metal carrier strip having longitudinal side edges, said strip having a series of spaced blade parts formed therein inwardly of said edges leaving continuous integral margins along both said edges thereof, said blade parts having the curved contour chordwise thereof of one face of the blade and having leading and trailing edges, integral necks at each end of said blade parts joining said turbines and the like comprising a first continuous sheet metal carrier strip having longitudinal side edges, said strip having a series of spaced blade parts formed therein inwardly of said edges leaving continuous margins along both said edges thereof, said blade parts having the curved contour of one face of the blade and having leading and trailing edges, integral necks joining said blade parts with said carrier strip along both of said margins in areas intermediate said leading and trailing edges, a second continuous sheet metal carrier strip having a second series of mating blade parts formed therein each having the contour of the other face of said blade, said second series of blade parts each overlying and mating with one of said first series of blade parts in assembled relation to form a series of streamline axial flow hollow blades having sharp trailing edges, and means on said strips for indexing the same relative to each other to establish proper mating relation.

5. A hollow axial flow blade structure for compressors, turbines and the like comprising a first continuous sheet metal carrier strip having longitudinal side edges, said strip having a series of spaced blade parts formed therein inwardly of said edges leaving continuous margins along both said edges thereof, said blade parts having the curved contour of one face of the blade and having leading and trailing edges, integral necks joining said blade parts with said carrier strip along both said margins in areas intermediate said leading and trailing edges, a second continuous sheet metal carrier strip having longitudinal side edges and a second series of mating blade parts formed therein inwardly of said edges leaving continuous margins along both said edges thereof, said mating blade parts having the contour of the other face of blade parts with said carrier strip along both said margins in areas intermediate said leading and trailing edges, a second continuous sheet metal carrier strip having longitudina-l side edges and a second series of mating blade parts formed therein inwardly of said edges leaving continuous margins along both longitudinal edges thereof, said mating blade parts having the contour of the other face of the blade, said first and second carrier strips being assembled in contact with each other such that each of said first series of blade parts is in overlying and mating relation with one of said second series of blade parts to form a continuous series of streamline axial flow hollow blades having sharp trailing edges.

4. A hollow axial flow blade structure for compressors,

theblade, said-first and second carrier strips being assembled in contact with each other such that corresponding margins of said respectivestrips are'in directmating relation with each other and each of said first series of blade parts is in overlying and mating relation with one of said second series of bladeparts to form a continuous series of streamline axial flow hollow blades having sharp trailing edges.

References Cited in the file of this patent UNITED STATES PATENTS 863,428 Nikonow Aug. 13, 1907 1,829,179 Back Oct. 27, 1931 2,428,728 Watson Oct. 7, 1947 2,432,185 Watson Dec. 9, 1947 2,514,525 Stulen July 11, 1950 2,604,298 Bachle July 22, 1952 2,649,278 Stalker Aug. 18, 1953

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