A sealing structure of an aero-engine through double-layer outer-duct casing structure

Abstract

The application belongs to the technical field of sealing design of aero-engine through double-layer outer-duct casing structure, and particularly relates to a sealing structure of an aero-engine through double-layer outer-duct casing structure, which is designed to realize sealing by a sliding sleeve and a floating ring, and is connected on the outer-duct casing by a small number of bolts and connecting pieces, is simple to disassemble and assemble, and is arranged across the outer-duct flow path between the outer casing and the inner casing, so that the problem of insufficient assembly space between the outer casing and the inner casing can be effectively avoided, interference with the outer casing does not occur, disassembly and assembly are facilitated, and due to the design of the annular mounting flange on the sliding sleeve, the sliding sleeve does not fall into the outer-duct flow path, and has good assembly and maintenance characteristics.

Description

Technical Field

[0001] This application belongs to the technical field of sealing design for aero-engine double-layer outer bypass casing structure, specifically relating to a sealing structure for an aero-engine double-layer outer bypass casing structure. Background Technology

[0002] The bypass casing is a crucial component of an aero-engine. Traditional aero-engines have only one bypass flow path, using a single-layer bypass casing. This single-layer casing, together with the internal core engine casing, forms one bypass flow path. Newer aero-engine configurations feature dual bypass flow paths. In addition to forming a bypass flow path with the internal core engine casing, the bypass casing itself employs a double-layer structure, creating a second bypass flow path between the two layers.

[0003] The outer bypass casing of an aero-engine contains various structures that penetrate it, such as ventilation lines, oil lines, lead wires, and inspection channels, all of which require sealing at the outer bypass casing. These structures are typically fixed to the core engine casing. During aero-engine operation, the materials and operating temperatures of the outer bypass casing and core engine casing differ, resulting in different thermal expansion rates and significant axial and radial deformation differences. Therefore, when designing the sealing structure for these penetrations, appropriate thermal compensation must be considered to prevent excessive stress between the outer bypass casing and the core engine casing.

[0004] Currently, the sealing structure at the outer bypass casing of aero-engines typically employs a floating seal structure. For a double-layer outer bypass casing structure, the design of the floating seal structure is as follows: Figure 1 As shown, sliding sleeves and their floating rings are respectively installed on the outer casing and the inner casing. Thermal compensation for the double-layer outer casing and the core casing is achieved by utilizing the relative movement between the double-layer outer casing structure and the floating ring, and between the floating ring and the sliding sleeve. This technical solution has the following drawbacks:

[0005] 1) Sliding sleeves and floating rings are installed on the outer and inner casings respectively, requiring a large number of bolts and connectors for connection. The disassembly and assembly process is cumbersome. In addition, the space between the outer and inner casings is small, and the assembly space is insufficient. It is inconvenient to disassemble and assemble the sliding sleeves and floating rings installed on the inner casing, and they are prone to interference with the outer casing.

[0006] 2) The sliding sleeve and its floating ring installed on the inner outer duct casing are located in the outer duct flow path. During the disassembly and assembly process, they fall into the outer duct flow path and are difficult to remove, which greatly increases the difficulty of the structure in terms of assembly and maintenance.

[0007] This application is made in view of the aforementioned technical deficiencies. Summary of the Invention

[0008] The purpose of this application is to provide a floating sealing structure for a sealing structure of an aero-engine through a double-layer outer bypass casing structure, so as to overcome or mitigate at least one of the known technical defects.

[0009] The technical solution of this application is:

[0010] A sealing structure for an aero-engine with a double-layer outer bypass casing, characterized in that it includes an outer casing, an inner casing, a sliding sleeve, a floating ring, and a cover plate;

[0011] The outer casing has an outer casing mounting hole, and the outer wall has an outer annular mounting boss surrounding the outer casing mounting hole;

[0012] The inner casing is disposed inside the outer casing and has an inner casing mounting hole and an inner annular mounting boss protruding towards the outer casing. The inner annular mounting boss surrounds the inner casing mounting hole and has an annular channel communicating with its interior.

[0013] The double-layer outer casing structure passes through the inner casing mounting hole and the outer casing mounting hole;

[0014] The lower end of the sliding sleeve passes through the mounting hole of the outer casing and extends into the annular channel. The outer wall of the sleeve is in sealed contact with the inner wall of the annular channel. The upper outer wall has an annular mounting flange, which is located on the outside of the outer casing.

[0015] The floating ring is installed inside the sliding sleeve. Its outer edge is in sealed contact with the inner wall of the sliding sleeve, and its inner edge is stuck in the annular moving groove opened on the double-layer outer casing structure. There is a movable gap between the floating ring and the annular moving groove.

[0016] The cover plate is fitted around the outer periphery of the sliding sleeve, with a movable gap between it and the sliding sleeve. It is connected to the outer wall of the outer casing, forming an annular mounting groove with the outer casing. The annular mounting flange is engaged in the annular mounting groove, with a movable gap between it and the annular mounting groove.

[0017] According to at least one embodiment of this application, in the sealing structure of the above-described double-layer outer bypass casing structure of an aero-engine, the lower end outer wall of the sliding sleeve is in spherical contact with the inner wall of the annular channel.

[0018] According to at least one embodiment of this application, in the sealing structure of the above-described double-layer outer bypass casing structure of an aero-engine, the outer edge of the floating ring is in spherical contact with the inner wall of the sliding sleeve.

[0019] According to at least one embodiment of this application, in the sealing structure of the above-described aero-engine double-layer outer bypass casing structure, the floating ring is a split structure.

[0020] According to at least one embodiment of this application, in the sealing structure of the above-described aero-engine double-layer outer casing structure, the cover plate is bolted to the outer wall of the outer casing.

[0021] This application has at least the following beneficial technical effects:

[0022] A sealing structure for an aero-engine with a double-layer outer bypass casing is provided. The design uses only a sliding sleeve and a floating ring to achieve the seal. The connection on the outer bypass casing can be achieved with a small number of bolts and connecting parts, making disassembly and assembly simple. The sliding sleeve is set across the outer bypass flow path between the outer and inner casings, which can effectively avoid the problem of insufficient assembly space between the outer and inner casings, and will not interfere with the outer casing. It is easy to disassemble and assemble. Due to the design of the annular mounting flange on the sliding sleeve, it will not fall into the outer bypass flow path, and has good assembly and maintenance characteristics. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the floating seal structure of an existing aero-engine with a double-layer outer bypass casing;

[0024] Figure 2 This is a schematic diagram of the floating sealing structure of the sealing structure of the double-layer outer bypass casing of the aero-engine provided in the embodiments of this application;

[0025] in:

[0026] 1-Outer casing; 2-Inner casing; 3-Sliding sleeve; 4-Floating ring; 5-Cover plate; 6-Double-layer outer casing structure.

[0027] 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

[0028] 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.

[0029] 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.

[0030] 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.

[0031] A sealing structure for an aero-engine with a double-layer outer bypass casing, such as Figure 2 As shown, it includes an outer casing 1, an inner casing 2, a sliding sleeve 3, a floating ring 4, and a cover plate 5.

[0032] The outer casing 1 has an outer casing mounting hole and an outer annular mounting boss surrounding the outer casing mounting hole on the outer wall.

[0033] The inner casing 2 is disposed inside the outer casing 1, and has an inner casing mounting hole and an inner annular mounting boss protruding towards the outer casing 1. The inner annular mounting boss surrounds the inner casing mounting hole and has an annular channel communicating with its interior.

[0034] The double-layer outer casing structure 6 passes through the inner casing mounting hole and the outer casing mounting hole.

[0035] The lower end of the sliding sleeve 3 passes through the mounting hole of the outer casing and extends into the annular channel. The outer wall of the sleeve makes spherical contact with the inner wall of the annular channel to achieve a seal. The upper outer wall has an annular mounting flange, which is located on the outside of the outer casing 1.

[0036] The floating ring 4 is disposed inside the sliding sleeve 3, close to the outer casing 1. Its outer edge makes spherical contact with the inner wall of the sliding sleeve 3 to achieve a seal, and its inner edge is engaged in an annular movable groove opened on the double-layer outer casing structure 6 to achieve a seal. There is a horizontal movement gap between the floating ring 4 and the annular movable groove. To facilitate assembly on the double-layer outer casing structure 6, the floating ring 4 can be designed as a half-structure.

[0037] The cover plate 5 is fitted around the outer periphery of the sliding sleeve 3, with a horizontal clearance between it and the sliding sleeve 3. It is connected to the outer wall of the outer casing 1, specifically by bolts, forming an annular mounting groove with the outer casing 1. The annular mounting flange is engaged in the annular mounting groove to achieve a seal, with a horizontal clearance between it and the annular mounting groove.

[0038] The sealing structure of the aero-engine through the double-layer outer bypass casing structure disclosed in the above embodiments can be assembled by referring to the following method:

[0039] The inner edge of the floating ring 4 is engaged in the annular moving groove provided on the double-layer outer casing structure 6;

[0040] The lower end of the sliding sleeve 3 passes through the outer casing mounting hole on the outer casing 1 and extends into the annular channel of the inner casing 2, where it is fitted onto the outside of the floating ring 4.

[0041] The cover plate 5 is attached to the outer wall of the outer casing 1, pressing down the annular mounting flange on the sliding sleeve 3.

[0042] In the sealing structure of the double-layer outer bypass casing structure of the aero-engine disclosed in the above embodiments, the axial deformation difference between the core casing and the inner casing 2 can be compensated by the sliding of the floating ring 4 in the annular moving groove on the double-layer outer bypass casing structure 6 along the x-direction; the radial deformation difference between the core casing and the inner casing 2 can be compensated by the sliding of the floating ring 4 in the sliding sleeve 3 along the y-direction; the axial deformation difference between the outer casing 1 and the inner casing 2 can be compensated by the sliding of the annular mounting flange on the sliding sleeve 3 in the annular mounting groove between the cover plate 5 and the outer casing 1 along the x-direction; and the radial deformation difference between the outer casing 1 and the inner casing 2 can be compensated by the sliding of the sliding sleeve 3 in the annular channel on the inner casing 2 along the y-direction.

[0043] The design incorporates a spherical contact between the lower outer wall of the sliding sleeve 3 and the inner wall of the annular channel, as well as a spherical contact between the outer edge of the floating ring 4 and the inner wall of the sliding sleeve 3. This design utilizes the spherical contact's ease of sliding and deflection to prevent jamming between the sliding sleeve 3 and the annular channel, and between the sliding sleeve 3 and the floating ring 4. It also adaptively compensates for irregular deformations at multiple angles between the outer casing 1, the inner casing 2, and the core casing.

[0044] The sealing structure of the aero-engine with a double-layer outer bypass casing structure disclosed in the above embodiments is designed to achieve sealing with only a sliding sleeve 3 and a floating ring 4. It can be connected to the outer bypass casing with a small number of bolts and their connecting parts, making disassembly and assembly simple. Moreover, the sliding sleeve 3 is set across the outer bypass flow path between the outer casing 1 and the inner casing 2, which can effectively avoid the problem of insufficient assembly space between the outer casing 1 and the inner casing 2, and will not interfere with the outer casing 1, making disassembly and assembly convenient. Furthermore, due to the design of the annular mounting flange on the sliding sleeve 3, it will not fall into the outer bypass flow path, and has good assembly and maintenance characteristics.

[0045] 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 with a double-layer outer bypass casing, characterized in that, It includes an outer casing (1), an inner casing (2), a sliding sleeve (3), a floating ring (4), and a cover plate (5); The outer casing (1) has an outer casing mounting hole and an outer annular mounting boss surrounding the outer casing mounting hole on the outer wall; The inner casing (2) is disposed inside the outer casing (1) and has an inner casing mounting hole and an inner annular mounting boss protruding toward the outer casing (1). The inner annular mounting boss surrounds the inner casing mounting hole and has an annular channel communicating with its interior. The double-layer outer casing structure (6) passes through the inner casing mounting hole and the outer casing mounting hole; The lower end of the sliding sleeve (3) passes through the mounting hole of the outer casing and extends into the annular channel. The outer wall is in sealed contact with the inner wall of the annular channel. The upper outer wall has an annular mounting flange, which is located outside the outer casing (1). The floating ring (4) is set inside the sliding sleeve (3), with its outer edge in sealed contact with the inner wall of the sliding sleeve (3), and its inner edge stuck in the annular moving groove opened on the double-layer outer casing structure (6), with an active gap between it and the annular moving groove. The cover plate (5) is fitted around the outer periphery of the sliding sleeve (3), and there is a movable gap between it and the sliding sleeve (3). It is connected to the outer wall of the outer casing (1) and forms an annular mounting groove with the outer casing (1). The annular mounting flange is stuck in the annular mounting groove, and there is a movable gap between it and the annular mounting groove.

2. The sealing structure of an aero-engine with a double-layer outer bypass casing according to claim 1, characterized in that, The outer wall of the lower end of the sliding sleeve (3) is in spherical contact with the inner wall of the annular channel.

3. The sealing structure of an aero-engine with a double-layer outer bypass casing according to claim 2, characterized in that, The outer edge of the floating ring (4) is in spherical contact with the inner wall of the sliding sleeve (3).

4. The sealing structure of an aero-engine with a double-layer outer bypass casing according to claim 3, characterized in that, The floating ring (4) is a half-structure.

5. The sealing structure of an aero-engine with a double-layer outer bypass casing according to claim 4, characterized in that, The cover plate (5) is bolted to the outer wall of the outer casing (1).

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