Aero-engine through outer-duct casing seal structure and structural parameter design method thereof

Abstract

This application belongs to the technical field of aero-engine bypass casing sealing structure design, specifically relating to an aero-engine bypass casing sealing structure and its structural parameter design method. The aero-engine bypass casing sealing structure includes an annular mounting base, a mounting cylinder, and a floating ring. The annular mounting base is connected to the outside of the bypass casing. The mounting cylinder is disposed inside the annular mounting base, with an annular mounting edge on its outer wall, which is connected above the annular mounting base. The floating ring is fitted onto the outer periphery of the bypass casing structure, engaging in a movable groove on the outer wall of the bypass casing structure, with reserved movement space between it and the movable groove. It is also disposed inside the mounting cylinder, with its outer edge in sealing contact with the inner wall of the mounting cylinder. Under cold conditions, the centerlines of the annular mounting base, mounting cylinder, and floating ring coincide, and are offset rearward along the aero-engine axis relative to the centerline of the bypass casing structure.

Description

Technical Field

[0001] This application belongs to the technical field of sealing structure design for aero-engine through-bypass casing, specifically relating to a sealing structure for aero-engine through-bypass casing and its structural parameter design method. Background Technology

[0002] The outer bypass casing of an aero-engine has various structures that extend out of the outer bypass casing, such as pipeline structures for oil, air, and lead wires. These structures that extend out of the outer bypass casing are often connected to the inner casing, such as the core engine casing, and need to be sealed at the outer bypass casing. Considering that the operating temperature and casing materials of the outer bypass casing and the inner casing are different, the amount of thermal expansion is different. The sealing structure at the outer bypass casing needs to be able to compensate for the thermal expansion difference between the outer bypass casing and the inner casing.

[0003] Currently, floating sealing structures are often used at the outer duct casing for structures that extend beyond the outer duct, such as... Figure 1 As shown, it includes an annular mounting base 1, a mounting cylinder 2, and a floating ring 3. The annular mounting base 1 is used to connect to the outside of the outer duct casing and can be integrally formed on the outer duct casing. The mounting cylinder 2 is disposed inside the annular mounting base 1, and its outer wall has an annular mounting edge, which is connected to the top of the annular mounting base 1. The floating ring 3 is used to fit onto the outer periphery of the outer duct casing structure 4, and is locked in the movable groove opened in the outer wall of the outer duct casing structure 4. A movement space is reserved between the floating ring 3 and the movable groove. It is disposed inside the mounting cylinder 2, and its outer edge is in sealed contact with the inner wall of the mounting cylinder 2. If the outer duct casing structure 4 has a tendency to rotate relative to the annular mounting base 1, the outer edge of the floating ring 3 can be designed as a spherical surface.

[0004] The existing floating sealing structure on the outer bypass casing uses the sliding of the floating ring 3 in the mounting cylinder 2 and the moving groove to compensate for the thermal expansion difference between the outer bypass casing and the inner casing. It generally adopts a symmetrical design, that is, when the aero-engine is in a cold state, the center line of the annular mounting seat 1, the mounting cylinder 2, and the floating ring 3 coincides with the center line of the structure 4 that extends out of the outer bypass casing. Based on the required expansion difference compensation amount in the hot state, and considering the machining deviation, the movement space between the floating ring 3 and the moving groove of the structure 4 that extends out of the outer bypass casing is reserved. In practice, when an aero-engine is operating, the operating temperature of the inner casing is higher than that of the outer bypass casing. The movement direction of the outer bypass casing structure 4, which connects the inner casing to the outer bypass casing, is fixed relative to the outer bypass casing, i.e., it moves backward along the aero-engine axis. The symmetrical design means that the forward movement space between the floating ring 3 and the outer bypass casing structure 4 along the aero-engine axis is consistent with the backward movement space along the aero-engine axis. This results in a larger size for the annular mounting seat 1, mounting cylinder 2, and floating ring 3, which increases the overall weight of the aero-engine and requires larger mounting holes on the outer bypass casing, which will adversely affect the strength of the outer bypass casing.

[0005] This application is made in view of the aforementioned technical deficiencies. Summary of the Invention

[0006] The purpose of this application is to provide a sealing structure for an aero-engine through-pass outer casing and a method for designing its structural parameters, so as to overcome or mitigate at least one of the known technical defects.

[0007] The technical solution of this application is:

[0008] On the one hand, a sealing structure for an aero-engine through-outer bypass casing is provided, including an annular mounting base, a mounting cylinder, and a floating ring;

[0009] The annular mounting bracket is used to connect to the outside of the outer bypass casing;

[0010] The mounting cylinder is located inside the annular mounting base, and its outer wall has an annular mounting edge, which is connected to the top of the annular mounting base.

[0011] The floating ring is used to fit onto the outer periphery of the through-hole casing structure, and is locked in the moving groove opened in the outer wall of the through-hole casing structure. A movement space is reserved between the floating ring and the moving groove, and it is set inside the mounting cylinder, with its outer edge in sealed contact with the inner wall of the mounting cylinder.

[0012] Under cold conditions, the centerlines of the annular mounting base, mounting cylinder, and floating ring coincide, and are offset rearward along the aero-engine axis relative to the centerline of the outer bypass casing structure.

[0013] According to at least one embodiment of this application, the aforementioned aero-engine extends out of the outer bypass casing sealing structure, and the annular mounting seat is integrally formed on the outer bypass casing or assembled on the casing.

[0014] According to at least one embodiment of this application, in the above-described aero-engine through-bypass casing sealing structure, the outer edge of the floating ring is spherical.

[0015] According to at least one embodiment of this application, in the above-mentioned aero-engine through-bypass casing sealing structure, under the cold state of the aero-engine, the centerline of the annular mounting base, mounting cylinder, and floating ring is offset backward by a distance S relative to the centerline of the through-bypass casing structure along the aero-engine axis. The relative movement distance between the through-bypass casing structure and the outer bypass casing is designed according to the aero-engine cruise time.

[0016] On the other hand, a method for designing the parameters of the sealing structure of the through-bypass casing of an aero-engine is provided. This method is used to design the inner diameter d1 and outer diameter d2 of the upstream moving groove in the through-bypass casing structure, the inner diameter D1 and outer diameter D2 of the floating ring, the reserved movement space L1 between the floating ring and the upstream moving groove in the through-bypass casing structure along the aero-engine axis, the overlap L2 between the floating ring and the upstream moving groove in the through-bypass casing structure along the aero-engine axis, the rearward distance L3 between the mounting cylinder and the through-bypass casing structure along the aero-engine axis, and the forward distance L4 between the mounting cylinder and the through-bypass casing structure along the aero-engine axis. The method includes:

[0017] The basic dimensions of d1 are determined based on the structural characteristics of the culvert.

[0018] Considering the machining deviation between the through-hole casing structure and the outer bypass casing, and the space required for the maximum motion compensation between the through-hole casing structure and the outer bypass casing when the aero-engine is hot, determine L1;

[0019] The calculated result is D1: L1 = 0.5 * D1 + S - 0.5 * d1;

[0020] Design L2 > L1;

[0021] The lower boundary of d2 is calculated as: L2 = 0.5 * d2 - (0.5 * D1 - S);

[0022] Design L3 > L1;

[0023] Calculate the lower boundary of the value of D2: L3 = 0.5 * D2 + S - 0.5 * d2;

[0024] Considering the machining deviation between the through-hole casing structure and the outer duct casing, determine L4.

[0025] According to at least one embodiment of this application, in the above-described design method for the sealing structure parameters of the aero-engine through-bypass casing, L4 is used as the design input value to determine the values ​​of d2 and D2, where L4 = 0.5 * D2 - S - 0.5 * d2.

[0026] According to at least one embodiment of this application, in the above-described design method for the sealing structure parameters of the aero-engine bypass casing, the values ​​of d2 and D2 should not affect the rotation of the bypass casing structure within a certain angle range.

[0027] This application has at least the following beneficial technical effects:

[0028] This invention provides a sealing structure for an aero-engine through-pass casing and a method for designing its structural parameters. Based on the fact that the movement direction of the through-pass casing structure relative to the outer bypass casing during aero-engine operation is rearward along the aero-engine axis, the cold-state design offsets the centerlines of the annular mounting base, mounting cylinder, and floating ring relative to the centerline of the through-pass casing structure along the aero-engine axis. This reduces the radial dimensions of the annular mounting base, mounting cylinder, and floating ring while ensuring that the reserved space along the movement direction remains unchanged. This reduces the overall weight of the aero-engine and mitigates the adverse effects on the strength of the outer bypass casing. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a floating seal structure that extends through the existing outer casing of the outer casing.

[0030] Figure 2 This is a schematic diagram of the sealing structure of the aero-engine through the outer bypass casing provided in the embodiments of this application;

[0031] Figure 3 This is a schematic diagram of the parameter design of the sealing structure of the aero-engine through-the-outer-brush casing provided in the embodiments of this application;

[0032] in:

[0033] 1-Annular mounting base; 2-Mounting cylinder; 3-Floating ring; 4-Extending structure through the outer casing;

[0034] S is the distance by which the center line of the annular mounting base (1), mounting cylinder (2), and floating ring (3) is offset backward along the axis of the aero-engine relative to the center line of the outer bypass casing structure (4);

[0035] d1 and d2 are the inner and outer diameters of the upstream moving groove of the outer culvert casing structure (4);

[0036] D1 and D2 are the inner and outer diameters of the floating ring (3);

[0037] L1 is a reserved space for movement along the aero-engine axis between the upstream moving slots of the floating ring (3) and the outer bypass casing structure (4);

[0038] L2 is the overlap between the floating ring (3) and the upstream moving slot of the outer bypass casing structure (4) along the forward axis of the aero-engine.

[0039] L3 is the distance along the rearward axis of the aero-engine between the mounting cylinder (2) and the outer bypass casing structure (4);

[0040] L4 is the forward distance along the axis of the aero-engine between the mounting cylinder (2) and the outer bypass casing structure (4).

[0041] To better illustrate this embodiment, some content in the accompanying drawings may be omitted, enlarged, or reduced. They are for illustrative purposes only and should not be construed as limiting the scope of this application. Detailed Implementation

[0042] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, and other related parts can be referred to the general design.

[0043] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The word "comprising" as used in this application description indicates that the concept preceding the word encompasses the concepts listed following the word and their equivalents, without excluding other related concepts.

[0044] Furthermore, the terms indicating location used in the description of this application are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation" and "connection" used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0045] This application provides a sealing structure for an aero-engine bypass casing, including an annular mounting base 1, a mounting cylinder 2, and a floating ring 3. Figure 2 As shown.

[0046] The annular mounting base 1 is used to connect to the outside of the outer bypass casing, and can be integrally formed on the outer bypass casing or assembled on the casing.

[0047] The mounting cylinder 2 is located inside the annular mounting base 1, and its outer wall has an annular mounting edge, which is connected to the top of the annular mounting base 1.

[0048] The floating ring 3 is used to fit around the outer periphery of the through-hole casing structure 4 and is locked in the moving groove opened in the outer wall of the through-hole casing structure 4. A movement space is reserved between the floating ring 3 and the moving groove. It is set inside the mounting cylinder 2, and its outer edge is in sealed contact with the inner wall of the mounting cylinder 2. If the through-hole casing structure 4 has a tendency to rotate relative to the annular mounting seat 1, the outer edge of the floating ring 3 can be designed as a spherical surface.

[0049] Under cold conditions, the centerlines of the annular mounting base 1, mounting cylinder 2, and floating ring 3 coincide, and are offset backward along the axis of the aero-engine relative to the centerline of the outer bypass casing structure 4. The backward offset distance is S, and its value is related to the amount of motion of the outer bypass casing structure 4 relative to the outer bypass casing under hot conditions. It can be designed according to the relative motion distance between the outer bypass casing structure 4 and the outer bypass casing when the aero-engine is in a cold state to a cruise operating state.

[0050] The key structural parameters of the sealing structure of the aero-engine through-bypass casing disclosed in the above embodiments include:

[0051] The inner diameter d1 and outer diameter d2 of the upstream moving groove protruding from the outer duct casing structure 4;

[0052] The inner diameter D1 and outer diameter D2 of the floating ring 3;

[0053] Floating ring 3, reserved movement space L1 along the rearward axis of the aero-engine between the upstream moving slots of the outer bypass casing structure 4;

[0054] Floating ring 3, the overlap L2 between the upstream moving slots of the outer bypass casing structure 4 along the forward axis of the aero-engine;

[0055] The distance L3 between the mounting cylinder 2 and the outer casing structure 4 along the rearward direction of the aero-engine axis;

[0056] The distance L4 between the mounting cylinder 2 and the outer bypass casing structure 4 along the forward direction of the aero-engine axis is as follows: Figure 3 As shown.

[0057] For the design of the above key structural parameters, please refer to the following:

[0058] The basic dimensions of d1 are determined based on the structural characteristics of the culvert.

[0059] Taking into account the machining deviation between the through-hole casing structure 4 and the outer bypass casing, and the space required for the maximum motion compensation between the through-hole casing structure 4 and the outer bypass casing when the aero-engine is hot, L1 is determined. L1 is an input value determined based on the aero-engine's operating parameters, material parameters, and machining technology level.

[0060] The calculated value is D1: L1 = 0.5 * D1 + S - 0.5 * d1.

[0061] Considering the hot state of the aero-engine, after the relative movement between the through-hole casing structure 4 and the outer bypass casing, the floating ring 3 cannot disengage from the floating groove on the through-hole casing structure 4. Therefore, L2>L1 is designed to ensure sufficient overlap.

[0062] The lower boundary of d2 is calculated as: L2 = 0.5 * d2 - 0.5 * D1 - S.

[0063] Considering the hot state of the aero-engine, the limit state of the movement of the through-outer bypass casing structure 4 relative to the outer bypass casing is that the bottom wall of the upstream moving groove of the through-outer bypass casing structure 4 contacts the inner ring of the floating ring 3, and a sufficient distance should be reserved between the mounting cylinder 2 and the through-outer bypass casing structure 4, with L3>L1 designed.

[0064] Calculate the lower boundary of the value of D2: L3 = 0.5 * D2 + S - 0.5 * d2.

[0065] Considering the machining deviation between the through-hole casing structure 4 and the outer duct casing, which may cause the actual position of the through-hole casing structure 4 to deviate from the theoretical position, L4 is determined. L4 is related to the machining level and can be used as a design input value to determine the values ​​of d2 and D2. L4 = 0.5 * D2 - S - 0.5 * d2.

[0066] If the outer bypass casing structure 4 has a tendency to rotate relative to the annular mounting base 1, when the outer edge of the floating ring 3 is designed as a spherical surface, the values ​​of d2 and D2 should not affect the rotation of the outer bypass casing structure 4 within a certain angle range.

[0067] The above-described embodiment discloses a sealing structure for an aero-engine through-pass casing and its structural parameter design method. Based on the fact that the movement direction of the through-pass casing structure 4 relative to the outer bypass casing during aero-engine operation is rearward along the aero-engine axis, the cold-state design makes the center lines of the annular mounting seat 1, mounting cylinder 2, and floating ring 3 offset rearward along the aero-engine axis relative to the center line of the through-pass casing structure 4. This can reduce the radial dimensions of the annular mounting seat 1, mounting cylinder 2, and floating ring 3 while ensuring that the reserved space along the movement direction remains unchanged, thereby reducing the overall weight of the aero-engine and reducing the adverse effects on the strength of the outer bypass casing.

[0068] In a typical example, when the centerlines of the annular mounting base 1, mounting cylinder 2, and floating ring 3 are offset backward by a distance S along the aero-engine axis relative to the centerline of the outer bypass casing structure 4, the reduction in the inner diameter d1 and outer diameter d2 of the floating groove through the outer bypass casing structure 4, and the reduction in the inner diameter D1 and outer diameter D2 of the floating ring 3 (i.e., the inner diameter of the mounting cylinder 2) are shown in the table below: Structural parameters Decrease amount d1 0 d2 -S D1 -2S D2 -4S

[0069] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A sealing structure for an aero-engine through-passage outer casing, characterized in that, It includes an annular mounting base (1), a mounting cylinder (2), and a floating ring (3); The annular mounting bracket (1) is used to connect to the outside of the outer bypass casing; The mounting cylinder (2) is set inside the annular mounting base (1), and the outer wall has an annular mounting edge, which is connected to the top of the annular mounting base (1). The floating ring (3) is used to be fitted onto the outer periphery of the through-outer duct casing structure (4), and is stuck in the moving groove opened on the outer wall of the through-outer duct casing structure (4). A movement space is reserved between it and the moving groove, and it is set inside the mounting cylinder (2). Its outer edge is in sealed contact with the inner wall of the mounting cylinder (2). Under cold conditions, the center lines of the annular mounting base (1), mounting cylinder (2), and floating ring (3) coincide, and are offset backward along the axis of the aero-engine relative to the center line of the outer bypass casing structure (4).

2. The sealing structure for the aero-engine through-beam casing according to claim 1, characterized in that, The annular mounting base (1) is integrally formed on the outer casing or assembled on the casing.

3. The sealing structure for the aero-engine through-beam casing according to claim 2, characterized in that, The outer edge of the floating ring (3) is a sphere.

4. The sealing structure for the aero-engine through-beam casing according to claim 3, characterized in that, Under cold conditions, the center lines of the annular mounting base (1), mounting cylinder (2), and floating ring (3) are offset backward by a distance S relative to the center line of the outer bypass casing structure (4) along the axis of the aircraft engine. The relative movement distance between the outer bypass casing structure (4) and the outer bypass casing is designed according to the cruise time of the aircraft engine.

5. A method for designing parameters of a sealing structure for an aero-engine through-bypass casing, used to design the inner diameter d1 and outer diameter d2 of the upstream moving groove of the through-bypass casing structure (4) in the sealing structure of the aero-engine through-bypass casing as described in claim 4; the inner diameter D1 and outer diameter D2 of the floating ring (3); the reserved movement space L1 between the floating ring (3) and the upstream moving groove of the through-bypass casing structure (4) along the aero-engine axis; the overlap L2 between the floating ring (3) and the upstream moving groove of the through-bypass casing structure (4) along the aero-engine axis; the rearward distance L3 between the mounting cylinder (2) and the through-bypass casing structure (4) along the aero-engine axis; and the forward distance L4 between the mounting cylinder (2) and the through-bypass casing structure (4) along the aero-engine axis, characterized in that... include: The basic dimensions of d1 are determined based on the structural characteristics of the culvert. Considering the machining deviation between the through-hole casing structure (4) and the outer casing, and the space required for the maximum motion compensation between the through-hole casing structure (4) and the outer casing when the aero-engine is hot, determine L1; The calculated result is D1: L1 = 0.5 * D1 + S - 0.5 * d1; Design L2 > L1; The lower boundary of d2 is calculated as: L2 = 0.5 * d2 - (0.5 * D1 - S); Design L3 > L1; Calculate the lower boundary of the value of D2: L3 = 0.5 * D2 + S - 0.5 * d2; Considering the machining deviation between the through-hole casing structure (4) and the outer duct casing, determine L4.

6. The method for designing the sealing structure parameters of the aero-engine through-bypass casing according to claim 5, characterized in that, L4 is used as the design input value to determine the values ​​of d2 and D2. L4 = 0.5 * D2 - S - 0.5 * d2.

7. The method for designing the sealing structure parameters of the aero-engine through-beam casing according to claim 6, characterized in that, The values ​​of d2 and D2 should not affect the rotation of the outer casing structure (4) within a certain angle range.

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