(19)
(11)EP 3 406 856 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
29.07.2020 Bulletin 2020/31

(21)Application number: 18173491.4

(22)Date of filing:  22.05.2018
(51)International Patent Classification (IPC): 
F01D 11/16(2006.01)

(54)

CERAMIC MATRIX COMPOSITE TURBINE BLADE AND METHOD OF MOUNTING THEREOF

TURBINENSCHAUFEL AUS KERAMIKMATRIXVERBUND UND VERFAHREN ZU DESSEN MONTAGE

AUBE DE TURBINE COMPOSITE À MATRICE CÉRAMIQUE ET SON PROCÉDÉ DE MONTAGE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 24.05.2017 US 201715604074

(43)Date of publication of application:
28.11.2018 Bulletin 2018/48

(73)Proprietor: General Electric Company
Schenectady, NY 12345 (US)

(72)Inventors:
  • KITTLESON, Jacob John
    Greenville, SC South Carolina 29615 (US)
  • DELVAUX, John McConnell
    Greenville, SC South Carolina 29615 (US)

(74)Representative: BRP Renaud & Partner mbB Rechtsanwälte Patentanwälte Steuerberater 
Königstraße 28
70173 Stuttgart
70173 Stuttgart (DE)


(56)References cited: : 
EP-A1- 2 014 874
WO-A1-96/41068
WO-A1-2014/165467
US-B2- 9 157 330
EP-A1- 2 719 865
WO-A1-2014/081496
WO-A2-99/64726
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    FIELD OF THE INVENTION



    [0001] The present embodiments are directed to ceramic matrix composite (CMC) turbine blade assemblies. More specifically, the present embodiments are directed to dovetail sleeves and CMC turbine blade assemblies including dovetail sleeves.

    BACKGROUND OF THE INVENTION



    [0002] The manufacture of a ceramic matrix composite (CMC) part typically includes laying up pre-impregnated composite fibers having a matrix material already present (prepreg) to form the geometry of the part (pre-form), autoclaving and burning out the pre-form, infiltrating the burned-out pre-form with the melting matrix material, and any machining or further treatments of the pre-form. Infiltrating the pre-form may include depositing the ceramic matrix out of a gas mixture, pyrolyzing a pre-ceramic polymer, chemically reacting elements, sintering, generally in the temperature range of 925 to 1650 °C (1700 to 3000 °F), or electrophoretically depositing a ceramic powder. With respect to turbine airfoils, the CMC may be located over a metal spar to form only the outer surface of the airfoil.

    [0003] Examples of CMC materials include, but are not limited to, carbon-fiber-reinforced carbon (C/C), carbon-fiber-reinforced silicon carbide (C/SiC), silicon-carbide-fiber-reinforced silicon carbide (SiC/SiC), alumina-fiber-reinforced alumina (Al2O3/Al2O3), or combinations thereof. The CMC may have increased elongation, fracture toughness, thermal shock, dynamic load capability, and anisotropic properties as compared to a monolithic ceramic structure.

    [0004] Conventional CMC blades typically only include one dovetail, which has two opposing pressure faces that contact the rotor tangs. As a result, the area that is required on each pressure face is high, and the fillet from the airfoil that transitions to these pressure faces may be large. If the fillet and pressure faces are large enough, the reduction in total rotor circumferential tang length may be reduced to a point at which the rotor is compromised. Additionally, it would be preferable for the fillet and neck region of the composite blade to be larger in order to maintain safe operation and reduced interlaminar tension generally seen in the neck region. CMC blades are highly orthotropic, and bending from the dovetail pressure contact faces induces a moment that attempts to pry the plies apart in the neck region perpendicular to the radial loading direction.

    [0005] A lower flank angle on the CMC dovetail increases fillet and interlaminar tension (ILT) stresses and increases wear concerns due to a higher normal force, but there is a risk of lock up for higher flank angles.

    [0006] WO 2014/081496 and US 9 157 330 B2 describe an apparatus and method to reduce wear and friction between CMC-to-metal attachment and interface.

    BRIEF DESCRIPTION OF THE INVENTION



    [0007] In an embodiment, a ceramic matrix composite (CMC) turbine blade assembly according to claim 1 is disclosed.

    [0008] In yet another embodiment, a method of mounting a ceramic matrix composite (CMC) turbine blade according to claim 6 is disclosed.

    [0009] Other features and advantages of the present invention will be apparent from the following more detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0010] 

    FIG. 1 is a cross sectional view of a portion of a prior art ceramic matrix composite (CMC) turbine blade.

    FIG. 2 is a cross sectional view of a portion of a prior art CMC turbine blade assembly.

    FIG. 3 is a cross sectional view of a CMC turbine blade assembly in an embodiment of the present invention.

    FIG. 4 is a cross sectional view of a CMC turbine blade assembly in another embodiment of the present invention.



    [0011] Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts.

    DETAILED DESCRIPTION OF THE INVENTION



    [0012] Provided is a ceramic matrix composite (CMC) turbine blade assembly, a dovetail sleeve, and a method of mounting a CMC turbine blade.

    [0013] Embodiments of the present disclosure, for example, in comparison to concepts failing to include one or more of the features disclosed herein, decrease fillet stresses, decrease interlaminar stresses, decrease interlaminar tension (ILT) in the CMC turbine blade, reduce wear on the rotor, reduce the maximum dovetail thickness, reduce normal forces, reduce material costs, promote locking during operation, reduce the risk of lockup during operation, increase rotor tang next section thickness, or combinations thereof.

    [0014] Referring to FIG. 1, the CMC turbine blade 10 includes a dovetail root 12 and a narrowed neck region 14. The shading in the narrowed neck region 14 represents the amount of interlaminar tension (ILT) in the CMC turbine blade 10, with an area of maximum ILT 42 shown in the middle of the narrowed neck region 14. Only a lower portion of the airfoil of the CMC turbine blade 10 is shown extending from the narrowed neck region 14 in FIG. 1.

    [0015] Referring to FIG. 2, the CMC turbine blade assembly 20 includes a CMC turbine blade 10 received in the blade slot 32 of a rotor 30. The blade slot 32 has a slot surface 34 that contacts the CMC turbine blade 10 at a slot angle 36 of about 55 degrees. The shading in FIG. 1 represents the stress in the CMC turbine blade 10 with radial fillet stress 44 from contact between the rotor 30 and the CMC turbine blade 10 causing a maximum stress in the CMC turbine blade 10.

    [0016] FIG. 3 shows a CMC turbine blade assembly 20 including a dovetail sleeve 60 located between the dovetail root 12 of the CMC turbine blade 10 and the rotor 30. The dovetail sleeve 60 prevents direct contact between the CMC turbine blade 10 and the rotor 30. The dovetail sleeve 60 includes a pair of outer surfaces 62 contacting the slot surfaces 34 of the blade slot 32 and a pair of inner surfaces 64 contacting the root surfaces 18 of the dovetail root 12. Only a lower portion of the airfoil of the CMC turbine blade 10 is shown extending from the dovetail root 12 in FIG. 3.

    [0017] The dovetail sleeve 60 permits the angle of the contact interface, and thus the direction of the contact stress, of the rotor 30 to be at a different angle than the contact interface of the dovetail root 12 of the CMC turbine blade 10. The outer surface 62 of the dovetail sleeve 60 is at an outer angle 66 substantially equal to the slot angle 36 of the blade slot 32 such that the outer surface 62 and the slot surface 34 are substantially complementary. The inner surface 64 of the dovetail sleeve 60 is at an inner angle 68 substantially equal to the root angle 16 of the dovetail root 12 such that the inner surface 64 and the root surface 18 are substantially complementary. The dovetail sleeve 60 tapers toward the upper end of the dovetail sleeve 60 (toward the narrowed neck region 14 of the CMC turbine blade 10) and acts as a wedge, because the root angle 16 is about 5 degrees or more greater than the slot angle 36.

    [0018] The root angle 16, the slot angle 36, the outer angle 66, and the inner angle 68 are defined with respect to a plane parallel to the axis of the dovetail root 12 of the CMC turbine blade 10 and perpendicular or normal to a radial vector from the engine axis, as shown in FIG. 3. It should be noted that the dovetail root 12 may be skewed by up to about 20 degrees relative to the rotor/engine centerline axis. In some embodiments, the skewing is about 15 degrees or less.

    [0019] Instead of a single dovetail sleeve 60 extending around to both root surfaces 18 of the dovetail root 12, a pair of dovetail sleeves 60 may alternatively be used, as shown in FIG. 4. The CMC turbine blade assembly 20 includes a pair of dovetail sleeves 60 located between the dovetail root 12 of the CMC turbine blade 10 and the rotor 30. The dovetail sleeves 60 prevent direct contact between the CMC turbine blade 10 and the rotor 30. Each dovetail sleeve 60 includes an outer surface 62 contacting one of the slot surfaces 34 of the blade slot 32 and an inner surface 64 contacting one of the root surfaces 18 of the rotor 30.

    [0020] Each of the pair of dovetail sleeves 60 preferably extends past the widest point of the dovetail root 12, as shown in FIG. 4, to aid in the positioning of the dovetail sleeves 60 and the dovetail root 12 with respect to the blade slot 32, but the dovetail sleeves 60 need not extend to the bottom of the dovetail root 12. The pair of dovetail sleeves 60 include significantly less material than a single dovetail sleeve 60 that extends around to both sides of the dovetail root 12. The pair of dovetail sleeves 60 may be interchangeable or substantially identical in shape, further reducing manufacturing costs. Alternatively, the dovetail sleeve 60 may include more than two fitted pieces.

    [0021] In some embodiments, the CMC turbine blade 10 and dovetail sleeve 60 address both packaging-related and wear-related issues. The separate dovetail sleeve 60 partially defines a portion of the dovetail root 12 of the CMC turbine blade 10, which reduces the maximum thickness of the dovetail root 12 and also provides wear protection for the rotor 30. The dovetail sleeve 60 permits assembly of a CMC turbine blade 10 with a greater root angle 16 in a rotor 30 with a conventional blade slot 32, such as a blade slot 32 having a slot angle 36 of about 55 degrees.

    [0022] The dovetail sleeve 60 is preferably metallic. In some embodiments, the dovetail sleeve 60 is a nickel-based alloy. In some embodiments, the nickel-based alloy is any high-temperature-suitable nickel-based superalloy. In some embodiment, the nickel-based alloy is Haynes 282, Inconel 625, Inconel 738, or Rene 108.

    [0023] As used herein, "Haynes 282" refers to a nickel-based alloy including a composition, by weight, of between about 18.5% and about 20.5% chromium (Cr), between about 9% and about 11% cobalt (Co), between about 8% and about 9% molybdenum (Mo), between about 1.9% and about 2.3% titanium (Ti), between about 1.38% and about 1.65% aluminum (Al), up to about 1.5% iron (Fe), up to about 0.3% manganese (Mn), up to about 0.15% silicon (Si), up to about 0.1% copper (Cu), between about 0.04% and about 0.08% carbon (C), up to about 0.02% zirconium (Zr), up to about 0.015% phosphorus (P), up to about 0.015% sulfur (S), between about 0.003% and about 0.01% boron (B), incidental impurities, and a balance of nickel (Ni).

    [0024] As used herein, "Inconel 625" refers to a nickel-based alloy including a composition, by weight, of between about 20% and about 23% Cr, between about 8% and about 10% Mo, up to about 5% iron (Fe), between about 3.2% and about 4.2% niobium (Nb) plus tantalum (Ta), up to about 1% Co, up to about 0.5% Mn, up to about 0.5% Si, up to about 0.4% Al, up to about 0.4% Ti, up to about 0.1% carbon (C), incidental impurities, and a balance (at least 58%) of Ni.

    [0025] As used herein, "Inconel 738" refers to a nickel-based alloy including a composition, by weight, of between about 15.7% and about 16.3% Cr, about 8.0% to about 9.0% Co, between about 3.2% and about 3.7% Ti, between about 3.2% and about 3.7% Al, between about 2.4% and about 2.8% tungsten (W), between about 1.5% and about 2.0% Ta, between about 1.5% and about 2.0% Mo, between about 0.6% and about 1.1% Nb, up to about 0.5% Fe, up to about 0.3% Si, up to about 0.2% Mn, between about 0.15% and about 0.20% C, between about 0.05% and about 0.15% Zr, up to about 0.015% S, between about 0.005% and about 0.015% B, incidental impurities, and a balance of Ni.

    [0026] As used herein, "Rene 108" refers to a nickel-based alloy including a composition, by weight, of between about 9% and about 10% Co, between about 9.3% and about 9.7% W, between about 8.0% and about 8.7% Cr, between about 5.25% and about 5.75% Al, between about 2.8% and about 3.3% Ta, between about 1.3% and about 1.7% Hf, up to about 0.9% Ti (for example, between about 0.6% and about 0.9% Ti), up to about 0.6% Mo (for example, between about 0.4% and about 0.6% Mo), up to about 0.2% Fe, up to about 0.12% Si, up to about 0.1% Mn, up to about 0.1% Cu, up to about 0.1% C (for example, between about 0.07% and about 0.1% C), up to about 0.1% Nb, up to about 0.02% Zr (for example, between about 0.005% and about 0.02% Zr), up to about 0.02% B (for example, between about 0.01% and about 0.02% B), up to about 0.01% phosphorus (P), up to about 0.004% S, incidental impurities, and a balance of Ni.

    [0027] In some embodiments, a coating is applied to one or more of the wear surfaces between the rotor 30 and the dovetail sleeve 60 or between the dovetail sleeve 60 and the CMC turbine blade 10. The coating may include cobalt, titanium, graphite or another carbon-containing composition, or combinations thereof.

    [0028] In some embodiments, the dovetail sleeve 60 is formed such that the stiffness of the dovetail sleeve 60 changes perpendicular to the pressure face of the CMC turbine blade 10 along the axial dovetail loading path. In some embodiments, the stiffness of the dovetail sleeve 60 is lowest at or near the middle of the dovetail sleeve 60 and increases toward the ends of the dovetail sleeve 60 corresponding to the leading edge and trailing edge of the CMC turbine blade 10 along the pressure face. Changing the local stiffness along the dovetail sleeve 60 permits a more constant predetermined loading of the airfoil during transient and normal operations. In some embodiments, the changing stiffness is achieved by casting the dovetail sleeve 60 in non-uniform ribs, by structural modification in the otherwise solid dovetail sleeve 60, or by an additive process.

    [0029] The difference between the root angle 16 and the slot angle 36 may be about 5 degrees or greater, alternatively about 10 degrees or greater, alternatively in the range of about 5 degrees to about 10 degrees, alternatively in the range of about 5 degrees to about 15 degrees, alternatively in the range of about 10 degrees to about 15 degrees, alternatively about 3 degrees or greater, alternatively in the range of about 3 degrees to about 5 degrees, alternatively in the range of about 4 degrees to about 6 degrees, alternatively in the range of about 5 degrees to about 7 degrees, or any value, range, or sub-range therebetween.

    [0030] The slot angle 36 may be about 55 degrees, alternatively about 55 degrees or less, alternatively in the range of about 50 degrees to about 55 degrees, alternatively about 60 degrees or less, alternatively in the range of about 50 degrees to about 60 degrees, alternatively in the range of about 54 degrees to about 56 degrees, alternatively in the range of about 53 degrees to about 55 degrees, or any value, range, or sub-range therebetween.

    [0031] The root angle 16 may be about 60 degrees or greater, alternatively about 65 degrees or greater, alternatively in the range of about 60 degrees to about 65 degrees, alternatively in the range of about 60 degrees to about 70 degrees, alternatively in the range of about 65 degrees to about 70 degrees, alternatively in the range of about 60 degrees to about 62 degrees, alternatively in the range of about 64 degrees to about 66 degrees, or any value, range, or sub-range therebetween.

    [0032] The difference between the inner angle 68 and the outer angle 66 may be about 5 degrees or greater, alternatively about 10 degrees or greater, alternatively in the range of about 5 degrees to about 10 degrees, alternatively in the range of about 5 degrees to about 15 degrees, alternatively in the range of about 10 degrees to about 15 degrees, alternatively about 3 degrees or greater, alternatively in the range of about 3 degrees to about 5 degrees, alternatively in the range of about 4 degrees to about 6 degrees, alternatively in the range of about 5 degrees to about 7 degrees, or any value, range, or sub-range therebetween.

    [0033] The outer angle 66 may be about 55 degrees, alternatively about 55 degrees or less, alternatively in the range of about 50 degrees to about 55 degrees, alternatively about 60 degrees or less, alternatively in the range of about 50 degrees to about 60 degrees, alternatively in the range of about 54 degrees to about 56 degrees, alternatively in the range of about 53 degrees to about 55 degrees, or any value, range, or sub-range therebetween.

    [0034] The inner angle 68 may be about 60 degrees or greater, alternatively about 65 degrees or greater, alternatively in the range of about 60 degrees to about 65 degrees, alternatively in the range of about 60 degrees to about 70 degrees, alternatively in the range of about 65 degrees to about 70 degrees, alternatively in the range of about 60 degrees to about 62 degrees, alternatively in the range of about 64 degrees to about 66 degrees, or any value, range, or sub-range therebetween.

    [0035] Although only a single dovetail section is shown, the dovetail section may be a single dovetail section or a double dovetail section. In some embodiments, the dovetail sleeve 60 is contained within the single or double dovetail section and continuously surrounds the convex and concave pressure faces of the dovetail root 12. In some embodiments, the root angle 16 of the dovetail root 12 to dovetail sleeve 60 contact is substantially greater than about 60 degrees to promote locking during operation, while the external surface of the sleeve is about 55 degrees or less to reduce the chance of lockup. Increasing the root angle 16 above 55 degrees is expected to reduce stress by about 5% to about 10%, thereby reducing material costs.

    [0036] Although only a dovetail root 12 is shown, the root of the CMC turbine blade 10 may alternatively be a fir tree root.

    [0037] Although the rotor 30 is shown as a single piece, the rotor 30 may alternatively include a rotor segment contacting the dovetail sleeve 60 that is an adapter segment fitted into the rotor wheel. In some embodiments, the rotor segment accommodates the thicker narrowed neck region 14 of the CMC turbine blade 10 relative to a comparable metal turbine blade. In some embodiments, a stronger high temperature adapter segment may also be used.

    [0038] While the invention has been described with reference to one or more embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the claims. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. In addition, all numerical values identified in the detailed description shall be interpreted as though the precise and approximate values are both expressly identified.


    Claims

    1. A ceramic matrix composite (CMC) turbine blade assembly (20) comprising:

    a rotor (30) having a blade slot (32) with at least one slot surface (34), the at least one slot surface (34) being at a slot angle (36); and

    a CMC turbine blade (10) received in the blade slot (32), the CMC turbine blade (10) comprising a dovetail root (12) having at least one root surface (18), the at least one root surface (18) being at a root angle (16), the root angle (16) being at least 5 degrees greater than the slot angle (36);

    at least one dovetail sleeve (60) received in the blade slot (32) of the rotor (30), the at least one dovetail sleeve (60) having at least one inner surface (64) contacting the at least one root surface (18) and at least one outer surface (62) contacting the at least one slot surface (34) to radially retain the CMC turbine blade (10) in the blade slot (32); and

    characterised in that the local stiffness of the dovetail sleeve (60) increases along a length of the dovetail sleeve (60) from a middle of the dovetail sleeve (60) toward a first end of the dovetail sleeve (60) and a second end of the dovetail sleeve (60) opposite the first end.


     
    2. The CMC turbine blade assembly (20) of claim 1, wherein the at least one inner surface (64) of the dovetail sleeve (60) is at an inner angle (68) complementary to the root angle (16) and the at least one outer surface (62) of the dovetail sleeve (60) is at an outer angle (66) complementary to the slot angle (36).
     
    3. The CMC turbine blade assembly (20) of claim 1 or 2, wherein the slot angle (36) is about 55 degrees or less and the root angle (16) is about 60 degrees or more.
     
    4. The CMC turbine blade assembly (20) of claim 1, 2 or 3, wherein the at least one dovetail sleeve (60) is a pair of dovetail sleeves (60), each of the pair of dovetail sleeves (60) contacting one of a pair of the at least one root surface (18) and one of a pair of the at least one slot surface (34).
     
    5. The CMC turbine blade assembly (20) of any preceding claim, wherein the CMC turbine blade (10) does not directly contact the rotor (30) in the CMC turbine blade assembly (20).
     
    6. A method of mounting a ceramic matrix composite (CMC) turbine blade (10), the method comprising:

    inserting at least one dovetail sleeve (60) into a blade slot (32) of a rotor (30), the blade slot (32) having at least one slot surface (34) at a slot angle (36); and

    inserting a dovetail root (12) of the CMC turbine blade (10) into a dovetail slot of a dovetail sleeve (60), the dovetail root (12) having at least one root surface (18) at a root angle (16), the root angle (16) being at least 5 degrees greater than the slot angle (36);

    wherein the at least one dovetail sleeve (60) has at least one inner surface (64) contacting the at least one root surface (18) and at least one outer surface (62) contacting the at least one slot surface (34) to radially retain the CMC turbine blade (10) in the blade slot (32).


     
    7. The method of claim 6, wherein the at least one inner surface (64) of the dovetail sleeve (60) is at an inner angle (68) complementary to the root angle (16) and the at least one outer surface (62) of the dovetail sleeve (60) is at an outer angle (66) complementary to the slot angle (36).
     


    Ansprüche

    1. Keramikmatrixverbund(CMC)-Turbinenschaufelanordnung (20), umfassend:

    einen Rotor (30), aufweisend einen Schaufelschlitz (32) mit zumindest einer Schlitzoberfläche (34), wobei die mindestens eine Schlitzoberfläche (34) in einem Schlitzwinkel (36) angeordnet ist; und

    eine im Schaufelschlitz (32) aufgenommene CMC-Turbinenschaufel (10), wobei die CMC-Turbinenschaufel (10) einen Schwalbenschwanzfuß (12) umfasst, der mindestens eine Fußoberfläche (18) aufweist, wobei die mindestens eine Fußoberfläche (18) in einem Fußwinkel (16) angeordnet ist, wobei der Fußwinkel (16) um mindestens 5 Grad größer als der Schlitzwinkel (36) ist;

    mindestens eine im Schaufelschlitz (32) des Rotors (30) aufgenommene Schwalbenschwanzmuffe (60), wobei die mindestens eine Schwalbenschwanzmuffe (60) mindestens eine Innenoberfläche (64), die die mindestens eine Fußoberfläche (18) berührt, und mindestens eine Außenoberfläche (62) aufweist, die die mindestens eine Schlitzoberfläche (34) berührt, um die CMC-Turbinenschaufel (10) radial im Schaufelschlitz (32) zu halten; und

    dadurch gekennzeichnet, dass die lokale Steifigkeit der Schwalbenschwanzmuffe (60) entlang einer Länge der Schwalbenschwanzmuffe (60) von einer Mitte der Schwalbenschwanzmuffe (60) zu einem ersten Ende der Schwalbenschwanzmuffe (60) und einem zweiten Ende der Schwalbenschwanzmuffe (60) zunimmt.


     
    2. CMC-Turbinenschaufelanordnung (20) nach Anspruch 1, wobei die mindestens eine Innenoberfläche (64) der Schwalbenschwanzmuffe (60) in einem zum Fußwinkel (68) komplementären Innenwinkel (16) angeordnet ist und die mindestens eine Außenoberfläche (62) der Schwalbenschwanzmuffe (60) in einem zum Schlitzwinkel (36) komplementären Außenwinkel (66) angeordnet ist.
     
    3. CMC-Turbinenschaufelanordnung (20) nach Anspruch 1 oder 2, wobei der Schlitzwinkel (36) etwa 55 Grad oder weniger beträgt und der Fußwinkel (16) etwa 60 Grad oder mehr beträgt.
     
    4. CMC-Turbinenschaufelanordnung (20) nach Anspruch 1, 2 oder 3, wobei die mindestens eine Schwalbenschwanzmuffe (60) ein Paar Schwalbenschwanzmuffen (60) ist, wobei jede des Paares Schwalbenschwanzmuffen (60) eine eines Paares der mindestens einen Fußoberfläche (18) und eine eines Paares der mindestens einen Schlitzoberfläche (34) berührt.
     
    5. CMC-Turbinenschaufelanordnung (20) nach einem der vorstehenden Ansprüche, wobei die CMC-Turbinenschaufel (10) den Rotor (30) in der CMC-Turbinenschaufelanordnung (20) nicht direkt berührt.
     
    6. Verfahren zum Montieren einer Keramikmatrixverbund(CMC)-Turbinenschaufel (10), wobei das Verfahren umfasst:

    Einsetzen mindestens einer Schwalbenschwanzmuffe (60) in einen Schaufelschlitz (32) eines Rotors (30), wobei der Schaufelschlitz (32) mindestens eine Schlitzoberfläche (34) in einem Schlitzwinkel (36) aufweist; und

    Einsetzen eines Schwalbenschwanzfußes (12) der CMC-Turbinenschaufel (10) in einen Schwalbenschwanzschlitz einer Schwalbenschwanzmuffe (60), wobei der Schwalbenschwanzfuß (12) mindestens eine Fußoberfläche (18) in einem Fußwinkel (16) aufweist, wobei der Fußwinkel (16) um mindestens 5 Grad größer als der Schlitzwinkel (36) ist;

    wobei die mindestens eine Schwalbenschwanzmuffe (60) mindestens eine Innenoberfläche (64), die die mindestens eine Fußoberfläche (18) berührt, und mindestens eine Außenoberfläche (62) aufweist, die die mindestens eine Schlitzoberfläche (34) berührt, um die CMC-Turbinenschaufel (10) radial im Schaufelschlitz (32) zu halten.


     
    7. Verfahren nach Anspruch 6, wobei die mindestens eine Innenoberfläche (64) der Schwalbenschwanzmuffe (60) in einem zum Fußwinkel (68) komplementären Innenwinkel (16) angeordnet ist und die mindestens eine Außenoberfläche (62) der Schwalbenschwanzmuffe (60) in einem zum Schlitzwinkel (36) komplementären Außenwinkel (66) angeordnet ist.
     


    Revendications

    1. Ensemble de pale de turbine (20) en composite à matrice céramique (CMC) comprenant :

    un rotor (30) ayant une fente de pale (32) avec au moins une surface de fente (34), l'au moins une surface de fente (34) étant à un angle de fente (36) ; et

    une pale de turbine en CMC (10) reçue dans la fente de pale (32), la pale de turbine en CMC (10) comprenant une racine en queue d'aronde (12) ayant au moins une surface de racine (18), l'au moins une surface de racine (18) étant à un angle de racine (16), l'angle de racine (16) étant supérieur d'au moins 5 degrés à l'angle de fente (36) ;

    au moins un manchon en queue d'aronde (60) reçu dans la fente de pale (32) du rotor (30), l'au moins un manchon en queue d'aronde (60) possédant au moins une surface interne (64) mettant en contact l'au moins une surface de racine (18) et au moins une surface extérieure (62) en contact avec l'au moins une surface de fente (34) de façon à retenir de façon radiale la pale de turbine en CMC (10) dans la fente de pale (32) ; et

    caractérisé en ce que la rigidité locale du manchon en queue d'aronde (60) augmente sur une longueur du manchon en queue d'aronde (60) du milieu du manchon en queue d'aronde (60) vers une première extrémité du manchon en queue d'aronde (60) et une deuxième extrémité du manchon en queue d'aronde (60) opposée à la première extrémité.


     
    2. Ensemble de pale de turbine (20) en CMC selon la revendication 1, dans lequel l'au moins une surface intérieure (64) du manchon en queue d'aronde (60) est à un angle intérieur (68) complémentaire à l'angle de racine (16) et l'au moins une surface extérieure (62) du manchon en queue d'aronde (60) est à un angle extérieur (66) complémentaire de l'angle de fente (36).
     
    3. Ensemble de pale de turbine (20) en CMC selon la revendication 1 ou 2, dans lequel l'angle de fente (36) est d'environ 55 degrés ou moins et l'angle de racine (16) est d'environ 60 degrés ou plus.
     
    4. Ensemble de pale de turbine (20) en CMC selon la revendication 1, 2 ou 3, dans lequel l'au moins un manchon en queue d'aronde (60) est une paire de manchons en queue d'aronde (60), chacun de la paire de manchons en queue d'aronde (60) venant en contact avec une d'une paire de l'au moins une surface de racine (18) et une d'une paire de l'au moins une surface de fente (34).
     
    5. Ensemble de pale de turbine (20) en CMC selon une quelconque revendication précédente, dans lequel la pale de turbine (10) en CMC n'est pas directement en contact avec le rotor (30) dans l'ensemble de pale de turbine (20) en CMC.
     
    6. Procédé de montage d'une pale de turbine (10) en composite à matrice céramique (CMC), le procédé comprenant :

    l'insertion d'au moins un manchon en queue d'aronde (60) dans une fente de pale (32) d'un rotor (30), la fente de pale (32) ayant au moins une surface de fente (34) à un angle de fente (36) ; et

    l'insertion d'une racine en queue d'aronde (12) de la pale de turbine (10) en CMC dans une fente en queue d'aronde d'un manchon en queue d'aronde (60), la racine en queue d'aronde (12) ayant au moins une surface de racine (18) à un angle de racine (16), l'angle de racine (16) étant supérieur d'au moins 5 degrés à l'angle de fente (36) ;

    dans lequel l'au moins un manchon en queue d'aronde (60) a au moins une surface interne (64) en contact avec l'au moins une surface de racine (18) et au moins une surface extérieure (62) en contact avec l'au moins une surface de fente (34) pour retenir radialement la pale de turbine (10) en CMC dans la fente de pale (32).


     
    7. Procédé selon la revendication 6, dans lequel l'au moins une surface intérieure (64) du manchon en queue d'aronde (60) est à un angle intérieur (68) complémentaire à l'angle de racine (16) et l'au moins une surface extérieure (62) du manchon en queue d'aronde (60) est à un angle extérieur (66) complémentaire de l'angle de fente (36).
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description