JP3401928B2 - Buffer material for turbine blade implant - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning material for a turbine blade implanting portion, and more particularly to a cushioning material for a turbine blade implanting portion having enhanced stress relaxation effect and shock absorbing effect.

[0002]

2. Description of the Related Art FIG. 6 shows a turbine rotor blade mounting structure for a gas turbine. As shown in the drawing, groove-shaped recesses b each having a narrow opening are formed at intervals in the circumferential direction on a turbine disk a as a mounting base, and these recesses b are shaped like a bulb of a turbine rotor blade c. The implant part d is fitted.
Here, since the concave portion b of the disk a and the implanting portion d of the turbine rotor blade c have fine irregularities when viewed microscopically, when these are directly contacted, stress concentration occurs in the convex portion and the material It breaks at a much lower level than the original critical stress. In particular, it is fatal when the turbine blade c is made of ceramics.

Therefore, a pad made of a heat-resistant metal is provided in the gap between the concave portion b of the turbine disk a and the implanting portion d of the turbine rotor blade c (Japanese Patent Laid-Open No. 5-321603).
No. However, even though the pad is made of a heat-resistant metal, it is oxidized by the combustion gas at a high temperature, and the stress relaxation effect is drastically reduced due to the dropping of the oxide film. Therefore, a technique has been proposed in which a ceramic plate material is interposed as a cushioning material in the gap along the surface direction thereof (Japanese Patent Application Laid-Open No. Hei 4-
26566 publication). According to this technique, the problem of the oxide film falling off does not occur, and the stress resistance and impact resistance are improved.

[0004]

However, in the above-mentioned ceramic plate material, after the ceramics are fired to a predetermined rough size in accordance with the recesses b, the blades are planted in the shape of a bulb by performing precision machining such as polishing. Since it must be finished at an accurate angle so as to be in close contact with the portion d, it is extremely expensive, and since there is a certain limit in the accuracy of machining, a minute error (unevenness) cannot be avoided. Therefore, if such a ceramic plate material is assembled in the gap between the turbine disk recess b and the turbine rotor blade implanting portion d, one-sided contact will occur due to the above error, and stress concentration will occur. Further, since it is impossible to make the assembling accuracy zero, this also causes the stress concentration.

A technique has been proposed in which a foil spring is provided in the gap between the turbine disk recess b and the turbine rotor blade implanting portion d along the surface direction of the foil so as to enhance the stress relaxation effect during pressure welding. However, in this technique, the stress is concentrated on the blade-implanted portion d or the disc recess b due to the projection of the foil spring in this technique.

An object of the present invention, which was devised in view of the above circumstances, is to provide a cushioning material for a turbine blade implanting portion which can alleviate stress concentration caused by poor machining accuracy and assembly accuracy.

[0007]

In order to achieve the above object, a first aspect of the present invention relates to a cushioning material interposed between a recess formed in a mounting base and a turbine blade implanting part fitted into the recess. and entangled short fibers of metals to form a metal cross knitting metal felt or long fibers, said metal carrier
Cel or metal cloth with sol-like alumina or zirconia
After soaking in etc. and pulling up and firing this,
The sol-like Al accumulated by the surface tension at the intersection of each fiber
Mina etc. are baked and solidified, and the intersection of each fiber is fixed with ceramics.
Sol-like alumina attached to the surface of each fiber
The surface of each fiber is coated with ceramics
It is the one that is made.

A second aspect of the present invention is a shock-absorbing material interposed between a recess formed in a mounting base and a turbine blade implanting section fitted into the recess. by knitting fibers to form a ceramic cloth, the ceramic felt also
Is a ceramic cloth for sol-like alumina or zirconia
After soaking in etc. and pulling up and firing this,
The sol-like Al accumulated by the surface tension at the intersection of each fiber
Mina etc. are baked and solidified, and the intersection of each fiber is fixed with ceramics.
Sol-like alumina attached to the surface of each fiber
The surface of each fiber is coated with ceramics
It is the one that is made.

[0009]

According to the first aspect of the invention, since the metal felt (or the metal cloth in which the long metal fibers are woven) in which the short metal fibers are entangled is used as the cushioning material, the turbine blade implanting portion is attached. When a tightening load is applied when it is installed in the concave portion of the base, the fine fibers of the metal felt (or cloth) are deformed into a dense structure and substantially complete surface contact is achieved. Therefore, non-uniformity of stress due to one-side contact does not occur. Further, the sudden impact during operation of the gas turbine is absorbed by the elasticity of the metal fibers. Therefore, the vibration absorption effect during operation is also enhanced . Well
In addition, metal felt (or cloth) is used as sol-like alumina or
By soaking in zirconia etc. and then pulling up,
Since sol-like alumina etc. automatically accumulates at the intersection of fibers,
By firing this, the intersections of the fibers can be accurately
It can be fixed with. Also, the surface of each metal fiber is
As it is coated with Ramix, it has a high temperature combustion gas.
The oxide film on the surface of the metal fiber oxidized by
It is possible to prevent the stress relaxation effect caused by
Oxidizing property is improved.

According to the second invention, since the ceramic felt (or cloth) is used instead of the metal felt, it is possible to endure higher temperature. Where usually
The ceramic felt (or cloth) of
Combined with a machine (polyvinyl, etc.) as a sizing material
Therefore, if the sizing material burns out at high temperatures,
I will understand. Therefore, in the present invention, the ceramics
Coating the surface of the fiber with another ceramic
This is to prevent this by fixing the intersection of each fiber.
Is.

That is, the ceramic felt (or black
Loss) after immersing it in sol-like alumina or zirconia
By pulling it up, the intersection of each ceramic fiber is automatically
Since sol-like alumina, etc. accumulates in the
You can accurately fix the intersection of the fibers with ceramics with
The intersection of each ceramic fiber accurately
Since it is fixed at, each ceramic is heated by the hot combustion gas.
Sizing material (polyvinyl
Even if organic substances such as
It can prevent spoiling.

[0012]

【Example】

[Outline of Gas Turbine] FIG. 2 shows an outline of a turbine portion of a gas turbine such as a jet engine. As shown in the drawing, turbine stationary blades 10 and turbine moving blades 4 are alternately arranged along a gas flow direction A in a gas passage between a conical nose cone 12 and a gas guide tube 11 surrounding the nose cone 12. Has been done.

The turbine vane 10 of the first stage is supported by a nose cone 12 and a gas guide pipe 11. The second stage turbine vane 10 includes an inner fixed portion 15 and a gas guide pipe 11.
Supported by. A plurality of these turbine vanes 10 are provided at a predetermined interval in the circumferential direction. On the other hand, a plurality of turbine moving blades 4 are provided in the turbine disk 1 attached to a rotating shaft (not shown) at predetermined intervals in the circumferential direction.

According to this structure, the combustion gas generated as a result of combustion in the combustion chamber upstream of the nose cone 12 alternately passes through the turbine stationary blades 10 and the turbine moving blades 4 to rotate the turbine disk 1. I will let you.

[Embodiment 1] An embodiment of the first invention will be described with reference to the accompanying drawings.

FIG. 3 is a sectional view taken along line III-III in FIG.
As shown, the turbine disk 1 of the gas turbine
In (corresponding to the mounting base in the claims), recesses 3 having narrowed openings 2 are engraved at intervals in the circumferential direction, and turbine blades 4 (claims) are formed in these recesses 3. (Corresponding to the turbine blade of the above), the bulb-shaped implant portion 5 is fitted. The turbine disk 1 is made of a heat-resistant metal such as Inconel or rhenium, and the turbine rotor blade 4 is made of a ceramic such as silicon nitride or silicon carbide.
The recessed portion 3 and the implanting portion 5 are formed so that a predetermined gap is created when these are assembled.

In the gap between the concave portion 3 and the implanting portion 5, FIG.
The cushioning material 6 having the structure shown in FIG. This cushioning material 6
Is a metal felt 8 formed by intertwining metal short fibers 7 (8 to 10 μm). Each short fiber 7 of the metal felt 8 is formed.
It is configured by fixing the intersection of (or long fibers, the same applies hereinafter) with metal or ceramics at a temperature equal to or lower than the melting point of the metal. Specifically, a nickel-based alloy or a cobalt-based alloy is used for the short metal fibers 7 constituting the metal felt 8. This is because these materials have sufficient high temperature strength and elasticity even in an ultrahigh temperature gas turbine in which ceramics are used for the turbine blade 4. Instead of the metal felt 8, a metal cloth in which long fibers are properly woven may be used.

The intersections 9 of the short metal fibers 7 are fixed by self-fusion. For self-bonding, use of electric resistance, use of frictional heat, hot pressing, or the like is used. However, it is performed at a temperature equal to or lower than the melting point of the short metal fiber 7. This is because the metal felt 8 loses its meaning if all the metal short fibers 7 are melted. Further, instead of self-bonding, another refractory metal (such as Inconel or rhenium) may be used to fix the intersections of the respective metal short fibers 7. In this case, CVD, PVD
Alternatively, plating or the like is used.

The intersections 9 of the short metal fibers 7 may be fixed with ceramics instead of metal. In this case, the metal felt 8 is soaked in sol-like alumina or zirconia, pulled up, and fired. As a result, alumina sol or zirconia sol accumulates at the intersections 9 of the respective short fibers 7 due to the surface tension, so that the intersections 9 of the respective short fibers 7 are fixed by the firing thereof. Also, since the surface of the short metal fibers 7 is coated with ceramics, heat resistance and
Oxidation resistance will also be improved. Such coating is preferably repeated a plurality of times to laminate the coating layers. Note that polycarbosilane or polysilazane may be used instead of the alumina sol or zirconia sol.

The cushioning material 6 of the turbine rotor blade implanting portion having the above structure is wound around the rotor blade implanting portion 5 and inserted into the recess 3 of the turbine disk 1 together with the implanting portion 5 to be assembled. At this time, when an assembling load (tightening load) is applied to the cushioning material 6, since the metal felt 8 is used as the cushioning material 6, the thin short fibers 7 of the metal felt 8 are deformed into a dense structure and the cushioning is performed. The material 6, the blade-implanted portion 5 and the recess 3 are substantially in surface contact with each other. Therefore, partial contact due to an error in the machining accuracy of the implanting portion 5 of the ceramic moving blade 4 or the concave portion 3 of the turbine disk 1 and the assembling accuracy of these is eliminated, and uneven stress does not occur. Therefore, reliability and durability are enhanced.

Further, vibrations generated during the operation of the gas turbine and loads for accelerating and decelerating the number of revolutions are absorbed by friction and elastic deformation of the short metal fibers 7. Therefore, the vibration absorption effect during operation is enhanced, and the stress relaxation effect is widely exerted from the low load region to the high load region. In this way, vibrations are effectively absorbed, so chattering can be prevented in advance, and fretting wear (small vibration wear)
Can be prevented.

Further, since the intersections 9 of the short metal fibers 7 are fixed by a heat-resistant metal or ceramics, the short metal fibers are not deteriorated even in an ultra-high temperature gas turbine using a ceramic for the rotor blade. It is possible to prevent 7 from being broken for a long time. Therefore, the service life is extended.

Further, since the cushioning member 6 is made of the flexible metal felt 8, the assembling property at the time of assembling it in the gap between the moving blade implanting portion 5 and the concave portion 3 becomes good. That is, the cushioning material 6 made of the metal felt 8 is attached to the moving blade implantation portion 5.
Is wound and is inserted into the concave portion 3 of the turbine disk 1. However, even when the insertion is difficult, the metal felt 8 can be easily inserted by appropriately deforming it.

[Embodiment 2] FIGS. 4 and 5 show a modified embodiment.
Shown in. In this embodiment, the cushioning material 6 is used for the turbine vane 10
It was used for. As shown in the figure, a ceramic nose cone 12 (corresponding to the mounting base in the claims) is formed inside the ceramic gas guide tube 11 in a cone shape at a predetermined distance from the inner peripheral surface. And a plurality of turbine turbine vanes 10 made of ceramics are arranged at predetermined intervals in the circumferential direction between them.

At both ends of the turbine vane 10, there are implanted portions 13
Is provided, and the nose cone 12 and the gas guide tube 11 are provided with a recess 14. The concave portion 14 and the implanting portion 13 are formed so that a predetermined gap is created when these are assembled. The same cushioning material 6 as in the previous embodiment is provided in the gap.

The cushioning material 6 is provided as follows.
First, the cushioning material 6 in the form of a metal felt 8 formed in conformity with the shape of the recess is attached to the recess 14 on the nose cone 12 side. The cushioning material 6 is divided into four in the circumferential direction and is attached to each one quarter. This is for improving the molding accuracy and the assembling property. Then, the implanting portion 13 on the inner peripheral side of the turbine stationary blade 10 is fitted on it. After that, the cushioning material 6 formed in conformity with the shape is attached to the implanting portion 13 on the outer peripheral side of the turbine stationary blade 10, and finally, the gas guide tube 11 is attached so as to be sandwiched from the front and rear.

In this embodiment as well, it is of course possible to obtain the same effects as in the previous embodiment, and in particular, ceramic parts by chattering (gas pipe 11 and nose cone 1).
The damage (cracking) in 2) can be effectively prevented.

[Embodiment 3] An embodiment of the second invention will be described below.

This embodiment basically has the same construction as that of the first embodiment of the first aspect of the invention, so that FIG. 1 and FIG. 2 are shared and only the cushioning material 6 which is substantially different will be described. I will decide. The turbine rotor blade 4 may be made of ceramics or heat-resistant metal, and the turbine disk 1 may be made of ceramics or heat-resistant metal.

As shown in FIG. 1, the cushioning material 6s provided in the gap between the concave portion 3 and the implanting portion 5 is a short fiber 7 of ceramics.
The ceramics felt 8s is formed by intertwining s (8 to 10 μm), and the intersections 9s of the short fibers 7s of the ceramics felt 8s are fixed by metal or ceramics. Specifically, ceramics felt 8s
Silicon nitride or silicon carbide is used for the ceramic short fibers 7s constituting the. In addition, ceramics felt 8s
Alternatively, a ceramic cloth in which long fibers are properly woven may be used.

Each ceramic short fiber 7s (or long fiber,
The same applies hereinafter) 9s of intersections are fixed by ceramics of the same kind or of other kinds. That is, the ceramics felt 8s is immersed in sol-like alumina or zirconia, then pulled up and fired. This allows
Since the alumina sol and the zirconia sol accumulate at the intersections 9s of the respective short fibers 7s due to the surface tension, the intersections 9s of the respective short fibers 7s are fixed by ceramics by the firing. The surface of the ceramic short fibers 7s is coated with ceramics such as alumina. Such coating is preferably repeated a plurality of times to laminate the coating layers. Note that polycarbosilane or polysilazane may be used instead of the alumina sol or zirconia sol.

The intersection 9 of each ceramic short fiber 7s
s is a refractory metal (Pt, TiC,
TiN or the like). This fixing may be carried out by immersing the ceramic felt 8s in a melt of the refractory metal and then pulling it up. This is because the molten liquid of the refractory metal accumulates at the intersection of the short fibers 7s due to the surface tension and solidifies after being pulled up. Needless to say, the melting point of the refractory metal (Pt or the like) is higher than the temperature at which the combustion gas of the gas turbine passes through the turbine moving blade 4. The intersection of the ceramic short fibers 7s may be fixed by CVD, PVD, sol-gel method, electrophoresis method, plating method, hydrothermal electrochemical method, or the like.

The turbine rotor blade implanting section 5 having the above-mentioned configuration
According to the shock absorbing material 6s, since the ceramic felt 8s is used instead of the metal felt 8, it is possible to endure higher temperature. That is, in the metal felt 8,
When the combustion temperature is high like a ceramic gas turbine or when the cooling mechanism is eliminated to improve the efficiency, the reliability must be lowered due to oxidation or creep, but if the ceramic felt 8s is used, the temperature becomes higher. Can bear. However, ordinary commercial ceramics felt 8s
Since each short fiber 7s is combined with an organic substance (polyvinyl or the like) as a sizing material, the sizing material is burned out and loosely separated at high temperatures. Therefore, in this embodiment, by coating the surface of the ceramic short fibers 7s with a heat-resistant metal or another ceramic,
The intersection 9s of each short fiber 7s is fixed to prevent this.

By the way, when a tightening load is applied when the rotor blade implanting part 5 is assembled in the recessed part 3, since the ceramic felt 8s is used as the cushioning material 6s, the thin ceramic short fibers 7s have a dense structure. Deformed, cushioning material 6s
The moving blade implanting portion 5 and the concave portion 3 are substantially in surface contact with each other. Therefore, the limit of the processing accuracy of the implanting portion 5 of the ceramic moving blade 4 and the concave portion 3 of the turbine disk 1 and the partial contact due to the error in the assembling accuracy of these are eliminated, and the unevenness of the stress does not occur. Therefore, as the gas sealability increases,
Improves reliability and durability. Therefore, the stress relaxation property and the compression sealing property between the ceramics-ceramics and the ceramics-metal are enhanced.

Further, the vibration generated during the operation of the gas turbine and the load for accelerating and decelerating the rotational speed are absorbed by the friction of the ceramic short fibers 7s and the bending force with the intersection 9s of each short fiber 7s as a fulcrum. In particular, it exerts a great effect on the impact load generated between the turbine rotor blade implant portion 5 and the turbine disk recess 3 at the time of startup. Therefore, the vibration absorption effect during operation is enhanced, and the stress relaxation effect is widely exerted from the low load region to the high load region. As described above, since the vibration is effectively absorbed, it is possible to prevent the occurrence of chattering and the occurrence of fretting wear. Therefore, damage to the ceramic component between the ceramic-ceramic and the ceramic-metal is prevented.

[Embodiment 4] In this embodiment, the cushioning material 6s made of the above-mentioned ceramic felt 8s is used as the cushioning material 6s of the turbine vane implant portion 13 according to the embodiment 2 shown in FIGS. 4 and 5. Since the essential operation and effect are exactly the same as those of the third embodiment, the drawings are shared and the detailed description is omitted.

[0037]

As described above, according to the present invention, the following excellent effects can be exhibited.

(1) One-sided contact due to the limit of machining accuracy and the error of assembly accuracy can be eliminated , stress concentration can be relaxed, and reliability and
The durability can be increased. Also, gas turbine operation
Vibration absorption effect from low load range to high load range
Can be increased widely. Therefore, the chattering
Raw material can be prevented in advance, and fretting wear can be prevented.
Wear.

(2) Ultra-high-performance ceramics
Even if it is a high temperature gas turbine, it does not deteriorate
Prevents loosening of fiber or ceramic fiber for a long time
Can be stopped. Therefore, the service life is extended. Also,
Assembling the cushioning material in the gap between the recess and the recess
Can be increased.

(3) Metal felt or cloth (ceramic
Sulfate or cloth) with sol-like alumina or zirconium
A) After soaking it in something like
Since sol-like alumina, etc. dynamically accumulates, it should be calcined.
Therefore, the intersections of the fibers can be accurately fixed with ceramics.
You can

(4) According to the invention of claim 1,
The surface of each metal fiber is coated with ceramics
So the surface of metal fibers oxidized by hot combustion gases
Drastically reduces the stress relaxation effect caused by the oxide film falling off
It can be prevented and heat resistance and oxidation resistance are improved.

(5) According to the invention of claim 2,
Precisely fix the intersection of each ceramic fiber with ceramics
Therefore, each ceramic is heated by the hot combustion gas.
Sizing material that binds fibers together (polyvinyl or other
Even if the machine is burned down, the fibers will come apart
And can be prevented.

[Brief description of drawings]

FIG. 1 is an enlarged view of a cushioning material showing an embodiment of the first and second inventions.

FIG. 2 is a schematic diagram showing a turbine portion of a gas turbine.

FIG. 3 is a schematic view of a turbine rotor blade showing an embodiment of the first and second inventions, and is a sectional view taken along line III-III of FIG.

FIG. 4 is a schematic view of a turbine vane showing an embodiment of the first and second inventions.

FIG. 5 is a perspective view of FIG.

FIG. 6 is a perspective view of a turbine rotor blade.

[Explanation of symbols]

1 Turbine disk as mounting base 3 recess 4 Turbine blades as turbine blades 5 Implantation department 6 cushioning material 7 Metal short fibers 8 metal felt 9 Intersection of short metal fibers 6s cushioning material 7s Ceramic short fiber 8s ceramics felt 9s Ceramic short fiber intersection

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-6-99011 (JP, A) JP-A-47-29708 (JP, A) JP-A-49-105015 (JP, A) 85039 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16F 7/00 F01D 5/30

Claims (2)

(57) [Claims] 1. A cushioning material interposed between a recess formed in a mounting base and a turbine blade implanting section fitted therein, in which metal short fibers are entangled to woven metal felt or long fiber. Form a metal cloth, and
Solt-like alumina or zirconia, etc.
After soaking in the
Sol-like aluminum accumulated by surface tension at the intersection of fibers
Baking solids etc. and fixing the intersections of each fiber with ceramics.
Sol-like alumina attached to the surface of each fiber
Is hardened and the surface of each fiber is coated with ceramics.
Turbine blade implanting portion of the buffer material, characterized by comprising grayed. 2. A cushioning material interposed between a recess formed in a mounting base and a turbine blade implanting portion fitted into the recess, wherein short fibers of ceramics are intertwined to knit a ceramic felt or a long fiber. Forming a ceramic cloth, the ceramic felt or ceramic
Dipping the cloth in sol-like alumina or zirconia
After pulling up and firing this, the intersection of each fiber
Sol-like alumina accumulated by surface tension
While solidifying and fixing the intersection of each fiber with ceramics,
The sol-like alumina etc. adhering to the surface of each fiber is baked and solidified.
A buffer material for a turbine blade implanting part, characterized in that the surface of each fiber is coated with ceramics .