Integral ceramic matrix turbine outer ring positioning structure

Abstract

The present invention discloses an integral ceramic matrix turbine outer ring positioning structure, comprising: a metal ring group, and a ceramic matrix turbine outer ring and an elastic seal adjustment assembly disposed in the inner cavity of the metal ring group. The first end of the ceramic matrix turbine outer ring abuts against the first end of the metal ring group to form a conical surface fitting structure, the second end of the ceramic matrix turbine outer ring abuts against the elastic seal adjustment assembly, and the opposite end of the elastic seal adjustment assembly abuts against the second end of the metal ring group. The positioning structure is used to convert the radial extrusion generated by the thermal deformation of the ceramic matrix turbine outer ring and the metal ring group into the axial displacement of the ceramic matrix turbine outer ring through the conical surface fitting structure, and then absorb the thermal deformation through the elastic seal adjustment assembly. In the structure of the present invention, the thermal deformation can be absorbed by the compression or expansion of the elastic structure of the elastic seal adjustment assembly, thereby effectively reducing the thermal stress, the ceramic matrix turbine outer ring is not easily broken, has a higher thermal fatigue life, and further improves the reliability of the positioning structure.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbine engines, and in particular, to an integral ceramic matrix turbine outer ring positioning structure. Background Art

[0002] The outer ring prepared from ceramic matrix composite (CMC) has certain advantages over the outer ring made of superalloy. It has higher temperature resistance, oxidation resistance, and thermal fatigue resistance, and at the same time can reduce the mass of the engine; in addition, the thermal deformation of the ceramic matrix composite is small, and designing it into an integral outer ring can maintain the tip clearance of the turbine rotor.

[0003] However, because the linear expansion coefficients of CMC materials and superalloy materials can differ by more than 3 times, at the working state of the engine, the temperature at the interface where the ceramic matrix outer ring is connected to the metal casing is extremely high. Since the thermal strain at the assembly position of the ceramic matrix outer ring is much smaller than that of the metal casing, the deformation mismatch at this place will cause thermal stress concentration, and its adverse effects are twofold:

[0004] 1. Thermal stress concentration affects the load-bearing capacity of the ceramic matrix composite, and in severe cases, it will cause the fracture of the ceramic matrix material;

[0005] 2. Thermal stress concentration may force the ceramic matrix composite to undergo unpredictable deformation, resulting in the inability to center the turbine outer ring assembly structure, and further causing the turbine rotor of the engine to scrape the turbine outer ring.

[0006] Therefore, a special connection structure must be designed between the metal part and the ceramic matrix composite part to ensure that their thermal deformation amounts are matched. In the high-temperature environment where the turbine outer ring is located, the matching degree determines the service life of the ceramic matrix composite.

[0007] The traditional hook-type connection form between the ceramic matrix turbine outer ring and the turbine casing needs to be improved. The current outer ring positioning structures include: adding a casing with an auxiliary support outer ring having a moderate coefficient of thermal expansion, or adopting a non-hook-type connection form, such as pin connection, spring connection, etc.

[0008] In the existing positioning structure design schemes, due to the high gas temperature level at the gas turbine position, the material selection of parts such as the casing with an auxiliary support outer ring and the spring is restricted, and the physical property parameters such as the coefficient of thermal expansion and elastic modulus of the existing materials are difficult to meet the design requirements. These ultimately result in the inability to center the ceramic matrix turbine outer ring, and the unstable cooperation between the metal casing and the ceramic matrix turbine outer ring, damage to the assembly surface, and low reliability of the positioning structure. Summary of the Invention

[0009] The present invention provides an integral ceramic matrix turbine outer ring positioning structure to solve the technical problems existing in the existing connection structure, such as the selection of materials for components such as the casing and springs that assist in supporting the outer ring being restricted, and the physical properties parameters such as the thermal expansion coefficient and elastic modulus of the existing materials being difficult to meet the design requirements, ultimately resulting in the inability to center the ceramic matrix turbine outer ring, and the unstable cooperation between the metal casing and the ceramic matrix turbine outer ring, damage to the assembly surface, and low reliability of the positioning structure.

[0010] The technical solution adopted by the present invention is as follows:

[0011] An integral ceramic matrix turbine outer ring positioning structure, comprising: a metal ring group arranged in a ring shape and serving as an installation and support, and a ceramic matrix turbine outer ring and an elastic seal adjustment component arranged in sequence along the axial direction in the inner ring cavity of the metal ring group; the first end of the ceramic matrix turbine outer ring abuts against the first end of the metal ring group to form a tapered surface fitting structure for limiting the ceramic matrix turbine outer ring in the radial and axial directions, the opposite second end of the ceramic matrix turbine outer ring abuts against the elastic seal adjustment component, and the opposite other end of the elastic seal adjustment component abuts against the second end of the metal ring group; the integral ceramic matrix turbine outer ring positioning structure is also used to convert the radial extrusion generated by thermal deformation between the ceramic matrix turbine outer ring and the metal ring group into the axial displacement of the ceramic matrix turbine outer ring through the tapered surface fitting structure, and then absorb the thermal deformation by the compression and expansion of the elastic seal adjustment component to reduce the thermal stress suffered by the ceramic matrix turbine outer ring.

[0012] Further, the metal ring group includes a metal casing and a limit retaining ring arranged in a ring shape, and multiple groups of fasteners for detachably fixing the metal casing and the limit retaining ring; the limit retaining ring is coaxially installed in the inner ring cavity of the metal casing, and the first ends of the two are detachably fixed by multiple groups of fasteners; the ceramic matrix turbine outer ring and the elastic seal adjustment component are sequentially limited between the second end of the limit retaining ring and the second end of the metal casing, and the first end of the ceramic matrix turbine outer ring is connected to the second end of the limit retaining ring to form a tapered surface fitting structure.

[0013] Further, the metal casing includes a casing cylinder body in a cylindrical shape, and a casing mounting edge connected to the outer circle of the first end of the casing cylinder body; the limit retaining ring includes a retaining ring body in a ring shape, and a retaining ring mounting edge connected to the outer circle of the first end of the retaining ring body; the retaining ring body is inserted into the first end of the casing cylinder body, and the retaining ring mounting edge abuts against the casing mounting edge for limiting, and is detachably fixed by multiple groups of fasteners arranged at equal intervals along the circumferential direction.

[0014] Further, the outer ring surface of the second end of the limit retaining ring is machined inward to form an outer tapered shaft surface with a gradually decreasing outer diameter dimension along the axial direction; the inner ring surface of the first end of the ceramic matrix turbine outer ring is machined outward at the connection with the end face to form an inner tapered hole surface matching the outer tapered shaft surface, and the ceramic matrix turbine outer ring and the limit retaining ring are connected through the cooperation of the inner tapered hole surface and the outer tapered shaft surface to form a tapered surface fitting structure.

[0015] Further, the inner ring surface of the second end of the limit retaining ring is machined by facing outward to form an inner tapered hole surface with a gradually increasing inner diameter dimension along the axial direction; the connection part between the outer ring surface and the end surface of the first end of the ceramic matrix turbine outer ring is machined by facing inward to form an outer tapered shaft surface matching the inner tapered hole surface, and the ceramic matrix turbine outer ring and the limit retaining ring are connected through the cooperation of the outer tapered shaft surface and the inner tapered hole surface to form a tapered surface fitting structure.

[0016] Further, the integral ceramic matrix turbine outer ring positioning structure further includes a plurality of anti-rotation pins for preventing the ceramic matrix turbine outer ring from rotating with the vibration of the engine and the gas flow; the plurality of anti-rotation pins are arranged at intervals in sequence along the circumferential direction, and the first ends of the anti-rotation pins are connected to the second end of the limit retaining ring, and the opposite second ends extend into the ceramic matrix turbine outer ring along the axial direction.

[0017] Further, the elastic seal adjustment assembly includes an adjustment pad for adjusting the clearance and an elastic seal ring for sealing; the adjustment pad and the elastic seal ring are clamped in sequence along the axial direction between the second end of the ceramic matrix turbine outer ring and the second end of the metal casing.

[0018] Further, a circumferentially protruding and annular limit flange is further provided on the inner ring surface of the second end of the metal casing; the first side of the adjustment pad abuts against the end surface of the second end of the ceramic matrix turbine outer ring for positioning, and the second side of the elastic seal ring abuts against the limit flange for positioning.

[0019] Further, a circumferentially protruding and annular limit flange is further provided on the inner ring surface of the second end of the metal casing; the outer ring surface of the second end of the ceramic matrix turbine outer ring is machined by facing inward to form a circumferential limit step ring; the adjustment pad and the elastic seal ring are sequentially installed on the outer ring surface of the limit step ring, and the first side of the adjustment pad also abuts against the vertical ring surface of the limit step ring for positioning, and the second side of the elastic seal ring also abuts against the limit flange for positioning.

[0020] Further, let the distance from the midpoint of the tapered surface fitting structure to the center of the integral ceramic matrix turbine outer ring positioning structure be R, the tapered angle of the tapered surface fitting structure be α, the elastic coefficient of the elastic seal ring at the working temperature be h, the tangential bending strength of the ceramic matrix turbine outer ring be g, the linear expansion coefficient of the metal casing be a1, and the linear expansion coefficient of the ceramic matrix turbine outer ring be a2; after the ceramic matrix turbine outer ring is simultaneously acted on by the positive pressure N applied by the limit retaining ring, the frictional force f it receives, and the elastic force F applied by the elastic seal adjustment assembly to reach force balance, where the calculation method of the elastic force F is: F = h × R × (a1 - a2) × cotα; the calculation method of the positive pressure N is: N = F × sinα; let the contact area of the tapered surface fitting structure be S, then the structural design needs to meet:

[0021] The present invention has the following beneficial effects:

[0022] The integrated ceramic-based turbine outer ring positioning structure of the present invention adopts a ceramic-based turbine outer ring made of a ceramic-based composite material and a metal ring group made of a high-temperature metal alloy to form a conical surface matching structure. If radial extrusion is generated at the interface where the ceramic-based turbine outer ring and the metal ring group are connected due to thermal deformation to form a radial thermal stress concentration phenomenon, it can be converted into axial displacement through the conical surface matching structure, and finally the thermal deformation is absorbed by the compression or expansion of the elastic structure of the elastic sealing adjustment component, thereby effectively reducing the thermal stress. The design structure has three advantages:

[0023] 1. The conical surface matching structure can solve the assembly problem of ceramic-based composite materials and high-temperature alloy parts under high temperature conditions, transform the contradiction between radial thermal stress and thermal strain (of the engine) to the axial direction of the engine, and avoid the thermal expansion of the metal ring group to damage the centering structure of the ceramic-based turbine outer ring, so that the ceramic-based turbine outer ring is accurately positioned and highly reliable, and is used to improve the accuracy of the positioning of the integral ceramic-based turbine outer ring, and avoid causing the engine turbine rotor to scratch the ceramic-based turbine outer ring;

[0024] 2. The scheme of the present invention can be effectively applied to high-temperature working environments of ceramic-based materials. In the case of complex casing design structure, limited manufacturing process and material selection, the positioning structure of the present invention is more flexible, the thermal stress on the ceramic-based turbine outer ring is smaller, and the bearing capacity of the ceramic-based turbine outer ring is less affected. The ceramic-based turbine outer ring is not easy to break and has a longer thermal fatigue life;

[0025] 3. Compared with the design scheme of elastic positioning structures such as radially installed springs, the technical scheme of the present invention can effectively avoid the problem of attenuation of the high-temperature elastic modulus value of existing materials, reduce the thermal stress caused by the uncoordinated thermal deformation at the positioning point of the ceramic-based turbine outer ring, save the design space of the positioning structure, reduce the number of parts, and thus improve the reliability of the positioning structure.

[0026] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 It is a schematic diagram of the cross-sectional front view of the integral ceramic-based turbine outer ring positioning structure of a preferred embodiment of the present invention;

[0029] Figure 2 yes Figure 1 Schematic diagram of the assembly method of the integral ceramic-based turbine outer ring positioning structure;

[0030] Figure 3 is Figure 1 Schematic diagram of the force analysis of the integral ceramic matrix turbine outer ring positioning structure in

[0031] Figure 4 is Figure 1 Schematic diagram of another embodiment of the integral ceramic matrix turbine outer ring positioning structure in

[0032] Figure 5 is Figure 1 Schematic diagram of yet another embodiment of the integral ceramic matrix turbine outer ring positioning structure in

[0033] Legend description

[0034] 10. Metal ring group; 11. Metal casing; 12. Limit retaining ring; 13. Fastener; 20. Ceramic matrix turbine outer ring; 30. Elastic seal adjustment assembly; 31. Adjusting pad; 32. Elastic seal ring; 40. Anti-rotation pin. Detailed implementation manners

[0035] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the following.

[0036] Referring to Figure 1 and Figure 2 , a preferred embodiment of the present invention provides an integral ceramic matrix turbine outer ring positioning structure, including: a metal ring group 10 arranged in a ring shape and serving as an installation support, and a ceramic matrix turbine outer ring 20 and an elastic seal adjustment assembly 30 which are sequentially arranged along the axial direction in the inner ring cavity of the metal ring group 10. The first end of the ceramic matrix turbine outer ring 20 abuts against the first end of the metal ring group 10 to form a tapered surface fitting structure for limiting the ceramic matrix turbine outer ring 20 in the radial and axial directions. The opposite second end of the ceramic matrix turbine outer ring 20 abuts against the elastic seal adjustment assembly 30, and the opposite other end of the elastic seal adjustment assembly 30 abuts against the second end of the metal ring group 10. The integral ceramic matrix turbine outer ring positioning structure is also used to convert the radial extrusion caused by thermal deformation between the ceramic matrix turbine outer ring 20 and the metal ring group 10 into the axial displacement of the ceramic matrix turbine outer ring 20 through the tapered surface fitting structure, and then absorb the thermal deformation by the compression and expansion of the elastic seal adjustment assembly 30 to reduce the thermal stress suffered by the ceramic matrix turbine outer ring 20.

[0037] When the integral ceramic matrix turbine outer ring positioning structure of the present invention is working, the gas temperature level at the turbine position increases. At this time, the difference in the linear expansion coefficients between the ceramic matrix turbine outer ring 20 and the metal ring group 10 made of superalloy material can reach more than 3 times. Therefore, the diameter change of the tapered hole surface in the tapered surface fitting structure at the first end of the ceramic matrix turbine outer ring 20 is smaller than the diameter of the tapered shaft surface in the metal ring group 10 that plays a fitting role. If in the tapered surface fitting structure, the tapered assembly surface of the ceramic matrix turbine outer ring 20 is the hole surface and the tapered assembly surface of the metal ring group 10 is the shaft surface, as Figure 1 and Figure 4 shown, then the tapered assembly surface of the metal ring group 10 radially extrudes the ceramic matrix turbine outer ring 20 from the inner side of the ceramic matrix turbine outer ring 20, and through the smooth tapered surface fitting structure, the ceramic matrix turbine outer ring 20 is pushed in the opposite axial direction, and the elastic seal adjustment assembly 30 is compressed; if in the tapered surface fitting structure, the tapered assembly surface of the ceramic matrix turbine outer ring 20 is the shaft surface and the tapered assembly surface in the metal ring group 10 is the hole surface, then the axial movement direction of the ceramic matrix turbine outer ring 20 under the hot condition is opposite, and the elastic seal adjustment assembly 30 squeezes and fits the metal ring group 10, so as to achieve the effect of accurately positioning the ceramic matrix turbine outer ring 20.

[0038] For the integral ceramic matrix turbine outer ring positioning structure of the present invention, the fitting surfaces of the ceramic matrix turbine outer ring 20 made of ceramic matrix composite material and the metal ring group 10 made of high-temperature metal alloy material form a tapered surface fitting structure. When radial extrusion occurs at the interface position where the ceramic matrix turbine outer ring 20 and the metal ring group 10 are connected due to thermal deformation, resulting in a radial thermal stress concentration phenomenon, it can be converted into an axial displacement through the tapered surface fitting structure, and finally the thermal deformation is absorbed by the compression or expansion of the elastic structure of the elastic seal adjustment assembly 30, thereby effectively reducing the thermal stress. The advantages of this design structure are as follows:

[0039] 1. The tapered surface fitting structure can solve the assembly problem of ceramic matrix composite material and superalloy material parts at high temperature, convert the contradiction between (engine) radial thermal stress and thermal strain to the engine axial direction, avoid the centering structure of the ceramic matrix turbine outer ring 20 being damaged by the thermal expansion of the metal ring group 10, make the positioning of the ceramic matrix turbine outer ring 20 accurate and reliable, and is used to improve the accuracy of the positioning of the integral ceramic matrix turbine outer ring 20, and avoid causing the engine turbine rotor to scrape the ceramic matrix turbine outer ring 20;

[0040] 2. The solution of the present invention can be effectively applied to the high-temperature working environment of ceramic matrix materials. When the design structure of the casing is complex, the manufacturing process and material selection are limited, the positioning structure of the present invention is more flexible, the thermal stress on the ceramic matrix turbine outer ring 20 is smaller, and thus the influence on the bearing capacity of the ceramic matrix turbine outer ring 20 is smaller. The ceramic matrix turbine outer ring 20 is not easily broken and has a higher thermal fatigue life;

[0041] 3. Compared with the design scheme of elastic positioning structures such as radially added springs, the technical scheme of the present invention can effectively avoid the problem of attenuation of the high-temperature elastic modulus value of existing materials, reduce the thermal stress caused by the uncoordinated thermal deformation at the positioning point of the ceramic-based turbine outer ring 20, save the design space of the positioning structure, reduce the number of parts, and thus improve the reliability of the positioning structure.

[0042] Alternatively, if Figure 1 and Figure 2 As shown, the metal ring assembly 10 includes a metal casing 11 and a stop ring 12 arranged in an annular shape, and a plurality of fasteners 13 for detachably fixing the metal casing 11 and the stop ring 12. The stop ring 12 is coaxially installed in the inner ring cavity of the metal casing 11, and the first ends of the two are detachably fixed by the plurality of fasteners 13. The ceramic-based turbine outer ring 20 and the elastic sealing adjustment assembly 30 are sequentially limited between the second end of the stop ring 12 and the second end of the metal casing 11, and the first end of the ceramic-based turbine outer ring 20 is connected to the second end of the stop ring 12 to form a conical surface matching structure.

[0043] In this option, if Figure 1 As shown, the metal casing 11 includes a casing body in the shape of a cylinder, and a casing mounting edge connected to the outer circle of the first end of the casing body. The limiting retaining ring 12 includes a retaining ring body in the shape of a ring, and a retaining ring mounting edge connected to the outer circle of the first end of the retaining ring body. After the retaining ring body is inserted into the casing body by the first end, the retaining ring mounting edge is pressed against the casing mounting edge for limiting position, and is detachably fixed by a plurality of groups of fasteners 13 evenly spaced along the circumferential direction. In this optional solution, the metal ring group 10 has a simple structure, is easy to process and prepare, and is simple to disassemble and assemble.

[0044] In this optional solution, the first embodiment of the conical surface matching structure is as follows: Figure 1 and Figure 4 As shown, the outer ring surface of the second end of the stop ring 12 is cut inward to form an outer conical axial surface with a gradually decreasing outer diameter along the axial direction. The inner ring surface of the first end of the ceramic-based turbine outer ring 20 and the end surface are cut outward to form an inner conical hole surface matching the outer conical axial surface. The ceramic-based turbine outer ring 20 and the stop ring 12 are connected by the inner conical hole surface and the outer conical axial surface to form a conical surface matching structure. Figure 1 and Figure 4As shown in the figure, a conical inner conical hole surface is designed on the left inner ring of the ceramic matrix turbine outer ring 20. Its assembly object is the limiting retaining ring 12 of the stator part, which has a conical outer conical shaft surface. Under the working condition of the engine, the radial thermal deformation of the limiting retaining ring 12 and the metal casing 11 will be greater than that of the ceramic matrix turbine outer ring 20. Therefore, it will squeeze the ceramic matrix turbine outer ring 20 to move to the right. The axial displacement of the ceramic matrix turbine outer ring 20 will be converted into the axial compression of the elastic sealing adjustment assembly 30, so as to achieve the design purpose of converting the radial thermal stress into axial elastic force, and further solve the related technical problems existing in the prior art.

[0045] In this alternative solution, a second embodiment of the conical surface fitting structure is as Figure 5 shown. The inner ring surface of the second end of the limiting retaining ring 12 is machined outward to form an inner conical hole surface with an axially increasing inner diameter dimension. The connection between the outer ring surface and the end surface of the first end of the ceramic matrix turbine outer ring 20 is machined inward to form an outer conical shaft surface matching the inner conical hole surface. The ceramic matrix turbine outer ring 20 and the limiting retaining ring 12 are connected through the cooperation of the outer conical shaft surface and the inner conical hole surface to form a conical surface fitting structure. As Figure 5 shown, a conical outer conical shaft surface is designed on the left outer ring of the integral ceramic matrix turbine outer ring 20. Its assembly object is the limiting retaining ring 12 of the stator part, which has a conical inner conical hole surface. Under the working condition of the engine, the radial thermal deformation of the limiting retaining ring 12 and the metal casing 11 will be greater than that of the ceramic matrix turbine outer ring 20. Therefore, the ceramic matrix turbine outer ring 20 will move to the left due to the extrusion of the elastic sealing adjustment assembly 30 on the right, so as to achieve the design purpose of converting the radial thermal stress into axial elastic force, and further solve the related technical problems existing in the prior art.

[0046] Preferably, as Figure 3 shown, in the first and second embodiments of the conical surface fitting structure, the angle between the inner conical hole surface and the outer conical shaft surface and the axis affects the magnitude of the extrusion thermal stress of the ceramic matrix turbine outer ring 20. After a large number of tests and calculations in this application invention, this angle is usually taken as 15° to 45°, and the specific value varies according to different engines.

[0047] Optionally, as Figure 1 shown, the integral ceramic matrix turbine outer ring positioning structure further includes a plurality of anti-rotation pins 40 for preventing the ceramic matrix turbine outer ring 20 from rotating with the vibration of the engine and the gas flow. The plurality of anti-rotation pins 40 are arranged at intervals in the circumferential direction, and the first ends of the anti-rotation pins 40 are connected to the second end of the limiting retaining ring 12, and the opposite second ends extend axially into the ceramic matrix turbine outer ring 20. In this alternative solution, as Figure 2As shown, the end face of the first end of the ceramic matrix turbine outer ring 20 is provided with notches evenly spaced circumferentially. The second end of the anti-rotation pin 40 extends axially into the corresponding notches of the ceramic matrix turbine outer ring 20, thereby preventing the ceramic matrix turbine outer ring 20 from rotating with the engine vibration and gas flow, and improving the accuracy and stability of its positioning.

[0048] Optionally, as Figure 1 and Figure 2 shown, the elastic seal adjustment assembly 30 includes an adjustment pad 31 for adjusting the clearance and an elastic seal ring 32 for sealing. The adjustment pad 31 and the elastic seal ring 32 are axially clamped in sequence between the second end of the ceramic matrix turbine outer ring 20 and the second end of the metal casing 11. In this optional solution, both the adjustment pad 31 and the elastic seal ring 32 are common parts in the turbine components of aeroengines, with convenient material selection, and the overall structure is simple and the number of parts is small; the adjustment pad 31 between the ceramic matrix turbine outer ring 20 and the W-shaped elastic seal ring 32 can adjust the initial compression amount of the W-shaped elastic seal ring 32 in the cold state; in the solution of the present invention, the elastic seal ring 32 not only has the function of isolating high-temperature gas, but also can absorb the thermal stress at the assembly of the metal ring group 10 and the ceramic matrix turbine outer ring 20 together with the adjustment pad 31, solving the existing technical problems.

[0049] In this optional solution, for the first embodiment of the positioning of the elastic seal adjustment assembly 30, as Figure 1 shown, a circumferentially protruding and annular limiting flange is further provided on the inner ring surface of the second end of the metal casing 11. The first side of the adjustment pad 31 abuts against the end face of the second end of the ceramic matrix turbine outer ring 20 for limitation, and the second side of the elastic seal ring 32 abuts against the limiting flange for limitation. In this optional solution, the processing is simple, and it is easy to install and position.

[0050] In this optional solution, for the second embodiment of the positioning of the elastic seal adjustment assembly 30, as Figure 4 and Figure 5 shown, a circumferentially protruding and annular limiting flange is further provided on the inner ring surface of the second end of the metal casing 11. A circumferential limiting step ring is formed by machining the outer ring surface of the second end of the ceramic matrix turbine outer ring 20 inward. The adjustment pad 31 and the elastic seal ring 32 are sequentially installed on the outer ring surface of the limiting step ring, and the first side of the adjustment pad 31 also abuts against the vertical ring surface of the limiting step ring for limitation, and the second side of the elastic seal ring 32 also abuts against the limiting flange for limitation. In this optional solution, a limiting step ring is designed at the second end of the ceramic matrix turbine outer ring 20, and the adjustment pad 31 and the elastic seal ring 32 are assembled, thereby reducing the corrosion of these two parts by gas.

[0051] Optionally, as Figure 3 shown, to achieve the above structural design purpose, it is necessary to calculate and analyze the key design elements of the structure:

[0052] Let the distance between the midpoint of the conical surface mating structure and the center of the integral ceramic matrix turbine outer ring positioning structure be \(R\), the conical angle of the conical surface mating structure be \(α\), the elastic coefficient of the elastic seal ring 32 at the working temperature be \(h\), the tangential bending strength of the ceramic matrix turbine outer ring 20 be \(g\), the linear expansion coefficient of the metal casing 11 be \(a_1\), and the linear expansion coefficient of the ceramic matrix turbine outer ring 20 be \(a_2\).

[0053] After the ceramic matrix turbine outer ring 20 is simultaneously acted on by the positive pressure \(N\) applied by the limit retaining ring 12, the frictional force \(f\), and the elastic force \(F\) applied by the elastic seal adjustment assembly 30, it reaches force balance. Among them, the calculation method of the elastic force \(F\) is:

[0054] \(F = h×R×(a_1 - a_2)×cotα\)

[0055] The calculation method of the positive pressure \(N\) is:

[0056] \(N = F×sinα\)

[0057] Let the contact area of the conical surface mating structure be \(S\), then the structural design needs to meet:

[0058]

[0059] Since in the above formulas, the elastic coefficient \(h\) of the elastic seal ring 32 at the working temperature, the tangential bending strength \(g\) of the ceramic matrix turbine outer ring 20, the linear expansion coefficient \(a_1\) of the metal casing 11, and the linear expansion coefficient \(a_2\) of the ceramic matrix turbine outer ring 20 are constants after the temperature and materials are selected, only the distance \(R\) and the conical angle \(α\) are variables in the above formulas. During actual design, by continuously adjusting \(R\) and \(α\), the strength of the conical assembly of the ceramic matrix turbine outer ring 20 at the working temperature can meet the design requirements, thereby solving the technical problems existing in the prior art.

[0060] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An integral ceramic matrix turbine outer ring positioning structure, characterized in that Comprising: A metal ring group (10) arranged in a ring shape and serving as an installation support, and a ceramic matrix turbine outer ring (20) and an elastic seal adjustment assembly (30) which are arranged in sequence along the axial direction in the inner ring cavity of the metal ring group (10); The first end of the ceramic matrix turbine outer ring (20) abuts against the first end of the metal ring group (10) to form a tapered surface fitting structure for limiting the ceramic matrix turbine outer ring (20) in the radial and axial directions. The opposite second end of the ceramic matrix turbine outer ring (20) abuts against the elastic seal adjustment assembly (30), and the opposite other end of the elastic seal adjustment assembly (30) abuts against the second end of the metal ring group (10); The integral ceramic matrix turbine outer ring positioning structure is also used to convert the radial extrusion caused by thermal deformation between the ceramic matrix turbine outer ring (20) and the metal ring group (10) into the axial displacement of the ceramic matrix turbine outer ring (20) through the tapered surface fitting structure, and then absorb the thermal deformation by the compression and expansion of the elastic seal adjustment assembly (30) to reduce the thermal stress borne by the ceramic matrix turbine outer ring (20); The metal ring group (10) includes a metal casing (11) and a limit retaining ring (12) arranged in a ring shape, and multiple groups of fasteners (13) for detachably fixing the metal casing (11) and the limit retaining ring (12); The elastic seal adjustment assembly (30) includes an adjustment pad (31) for adjusting the gap and an elastic seal ring (32) for sealing; the adjustment pad (31) and the elastic seal ring (32) are clamped in sequence along the axial direction between the second end of the ceramic matrix turbine outer ring (20) and the second end of the metal casing (11).

2. The integral ceramic matrix turbine outer ring positioning structure according to claim 1, characterized in that The limit retaining ring (12) is coaxially installed in the inner ring cavity of the metal casing (11), and the first ends of the two are detachably fixed by multiple groups of fasteners (13); The ceramic matrix turbine outer ring (20) and the elastic seal adjustment assembly (30) are sequentially limited between the second end of the limit retaining ring (12) and the second end of the metal casing (11), and the first end of the ceramic matrix turbine outer ring (20) is connected to the second end of the limit retaining ring (12) to form a tapered surface fitting structure.

3. The integral ceramic matrix turbine outer ring positioning structure according to claim 2, characterized in that The metal casing (11) includes a cylindrical casing body and a casing mounting edge connected to the outer circle of the first end of the casing body; The limit retaining ring (12) includes an annular retaining ring body and a retaining ring mounting edge connected to the outer circle of the first end of the retaining ring body; The retaining ring body is inserted into the first end of the casing body, and then the retaining ring mounting edge abuts against the casing mounting edge for limiting, and is detachably fixed by multiple groups of fasteners (13) evenly spaced along the circumferential direction.

4. The integral ceramic matrix turbine outer ring positioning structure according to claim 2, characterized in that The outer ring surface of the second end of the limit retaining ring (12) is machined by turning inward to form an outer tapered shaft surface with a gradually decreasing outer diameter dimension along the axial direction; The inner ring surface at the first end of the ceramic matrix turbine outer ring (20) is machined outward at the connection with the end face to form an inner tapered hole surface matching the outer tapered shaft surface. The ceramic matrix turbine outer ring (20) and the limit retaining ring (12) are connected through the cooperation of the inner tapered hole surface and the outer tapered shaft surface to form a tapered surface matching structure.

5. The integral ceramic matrix turbine outer ring positioning structure according to claim 2, wherein the inner ring surface at the second end of the limit retaining ring (12) is machined outward to form an inner tapered hole surface with an axially increasing inner diameter dimension; the outer ring surface at the first end of the ceramic matrix turbine outer ring (20) is machined inward at the connection with the end face to form an outer tapered shaft surface matching the inner tapered hole surface. The ceramic matrix turbine outer ring (20) and the limit retaining ring (12) are connected through the cooperation of the outer tapered shaft surface and the inner tapered hole surface to form a tapered surface matching structure.

6. The integral ceramic matrix turbine outer ring positioning structure according to claim 2, wherein the integral ceramic matrix turbine outer ring positioning structure further includes a plurality of anti-rotation pins (40) for preventing the ceramic matrix turbine outer ring (20) from rotating with the vibration of the engine and the gas flow; the plurality of anti-rotation pins (40) are arranged at intervals in sequence along the circumferential direction, and the first ends of the anti-rotation pins (40) are connected to the second end of the limit retaining ring (12), and the opposite second ends extend axially into the ceramic matrix turbine outer ring (20).

7. The integral ceramic matrix turbine outer ring positioning structure according to claim 2, wherein a ring-shaped limit flange protruding toward the center is further provided on the inner ring surface at the second end of the metal casing (11); the first side of the adjusting pad (31) abuts against the end face at the second end of the ceramic matrix turbine outer ring (20) for positioning, and the second side of the elastic sealing ring (32) abuts against the limit flange for positioning.

8. The integral ceramic matrix turbine outer ring positioning structure according to claim 2, wherein a ring-shaped limit flange protruding toward the center is further provided on the inner ring surface at the second end of the metal casing (11); the outer ring surface at the second end of the ceramic matrix turbine outer ring (20) is machined inward to form a circumferential limit step ring; the adjusting pad (31) and the elastic sealing ring (32) are sequentially installed on the outer ring surface of the limit step ring, and the first side of the adjusting pad (31) also abuts against the vertical ring surface of the limit step ring for positioning, and the second side of the elastic sealing ring (32) also abuts against the limit flange for positioning.

9. The integral ceramic matrix turbine outer ring positioning structure according to claim 2, wherein let the distance from the midpoint of the tapered surface matching structure to the center of the integral ceramic matrix turbine outer ring positioning structure be R, the tapered angle of the tapered surface matching structure be α, the elastic coefficient of the elastic sealing ring (32) at the working temperature be h, the tangential bending strength of the ceramic matrix turbine outer ring (20) be g, the linear expansion coefficient of the metal casing (11) be a1, and the linear expansion coefficient of the ceramic matrix turbine outer ring (20) be a2; the ceramic matrix turbine outer ring (20) reaches force balance after being simultaneously acted on by the positive pressure N applied by the limit retaining ring (12), the frictional force f, and the elastic force F applied by the elastic sealing adjustment assembly (30). Among them, the calculation method of the elastic force F is: F = h × R × (a1 - a2) × cotα; The calculation method of the normal pressure N is as follows: N = F × sinα; Let the contact area of the conical surface mating structure be S, then the structural design needs to meet:

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