A small aeroengine combustion chamber casing

Abstract

The application provides a small aero-engine combustion chamber case, and belongs to the technical field of aero-engines, which comprises a combustion chamber shell, a combustion chamber inner ring and a front support plate, the air inlet end of the combustion chamber shell and the proximal end of the combustion chamber inner ring are connected to the front support plate, the combustion chamber shell surrounds the outer periphery of the combustion chamber inner ring, the combustion chamber inner ring and the combustion chamber outer ring are provided with an annular support plate at the end close to the front support plate, the annular support plate, the combustion chamber inner ring and the front support plate form a containing cavity, and the containing cavity is filled with a support structure; the combustion chamber inner ring, the combustion chamber shell, the front support plate, the annular support plate and the support structure are obtained by additive printing, the annular support plate and the support structure are used for providing support for the front support plate when the front support plate is printed, the added support structure does not need to be removed after forming, the capacity of bearing external load can be strengthened, the support structure is utilized, and resource waste is reduced.

Description

Technical Field

[0001] This application relates to the field of aircraft engines, and more particularly to a small aircraft engine combustion chamber casing. Background Technology

[0002] Current development of small aero engines is moving towards lightweighting and cost reduction. The main structure of an engine includes the air intake, compressor, combustion chamber, and turbine. The casing outside the combustion chamber, as a load-bearing component, mainly withstands various loads such as radial force, axial force, torque, bending moment, inertial force, and vibration. Current manufacturing methods primarily involve forging and milling, which are not optimal in structure. Furthermore, limitations imposed by fixtures and other factors result in long lead times and high manufacturing costs.

[0003] Laser selective melting (LSM) in additive manufacturing is a near-net-shape forming technology that uses lasers as an energy source, digital models as a basis, and the principle of layer-by-layer material deposition. It is a key development direction in aerospace manufacturing, offering significant efficiency and cost advantages in model production and the production of single or small-batch complex components. Using additive manufacturing to form the combustion chamber casing can shorten the manufacturing cycle and reduce manufacturing costs.

[0004] To address the economic requirements of small aero-engines, additive manufacturing technology is used to fabricate the combustion chamber casing. However, additive manufacturing often requires the addition of additional support structures when printing planar structures. These supports are not only difficult to remove but also increase powder consumption, resulting in resource waste. Summary of the Invention

[0005] In view of this, this application provides a small aero-engine combustion chamber casing that solves the problems in the prior art. The original casing structure is optimized, and self-support is provided for planar printing in the additive manufacturing process. After molding, the added support structure does not need to be removed, which can enhance the ability to bear external loads and reduce resource waste by utilizing the support structure.

[0006] The technical solution for a small aircraft engine combustion chamber casing provided in this application is as follows:

[0007] A small aero-engine combustor casing includes a combustor shell, an inner combustor ring, and a front support plate. The air intake end of the combustor shell and the proximal end of the inner combustor ring are connected to the front support plate. The combustor shell surrounds the outer periphery of the inner combustor ring. The inner and outer combustor rings are provided with annular support plates at their ends near the front support plate. The inner ring of the annular support plate is connected to the inner combustor ring, and the outer ring of the annular support plate is connected to the front support plate. The outer ring of the annular support plate is closer to the front support plate than the inner ring. The annular support plate, the inner combustor ring, and the front support plate form a receiving cavity, which is filled with a support structure.

[0008] The combustion chamber inner ring, combustion chamber outer shell, front support plate, annular support plate, and support structure are manufactured by additive printing. The annular support plate and support structure are used to provide support for the front support plate during printing.

[0009] Optionally, the combustion chamber inner ring, combustion chamber outer shell, annular support plate, and support structure are made of the same material.

[0010] Optionally, the annular support plate includes an annular inclined plate, the inner ring of which is connected to the inner ring of the combustion chamber, and the outer ring of which is connected to the front support plate, wherein the outer ring of the annular inclined plate is closer to the front support plate than the inner ring.

[0011] Optionally, the annular support plate includes an annular inclined plate and an annular connecting plate. The annular connecting plate is perpendicular to the axial direction of the combustion chamber ring. The inner ring of the annular connecting plate is connected to the combustion chamber ring, and the outer ring of the annular connecting plate is connected to the inner ring of the annular inclined plate. The outer ring of the annular inclined plate is connected to the front support plate, and the outer ring of the annular inclined plate is closer to the front support plate than the inner ring.

[0012] Optionally, the angle between the annular inclined plate and the central axis of the combustion inner ring is greater than 20°.

[0013] Optionally, the support structure is a porous structure.

[0014] Optionally, the support structure is formed by stacking multiple lattice units, each lattice unit including several support rods. One end of each support rod of a lattice unit is connected together to form the center of the lattice unit. All the support rods of the lattice unit are in a body-centered cubic structure. The support rods of adjacent lattice units of the support structure are connected to each other. The support rods on the outermost layer of the lattice unit of the support structure in the receiving chamber are connected to the inner wall of the receiving chamber.

[0015] Optionally, the ends of the support rods aligned with each other along the inner combustion ring axis in the dot matrix unit are connected by a column.

[0016] Optionally, the length and / or diameter of the struts of the lattice units in the receiving chamber gradually decrease from the inside out.

[0017] Optionally, a straight line passing through the center of the lattice unit and parallel to the axial direction of the combustion chamber ring is a first straight line, and the acute angle between the support rod of the lattice unit and the first straight line is less than 45° and greater than 20°.

[0018] In summary, this application includes the following beneficial technical effects:

[0019] The combustion chamber casing of this application combines the characteristics of additive manufacturing and optimizes the original casing structure. An annular support plate and a support structure are added near the front support plate in the combustion chamber area. The annular support plate is located between the outer shell of the combustion chamber and the inner ring of the combustion chamber, forming a receiving cavity. The support structure is located in the receiving cavity. A conical structure is designed inside the casing structure at the compressor end, while reducing the thickness of the original plane. This not only provides support for the printing of the front support plate plane during the additive manufacturing process, playing a self-supporting role, but also, as part of the combustion chamber casing, the added annular support plate and support structure do not affect the normal operation of the combustion chamber. After the combustion chamber casing is formed, the support structure does not need to be removed, and the support structure is used to enhance the combustion chamber casing's ability to bear external loads.

[0020] This application employs a method to increase the density of lattice unit filling at the boundary region by altering the size of the lattice units and reducing the length and / or diameter of the support rods. The relative dimensions of the lattice units are varied according to their spatial location within the accommodating chamber, resulting in variable-density filling from the boundary towards the interior. Simultaneously, the strength and stiffness of the casing are analyzed. If the preset requirements are not met, the rod diameter and density distribution of the filling lattice units are further modified, ultimately ensuring that the lattice unit arrangement closely approximates the shape of the filling domain. This effectively reduces the phenomenon of incomplete lattice units at irregular structural boundaries, preventing lattice unit detachment and structural failure during load-bearing. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the combustion chamber casing of the small aircraft engine in this application;

[0023] Figure 2 This is a structural diagram of the cavity and supporting structure of this application;

[0024] Figure 3 This is a schematic diagram of the lattice elements of the body-centered cubic structure in this application;

[0025] Figure 4 This is a schematic diagram of the lattice unit with columns added to the body-centered cubic structure in this application.

[0026] Explanation of reference numerals in the attached drawings: 1. Combustion chamber outer shell; 2. Inner ring of the combustion chamber; 3. Front support plate; 4. Fuel delivery pipe; 5. Combustion chamber area; 6. Receiving chamber; 61. Annular inclined plate; 62. Annular connecting plate; 63. Support structure; 7. Support rod; 71. Column. Detailed Implementation

[0027] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0028] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0030] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0031] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0032] This application provides a small aircraft engine combustion chamber casing.

[0033] like Figure 1 As shown, a small aero-engine combustor casing includes a combustor outer shell 1, an inner combustor ring 2, and a front support plate 3. The air intake end of the combustor outer shell 1 and the proximal end of the inner combustor ring 2 are connected to the front support plate 3. The combustor outer shell 1 surrounds the outer periphery of the inner combustor ring 2, forming a combustor region 5 between the combustor outer shell 1 and the inner combustor ring 2. A compressor rotor is installed at the position of the front support plate 3 of the combustor casing, and a turbine stator is installed at the other end of the combustor casing for connection with the tail nozzle. The combustor casing also includes a fuel supply pipe 4 for supplying fuel to the combustor. The combustor casing is the load-bearing housing of the engine. The front section of the combustor outer shell 1 and the inner combustor ring 2 constitute a diffuser to reduce the compressor airflow velocity. The combustor outer shell 1 and the inner combustor ring 2 form an annular airflow channel to ensure airflow stability.

[0034] The inner ring 2 and outer ring of the combustion chamber are provided with annular support plates at their ends near the front support plate 3. The inner ring of the annular support plate is connected to the inner ring 2 of the combustion chamber, and the outer ring of the annular support plate is connected to the front support plate 3. The outer ring of the annular support plate is closer to the front support plate 3 than the inner ring. The annular support plate, the inner ring 2 of the combustion chamber, and the front support plate 3 form a receiving chamber 6, which is filled with a support structure 63. The inner ring 2 of the combustion chamber, the outer ring 1 of the combustion chamber, the front support plate 3, the annular support plate, and the support structure 63 are manufactured by additive printing. The annular support plate and the support structure 63 are used to provide support for the front support plate 3 when it is printed.

[0035] like Figure 1 and Figure 2 As shown, to meet the economic requirements of small aero-engines, additive manufacturing technology is used to prepare the combustion chamber casing. Since additive manufacturing often requires additional support structures when printing planar structures, these supports are not only difficult to remove but also increase powder usage, resulting in resource waste. Therefore, the combustion chamber casing of this application combines the characteristics of additive manufacturing and optimizes the original casing structure. An annular support plate and support structure 63 are added near the front support plate 3 within the combustion chamber region 5. The annular support plate is located between the combustion chamber outer shell 1 and the inner ring 2 of the combustion chamber, forming a receiving chamber 6. The support structure 63 is located within the receiving chamber 6. A conical structure is designed inside the casing structure at the compressor end, while reducing the thickness of the original plane. This not only provides support for the planar printing of the front support plate 3 during the additive manufacturing process, acting as a self-supporting mechanism, but the added annular support plate and support structure 63, as part of the combustion chamber casing, do not affect the normal operation of the combustion chamber. After the combustion chamber casing is formed, the support structure 63 does not need to be removed, and it is used to enhance the combustion chamber casing's ability to bear external loads.

[0036] In one embodiment, the combustion chamber inner ring 2, the combustion chamber outer shell 1, the annular support plate, and the support structure 63 are made of the same material.

[0037] like Figure 1 As shown, regarding the annular support plate, in one embodiment, the annular support plate includes an annular inclined plate 61, the inner ring of which is connected to the combustion chamber ring 2, and the outer ring of which is connected to the front support plate 3, wherein the outer ring of the annular inclined plate 61 is closer to the front support plate 3 than the inner ring. Figure 2 As shown, in another embodiment, the annular support plate includes an annular inclined plate 61 and an annular connecting plate 62. The annular connecting plate 62 is perpendicular to the axial direction of the combustion chamber ring 2. The inner ring of the annular connecting plate 62 is connected to the combustion chamber ring 2, and the outer ring of the annular connecting plate 62 is connected to the inner ring of the annular inclined plate 61. The outer ring of the annular inclined plate 61 is connected to the front support plate 3, and the outer ring of the annular inclined plate 61 is closer to the front support plate 3 than the inner ring. The angle between the annular inclined plate 61 and the central axis of the combustion chamber ring is greater than 20°.

[0038] Regarding the support structure 63, in this embodiment, the support structure 63 is a porous structure, which can reduce the weight of the engine. In other embodiments, the support structure 63 can be a solid filler.

[0039] like Figure 3 As shown, in this embodiment of the application, the support structure 63 is formed by stacking multiple lattice units. Each lattice unit includes several support rods 7. One end of each support rod 7 of a lattice unit is connected together to form the center of the lattice unit. All the support rods 7 of the lattice unit have a body-centered cubic structure, that is, a BBC-type lattice unit. The support rods 7 of adjacent lattice units of the support structure 63 are connected to each other. The support rods 7 on the outermost layer of the lattice unit of the support structure 63 in the receiving chamber 6 are connected to the inner wall of the receiving chamber 6.

[0040] The specific description of the lattice unit is as follows: a straight line passing through the center of the lattice unit and parallel to the axial direction of the combustion chamber ring 2 is designated as the first straight line; a plane passing through the center of the lattice unit and perpendicular to the first straight line is designated as the first plane. A portion of the supports 7 in one lattice unit is designated as the first support, and the remaining portion is designated as the second support. The first support extends from the center of the lattice unit toward the side closer to the front support plate 3, and the second support extends from the center of the lattice unit toward the side farther from the front support plate 3. Figure 3 The upward-facing support rod 7 is the first rod, and the downward-facing support rod 7 is the second rod; all the first rods in a lattice unit are evenly distributed around the first straight line, and all the second rods in a lattice unit are evenly distributed around the first straight line, and the lattice unit is symmetrical about the first plane.

[0041] like Figure 4 As shown, in one embodiment, the ends of the support rods 7 aligned with each other along the combustion inner ring axis in the lattice unit can be connected by columns 71. That is, the aligned first and second rods are connected by columns 71. The lattice unit is a BBCZ type structure, and BCCZ adds columns 71 at the two corresponding nodes above and below BCC to enhance the rigidity and strength of its structural unit. The BBCZ type lattice unit has a firm connection of rods, good structural stability, and good bending and compressive strength. At the same time, there are no horizontal rods inside the lattice unit, which meets the requirements of additive manufacturing technology. Other lattice units with good mechanical properties can also be selected. This makes the support structure 63 a hollow structure composed of multiple lattice units, which can effectively reduce the weight of the casing.

[0042] For the annular support plate and support structure 63 inside the combustion chamber casing, under the premise of calculating the strength and stiffness of the structural model through the finite element analysis method, lattice units are filled inside the accommodating chamber 6. The lattice units in the lattice design are mainly divided into truss type and three-period minimal surface. Since the three-period minimal surface is not suitable for drawing with traditional 3D software, and the surface of the lattice unit is difficult to remove powder during the manufacturing process, truss type lattice units based on columns are adopted. The three-dimensional lattice unit in the lattice design is a porous structure composed of trusses. The rod diameter and tilt angle of its lattice unit have strong designability and outstanding specific strength and specific stiffness.

[0043] The acute angle between the support rod 7 of the lattice unit and the first straight line is less than 45° and greater than 20°.

[0044] During the filling process of lattice units, the connection between the lattice units and the receiving chamber 6 often plays a crucial role in load transfer. When filling irregular structures, lattice units are prone to cuts and incompleteness at the boundaries, causing interface peeling between the lattice units and the components under load. This results in the external load not being effectively transferred to the internal lattice units, leading to the lattice units being unable to bear the load effectively. If large-sized lattice units are used to uniformly fill the structural areas inside the casing, cuts and incomplete units will appear at the filling boundaries, causing interface peeling between the lattice units and the components under load, resulting in the lattice units being unable to bear the load effectively. If small-sized lattice units are used, a large number of lattice units will be generated, which will greatly affect modeling efficiency and increase the amount of manufacturing powder used in the additive manufacturing process.

[0045] In this application, the length and / or diameter of the support rods 7 of the lattice units in the receiving chamber 6 gradually decrease from the inside out. In the boundary region, the size of the lattice units is changed, reducing the length and / or diameter of the support rods 7. This results in denser filling at the boundary. The relative size of the lattice units is adjusted according to different spatial locations within the receiving chamber 6, achieving variable density filling from the boundary inwards. Simultaneously, the strength and stiffness of the casing are analyzed. If the preset requirements are not met, the diameter and density distribution of the filled lattice units are further modified, ultimately making the lattice unit arrangement approximate the shape of the filling domain. This effectively reduces the phenomenon of incomplete lattice units at irregular structural boundaries, preventing lattice unit detachment and structural failure at the boundary during load-bearing.

[0046] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A small aircraft engine combustor casing, comprising a combustor outer shell (1), a combustor inner ring (2), and a front support plate (3), wherein the air intake end of the combustor outer shell (1) and the proximal end of the combustor inner ring (2) are connected to the front support plate (3), and the combustor outer shell (1) surrounds the outer periphery of the combustor inner ring (2), characterized in that, The combustion chamber inner ring (2) and the combustion chamber outer ring are provided with annular support plates at the ends near the front support plate (3). The inner ring of the annular support plate is connected to the combustion chamber inner ring (2), and the outer ring of the annular support plate is connected to the front support plate (3). The outer ring of the annular support plate is closer to the front support plate (3) than the inner ring. The annular support plate, the combustion chamber inner ring (2) and the front support plate (3) form a receiving chamber (6), and the receiving chamber (6) is filled with a support structure (63). The combustion chamber inner ring (2), combustion chamber outer shell (1), front support plate (3), annular support plate and support structure (63) are manufactured by additive printing. The annular support plate and support structure (63) are used to provide support for the front support plate (3) when printing the front support plate (3). The support structure (63) is a porous structure, which is formed by stacking multiple lattice units. Each lattice unit includes several support rods (7). One end of each support rod (7) of a lattice unit is connected together to form the center of the lattice unit. All the support rods (7) of the lattice unit are in a body-centered cubic structure. The support rods (7) of adjacent lattice units of the support structure (63) are connected to each other. The support rods (7) on the outermost layer of the lattice unit of the support structure (63) in the receiving chamber (6) are connected to the inner wall of the receiving chamber (6). The length and / or diameter of the struts (7) of the lattice units in the receiving chamber (6) gradually decrease from the inside to the outside; The first straight line is a straight line passing through the center of the lattice unit and parallel to the axial direction of the combustion chamber ring (2). The acute angle between the support rod (7) of the lattice unit and the first straight line is less than 45° and greater than 20°.

2. The small aero-engine combustion chamber casing according to claim 1, characterized in that, The combustion chamber inner ring (2), combustion chamber outer shell (1), annular support plate and support structure (63) are made of the same material.

3. The small aero-engine combustion chamber casing according to claim 1, characterized in that, The annular support plate includes an annular inclined plate (61), the inner ring of which is connected to the combustion chamber ring (2), and the outer ring of which is connected to the front support plate (3). The outer ring of the annular inclined plate (61) is closer to the front support plate (3) than the inner ring.

4. The small aero-engine combustion chamber casing according to claim 1, characterized in that, The annular support plate includes an annular inclined plate (61) and an annular connecting plate (62). The annular connecting plate (62) is perpendicular to the axial direction of the combustion chamber ring (2). The inner ring of the annular connecting plate (62) is connected to the combustion chamber ring (2). The outer ring of the annular connecting plate (62) is connected to the inner ring of the annular inclined plate (61). The outer ring of the annular inclined plate (61) is connected to the front support plate (3). The outer ring of the annular inclined plate (61) is closer to the front support plate (3) than the inner ring.

5. The small aircraft engine combustion chamber casing according to claim 3 or 4, characterized in that, The angle between the annular inclined plate (61) and the central axis of the combustion inner ring is greater than 20°.

6. The small aero-engine combustion chamber casing according to claim 1, characterized in that, The ends of the support rods (7) aligned with each other along the inner ring axis of the combustion in the dot matrix unit are connected by columns (71).

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