An air extraction structure for core engine tests

Abstract

This application belongs to the field of core engine design and is an air extraction structure for core engine tests, including an air extraction pipe installation section, an air extraction pipe sealing section, and an air extraction pipe insertion section. When installing the air extraction pipe, the air extraction pipe is directly inserted from the outside of the rear bearing housing to the inside of the rear bearing housing, and then the air extraction pipe installation section is fixed to complete the installation, which is convenient for installation; when it is necessary to replace or repair the air extraction pipe, the fixing position of the air extraction pipe installation section is opened, and the entire air extraction pipe can be pulled outwards, which is convenient for disassembly. It is not necessary to remove the core engine to complete effective disassembly and assembly, which is convenient for use; by setting the first axially movable sealing structure and the second axially movable sealing structure, after the air extraction pipe is installed, the outer end of the air extraction pipe is sealed by the first axially movable sealing structure, and the inner end of the air extraction pipe is sealed by the second axially movable sealing structure. The air extraction pipe is tightly sealed during use and there will be no leakage of cold air, and the work is stable.

Description

Technical Field

[0001] This application belongs to the field of core engine design, and particularly relates to an air extraction structure for core engine tests. Background Art

[0002] The core engine refers to the core part composed of a high-pressure compressor, a combustion chamber, and a high-pressure turbine in a gas turbine engine. Core engine components are in the most severe working environment (high temperature, high pressure, high speed) in a gas turbine engine and are the most core components of the engine. Therefore, during the engine engineering development process, a series of core engine tests and experiments will be carried out independently to support the development of engine products or for technical reserves. During the core engine test process, a large amount of bench cold air needs to be introduced through the afterbody air extraction structure located between the high-pressure turbine outlet and the exhaust device (nozzle) to cool the bearings and the inner cone of the nozzle. The working environment of the afterbody air extraction structure is as Figure 1 shown.

[0003] Currently, the commonly used afterbody air extraction structure is to weld an air extraction pipe cone head 2 at the lower end of the air extraction pipe 1, an external nut 3 for the air extraction pipe is installed outside the cone head, and an air extraction pipe ball head 4 is installed inside the afterbody. During assembly, the air extraction pipe is inserted inward from the outer casing, and the threads of the nut and the ball head are tightened. The structure is as Figure 2 shown. It is mainly used for the afterbody structure of the whole machine, located behind the low-pressure turbine, where the environmental temperature and pressure are relatively low.

[0004] The existing afterbody air extraction structure has the following disadvantages:

[0005] 1) Limited cold air flow

[0006] Since the lower ends of the existing air extraction pipes all use threaded connections, the cross-section of the air extraction pipe needs to be a circular pipe. Limited by the space of the rear bearing housing support plate, the air extraction flow of the circular air extraction pipe is limited and cannot meet the cold air demand of the nozzle inner cone.

[0007] 2) Insufficient thermal deformation coordination ability

[0008] The air extraction pipe passes through five layers of structures, from the inside out, namely the bearing housing 5, the heat insulation cover 6, the inner ring 7 of the rear bearing housing, the outer ring 8 of the rear bearing housing, and the outer casing 9, as Figure 2 shown. The temperature gradient of these five layers of structures is above 400°C, and it is difficult to coordinate the thermal deformation between different layers of structures. The existing structure only designs a sealing ring at the outer end of the air extraction pipe to adjust the thermal deformation amount, which cannot meet the use requirements.

[0009] 3) Complicated disassembly, installation and maintenance

[0010] The existing air extraction structures are all thread-connected. To prevent the threads from loosening during the test run, the lower end of the air extraction pipe is locked with wire. If the air extraction pipe needs to be disassembled and installed during the bench test run of the core engine, the rear cover plate 10 (see Figure 2)It can only be disassembled for decomposition. The disassembly and assembly operations are complex and highly restricted by space. Generally, only the core engine can be removed from the platform for disassembly, which is time-consuming and costly, bringing many inconveniences to the tests.

[0011] Therefore, how to ensure the convenient installation and removal of the air intake pipe while increasing the cold air flow rate of the air intake pipe is a problem that needs to be solved. Summary of the Invention

[0012] The purpose of the present application is to provide an air intake structure for core engine tests to solve the problems of low air intake flow rate and inconvenient installation and removal of the air intake pipe in the prior art.

[0013] The technical solution of the present application is: an air intake structure for core engine tests, including an air intake pipe installation section, an air intake pipe sealing section, and an air intake pipe insertion section; the air intake pipe installation section is located at the outer end of the air intake pipe, the air intake pipe insertion section is located at the inner end of the air intake pipe, the air intake pipe sealing section is connected to the air intake pipe installation section, the air intake pipe installation section is detachably and fixedly connected to the air intake pipe, a first axially movable sealing structure capable of moving axially along the air intake pipe is connected between the air intake pipe sealing section and the rear bearing housing, and a second axially movable sealing structure capable of moving axially along the air intake pipe is connected between the air intake pipe insertion section and the rear bearing housing.

[0014] Preferably, the cross-section of the air intake pipe is oval.

[0015] Preferably, the installation structure of the air intake pipe installation section includes an outer flange and a housing installation seat. The outer flange is integrally and coaxially connected to the air intake pipe installation section, the housing installation seat is arranged on the rear bearing housing, and the outer flange is bolted to the housing installation seat.

[0016] Preferably, the first axially movable sealing structure includes a limit ring, a limit sleeve, and a sealing ring. There are two groups of limit rings, and the two groups of limit rings are coaxially connected to the air intake pipe sealing section along the axial direction of the air intake pipe. A first installation groove is formed between the two groups of limit rings. The sealing ring is installed in the first installation groove. The limit sleeve is arranged on the rear bearing housing and is coaxially arranged with the air intake pipe. The outer wall of the limit ring is in contact with the inner wall of the limit sleeve.

[0017] Preferably, the second axially movable sealing structure includes a support sleeve, a sealing rubber ring, and a sealing mechanism. The support sleeve is integrally and coaxially connected to the air intake pipe insertion section. There are at least two groups of support sleeves. There is at least one group of sealing rubber rings in each group, and each group of sealing rubber rings is arranged between two adjacent groups of support sleeves; the sealing mechanism is arranged on the rear bearing housing, and a sealing sleeve sleeved on the outside of the support sleeve and the sealing rubber ring is provided on the sealing mechanism.

[0018] Preferably, the sealing mechanism further includes a first support frame connected to one side of the sealing sleeve and a second support frame connected to the other side of the sealing sleeve. The first support frame is bolted to the bearing seat of the rear bearing housing, and the second support frame is bolted to the cover plate on the rear bearing housing. A first fixing plate arranged along the axial direction of the air guide pipe is provided on the first support frame, and a second fixing plate arranged along the axial direction of the air guide pipe is provided on the second support frame. The first fixing plate and the second fixing plate are mutually attached, and a fastening bolt for fixing the two is connected between the first fixing plate and the second fixing plate.

[0019] Preferably, it further includes an outer section of the air guide pipe, a positioning section of the air guide pipe, and an inner section of the air guide pipe. The outer section of the air guide pipe is connected to the air guide pipe sealing section and the outer section of the air guide pipe passes through the main gas passage. The positioning section of the air guide pipe is connected to the outer section of the air guide pipe and the positioning section of the air guide pipe is arranged between the main gas passage and the inner cavity of the rear bearing housing. The inner section of the air guide pipe is connected between the positioning section of the air guide pipe and the insertion section of the air guide pipe and the inner section of the air guide pipe is arranged inside the inner cavity of the rear bearing housing. A positioning ring is provided on the positioning section of the air guide pipe, and an air guide pipe mounting seat is provided on the outer side of the positioning ring. The air guide pipe mounting seat includes a left half mounting seat and a right half mounting seat. A first positioning half groove is formed in the left half mounting seat, and a second positioning half groove is formed in the right half mounting groove. The first positioning half groove and the second positioning half groove are respectively in clamping fit with both sides of the positioning ring. The left half mounting seat and the right half mounting seat are bolted to the rear bearing housing.

[0020] An air extraction structure for a core engine test in the present application includes an air guide pipe installation section, an air guide pipe sealing section, and an air guide pipe insertion section. When installing the air guide pipe, the air guide pipe is directly inserted from the outside of the rear bearing housing to the inside of the rear bearing housing, and then the air guide pipe installation section is fixed to complete the installation, which is convenient for installation. When it is necessary to replace or repair the air guide pipe, the fixed position of the air guide pipe installation section is opened, and the entire air guide pipe can be pulled outwards, which is convenient for disassembly. During the process of disassembling and assembling the air guide pipe, the core engine does not need to be removed to complete effective disassembly and assembly, which is convenient for use. By setting the first axially movable sealing structure and the second axially movable sealing structure, after the air guide pipe is installed, the outer end of the air guide pipe is sealed by the first axially movable sealing structure, and the inner end of the air guide pipe is sealed by the second axially movable sealing structure. The air guide pipe is tightly sealed during use and cold air leakage will not occur, and the work is stable. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions provided by the present application, the drawings will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application.

[0022] Figure 1 It is a schematic diagram of the air extraction structure of the rear bearing housing in the background art;

[0023] Figure 2 is a schematic diagram of the connection structure between the rear bearing casing and the air intake pipe in the background art;

[0024] Figure 3 is a schematic diagram of the air intake pipe structure of the present application;

[0025] Figure 4 is a schematic diagram of the connection structure between the rear bearing casing and the air intake pipe of the present application;

[0026] Figure 5 is a schematic diagram of the air intake pipe mounting seat structure of the present application.

[0027] 1. Air intake pipe; 2. Air intake pipe cone head; 3. External nut of air intake pipe; 4. Ball head of air intake pipe; 5. Bearing seat; 6. Heat shield; 7. Inner ring of rear bearing casing; 8. Outer ring of rear bearing casing; 9. Outer casing; 10. Cover plate; 11. Installation section of air intake pipe; 12. Sealing section of air intake pipe; 13. Outer section of air intake pipe; 14. Positioning section of air intake pipe; 15. Inner section of air intake pipe; 16. Insertion section of air intake pipe; 17. Outer flange; 18. Casing mounting seat; 19. Limit ring; 20. Limit sleeve; 21. Sealing ring; 22. Support sleeve; 23. Sealing rubber ring; 24. Sealing sleeve; 25. First support frame; 26. Second support frame; 27. Tightening bolt; 28. Positioning ring; 29. Left half mounting seat; 30. Right half mounting seat; 31. First positioning half groove; 32. Second positioning half groove. Specific embodiments

[0028] To make the purpose, technical solutions and advantages of the implementation of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application.

[0029] An air intake structure for a core engine test, as Figure 3-4 shown, includes an installation section 11 of the air intake pipe, a sealing section 12 of the air intake pipe, an outer section 13 of the air intake pipe, a positioning section 14 of the air intake pipe, an inner section 15 of the air intake pipe, and an insertion section 16 of the air intake pipe. Welding points are provided between any two adjacent groups of air intake pipes. During processing, they can be processed separately and then welded and fixed between different air intake pipes. The installation section 11 of the air intake pipe is located at the outer end of the air intake pipe, the insertion section 16 of the air intake pipe is located at the inner end of the air intake pipe, the sealing section 12 of the air intake pipe is connected to the installation section 11 of the air intake pipe, the installation section 11 of the air intake pipe is detachably and fixedly connected to the air intake pipe, a first axially movable sealing structure capable of moving axially along the air intake pipe is connected between the sealing section 12 of the air intake pipe and the rear bearing casing, and a second axially movable sealing structure capable of moving axially along the air intake pipe is connected between the insertion section 16 of the air intake pipe and the rear bearing casing.

[0030] The air intake pipe is detachably and fixedly connected to the rear bearing housing only at the position of the air intake pipe installation section 11, and non-fixed connections are used at other positions. The connection methods of the detachable and fixed connection include connection methods such as bolts and pins. When installing the air intake pipe, the air intake pipe is directly inserted from the outside of the rear bearing housing to the inside of the rear bearing housing, and then the air intake pipe installation section 11 is fixed to complete the installation, which is convenient for installation; when it is necessary to replace or repair the air intake pipe, the fixed position of the air intake pipe installation section 11 is opened, and the entire air intake pipe can be pulled outwards, which is convenient for disassembly. During the disassembly and assembly of the air intake pipe, effective disassembly and assembly can be completed without removing the core engine, which is convenient to use.

[0031] By setting the first axially movable sealing structure and the second axially movable sealing structure, after the air intake pipe is installed, the outer end of the air intake pipe is sealed by the first axially movable sealing structure, and the inner end of the air intake pipe is sealed by the second axially movable sealing structure. The air intake pipe is tightly sealed during use, and cold air leakage will not occur, and the work is stable.

[0032] In this application, the outer end of the air intake pipe is the end close to the outside of the rear bearing housing, and the inner end of the air intake pipe is the end close to the inside of the rear bearing housing.

[0033] The outer section 13 of the air intake pipe is connected to the sealing section 12 of the air intake pipe and the outer section 13 of the air intake pipe passes through the main gas passage. The positioning section 14 of the air intake pipe is connected to the outer section 13 of the air intake pipe and the positioning section 14 of the air intake pipe is arranged between the main gas passage and the inner cavity of the rear bearing housing. The inner section 15 of the air intake pipe is connected between the positioning section 14 of the air intake pipe and the insertion section 16 of the air intake pipe and the inner section 15 of the air intake pipe is arranged in the inner cavity of the rear bearing housing.

[0034] Preferably, the cross-section of the air intake pipe is oval. Compared with the air intake pipe with a circular cross-section, the air intake volume of the air intake pipe is larger. The oval structure is more inconvenient to fix than the circular structure. However, since the air intake pipe of this application only needs to be fixed at one end, the disadvantage of inconvenient fixing of the oval air intake pipe can be effectively avoided.

[0035] Preferably, the installation structure of the air intake pipe installation section 11 includes an outer flange 17 and a housing installation seat 18. The outer flange 17 is integrally and coaxially connected to the air intake pipe installation section 11. The housing installation seat 18 is arranged on the rear bearing housing, and the outer flange 17 is bolted to the housing installation seat 18. By setting the outer flange 17 and the housing installation seat 18, the bolt connection between the air intake pipe and the rear bearing housing is realized, and the installation and disassembly are convenient.

[0036] Preferably, the first axially movable sealing structure includes a limiting ring 19, a limiting sleeve 20 and a sealing ring 21. There are two groups of limiting rings 19, and the two groups of limiting rings 19 are coaxially connected to the sealing section 12 of the air guide pipe along the axial direction of the air guide pipe. A first installation groove is formed between the two groups of limiting rings 19. The sealing ring 21 is made of rubber or other soft materials and is installed in the first installation groove. The limiting sleeve 20 is arranged on the outer ring 8 of the rear bearing housing and is coaxially arranged with the air guide pipe. The outer wall of the limiting ring 19 is in contact with the inner wall of the limiting sleeve 20. The sealing ring 21 is oval and can move along the axial direction of the air guide pipe. When it reaches the position of the limiting sleeve 20, it can achieve the sealing effect between the air guide pipe and the rear bearing housing. The limiting ring 19 axially limits the sealing ring 21, and the limiting sleeve 20 radially limits the limiting ring 19. In this way, the sealing ring 21 between the limiting ring 19 and the limiting sleeve 20 can effectively seal between the rear bearing housing and the air guide pipe, prevent the leakage of external bypass gas, and has the ability of axial, circumferential and radial deformation, and strong thermal deformation coordination ability.

[0037] Preferably, the second axially movable sealing structure includes a support sleeve 22, a sealing rubber ring 23 and a sealing mechanism. The support sleeve 22 is integrally and coaxially connected to the insertion section 16 of the air guide pipe. At least two groups of support sleeves 22 are provided, and at least one group of sealing rubber rings 23 is provided in each group. And each group of sealing rubber rings 23 is arranged between two adjacent groups of support sleeves 22; The sealing mechanism is arranged on the rear bearing housing, and a sealing sleeve 24 sleeved outside the support sleeve 22 and the sealing rubber ring 23 is arranged on the sealing mechanism. In this application, three groups of support sleeves 22 are provided, the sealing rubber rings 23 are oval, and two groups are provided. The sealing rubber rings 23 can move along the axial direction of the air guide pipe. When it reaches the position of the sealing mechanism, the sealing between the air guide pipe and the rear bearing housing can be realized. The support sleeve 22 axially limits the sealing ring 21, the sealing sleeve 24 radially limits the support sleeve 22, and the sealing ring 21 effectively seals between the rear bearing housing and the air guide pipe under the limitation of the support sleeve 22 and the sealing sleeve 24, prevents the leakage of external bypass gas, and has strong radial deformation ability and thermal deformation coordination ability.

[0038] Preferably, the sealing mechanism further includes a first support frame 25 connected to one side of the sealing sleeve 24 and a second support frame 26 connected to the other side of the sealing sleeve 24. The first support frame 25 is bolted to the bearing seat of the rear bearing housing, and the second support frame 26 is bolted to the cover plate 10 on the rear bearing housing; A first fixing plate arranged along the axial direction of the air guide pipe is provided on the first support frame 25, a second fixing plate arranged along the axial direction of the air guide pipe is provided on the second support frame 26, the first fixing plate and the second fixing plate are mutually attached, and a fastening bolt 27 for fixing the two is connected between the first fixing plate and the second fixing plate.

[0039] The sealing sleeve 24 is formed by setting the first support frame 25 and the second support frame 26. The first support frame 25 and the second support frame 26 ensure the sealing stability of the sealing sleeve 24 by being respectively fixed on the bearing seat and the cover plate 10, and the support strength of the first support frame 25 and the second support frame 26 is ensured by setting the fastening bolts 27.

[0040] As Figure 4 - Figure 5 shown, preferably, a positioning ring 28 is provided on the air intake pipe positioning section 14. The positioning ring 28 is oval. An air intake pipe mounting seat is provided on the outer side of the positioning ring 28. The air intake pipe mounting seat includes a left half mounting seat 29 and a right half mounting seat 30. A first positioning half groove 31 is formed in the left half mounting seat 29, and a second positioning half groove 32 is formed in the right half mounting groove. The first positioning half groove 31 and the second positioning half groove 32 are respectively clamped and matched with both sides of the positioning ring 28. The left half mounting seat 29 and the right half mounting seat 30 are bolted to the rear bearing housing. By setting the left half mounting seat 29 and the right half mounting seat 30 to clamp and fix the oval positioning ring 28, the positioning ring 28 can prevent the gas in the inner cavity of the rear bearing housing from leaking, limit the radial position of the air intake pipe, and has circumferential and axial deformation capabilities. At the same time, the installation is convenient, and the left half mounting seat 29 and the right half mounting seat 30 can complete the clamping and fixing of the positioning ring 28.

[0041] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claimed rights.

Claims

1. An air extraction structure for core engine tests, characterized in that: It includes an air intake pipe installation section (11), an air intake pipe sealing section (12), and an air intake pipe insertion section (16); the air intake pipe installation section (11) is located at the outer end of the air intake pipe, the air intake pipe insertion section (16) is located at the inner end of the air intake pipe, the air intake pipe sealing section (12) is connected to the air intake pipe installation section (11), the air intake pipe installation section (11) is detachably and fixedly connected to the air intake pipe, a first axially movable sealing structure capable of moving axially along the air intake pipe is connected between the air intake pipe sealing section (12) and the rear bearing casing, and a second axially movable sealing structure capable of moving axially along the air intake pipe is connected between the air intake pipe insertion section (16) and the rear bearing casing; The first axially movable sealing structure includes a limit ring (19), a limit sleeve (20), and a sealing ring (21). There are two groups of limit rings (19), and the two groups of limit rings (19) are coaxially connected to the air intake pipe sealing section (12) along the axial direction of the air intake pipe. A first installation groove is formed between the two groups of limit rings (19). The sealing ring (21) is installed in the first installation groove. The limit sleeve (20) is arranged on the rear bearing casing and is coaxially arranged with the air intake pipe. The outer wall of the limit ring (19) is in contact with the inner wall of the limit sleeve (20); The second axially movable sealing structure includes a support sleeve (22), a sealing rubber ring (23), and a sealing mechanism. The support sleeve (22) is integrally and coaxially connected to the air intake pipe insertion section (16). There are at least two groups of support sleeves (22). There is at least one group of each sealing rubber ring (23), and each group of sealing rubber rings (23) is arranged between two adjacent groups of support sleeves (22); the sealing mechanism is arranged on the rear bearing casing, and a sealing sleeve (24) sleeved on the outer sides of the support sleeve (22) and the sealing rubber ring (23) is arranged on the sealing mechanism; It further includes an outer section of the air intake pipe (13), a positioning section of the air intake pipe (14), and an inner section of the air intake pipe (15); the outer section of the air intake pipe (13) is connected to the air intake pipe sealing section (12) and the outer section of the air intake pipe (13) passes through the main gas passage. The positioning section of the air intake pipe (14) is connected to the outer section of the air intake pipe (13) and the positioning section of the air intake pipe (14) is arranged between the main gas passage and the inner cavity of the rear bearing casing. The inner section of the air intake pipe (15) is connected between the positioning section of the air intake pipe (14) and the air intake pipe insertion section (16) and the inner section of the air intake pipe (15) is arranged in the inner cavity of the rear bearing casing; A positioning ring (28) is arranged on the positioning section of the air intake pipe (14). An air intake pipe mounting seat is arranged on the outer side of the positioning ring (28). The air intake pipe mounting seat includes a left half mounting seat (29) and a right half mounting seat (30). A first positioning half groove (31) is formed in the left half mounting seat (29), and a second positioning half groove (32) is formed in the right half mounting groove. The first positioning half groove (31) and the second positioning half groove (32) are respectively in clamping fit with both sides of the positioning ring (28). The left half mounting seat (29) and the right half mounting seat (30) are bolted to the rear bearing casing.

2. The bleed air structure for core engine test according to claim 1, wherein: The cross-section of the air intake pipe is oval.

3. The bleed air structure for core engine test according to claim 1, wherein: The installation structure of the air intake pipe installation section (11) includes an outer flange (17) and a casing mounting seat (18). The outer flange (17) is integrally and coaxially connected to the air intake pipe installation section (11). The casing mounting seat (18) is arranged on the rear bearing casing, and the outer flange (17) is bolted to the casing mounting seat (18).

4. The bleed air structure for core engine test according to claim 1, wherein: The sealing mechanism further includes a first support frame (25) connected to one side of the sealing sleeve (24) and a second support frame (26) connected to the other side of the sealing sleeve (24). The first support frame (25) is bolted to the bearing seat of the rear bearing casing, and the second support frame (26) is bolted to the cover plate (10) on the rear bearing casing. A first fixing plate arranged along the axial direction of the air intake pipe is provided on the first support frame (25), and a second fixing plate arranged along the axial direction of the air intake pipe is provided on the second support frame (26). The first fixing plate and the second fixing plate are mutually attached, and a fastening bolt (27) for fixing the two is connected between the first fixing plate and the second fixing plate.

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