Adaptive rear thrust casing outer ring fairing heat shield structure

Abstract

The application belongs to the field of design of aero-engines and gas turbines, and relates to a self-adaptive outer ring fairing and heat shield structure of a rear load-bearing casing, which comprises a second front mounting edge, a cylinder body and a second rear mounting edge, and the cylinder body is circumferentially divided into a plurality of identical parts; each part is integrally connected with the second front mounting edge and the second rear mounting edge, so that no connecting structure is needed between any two parts, the connecting bolts of the middle mounting edge are cancelled, radial space is saved, the diameter of the outer channel of the load-bearing casing is reduced, and the weight is reduced; meanwhile, the flow channel profile has no height difference along the axial direction, the smoothness is improved, and the aerodynamic loss is reduced; by arranging a plurality of parts uniformly, the circumferentially spliced outer ring fairing and heat shield structure is formed, so that the circumferential stress can be self-adaptively released during the working process, and the crack problems of the second avoiding groove flanging, the second crack stopping hole and other weak parts of the fairing can be avoided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of design of aero-engines and gas turbines, and particularly relates to a self-adaptive rear load-bearing casing outer ring fairing heat shield structure. BACKGROUND

[0002] The rear load-bearing casing is a main load-bearing component of the engine and a main component of the high-temperature gas passage. With the development of aero-engines towards high thrust-to-weight ratio and high turbine inlet temperature, the design of the rear load-bearing casing needs to take into account the requirements of light weight, high load, high temperature resistance and high performance. With the gradual increase of turbine temperature, the gas temperature exceeds the allowable temperature of the load-bearing casing material, so the fairing heat shield of the rear load-bearing casing is designed to avoid the effect of gas thermal shock, separate the high-temperature gas from the rear load-bearing casing, and at the same time play a certain fairing effect to improve performance.

[0003] The current rear load-bearing casing is generally composed of a load-bearing inner ring 1, a load-bearing outer ring 2, a load-bearing support plate 3, an inner mounting edge 4, a load-bearing outer ring front mounting edge 5, a positioning ring 8, a load-bearing outer ring rear mounting edge 9, a load-bearing outer ring fairing heat shield 6, a load-bearing support plate fairing shield 7, an internal support system and a load-bearing inner ring fairing heat shield (not shown). The load-bearing support plates are distributed in a certain number in the circumferential direction, and the overall structure is similar to that of a wheel spoke, as shown in Figure 1 、 Figure 2 The load-bearing outer ring fairing heat shield 6 is wrapped on the surface of the load-bearing outer ring 2 of the rear load-bearing casing, and is designed by axially splitting the front half 61 and the rear half 62, and the first avoiding slot 63 is opened at the load-bearing support plate, and the middle mounting edge 64 is connected together by bolts.

[0004] The existing heat shield structure has the following defects:

[0005] 1) The load-bearing outer ring fairing heat shield adopts a bolt connection structure of axially splitting the front half and the rear half, and the structure of the middle mounting edge 64 occupies a radial height of at least 12 mm. The rear load-bearing casing needs to adapt to the increase of the diameter of the load-bearing outer ring of the flow passage profile, and the weight is correspondingly increased. The middle mounting edge 64 of the front and rear halves is affected by tolerances, and is prone to height difference along the axial direction, the flow passage profile is not smooth, and the aerodynamic performance is affected.

[0006] 2) The outer side of the load-bearing outer ring 2 of the rear load-bearing casing is cold gas, and the inner side of the fairing heat shield 6 is high-temperature gas, and the temperature difference between the two is large. During work, the deformation is not coordinated, the circumferential stress of the fairing shield of the axially split front and rear halves cannot be released, and cracks occur in the first avoiding slot 63 of the fairing shield 6 and the first crack stop hole 65.

[0007] 3) The radial temperature gradient of the front mounting edge 5 and the rear mounting edge 9 of the rear load-bearing casing is large, the deformation is not coordinated, the local stress is high, and the service life of the load-bearing casing is affected.

[0008] 4) The interlayer cavity between the rectifier heat shield 6 and the load-bearing outer ring 2 is a dead cavity. There is a risk of gas backflow in the gap between the first relief groove 63 and the load-bearing support plate 7, and the first crack-stopping hole 65. In addition, the pressure change of the main channel during the transition state is drastic, and the pressure change of the interlayer cavity is not synchronized with that of the main channel. The rectifier heat shield may become unstable due to transient pressure difference load.

[0009] Therefore, improving the aerodynamic performance around the heat shield and reducing thermal deformation inconsistencies during operation is a problem that needs to be solved. Summary of the Invention

[0010] The purpose of this application is to provide an adaptive rear load-bearing casing outer ring rectifier heat shield structure to solve the problems of heat shields affecting aerodynamic performance and large temperature difference between the inner and outer sides of the heat shield in the prior art.

[0011] The technical solution of this application is: an adaptive rear load-bearing casing outer ring rectifier heat insulation cover structure, disposed on the load-bearing casing, the load-bearing casing including a load-bearing support plate, a first front mounting edge and a first rear mounting edge, including a second front mounting edge, a cylinder and a second rear mounting edge, the cylinder being connected between the second front mounting edge and the second rear mounting edge; the second front mounting edge is correspondingly connected to the first front mounting edge, and the second rear mounting edge is correspondingly connected to the first rear mounting edge; the cylinder is divided into several parts of the same size along the circumference, and two parts are provided between any two adjacent sets of load-bearing support plates, a second clearance groove sleeved on the rectifier is opened between the two parts located on both sides of the load-bearing support plate, a first axial gap is formed between the two parts located between adjacent load-bearing support plates, a first sealing structure connecting the adjacent parts is provided at the first axial gap; a second axial gap is formed between the two parts located on both sides of the load-bearing support plate, a second sealing structure connecting the adjacent parts is provided at the second axial gap.

[0012] Preferably, the first sealing structure includes a supporting sealing ring and a long sealing plate. There are two sets of supporting sealing rings, which are respectively disposed on the two sides of the first axial gap. The supporting sealing rings are Z-shaped and the two supporting sealing rings on both sides are symmetrically arranged through the first axial gap. The two sets of supporting sealing rings and the two sides form a sealing cavity. The long sealing plate is sealed and connected in the sealing cavity. The two sides of the long sealing plate do not contact the sidewalls of the supporting sealing rings.

[0013] Preferably, the second sealing structure includes a short sealing piece, which is disposed at one end of the second clearance groove and is sealed to the two separate parts on both sides of the second clearance groove.

[0014] Preferably, a positioning ring is coaxially provided between the second front mounting edge and the first front mounting edge, and the outer side of the second front mounting edge is connected to the inner stop of the positioning ring; a bolt is connected between the second rear mounting edge and the first rear mounting edge.

[0015] Preferably, the positioning ring, the first front mounting edge and the second front mounting edge form a first cooling cavity, the positioning ring is provided with a plurality of first air guide grooves which are spaced apart circumferentially near the side close to the first cooling cavity, the outer side of the first air guide groove is communicated with the outer channel and the inner side is communicated with the first cooling cavity, and the first air guide groove is arranged corresponding to the overlapping transition area between the positioning ring and the first front mounting edge; the first rear mounting edge and the second rear mounting edge form a second cooling cavity, the second rear mounting edge is provided with a plurality of second air guide grooves which are spaced apart circumferentially near the side close to the second cooling cavity, the outer side of the second air guide groove is communicated with the outer channel and the inner side is communicated with the second cooling cavity, and the second air guide groove is arranged corresponding to the overlapping transition area between the first rear mounting edge and the second rear mounting edge.

[0016] Preferably, a plurality of groups of positioning protrusions are arranged circumferentially at the joint between the positioning ring and the second front mounting edge and the joint between the positioning ring and the first front mounting edge.

[0017] Preferably, an annular flange is attached to the position of the outer wall of the fairing of the force casing, and a second crack stopping hole is arranged on one side of the second avoiding groove.

[0018] The self-adaptive outer ring fairing heat shield structure of the present application comprises a second front mounting edge, a cylinder and a second rear mounting edge, and the cylinder is divided into a plurality of parts of the same size along the circumference; each part is integrally connected with the second front mounting edge and the second rear mounting edge, so that no connecting structure is needed between any two parts, the connecting bolts of the middle mounting edge are cancelled, the radial space is saved, the diameter of the outer channel of the force casing is reduced, and the weight is reduced; at the same time, the flow channel profile has no height difference along the axial direction, the smoothness is improved, and the aerodynamic loss is reduced; by arranging a plurality of parts arranged uniformly, a circumferential splicing type outer ring fairing heat shield structure is formed, which can release circumferential stress self-adaptively in the working process, solve the problem of inharmonious thermal deformation, and avoid the problem of cracks in the weak parts such as the fairing second avoiding groove flange and the second crack stopping hole. Moreover, the fairing profile is continuous along the axial direction without height difference, and the aerodynamic performance loss is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions provided by the present application, the following will briefly introduce the drawings. Obviously, the drawings described below are only some embodiments of the present application.

[0020] Figure 1 It is a schematic diagram of the overall structure of the force casing in the background art;

[0021] Figure 2 It is an exploded structural schematic diagram of the heat shield in the background art;

[0022] Figure 3 It is a schematic diagram of the overall structure of the heat shield of the present application.

[0023] Figure 4 The first axial slit structure schematic diagram of the application;

[0024] Figure 5 The local structure schematic diagram of the barrel and the fairing connection of the application;

[0025] Figure 6 The Figure 5 The A part enlarged view;

[0026] Figure 7 The second axial slit structure schematic diagram of the application;

[0027] Figure 8 The structure schematic diagram of the application highlighting the bolt;

[0028] Figure 9 The first air slot structure schematic diagram of the application;

[0029] Figure 10 The second air slot structure schematic diagram of the application.

[0030] 1, force bearing inner ring; 2, force bearing outer ring; 3, force bearing support plate; 4, inner mounting edge; 5, first front mounting edge; 6, heat shield; 61, front half; 62, rear half; 63, first avoidance slot; 64, middle mounting edge; 65, first crack stop hole; 7, fairing; 8, positioning ring; 9, first rear mounting edge; 10, barrel; 101, second avoidance slot; 102, first axial slit; 103, second axial slit; 104, second crack stop hole; 11, second front mounting edge; 12, second rear mounting edge; 13, split body; 14, support sealing ring; 15, long sealing piece; 16, short sealing piece; 17, bolt; 18, first air slot; 19, first cooling cavity; 20, second air slot; 21, second cooling cavity; 22, positioning protrusion; 23, flange. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the application clearer, the technical scheme in the embodiment of the application will be described in more detail below with reference to the drawings in the embodiment of the application.

[0032] An adaptive rear force bearing engine case outer ring fairing heat shield structure, like Figure 3As shown, the force-bearing case is arranged on the force-bearing case, which includes a force-bearing outer ring 2, a force-bearing support plate 3 and a force-bearing inner ring 1. The outer side of the force-bearing outer ring 2 and the outer channel case form an outer channel. The force-bearing support plate 3 is connected between the force-bearing outer ring 2 and the force-bearing inner ring 1. The force-bearing outer ring 2 and the force-bearing inner ring 1 form an inner channel. The front and rear sides of the force-bearing outer ring 2 are respectively provided with a first front mounting edge 5 and a first rear mounting edge 9. The outer side of the force-bearing support plate 3 is provided with a fairing 7. These structures are prior art and will not be described in detail.

[0033] The second front mounting edge 11, the cylinder body 10 and the second rear mounting edge 12 are included. The second front mounting edge 11 is connected with the first front mounting edge 5, and the second rear mounting edge 12 is connected with the first rear mounting edge 9. The second front mounting edge 11 and the second rear mounting edge 12 are both arranged in a ring structure. The cylinder body 10 is connected between the second front mounting edge 11 and the second rear mounting edge 12.

[0034] The cylinder body 10 is divided into several parts 13 of the same size along the circumference. Two groups of parts 13 are arranged between any two adjacent groups of force-bearing support plates 3. A second avoiding groove 101 is arranged on the fairing 7 between the two groups of parts 13 on both sides of the force-bearing support plate 3. A first axial gap 102 is formed between the two groups of parts 13 between adjacent force-bearing support plates 3. A first sealing structure is arranged at the first axial gap 102 to connect the adjacent parts 13. A second axial gap 103 is formed between the two groups of parts 13 on both sides of the force-bearing support plate 3. A second sealing structure is arranged at the second axial gap 103 to connect the adjacent parts 13.

[0035] Compared with the existing structure of separating the heat shield 6 axially, the heat shield 6 is divided into several parts 13 along the circumference. The number of parts 13 is about twice the number of force-bearing support plates 3. For example, if the number of force-bearing support plates 3 is 8, the number of parts 13 is 16. That is, two groups of parts 13 are arranged between any two adjacent groups of force-bearing support plates 3.

[0036] Each part 13 is integrally connected with the second front mounting edge 11 and the second rear mounting edge 12. Therefore, no connecting structure is needed between any two parts 13, and the bolts required for intermediate connection are cancelled, saving radial space, reducing the diameter of the outer channel of the force-bearing case and reducing the weight. At the same time, the flow passage profile has no height difference along the axial direction, the smoothness is improved, and the aerodynamic loss is reduced.

[0037] By arranging several parts 13 uniformly, a circumferentially spliced outer ring fairing heat shield 6 structure is formed, which can release circumferential stress adaptively during operation, solve the problem of incoordination of thermal deformation, and avoid the problem of cracks in the second avoiding groove 101 of the fairing 7, the second crack stop hole 104 and other weak parts. The fairing 7 profile is continuous along the axial direction without height difference, and the aerodynamic performance loss is reduced.

[0038] By setting the first axial gap 102 and the second axial gap 103, when each component 13 undergoes thermal expansion due to heat, it can expand towards the two axial gaps, thus preventing additional deformation of the component 13 structure and ensuring structural stability. The first sealing structure and the second sealing structure can seal the first axial gap 102 and the second axial gap 103 respectively, achieving separation between the inner and outer sides of the cylinder 10.

[0039] Combination Figures 4-6 Preferably, the first sealing structure includes a supporting sealing ring 14 and a long sealing plate 15. There are two sets of supporting sealing rings 14, which are respectively disposed on the split bodies 13 on both sides of the first axial gap 102. The supporting sealing rings 14 have a Z-shaped structure and the supporting sealing rings 14 on both sides are symmetrically arranged through the first axial gap 102. A sealing cavity is formed between the two sets of supporting sealing rings 14 and the split bodies 13. The long sealing plate 15 is sealed and connected in the sealing cavity. The two sides of the long sealing plate 15 do not contact the sidewalls of the supporting sealing rings 14.

[0040] By combining the support sealing ring 14 and the long sealing plate 15, the first axial gap 102 is sealed. While ensuring a stable seal, the long sealing plate 15 has a certain floating space in the sealing cavity when there is circumferential stress or thermal expansion, so as to ensure the stability of the sealing structure.

[0041] Combination Figure 7 Preferably, the second sealing structure includes a short sealing piece 16, which is disposed at one end of the second relief groove 101. The short sealing piece 16 is sealed to the split parts 13 on both sides of the second relief groove 101. Specifically, the short sealing piece 16 is disposed at the front end of the second relief groove 101 to ensure stable sealing of the second axial gap 103.

[0042] Combination Figure 3 and Figure 8 Preferably, a positioning ring 8 is coaxially arranged between the second front mounting edge 11 and the first front mounting edge 5. The positioning ring 8 is connected to the first front mounting edge 5 by countersunk screws. The positioning ring 8 and the first front mounting edge 5 also have a stop fit structure. The outer side of the second front mounting edge 11 connects to the inner stop of the positioning ring 8, with the stop direction being axial, resulting in a simple and stable connection. A bolt 17 connects the second rear mounting edge 12 and the first rear mounting edge 9 for stable fixing. This two-part connection structure achieves a stable connection between the fairing 7 and the load-bearing outer ring 2, eliminating the need for other connection structures, simplifying the connection and minimizing space requirements.

[0043] Preferably, the positioning ring 8, the first front mounting edge 5 and the second front mounting edge 11 form a first cooling cavity 19, and the positioning ring 8 is provided with a plurality of first air bleeding grooves 18 on the side close to the first cooling cavity 19 and spaced apart circumferentially, the outer side of the first air bleeding groove 18 is communicated with the outer channel, and the inner side is communicated with the first cooling cavity 19, the first air bleeding groove 18 is arranged corresponding to the overlapping transition area between the positioning ring 8 and the first front mounting edge 5, and the flow area is prevented from being cut off, as shown in Figure 9 The outer channel cooling gas in the outer channel enters the first cooling cavity 19 through the first air bleeding groove 18, and then flows into the inner channel through the gap between the cylinder 10 and the fairing 7, and the heat shield 6 is cooled along the way to prevent gas backflow.

[0044] The first rear mounting edge 9 and the second rear mounting edge 12 form a second cooling cavity 21, as shown in Figure 10 The second rear mounting edge 12 is provided with a plurality of second air bleeding grooves 20 on the side close to the second cooling cavity 21 and spaced apart circumferentially, the outer side of the second air bleeding groove 20 is communicated with the outer channel, and the inner side is communicated with the second cooling cavity 21, the second air bleeding groove 20 is arranged corresponding to the overlapping transition area between the first rear mounting edge 9 and the second rear mounting edge 12, and the throttle is prevented. The outer channel cooling gas in the outer channel enters the second cooling cavity 21 through the second air bleeding groove 20, and then cools the heat shield 6 along the way by passing through the gap between the cylinder 10 and the fairing 7 to prevent gas backflow; at the same time, it can adapt to the transient pressure difference load in the transition state to prevent instability.

[0045] By arranging the cooling structure around the second front mounting edge 11 and the second rear mounting edge 12, the radial temperature gradient of the second front mounting edge 11 and the second rear mounting edge 12 can be reduced, and the local point stress can be reduced to meet the design requirements.

[0046] Preferably, the positioning ring 8 and the second front mounting edge 11 are provided with a plurality of groups of positioning protrusions 22 spaced apart circumferentially at the joint of the positioning ring 8 and the second front mounting edge 11 and the joint of the positioning ring 8 and the first front mounting edge 5, so as to reduce the contact area of the two layers of positioning joints, reduce the heat conduction effect, and reduce the temperature of the positioning ring 8 and the first front mounting edge.

[0047] Preferably, the cylinder 10 is provided with an annular flange 23 at the position corresponding to the outer side wall of the fairing 7 of the force casing, which can strengthen the support of the heat shield 6 and reduce the friction between the fairing 7 and the cylinder 10; the second gap 101 is provided with a second crack stopping hole 104 on one side, and the second crack stopping hole 104 is a special-shaped hole, which can increase the wire length and reduce the hole edge stress.

[0048] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An adaptive afterburner outer ring fairing heat shield structure, arranged on a bearing casing, the bearing casing comprising a bearing support plate (3), a first front mounting edge (5) and a first rear mounting edge (9), characterized in that: The second front mounting edge (11) is connected with the first front mounting edge (5) in correspondence, the second rear mounting edge (12) is connected with the first rear mounting edge (9) in correspondence, and the barrel (10) is connected between the second front mounting edge (11) and the second rear mounting edge (12); The barrel (10) is circumferentially divided into a plurality of sub-bodies (13) of the same size, two groups of sub-bodies (13) are arranged between any adjacent two groups of force support plates (3), a second avoiding groove (101) sleeved on the fairing (7) is arranged between the two groups of sub-bodies (13) on both sides of the force support plate (3), a first axial gap (102) is formed between the two groups of sub-bodies (13) between adjacent force support plates (3), and a first sealing structure connecting adjacent sub-bodies (13) is arranged at the first axial gap (102); a second axial gap (103) is formed between the two groups of sub-bodies (13) on both sides of the force support plate (3), and a second sealing structure connecting adjacent sub-bodies (13) is arranged at the second axial gap (103).

2. The adaptive rear load-bearing casing outer ring rectifier heat shield structure as described in claim 1, characterized in that: The first sealing structure comprises a support sealing ring (14) and a long sealing piece (15), the support sealing ring (14) is provided on the sub-body (13) on both sides of the first axial gap (102), the support sealing ring (14) has a Z-shaped structure, and the support sealing rings (14) on both sides are symmetrically arranged through the first axial gap (102), the support sealing rings (14) and the sub-body (13) form a sealing cavity, the long sealing piece (15) is sealingly connected in the sealing cavity, and the long sealing piece (15) is not in contact with the side wall of the support sealing ring (14) on both sides.

3. The self-adapting aft-structure fairing heat shield of claim 1, wherein: The second sealing structure comprises a short sealing piece (16), the short sealing piece (16) is arranged at one end of the second avoiding groove (101), and the short sealing piece (16) is sealingly connected to the sub-bodies (13) on both sides of the second avoiding groove (101).

4. The self-adapting aft-structure fairing heat shield of claim 1, wherein: The positioning ring (8) is coaxially arranged between the second front mounting edge (11) and the first front mounting edge (5), and the outer side of the second front mounting edge (11) is connected with the inner side stop of the positioning ring (8); The second rear mounting edge (12) is connected with the first rear mounting edge (9) through a bolt (17).

5. The self-adapting aft-structure fairing heat shield of claim 4, wherein: A first cooling cavity (19) is formed between the positioning ring (8), the first front mounting edge (5) and the second front mounting edge (11), a plurality of first air guide grooves (18) are circumferentially and intervally arranged on the side of the positioning ring (8) close to the first cooling cavity (19), the outer side of the first air guide groove (18) is in communication with the outer channel, the inner side is in communication with the first cooling cavity (19), and the first air guide groove (18) is arranged in correspondence with the overlapping transition region between the positioning ring (8) and the first front mounting edge (5). The first rear mounting edge (9) and the second rear mounting edge (12) form a second cooling cavity (21) therebetween, and a plurality of second air bleeding grooves (20) are circumferentially spaced apart on the side of the second rear mounting edge (12) close to the second cooling cavity (21), the outer side of the second air bleeding grooves (20) communicates with the outer channel, and the inner side thereof communicates with the second cooling cavity (21), and the second air bleeding grooves (20) are arranged corresponding to the overlapping transition area between the first rear mounting edge (9) and the second rear mounting edge (12).

6. The self-adapting aft-structure fairing heat shield of claim 4, wherein: A plurality of groups of positioning protrusions (22) are circumferentially spaced apart at the joint of the positioning ring (8) and the stop opening of the second front mounting edge (11) and the joint of the positioning ring (8) and the stop opening of the first front mounting edge (5).

7. The self-adapting aft-structure fairing heat shield of claim 1, wherein: An annular flange (23) is attached to the position corresponding to the outer side wall of the fairing (7) of the force-bearing casing of the barrel (10), and a second crack stopping hole (104) is arranged on one side of the second avoiding groove (101).

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