DE2413292A1 - SHEET COOL INSERT HOLDER FOR TURBO MACHINERY - Google Patents

Description

Dr. rer. nest. Horst pupil

PATENT ADVOCATE

Frankfurt / Main 1, l8. March

Niddastraße 52 Vo. / hey

Telephone (0611) 237220 Telex: 04-16759 mapat d Postal check account: 282420-602 Frankfurt / M Bank account: 225/0389 Deutsche Bank AG, Frankfurt / M.

2668-13DV-6OO4

General Electric Company

1 River Road Schenectady, N.Y./U.S.A.

Leaf cooler insert holder for turbo machines

The invention relates generally to gas turbine engines and, more particularly, to an improved fluid-cooled engine Turbomachine blade structure for use in high temperature gas turbines.

In known attempts, a blade insert in its position to hold, an enlarged splash was provided on the foot

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of the insert was formed integrally therewith, and further provided a stress-bearing surface on which the splash should rest. Such a structure is described in US Pat. No. 3,715,170. Inserts with such a load-bearing Flanges have proven extremely successful, but in many applications there is no such splash practically. For example, due to the increase in the top speed of newer turbine rotors the blade must be made as light as possible to match the size and weight of the Keep slice to a minimum. One method, sheet weight Keeping it small is to make the wing walls as thin as possible. When designing such a sheet a minimum practical wall thickness is chosen for the tip portion of the blade, but the wing wall thickness must be increased with Approach to the blade platform can be enlarged to accommodate the increasing load on the wing. This centrifugal load and the radial temperature gradient of the wing cooperate to produce sheets with walls that are thicker than the Tip is constant up to a point above the pitch line, then up to a short distance below of the pitch circle increases in thickness and then to the root section of the wing remains essentially constant in thickness. With these changes in wall thickness, the size also changes of the inner cavity formed by the hollow body part of the sheet, a sheet as described above bottle-shaped cavity, the largest opening of which is close to the Blade tip lies.

As is well known, it is highly desirable to have a constant margin to form between the loading inserts and the inner wall of the sheet. It would be virtually impossible to have a baffle from the root end of the blade to install when such a specified clearance between the baffle and this bottle-shaped Cavity would have to be maintained. Support approaches,

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which are arranged on the outside of the inserts further impede the assembly. To further complicate matters, ■ many wing sections are twisted or wound. Since the loading operations cannot be installed from the root end of the wings, they must necessarily be installed from the tip end and this makes it practically impossible to use an insert that has an enlarged, Has load-bearing flange.

Attempts have also been made in the past that Bottle-like inserts with pins to fix in place, but the base wall thickness of 0.25 to 0.5 mm (0.010 to 0.020 Inches) provides insufficient strength to withstand the stresses placed on the pins due to centrifugal force which is exerted on the blade and the insert during normal operation of the gas turbine. One Another alternative is to bet directly on the To solder or weld blade part, but the arrangement of the soldered connection in an area of limited accessibility makes it difficult to properly apply the solder and the connection to inspect.

Accordingly, an object underlying the invention is to provide a device for the mechanical attachment of a cooling To create use in a turbine blade, which avoids the problems described above that occur in the known Facilities occur. It is also an object to provide a secure mechanical fastening device of the type described above To create a type that does not significantly interfere with the coolant flow »is easy to assemble and has a coolant ' leakage essentially eliminated.

Briefly, these tasks are carried out according to the invention by a Insert released, which has an opening that is drilled or machined through its two sides near the lower end of the insert

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is punching. A bushing in the manner of a grommet is arranged in the openings and on both sides of the insert attached. Then a hole is drilled through the bushing and the insert is pushed into the interior of the blade until the hole is made in the socket coincides with suitable holes in the stem part of the blade. Then a pen is in alignment Holes inserted and around each end of the pin and the insert base a solder alloy is placed around the ends of the To fuse or seal the pin and the insert base and to hold the pin in place. The socket is with Splash about the same thickness as the thickness of the walls of the insert to ensure optimal welding.

The invention will now be based on further features and advantages explained in more detail in the following description and the drawings of various exemplary embodiments.

Figure 1 is a partial cross-sectional view and shows schematically an embodiment of the insert retaining means according to the invention.

Figure 2 is a cross-sectional view after cutting along the line 2 - 2 in Figure 1.

FIG. 3 is a cross-sectional view after a section taken along line 3-3 in FIG.

FIG. 4 is an enlarged partial cross-sectional view and shows details of a section from FIG.

Figure 5 is a partial cross-sectional view of an alternative support means.

Figure 6 is a cross-sectional view after a section along the line 6-6 in Figure 5.
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Figure 7 is an axial cross-sectional view of a second alternative support means.

Figure 8 is a cross-sectional view after a section taken along line 8-8 in Figure 7 with some parts omitted. _O

Figure 9 is a partial sectional view similar to Figure 5 of one further alternative embodiment.

Figure 10 is a sectional view after a section taken along line 10-10 in Figure 9 with some parts omitted are.

In the various figures, the same reference numbers correspond to the same elements. Figures 1 to 4 will be discussed first, in which a turbomachine blade with the insert holder device is shown according to the invention, which is provided with the reference numeral 10 as a whole. The sheet 10 contains a root portion 12 having a pair of shafts 14 which can be attached in a dovetail slot (not shown) leading to a guest turbine rotor disc (not shown) belong. Furthermore, the blade 10 includes a wing-shaped, hollow body portion 16, which is supported by a blade platform 18 of the root section 12 is separated.

The wing-shaped, hollow body portion 16 has a leading edge 20 and a trailing edge 22 and two wing-shaped or streamlined Side walls 24 and 26 which extend therebetween and which are suitably shaped and adapted to an overflowing Work equipment to withdraw energy. The side walls and 26 together form an inner cavity 28, which in the present Case is divided into two separate sections, namely a cavity 30 at the leading edge and one Cavity 32 at the trailing edge. This separation takes place through

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a rib portion 34 integral with the hollow body portion 16 is formed and runs between the side walls 24 and 26 .

As can be seen particularly clearly from FIG. 2, the thickness of the side walls 24 and 26 changes from a relatively thin cross-section near the tip of the hollow body part 16 to a thicker cross-section near the blade platform 18. Due to the As the thickness changes, the chamber 30 at the leading edge and the cavity 32 at the trailing edge are bottle-shaped Cavities that are wider near the tip end of the hollow body part 16 than near the base platform 18.

As further shown in Figures 1 and 2, there is a loading insert 36 of thin sheet metal arranged within the cavity 30 at the leading edge, while a similar Acting attachment 38 in the cavity 32 on the outflowing Edge is arranged. Each of the inserts 36 and 38 is available as a thin walled jacket is shown, the side walls 40 and 42 of which generally coincide with the sheet side walls 24 and 26. the Side walls 40 and 42 are provided with a plurality of nozzles or openings 44 which are defined by suitable spacers 46 in the Distance to the inner surfaces of the cavities 30 and 32 are arranged. As best seen in FIG. 2, the inserts 36 are and 38 closed at one end 48 and form therein a chamber 50, which at the end 52 for receiving a flowing coolant is open.

To direct the flow of coolant into the chambers 50 are suitable Flow channels 54 in the root section 12 of the leaf 10 intended. Furthermore, the open or lower ends 52 of the inserts 36 and 38 are sized so that they are in sealing engagement come with side walls 56 that are near the top of the channel means 54 are arranged. As will be described in more detail below, the connection between the base end 52 and

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the side edges 56 are filled with a solder alloy to to seal or fuse this connection further. In this way, a coolant is supplied through the channels 54 is, on the chamber .50 and thus on the numerous openings or nozzles 44 and cannot directly around the open ends 52 of the inserts 36 and 38 into the cavities 30 and 32 stream. In the flow through the openings 44, the coolant hits directly onto the insides of the leading edge 20 and the side walls 24 and 26 of the sheet 10, thereby turning these walls into known Way to cool. The coolant in the cavity 30 at the front edge then passes through openings 60 (from the one shown in FIG one is shown) provided in a tip cap 62, polygons, the outer end of the cavities 30 and 32, and through Film openings (not shown) in the hollow body part 16 therethrough. The coolant in the one on the downstream edge Chamber 32 passes through openings in the tip cap and through. slots 64 provided on the trailing edge therethrough which are arranged in the trailing edge 22 of the sheet 10.

In FIGS. 1 to 4, means are shown for mechanically fastening the inserts 36 and 38 in the position shown in FIG. The means for mechanically fastening the inserts in their position are generally provided with the reference numeral 66 and comprise a bushing 68 in the manner of a bushing, which is arranged in openings 70 and 72, which are located in the side walls 40 and 42 of the inserts 36 and 38 are located. Since the means for mechanically fastening the inserts 36 and 38 are essentially are identical, only the structure associated with insert 36 is described.

As best seen in Figures 3 and 4, the bushing 68 includes a pair of thin flanges 74 and 76 which are secured by a Inner core 78 are connected to one another. The flanges 74 and 76

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are dimensioned so that their shape corresponds to that of the openings 70 and 72 associated with side walls 40 and 42. In the embodiment shown in Figures 1 to 4 have openings 70 and 72 have a generally circular configuration, although other configurations may be suitable, Furthermore, as can be clearly seen from FIG. 3, the flanges 74 and 76 are of approximately the same thickness as the thickness of the Sidewalls 40 and 42 so as to provide a configuration suitable for optimal welding. Additionally the openings 70 and 72 provide a much larger circumference than that of the inner core 78 in order for a large To ensure welding surface, which further strengthens the strength of the weld.

As can best be seen from FIGS. 3 and 4, the inner core 78 is provided with two flat areas 80 and 82 which run parallel to the side walls 56 of the channels 54 when the flanges 74 and Io are arranged in the openings 70 and 72 . In this manner, the flat surfaces 80 and 82 allow the proper volume of air to flow through the open end 52 and into the chamber 50 of the insert 36.

Prior to installing the insert 36 in the blade 10, the bushing 68 is placed in the insert and welded in place. then a hole 84 is drilled through the center of the sleeve 68 and the insert 36 is inserted into the hollow body portion 16 of the blade 10 through whose open end is arranged therethrough. Hole 84 is aligned with two holes 86 and 88 which are in the root section 12 of the sheet 10 are arranged. Then a pin 90 is inserted through holes 84, 86 and 88 as it is is shown in FIG.

The holes 86 and 88 in the root portion of the blade 10 are oversized with respect to the diameter of the pin 90, so for a certain tolerance in the construction of the various parts and also in the arrangement of a soldering sleeve or

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a weld collar around the ends of the pin 90. The hole 84 is sized to fit relatively tightly around the pin in order to allow for precise placement of the insert 36 within of the hollow body part l6. The solder alloy sleeve ^ which is arranged around both ends of the pin 90, not only secures the pin 90 to the root portion 12 of the blade but also acts as a seal preventing coolant flow around the pin 90 before it enters the chamber 50 associated with the insert 36. Furthermore can on Desire the base end 52 of the insert be sized so that a small gap between the outer wall of the insert 36 and the Sidewalls 56 of the sheet is formed. In one of those Case, the soldered connection not only seals the pins 90, but also flows into the gap between the insert and the wall 50 and effectively seals that gap. In this way all coolant flowing through channels 54 must be in the chamber 50 flowing to one of the inserts 36 or 38 heard.

When installing the inserts in the blade, if the inserts 36 and 38 are located in the hollow body part 16 and are the pins 90 are in holes 84, 86 and 88, the solder alloy arranged around each of the pins 90. Then the tip cap 82 is placed in place, an appropriate one Solder alloy is applied to the tip cap 62 and then the entire sheet is heated, causing the solder alloy to melt. This will remove each end of the pins 90 and the base ends of the Inserts are also sealed in addition to securing pins 90 and tip cap 62 in their respective positions.

In Figures 5 to 10 are a number of alternative embodiments of the mechanical fastening means for the cooling inserts shown. As can be seen from Figures 5 and 6, a bushing 9 ^ could have a pair of relatively elongated flanges and 98 can be used in place of bushing 68. In one of the

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like pall could splash down to the open end of the Insert downwards. An inner core 100 connects the paddles 96 and 98 and if desired the flat surfaces can 102 and 104 may be provided on each side of the core 100. As in the case of the bushing 68, when the bushing 94 is with the insert 36 is welded, a hole 106 is drilled through and a Pin 108 is positioned so that insert 36 'is attached to blade 10.

As shown in Figures 7 and 8, in certain applications a socket 110 is shaped to fit into the open end 52 of the J> 6 insert. In such a case, the bushing 110 would have an outer contour which is in the shape of a wing or is streamlined and is dimensioned to fit into an insert ^36f '. The bushing 110 would be hollow and define a passageway 112 for the flow of coolant into a chamber 50 ^{fl of} the insert 36 ^ft .

When installing the insert 36 in the blade, the bushing 110 could initially be in its position with the insert 36 ^t! Then place the insert 36 "in the sheet 10. Then holes 114 and II6 could be drilled through the root section 12 and each side of the insert 36. Then pins II8 and 120 would then be placed in the holes 114 and Ho and would be added to this are used to attach the socket 110 and thus the insert 36 ^'T in position.

While the bushing 68 described in connection with FIGS. 1 to 4 ensures extremely secure installation, in certain Applications a simple cylindrical sleeve-shaped Bushing or teardrop shaped feedthrough as shown in Figures 9 and 10 at 130 may be all that is required is to fix the insert in place. In such a case, the bushing or sleeve 130 with the inner

4 09 84 1/0 26 7

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Sides of the insert 36 '"welded or soldered and then would make a hole 132 through the insert 36 '' 'and the implementation 130 drilled. When the insert 36 '' 'is placed in the sheet 10 a pin 134 would be inserted into the hole and -welded or soldered in its position as described below.

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Claims (14)

- 12 claims 1.) Turbomachine blade with a root section, a blade platform, a hollow body part which surrounds an inner cavity ■ at least one thin-walled, hollow insert which can be attached in the hollow body part, and means for introducing a coolant into the interior of the insert , characterized in that means (66) are provided for mechanically fastening the insert (36) to the hollow body part (16) which comprise a bushing (68) which can be fastened to the insert (36) and pin means (90) which both connect to the socket (68) and also on the blade (10) are attachable. 2. Turbomachine blade according to claim 1, characterized in that the impingement insert (36) has an inlet (52) at its / end and a plurality of relatively small holes (44) passing therethrough, which are directed to surfaces (24, 26) which the inner cavity (28) are surrounded and can be acted upon with cooling air. • 3 · turbo machine blade according to claim 2, characterized characterized in that the socket (68) in the Inlet (52) is attachable and has at least one pad (74) of approximately the same thickness as the thickness of the insert wall, which has an opening (70) for receiving the flange (74). 4. Turbomachine blade according to claim 3, characterized in that the bushing (68) has a second plan (76) of approximately the same thickness as the thickness of the insert wall, which has a second opening (72) for receiving the second flange (76), and the first and second flanges (74, 76) attachable to the insert (36) are when the plansche (74, 76) are arranged in the openings (70, 72). 409841/0267 5. Turbomachine blade according to claim 3, characterized in that the insert (36) is a Has a base end (52) containing the inlet and sized to leave a small gap between the side walls (56) of the inner cavity (30) and the base end is formed, and the gap is filled with a sealant. 6. Turbomachine blade according to claim 2, characterized in that the sleeve is a sleeve (130) which can be arranged in the inlet and attached to the inner walls of the insert (36 ' ^ft ). 7. Turbomachine blade, characterized by. a root section (12), a streamlined, hollow body part (ΐβ) which forms an inner cavity (28) therein, a blade platform (18) which separates the root section (12) and the hollow body part (l6) from one another and the inner boundaries of the wing forms at least one thin-walled, hollow insert (36) which is disposed in the hollow body portion (l6), channel means (5 ² O, which can perform a cooling medium into the interior of the insert, and by means (66) for mechanical fastening the insert (36) in a position within the inner cavity comprising a socket (68) attachable to the insert (36) and pin means (90) attached to both the socket (68) and the blade (10) can be fastened. 8. Turbomachine blade according to claim 7, characterized by a loading insert (36) with an inlet (52) at its one end and a plurality of relatively small holes (M) ₄ passing therethrough which are directed onto surfaces (24, 26) which define the cavity ( 28) and can be supplied with cooling air. 409841/026 7 9. Turbomachine blade according to claim 8, characterized characterized in that the bushing (68) has at least one flange (74) of approximately the same thickness as the Thickness of the insert wall having an opening (70) to Receiving the flange includes, and the sheet further includes means for securing the flange in the opening. 10. Turbomachine blade according to claim 9, characterized in that the bushing (68) has a second flange (76) of approximately the same thickness as that of the insert wall, which has a second opening (72) for receiving the second flange (76), and means for fastening the second flange in the second opening are provided. 11. Turbomachine blade according to claim 9, characterized in that the bushing (68) has a Has inner core (78) which extends over the inlet (52) of the insert (36). 12. Turbomachine blade according to claim 11, characterized characterized in that the core (78) includes at least one flat face (80). 13. Turbomachine blade according to claim 8, characterized in that means (34) for subdivision of the inner cavity (28) are provided in at least two separate cavities (30, 32), each with one of the loading inserts (36, 38) are provided and the respective means (66) for mechanical fastening of the insert (36, 38) on the sheet (10) included. 14.Turbomaschinenblatt according to claim 9, characterized characterized in that the root portion (12) of the blade (10) contains at least one hole (86), the socket (68) has at least one hole (84) which communicates with the hole (86) 409 84 1/0 267 in the root section (12) can be brought into alignment, and a pin (90) is provided which in each of the holes (84, 86) can be arranged. 15 · Turbomachine blade according to claim 14, characterized characterized in that the hole (86) in the root section (12) is slightly larger than the outer diameter of the Pin (90) 1st and a solder collar is arranged in the gap between the pin and the hole. 409841/026 7