Thermal mismatch prevention assembly, CMC component and metal connecting piece

Abstract

The invention relates to a thermal mismatch prevention assembly, a CMC component and a metal connecting piece. The assembly includes a metal member, a CMC member having a mounting hole, and a metal connector having a base portion at one end, a connecting portion at the other end, and a shaft portion between the base portion and the connecting portion. Wherein the shaft part of the metal connecting piece penetrates through an assembly hole of the CMC component, the base part abuts against the surface of one side of the CMC component, and the connecting part is connected with the metal component; the mounting hole has a hole slope inclined in the height direction and inclined in one direction perpendicular to the height direction on each of the at least one set of opposite side walls, and the shaft portion has a shaft slope inclined in the height direction and inclined in one direction perpendicular to the height direction on each of the at least one set of opposite side walls. A set of opposing hole ramps and a set of opposing shaft ramps correspond and cooperate with each other, and are in contact fit in a section proximate the base portion in the height direction, and are in clearance fit in a section proximate the connecting portion.

Description

Technical Field

[0001] The invention relates to a component for preventing thermal mismatch, in particular to an assembly structure for preventing thermal mismatch between a CMC turbine blade and a metal casing. Background Art

[0002] Ceramic matrix composites (CMC) have high specific strength and specific stiffness at high temperatures, and are lightweight and corrosion-resistant. They can adapt to the working environment of the hot end components of aircraft engine turbines, significantly improve the upper temperature limit of the hot end components and the overall efficiency of the engine, and reduce pollution emissions, making them very promising in the field of aircraft engines. At present, advanced aircraft engine manufacturers at home and abroad have successively applied CMC materials to the hot end components of aircraft engines, such as combustion chamber flame tubes, turbine outer rings, turbine blades, etc.

[0003] Compared with metal, the existing CMC process is difficult to form, with low forming accuracy, and it is difficult to form a complex assembly structure for assembly and connection with other metal parts. In addition, since CMC is anisotropic material and has low tensile strength in the thickness direction, in the assembly structure of CMC turbine blades, the existing solution is to construct a flange on the CMC blade edge plate and assemble the flange with the front and rear metal casings, but this can easily cause the delamination stress at the flange position to exceed the tensile strength of the material in the thickness direction. Summary of the invention

[0004] An object of the present invention is to provide an assembly that prevents thermal mismatch and avoids the problem of excessive delamination stress of CMC components caused by the assembly structure.

[0005] Another object of the present invention is to provide a CMC component suitable for the aforementioned assembly.

[0006] Another object of the present invention is to provide a metal connector suitable for the aforementioned assembly.

[0007] According to another aspect of the present invention, a component for preventing thermal mismatch includes a metal component, a CMC component having an assembly hole, and a metal connector having a base portion at one end, a connecting portion at the other end, and a shaft portion between the base portion and the connecting portion. The shaft portion of the metal connector passes through the assembly hole of the CMC component, the base portion and one side surface of the CMC component are in abutment, and the connecting portion is connected to the metal component; each of at least one set of opposite side walls of the assembly hole has a hole slope that is inclined in the height direction and in a direction perpendicular to the height direction, and each of at least one set of opposite side walls of the shaft portion has a shaft slope that is inclined in the height direction and in a direction perpendicular to the height direction, the set of opposite hole slopes and the set of opposite shaft slopes correspond to and match each other, and the section close to the base portion in the height direction is in contact with each other, and the section close to the connecting portion is in clearance with each other.

[0008] In one embodiment, the connecting portion of the metal connecting piece is a hook.

[0009] In one embodiment, the CMC component has an opening at the edge corresponding to the assembly hole, and in the metal connector, the shaft portion and the connecting portion and the base portion are transitioned in a step shape; the connecting portion of the metal connector enters the assembly hole through the opening, and further allows the shaft portion to be pushed into the assembly hole from one side of the base portion.

[0010] In one embodiment, the connecting portion of the metal connecting piece is connected to the metal component via a fastener.

[0011] In one embodiment, the connecting portion of the metal connector is configured to allow entry into and then penetration out of the assembly hole from one side of the CMC component to guide the hole bevel and the shaft bevel into a state of mating with each other.

[0012] In one embodiment, the CMC component is an edge plate provided by a CMC turbine blade, the metal component is a metal casing, and the edge plate has the assembly holes at the front and rear edges respectively, so that the metal casing and the edge plate are connected at the front and rear edges through the metal connectors.

[0013] In one embodiment, the direction perpendicular to the height direction is the front-rear direction of the edge plate.

[0014] In one embodiment, the wall surfaces of the assembly hole and the shaft portion at the front and rear sides are inclined in the height direction, and are contact-fitted in a section close to the base portion in the height direction, and are clearance-fitted in a section close to the connecting portion.

[0015] A CMC component according to another aspect of the present invention is applicable to any of the above-mentioned components for preventing thermal mismatch, comprising a mounting hole, wherein each of at least one set of opposite side walls of the mounting hole has a hole slope inclined in the height direction and in a direction perpendicular to the height direction,

[0016] The set of relative hole bevels and the set of relative shaft bevels correspond to and match each other, and are contact-matched in a section close to the base portion in the height direction, and are clearance-matched in a section close to the connecting portion.

[0017] A metal connector according to another aspect of the present invention is applicable to any of the above-mentioned components for preventing thermal mismatch, and has a base portion at one end, a connecting portion at the other end, and an axis portion between the base portion and the connecting portion, wherein each of at least one set of opposite side walls of the axis portion has an axis inclined surface inclined in the height direction and in a direction perpendicular to the height direction,

[0018] The set of relative hole bevels and the set of relative shaft bevels correspond to and match each other, and are contact-matched in a section close to the base portion in the height direction, and are clearance-matched in a section close to the connecting portion.

[0019] According to an embodiment of the present invention, a metal connector is introduced to connect with the CMC component, and the metal connector and the metal component are assembled. This assembly structure does not require the CMC component to be flanged to form an assembly surface, thereby avoiding the problem of excessive delamination stress at the flange. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0021] Figure 1 It is a schematic diagram of the assembly of CMC turbine blades and metal casing;

[0022] Figure 2 is a schematic diagram of a CMC turbine blade with metal connectors;

[0023] Figure 3 yes Figure 2 A partial enlarged view of point I in the middle;

[0024] Figure 4 is a partial cross-sectional view along the ZY plane of an embodiment of a CMC component with a metal connector;

[0025] Figure 5 is a partial cross-sectional view along the XY plane of an embodiment of a CMC component with a metal connector;

[0026] Figure 6is a partial cross-sectional view along the ZY plane of another embodiment of a CMC component with a metal connector;

[0027] Figure 7 is a partial cross-sectional view along the XY plane of another embodiment of a CMC component with a metal connector;

[0028] Figure 8 is a schematic diagram of a CMC turbine blade with metal connectors;

[0029] Fig. 9 yes Figure 8 A partial enlarged view of point II in the middle. DETAILED DESCRIPTION

[0030] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided to explain the present invention, not to limit the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature illustrated or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present invention is intended to cover these modifications and variations within the scope of the appended claims and their equivalents.

[0031] In the following embodiments, the components for preventing thermal mismatch are described by taking the edge plate of a CMC turbine blade and a metal casing as an example, but the implementation of the present invention is not limited thereto. In the following description, the edge plate of a CMC turbine blade, a CMC component, or a metal casing, a metal component, when used in conjunction with the accompanying drawings, refers to the same components in the drawings.

[0032] Figure 1 The figure shows the state of CMC turbine blades and metal casings being assembled, wherein the front metal casing 105 and the rear metal casing 107 are schematically shown in simplified structures. The term "CMC turbine blade" means that the main material of the turbine blade is CMC, i.e., ceramic matrix composite, and the term "metal casing" means that the main material of the casing is metal. Multiple turbine blades are arranged in parallel along the circumferential direction to form one stage of the turbine. Figure 1 The turbine blades shown form the stator part of one stage of the turbine. The circumferential sides of the blades of adjacent turbine blades are adjacent, and the inner surface of the blade is the surface close to the blade body of the turbine blade, which forms part of the flow path surface. Figure 1In the figure, the coordinate system XYZ is used as a reference, and the directions parallel to the X-axis, Y-axis, and Z-axis are the X-direction, Y-direction, and Z-direction. The front side of the blade 102 in the Y direction is the leading edge of its airfoil, and the rear side is the trailing edge of its airfoil. The terms "upstream" and "downstream" refer to the relative directions relative to the flow of the fluid in the fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction to which the fluid flows. The leading edge of the blade 102 is its upstream, and the trailing edge is its downstream. The CMC turbine blade includes an upper edge plate 101 and a lower edge plate 103, and the blade 102 is arranged between the upper edge plate 101 and the lower edge plate 103. From the perspective of the stator of one stage of the turbine, the lower edge plate 103 is located on the inner side of the upper edge plate 101. The Z direction is the blade height direction of the blade 102, or the radial direction of the stator of one stage of the turbine. The two side walls of the blade 102 in the X direction are aerodynamic surfaces, one of which is a suction surface and the other is a pressure surface.

[0033] Continue to refer to Figure 1 In the illustrated assembly for preventing thermal mismatch, a CMC component or a CMC turbine blade is connected to a metal component or a metal casing through metal connectors 104 and 106. The metal connectors 104 and 106 will be understood from the following description, and the two can be of the same structure or different structures.

[0034] Figure 2 , Figure 8 The thermal mismatch protection assembly shown hides the metal casing to facilitate viewing of the mating structure of the metal connector and the CMC component.

[0035] Figure 2 It can be understood as Figure 8 Right side view of the assembly shown. Figure 2 and Figure 8 In the embodiment, the structures of the metal connectors on the left and right sides are different, the upper end of the metal connector on the left side is a hook, and the upper end of the metal connector on the right side has a connection hole. In another embodiment, the metal connectors on the left and right sides are the same, for example, both have a hook structure, or both have a connection hole structure.

[0036] Figure 4 The cross-sectional view shown can be understood as a metal connector with a connection hole at the upper end attached to Figure 2 or Figure 8 The position of the left assembly hole of the CMC component is shown, and then a cross-sectional view is obtained by cutting along the ZY plane from this position. Figure 4 and Figure 5 The structures shown are of the same embodiment.

[0037] The CMC component 101 has an assembly hole 101c. The metal connector 106 has a base portion 106a at the lower end, a connection portion 106c at the upper end, and a shaft portion 106b between the base portion 106a and the connection portion 106c. The shaft portion 106b of the metal connector 106 passes through the assembly hole 101c of the CMC component, the base portion 106a abuts against a side surface 101a of the CMC component 101, and the connection portion 106c is connected to the metal component 107.

[0038] Figure 5 The cross-sectional view is obtained by cutting along the XY plane, and the cutting position is approximately Figure 4 The thickness or height of the CMC component shown in FIG. 1 is half. Each of a set of opposite side walls of the assembly hole 101c in the X direction has a hole slope 301 that is inclined in the height direction and in a direction perpendicular to the height direction. In the figure, the Z direction is the height direction, and the Y direction is the direction perpendicular to the height direction. The inclination in the Z direction is not shown in the figure. If it is seen from the cross-sectional view cut along the XZ plane, the inclination in the Z direction makes the side of the assembly hole 101c close to the base portion 106a larger, and the side close to the connecting portion 106c smaller.

[0039] Likewise, each of a set of opposite side walls of the shaft portion 106b in the X direction has a shaft slope 306 that is inclined in the height direction and in a direction perpendicular to the height direction. Figure 5 In the figure, the shaft bevel 306 and the hole bevel 301 are in a basically fitted state, and the two are expressed by the same projection line. The set of opposite side walls of the shaft portion 106b in the X direction are also not shown in the figure. If it is seen from the cross-sectional view cut along the XZ plane, the inclination in the Z direction makes the side of the shaft portion 106b close to the base portion 106a larger, and the side close to the connecting portion 106c smaller.

[0040] The aforementioned set of relative hole bevels 301 and the aforementioned set of relative shaft bevels 306 correspond to and match each other, and the section close to the base portion 106a in the height direction is in contact with each other, while the section close to the connection portion 106c is in clearance with each other. The boundary between contact and clearance can be determined by testing based on the actual working conditions, size, and heat load of the product, for example, at a position of 1 / 3 to 1 / 2 of the height of the assembly hole 101c.

[0041] When the thermal load changes, such as switching from a normal temperature state to a high temperature state, the thermal deformation of the metal connector 106 is much greater than the thermal deformation of the CMC component. Since the matching part between the shaft portion 106b of the metal connector 106 and the assembly hole 10c is a bevel / bevel match, relative sliding is allowed, thereby releasing thermal deformation and preventing unnecessary stress caused by thermal deformation. At the same time, the sliding will be carried out along the bevel. Therefore, even if there is thermal deformation, the shaft portion 106b and the assembly hole 10c can be maintained, thereby avoiding thermal mismatch.

[0042] Figure 1 It is shown that the front and rear sides of the CMC component 101 are connected to the metal components 105 and 107 through metal connectors 104 and 106, respectively, wherein the upper end of the metal connector 104 is a hook, and the upper end of the metal connector 106 needs to be connected with the help of fasteners, which include but are not limited to pins and bolts. However, as mentioned above, the metal connectors 104 and 106 can be used separately or in combination. When the entire assembly is in a working state, the force or load between the CMC component 101 and the metal components 105 and 107 is transmitted through the metal connectors 104 and 106, and the force is transmitted between the base portion 106a and the inner side surface of the CMC component 101, and then transmitted to the connecting portion 106c through the shaft portion 106b, and then transmitted to the metal components 105 and 107 by punching the connecting portion 106c. By observing the stress of the CMC component 101 at the assembly hole 10c, it can be understood that the CMC component mainly bears in-plane stress rather than delamination stress. The in-plane tensile strength of the CMC material is much greater than the tensile strength in the thickness direction, which can effectively avoid material damage. If the CMC component is folded to form an assembly surface with the metal component, not only is the processing difficult, but when the CMC component is swung along the -Y direction under the aerodynamic load, the delamination stress at the corner position is very large, even exceeding the tensile strength in the thickness direction of the CMC, causing material damage.

[0043] Continue to refer to Figure 4 The connecting portion 106c of the metal connecting piece 106 is provided with a connecting hole 106d, and a fastener not shown in the figure can pass through the connecting hole 106d to connect with the metal components 105 and 107.

[0044] Figure 6 and Figure 7 Another embodiment of the metal connector is shown. Figure 1 Metal connector 104 or Figure 8 The metal connector on the left.

[0045] The connection portion of the metal connector 104 has a base portion 104a at the lower end, a connection portion 104c at the upper end, and a shaft portion 104b between the base portion 104a and the connection portion 104c. The shaft portion 104b of the metal connector 104 passes through the assembly hole 101c of the CMC component, the base portion 104a abuts against the inner surface 101a of the CMC component 101, and the connection portion 104c is connected to the metal component 105. The difference between the metal connector 104 and the metal connector 106 is that the connection portion 104c of the metal connector 104 includes a hook 104e.

[0046] Continue to refer to Figure 7 , the CMC component 101 has an opening 402 at the edge of the corresponding assembly hole 101c, such as Figure 6 As shown, the shaft portion 104b of the metal connector 104 transitions with the connecting portion 104c and the base portion 104a in a stepped shape. The connecting portion 104c of the metal connector 104 enters the assembly hole 101c through the opening 402, and then allows the shaft portion 104b to be moved from one side of the base portion 104a according to Figure 7 The width of the opening 402 is smaller than the width of the assembly hole 101c, so that the protrusion 403 is retained to limit the movement of the metal connector in the Y direction.

[0047] Similar, such as Figure 4 As shown, the connection portion 106 c of the metal connector 106 is configured to allow entry into and then penetration out of the assembly hole 101 c from the inner side of the CMC component 101 to guide the hole bevel 301 and the shaft bevel 306 into a state of mating with each other.

[0048] Back to Figure 5 , the wall surfaces 303 of the assembly hole 101c on the front and rear sides are also inclined in the height direction. The wall surfaces 304 on the front and rear sides of the shaft of the metal connector 104 are also inclined in the height direction. The wall surfaces 303 and 304 are in contact fit in the section close to the base portion 106a in the height direction, and are clearance fit in the section close to the connecting portion 106c. The shaft portion 104b of the metal connector 104 and the corresponding assembly hole 101c are also inclined on their respective front and rear side walls, and have a contact fit and clearance fit relationship similar to the above. The matching relationship of the inclined surface / inclined surface can further limit the movement of the metal connector in the Y direction.

[0049] As mentioned above, CMC components are not limited to the edge plates provided by turbine blades, but when the aforementioned components are applied to the connection between turbine blades and metal casings, they have obvious advantages:

[0050] (1) The CMC blade edge plate is not flanged, but is hung on a specially designed metal part through slotting, which avoids the risk of high delamination stress at the flange position of the CMC blade, simplifies the structure of the CMC blade, avoids the requirement for high-precision assembly surfaces of the CMC blade, and reduces the amount of machining;

[0051] (2) Assembly with front and rear metal parts is completed by metal parts, which solves the problem that CMC turbine blades cannot form complex assembly structures;

[0052] (3) The CMC blade edge plate assembly holes and metal parts are matched to solve the thermal mismatch problem.

[0053] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A component for preventing thermal mismatch, characterized in that include Metal components, A CMC component having a mounting hole, and A metal connector having a base portion at one end, a connecting portion at the other end, and a shaft portion between the base portion and the connecting portion; Wherein, the shaft portion of the metal connector passes through the assembly hole of the CMC component, the base portion abuts against a side surface of the CMC component, and the connecting portion is connected to the metal component; Each of the at least one set of opposite side walls of the assembly hole has a hole slope that is inclined in the height direction and in a direction perpendicular to the height direction. The shaft portion has, at least in each of a set of opposite side walls, a shaft inclined surface inclined in the height direction and in a direction perpendicular to the height direction. The set of relative hole bevels and the set of relative shaft bevels correspond to and match each other, and are contact-matched in a section close to the base portion in the height direction, and are clearance-matched in a section close to the connecting portion.

2. The thermal mismatch protection component according to claim 1, characterized in that: The connecting portion of the metal connecting piece is a hook.

3. The thermal mismatch protection component according to claim 2, characterized in that: The CMC component has an opening at an edge corresponding to the assembly hole, In the metal connector, the shaft portion and the connecting portion and the base portion are transitioned in a step shape respectively; The connecting portion of the metal connecting member enters the assembly hole through the opening, and further allows the shaft portion to be pushed into the assembly hole from one side of the base portion.

4. The thermal mismatch protection component according to claim 1, characterized in that: The connecting portion of the metal connecting piece is connected to the metal component through a fastener.

5. The thermal mismatch protection component according to claim 4, characterized in that The connecting portion of the metal connector is configured to allow entry into and then penetration out of the assembly hole from one side of the CMC component to guide the hole bevel and the shaft bevel into a state of mating with each other.

6. The thermal mismatch protection component according to any one of claims 1 to 5, characterized in that: The CMC component is an edge plate provided by a CMC turbine blade, the metal component is a metal casing, and the edge plate has the assembly holes at the front and rear edges respectively, so that the metal casing and the edge plate are connected at the front and rear edges through the metal connectors.

7. The thermal mismatch protection component according to claim 6, characterized in that The direction perpendicular to the height direction is the front-rear direction of the edge plate.

8. The thermal mismatch protection component according to claim 6, characterized in that The wall surfaces of the assembly hole and the shaft portion at the front and rear sides are inclined in the height direction, and are contact-fitted in the section close to the base portion in the height direction, and are clearance-fitted in the section close to the connection portion.

9. A CMC component, characterized in that: The component for preventing thermal mismatch according to any one of claims 1 to 8, comprising a mounting hole, Each of the at least one set of opposite side walls of the assembly hole has a hole slope that is inclined in the height direction and in a direction perpendicular to the height direction. The set of relative hole bevels and the set of relative shaft bevels correspond to and match each other, and are contact-matched in a section close to the base portion in the height direction, and are clearance-matched in a section close to the connecting portion.

10. A metal connector, characterized in that: The component for preventing thermal mismatch according to any one of claims 1 to 8 has a base portion at one end, a connecting portion at the other end, and a shaft portion between the base portion and the connecting portion. The shaft portion has, at least in each of a set of opposite side walls, a shaft inclined surface inclined in the height direction and in a direction perpendicular to the height direction. The set of relative hole bevels and the set of relative shaft bevels correspond to and match each other, and are contact-matched in a section close to the base portion in the height direction, and are clearance-matched in a section close to the connecting portion.

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