Diffuser case and aircraft engine

Abstract

The invention discloses a diffuser casing and an aero-engine, which are used for connecting a diffuser, and comprise an auxiliary positioning ring, a first air induction ring, a main positioning ring, a second air induction ring and a mounting ring which are sequentially connected from the inside to the outside; an auxiliary connecting seat and a main connecting seat are arranged on the diffuser; a stop for locating the radial position of the diffuser casing is arranged at the connection between the auxiliary positioning ring and the first air induction ring and at the connection between the main positioning ring and the second air induction ring; a detachable auxiliary mounting section is arranged on the mounting ring; the auxiliary mounting section is detachably connected to the mounting ring and the combustion chamber casing by a second precision bolt; the stability of the connection between the diffuser casing and the diffuser can be improved, and the risk of cracks in the diffuser blades due to unstable fixation can be effectively suppressed; the auxiliary mounting section and the diffuser casing adopt a split structure, which can simplify the structure of the diffuser casing, reduce processing costs, and solve the problem of limited engine installation objects; during use, the damaged auxiliary mounting section can be replaced, and the use cost can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft engines, and in particular, to a diffuser casing. In addition, the present invention also relates to an aircraft engine comprising the diffuser casing. Background Art

[0002] The diffuser casing is the main load-bearing part in an aircraft engine, bearing complex loads from multiple components, including the force and torque loads of the axial flow casing, combustion chamber casing, diffuser, impeller cover, auxiliary mounting joints and other parts. It also has to withstand thermal loads and pressure loads of each chamber. The force is complex and it is usually designed as a single-function load-bearing part. Its reliability is ensured by increasing the wall thickness, and it is heavy.

[0003] like Figure 1 As shown, the conventional diffuser casing 1 is integrated with the auxiliary mounting joint 106. The auxiliary mounting joint 106 is subjected to large and complex forces and has high requirements on casting quality. When the auxiliary mounting joint 106 is damaged, the entire conventional diffuser casing 1 cannot be used. As a key component, the auxiliary mounting joint 106 makes the cost of the conventional diffuser casing 1 high throughout its life cycle. In addition, the conventional diffuser casing 1 usually adopts a high-radius stop 2 to cooperate with the combustion chamber casing 3 at the maximum size connection position of the casing. Since the conventional diffuser casing 1 is a large-size thin-walled structure, the high-precision high-radius stop 2 in the radial direction is easily deformed during processing, and its processing difficulty and cost are high. The conventional diffuser casing 1 is connected to the diffuser 200 through the connecting seat 203 and the high-radius stop 2, which is unstable. The diffuser blades vibrate due to unstable fixation, and long-term use may cause cracks in the diffuser blades. Summary of the invention

[0004] The present invention provides a diffuser casing and an aircraft engine to solve the technical problems of a traditional diffuser casing having a short service life, great processing difficulty, high processing cost, poor connection stability, and the possibility of cracks in diffuser blades.

[0005] According to one aspect of the present invention, there is provided a diffuser casing for connecting a diffuser, comprising an auxiliary positioning ring, a first air induction ring, a main positioning ring, a second air induction ring and a mounting ring which are sequentially connected from the inside to the outside, the diffuser being provided with an auxiliary connecting seat and a main connecting seat, a stop for locating the radial position of the diffuser casing being provided at the connection between the auxiliary positioning ring and the first air induction ring and at the connection between the main positioning ring and the second air induction ring, a detachable auxiliary mounting section being provided on the mounting ring, and the auxiliary mounting section being detachably connected to the mounting ring and the combustion chamber casing by a second precision bolt.

[0006] Furthermore, a slot is arranged on the auxiliary mounting node, and the slot is clamped on the mounting ring and the combustion chamber casing and is locked by the second precision bolt.

[0007] Furthermore, the stopper includes a first stopper adapted to the auxiliary connection seat and a second stopper adapted to the main connection seat.

[0008] Furthermore, the auxiliary positioning ring is connected to the auxiliary connecting seat via a positioning pin, and the main positioning ring is connected to the main connecting seat via a first precision bolt.

[0009] Furthermore, an adjustment pad is arranged between the auxiliary positioning ring and the auxiliary connecting seat.

[0010] Furthermore, it also includes reinforcing ribs for connecting the first air entraining ring, the main positioning ring and the second air entraining ring, and the reinforcing ribs are arranged on the outer wall surface of the diffuser casing along the radial direction.

[0011] Furthermore, an anti-icing air bleed interface is arranged on the first air bleed ring, and the reinforcing ribs are arranged on both sides of the anti-icing air bleed interface.

[0012] Furthermore, a P3 air bleed interface and a cabin air bleed interface are arranged on the second air bleed ring, and the reinforcing ribs are arranged on both sides of the P3 air bleed interface and the cabin air bleed interface respectively.

[0013] Furthermore, the mounting ring is provided with a through hole, and the through hole is provided with a bushing for passing the second precision bolt.

[0014] According to another aspect of the present invention, there is also provided an aircraft engine, which comprises the above-mentioned diffuser casing.

[0015] The present invention has the following beneficial effects:

[0016] The compressor casing of the present invention is annular, and is sequentially connected with an auxiliary positioning ring, a first air induction ring, a main positioning ring, a second air induction ring and a mounting ring from a low radius to a high radius. The low radius of the compressor casing is connected to the auxiliary connecting seat by an auxiliary positioning ring through an overfitting method of a stopper, and the middle position of the compressor casing is connected to the main connecting seat by a main positioning ring through an overfitting method of a stopper, which can enhance the strength and rigidity of the compressor casing in use and make up for the shortcoming that the thin-walled load-bearing casing is easy to deform; the mounting ring at the maximum radius of the compressor casing is locked with the auxiliary mounting section and the combustion chamber casing by a second precision bolt, It can improve the stability of the connection between the diffuser casing and the diffuser, and effectively suppress the risk of cracks in the diffuser blades due to unstable fixation; since the auxiliary mounting section and the diffuser casing adopt a split structure, on the one hand, the structure of the diffuser casing is simplified, and the stop position is set at the low radius and medium radius position, the processing qualification rate of the diffuser casing is improved by 25%, which can greatly reduce the processing cost; on the other hand, it can be flexibly adjusted according to the characteristics of the engine installation object, eliminating the problem of engine installation object restrictions; in addition, during use, the damaged auxiliary mounting section can be replaced, thereby reducing the use cost.

[0017] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 It is a schematic diagram of the structure of a traditional diffuser casing;

[0020] Figure 2 It is a structural schematic diagram of a diffuser casing of a preferred embodiment of the present invention;

[0021] Figure 3 is a side view of a diffuser casing according to a preferred embodiment of the present invention;

[0022] Figure 4 yes Figure 2 The AA section view shown;

[0023] Figure 5 is a schematic structural diagram of an adjustment pad according to a preferred embodiment of the present invention;

[0024] Figure 6 It is a structural schematic diagram of an auxiliary installation section of a preferred embodiment of the present invention;

[0025] Figure 7 It is a schematic structural diagram of the anti-icing air bleed cavity and the cabin air bleed cavity of the preferred embodiment of the present invention.

[0026] Legend:

[0027] 1. Traditional diffuser casing; 2. High-radius stopper; 3. Combustion chamber casing; 100. Diffuser casing; 101. Auxiliary positioning ring; 102. First air bleed ring; 103. Main positioning ring; 104. Second air bleed ring; 105. Mounting ring; 106. Auxiliary mounting section; 107. Positioning pin; 108. First precision bolt; 109. First stopper; 110. Second stopper; 111. Through hole; 112. Second precision bolt; 113. Adjustment pad; 114. Anti-icing air bleed interface; 115. P3 air bleed interface; 116. Cabin air bleed interface; 117. Reinforcement rib; 118. Bushing; 119. Positioning hole; 120. Slot; 121. Mounting hole; 122. Step groove; 200. Diffuser; 201. Auxiliary connector; 202. Main connector; 203. Connector. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0029] Please also read Figures 1 to 7 The diffuser casing 100 of the present embodiment is used to connect the diffuser 200, and includes an auxiliary positioning ring 101, a first air induction ring 102, a main positioning ring 103, a second air induction ring 104 and a mounting ring 105 which are sequentially connected from the inside to the outside. An auxiliary connecting seat 201 and a main connecting seat 202 are arranged on the diffuser 200. A stop for locating the radial position of the diffuser casing 100 is arranged at the connection between the auxiliary positioning ring 101 and the first air induction ring 102 and at the connection between the main positioning ring 103 and the second air induction ring 104. A detachable auxiliary mounting node 106 is arranged on the mounting ring 105. The auxiliary mounting node 106 is connected to the mounting ring 105 and the combustion chamber casing 3 by a second precision bolt 112.

[0030] The compressor casing 100 of the present embodiment is annular, and is sequentially connected from low radius to high radius, including an auxiliary positioning ring 101, a first air inlet ring 102, a main positioning ring 103, a second air inlet ring 104 and a mounting ring 105. The low radius of the compressor casing 100 is connected to the auxiliary connecting seat 201 by means of an auxiliary positioning ring 101, and the middle position of the compressor casing 100 is connected to the main connecting seat 202 by means of an auxiliary positioning ring 101 and a stopper overfitting method, which can enhance the strength and rigidity of the compressor casing 100 during use and make up for the shortcoming that the thin-walled load-bearing casing is easy to deform; the mounting ring 105 at the maximum radius of the compressor casing 100 is locked by the second precision bolt 112 to tighten the auxiliary The mounting joint 106 and the combustion chamber casing 3 can improve the stability of the connection between the diffuser casing 100 and the diffuser 200, and effectively suppress the risk of cracks in the diffuser blades due to unstable fixation; because the auxiliary mounting joint 106 and the diffuser casing 100 adopt a split structure, on the one hand, the structure of the diffuser casing 100 is simplified, the stop position is set at the low radius and the middle radius position, the processing qualification rate of the diffuser casing 100 is improved by 25%, and the processing cost can be reduced by 20%; on the other hand, it can be flexibly adjusted according to the characteristics of the engine installation object to eliminate the problem of engine installation object limitation; in addition, during use, the damaged auxiliary mounting joint 106 can be replaced, thereby reducing the use cost. Optionally, a plurality of auxiliary mounting joints 106 are evenly spaced on the mounting ring 105. In this embodiment, there are six auxiliary mounting joints 106. It can be understood that according to the installation requirements, the number of auxiliary mounting joints 106 can be increased or decreased to adapt to different engine installation objects.

[0031] like Figure 6 As shown, in this embodiment, a slot 120 is arranged on the auxiliary mounting node 106, and the slot 120 is clamped on the mounting ring 105 and the combustion chamber casing 3 and locked by the second precision bolt 112, which can ensure the stability of the maximum size connection of the diffuser casing, thereby reducing the vibration of the diffuser blades caused by unstable fixation, and further extending the service life of the diffuser; during installation, the slot 120 is clamped on the mounting ring 105 and the combustion chamber casing 3, and the second precision bolt 112 passes through the slot 120, the mounting ring 105 and the combustion chamber casing 3 to fix the auxiliary mounting node 106 to the mounting ring 105; during disassembly, the auxiliary mounting node 106 can be separated from the mounting ring 105 by removing the second precision bolt 112, which simplifies the structure of the diffuser casing 100 and can reduce the processing and use costs. Optionally, a stepped groove 122 is arranged on the auxiliary mounting joint 106, which can reduce the weight of the auxiliary mounting joint 106 on the one hand, and on the other hand, when the auxiliary mounting joint 106 is connected to the engine installation object, the connecting bolt can be flush with the auxiliary mounting joint 106, which has a stronger anti-loosening effect and can ensure that the connecting parts remain tightened for a long time.

[0032] like Figure 4and Figure 5 As shown, in this embodiment, the stopper includes a first stopper 109 adapted to the auxiliary connecting seat 201 and a second stopper 110 adapted to the main connecting seat 202, that is, the first stopper 109 adapted to the auxiliary connecting seat 201 is arranged at the connection between the auxiliary positioning ring 101 and the first air induction ring 102; a plurality of auxiliary connecting seats 201 are evenly spaced and arranged on the diffuser 200, and the first stopper 109 cooperates with the auxiliary connecting seat 201 to realize centering and positioning of the auxiliary positioning ring 101, and to increase the stability of the connection between the auxiliary positioning ring 101 and the diffuser 200, thereby reducing the vibration of the diffuser blades caused by unstable fixation, thereby extending the service life of the diffuser. A second stop 110 adapted to the main connecting seat 202 is arranged at the connection between the main positioning ring 103 and the second air induction ring 104; a plurality of main connecting seats 202 are evenly spaced on the diffuser 200, and the second stop 110 cooperates with the main connecting seat 202 to achieve centering and positioning of the main positioning ring 103, thereby increasing the stability of the connection between the main positioning ring 103 and the diffuser 200, thereby reducing the vibration of the diffuser blades caused by unstable fixation, thereby extending the service life of the diffuser.

[0033] like Figure 2 and Figure 5As shown, in this embodiment, the auxiliary positioning ring 101 is connected to the auxiliary connecting seat 201 by positioning pins 107, and there are three positioning pins 107. The auxiliary positioning ring 101 is provided with positioning holes 119 for passing the positioning pins 107. The number of positioning holes 119 is the same as the number of positioning pins 107, and the positioning holes 119 are evenly spaced on the auxiliary positioning ring 101 to ensure that the auxiliary positioning ring 101 is evenly stressed. The number of auxiliary connecting seats 201 is the same as the number of positioning holes 119, and the auxiliary connecting seats 201 are evenly spaced on the diffuser 200; the positioning pins 107 pass through the corresponding auxiliary positioning rings 101 and auxiliary connecting seats 201, and the axial positions of the auxiliary positioning rings 101 and the auxiliary connecting seats 201 are limited by locking nuts, which can further increase the stability of the connection between the auxiliary positioning rings 101 and the diffuser 200, thereby reducing the diffuser blades from being fixed. The vibration caused by instability can extend the service life of the diffuser; it is understandable that the locating pins 107 can also be four, five, six or more, and the number of locating holes 119 and the number of auxiliary connecting seats 201 can be adjusted accordingly, which can be increased or decreased according to the size of the diffuser 200; the main locating ring 103 and the main connecting seat 202 are connected by first precision bolts 108, and there are three first precision bolts 108. The first precision bolts 108 can lock the axial position and radial position of the main locating ring 103 and the main connecting seat 202, which can further increase the stability of the connection between the main locating ring 103 and the diffuser 200, thereby reducing the vibration caused by the unstable fixation of the diffuser blades, thereby extending the service life of the diffuser; it is understandable that the auxiliary connecting seats 201 can also be four, five, six or more, which can be increased or decreased according to the size of the diffuser 200.

[0034] like Figure 5 As shown, in this embodiment, an adjustment pad 113 is arranged between the auxiliary positioning ring 101 and the auxiliary connecting seat 201. By selecting adjustment pads 113 of different specifications to fill the gap between the auxiliary positioning ring 101 and the auxiliary connecting seat 201, the difference in machining precision between the first stop 109 and the auxiliary connecting seat 201 can be compensated, the machining cost can be reduced, and the stability of the connection between the auxiliary positioning ring 101 and the diffuser 200 can be ensured.

[0035] like Figure 2 , Figure 3 and Figure 4 As shown, in this embodiment, it also includes a reinforcing rib 117 for connecting the first air entraining ring 102, the main positioning ring 103 and the second air entraining ring 104, and the reinforcing rib 117 is arranged on the outer wall surface of the diffuser casing along the radial direction; the reinforcing rib 117 can ensure the reliability of the diffuser casing 100 without increasing the wall thickness of the diffuser casing 100, can effectively reduce the weight of the diffuser casing 100, improve the yield of parts, and greatly reduce the processing and maintenance costs of the diffuser casing 100.

[0036] like Figure 2 , Figure 3 , Figure 4 and Figure 7 As shown, in this embodiment, an anti-icing air bleed interface 114 is arranged on the first air bleed ring 102, and the anti-icing air bleed is bleed from the centrifugal impeller outlet position. Compared with the centrifugal inlet or centrifugal middle air bleed, the temperature and pressure there are higher, which can effectively reduce the amount of bleed air; at the same time, there is a larger cavity at the corresponding position of the diffuser 200, and the anti-icing air bleed cavity naturally formed in the casing is utilized without the need for additional structural design, the weight is not increased, and the structure is relatively simple. In addition, the air bleed port of the anti-icing air bleed interface 114 is opened at the anti-icing air bleed cavity of the diffuser 200, which can effectively reduce the interference of the bleed air on the smoothness, minimize the influence of the anti-icing air bleed on the engine performance, and ensure the simplicity and reliability of the structure without adding additional weight; the reinforcing ribs 117 are arranged on both sides of the anti-icing air bleed interface 114; the anti-icing air bleed cavity is used to stabilize the airflow pressure and promote the airflow The air flows into the anti-icing air external pipeline through the anti-icing air bleed interface 114; after the anti-icing air flow flows into the inlet guide vane anti-icing channel or other anti-icing components through the external pipeline, the heat of the air flow itself is used to heat the parts, thereby achieving the anti-icing effect; the introduction of the anti-icing air bleed interface 114 makes the structure of the diffuser casing 100 more complicated, and the diffuser casing 100 itself is a thin-walled structure, which brings certain difficulties to the casting process. In addition, the gas in the anti-icing air bleed cavity is high-temperature and high-pressure gas, and there are many pipelines and leads arranged near the anti-icing air bleed interface 114. A large amount of high-temperature and high-pressure gas leaking here will cause varying degrees of damage to the working stability of the engine accessory system. Therefore, arranging reinforcing ribs 117 on both sides of the anti-icing air bleed interface 114 can effectively increase the structural strength of the anti-icing air bleed interface 114 and avoid gas leakage at the anti-icing air bleed interface 114.

[0037] like Figure 2 and Figure 3As shown, in this embodiment, the second air bleed ring 104 is provided with a P3 air bleed interface 115 and a cabin air bleed interface 116 to improve cabin ventilation and temperature environment. The P3 air bleed interface 115 and the cabin air bleed interface 116 are located at the compressor outlet, where the bleed air has less interference with the flow field, and the temperature and pressure are higher, which can ensure that the bleed air volume is sufficient. The axial flow centrifugal interstage bleed air will cause the compressor boosting capacity to be weakened and the compressor power to be reduced, while the compressor outlet bleed air has almost no effect on the compressor power and boosting capacity, and the impact on the engine performance is minimized; the reinforcing ribs 117 are respectively arranged on the P3 air bleed interface 115 and the cabin air bleed interface 1 16 on both sides; the introduction of P3 air bleed interface 115 and cabin air bleed interface 116 makes the structure of diffuser casing 100 more complicated. In addition, diffuser casing 100 itself is a thin-walled structure, which brings certain difficulties to the casting process. In addition, the gas in the anti-icing air bleed cavity is high-temperature and high-pressure gas, and many pipelines and leads are arranged near the anti-icing air bleed interface 114. A large amount of high-temperature and high-pressure gas leakage here will cause varying degrees of damage to the working stability of the engine accessory system. Therefore, arranging reinforcing ribs 117 on both sides of the anti-icing air bleed interface 114 can effectively increase the structural strength of the P3 air bleed interface 115 and the cabin air bleed interface 116 to avoid gas leakage.

[0038] like Figure 2 and Figure 4 As shown, in this embodiment, the mounting ring 105 is provided with a through hole 111, and the through hole 111 is provided with a bushing 118 for passing the second precision bolt 112. The mounting ring 105 is provided with six groups of through holes 111, each group of through holes 111 is one, and the through hole 111 is provided with a bushing 118. The second precision bolt 112 passes through the bushing 118 to lock the auxiliary mounting section 106, the mounting ring 105 and the combustion chamber casing 3. The bushing 118 can reduce wear and vibration, and can ensure the stability of the maximum size connection of the diffuser casing. Optionally, there are three through holes 111 in each group, and there are also three mounting holes 121 on each auxiliary mounting section 106. Each auxiliary mounting section 106 locks the auxiliary mounting section 106, the mounting ring 105 and the combustion chamber casing 3 through three second precision bolts 112, which can further improve the stability of the maximum size connection of the diffuser casing.

[0039] An aircraft engine includes the above-mentioned diffuser casing 100; the diffuser casing 100 is connected to the auxiliary connecting seat 201 by the auxiliary positioning ring 101 at the low radius by the stopper overfitting mode, and the middle position of the diffuser casing 100 is connected to the main connecting seat 202 by the main positioning ring 103 by the stopper overfitting mode, which can enhance the strength and rigidity of the diffuser casing 100 during use; the mounting ring 105 at the maximum radius of the diffuser casing 100 is locked with the auxiliary mounting section 106 and the combustion chamber casing 3 by the second precision bolt 112, which can improve the connection between the diffuser casing 100 and the diffuser 200. The stability of the connection is improved, and the risk of cracks in the diffuser blades due to unstable fixation is effectively suppressed; since the auxiliary mounting node 106 and the diffuser casing 100 adopt a split structure, on the one hand, the structure of the diffuser casing 100 is simplified, and the stop position is set at the low radius and the middle radius position, the processing qualification rate of the diffuser casing 100 is improved by 25%, which can greatly reduce the processing cost; on the other hand, it can be flexibly adjusted according to the characteristics of the engine installation object, eliminating the problem of engine installation object restrictions; in addition, during use, the damaged auxiliary mounting node 106 can be replaced, thereby reducing the use cost.

[0040] In addition to maintaining the load-bearing capacity, the diffuser casing 100 of the present invention also integrates an anti-icing air bleed interface 114, a cabin air bleed interface 116 and a P3 air bleed interface 115, with a high degree of integration. The air bleed interface fastening position adopts a wire screw sleeve structure, which can be disassembled and replaced, thereby improving the reliability and economy of long-term disassembly and assembly.

[0041] The diffuser casing 100 of the present invention adopts the first stop 109 and the second stop 110 at the assembly connection position to cooperate with the diffuser 200 to achieve centering and positioning, which simplifies the connection structure and eliminates the matching structure at the high-radius stop 2, thereby reducing the machining difficulty of the diffuser casing 100. At the same time, through the reasonable design of the reinforcing ribs 117, the weight of the diffuser casing 100 is effectively reduced while meeting the use requirements, the parts yield rate is improved, and the processing and use costs of the diffuser casing 100 are greatly reduced.

[0042] The auxiliary mounting section 106 of the diffuser casing 100 of the present invention adopts a split structure, which can be flexibly adjusted according to the characteristics of the engine installation object, solving the problem of limited engine installation objects, while reducing the difficulty of casting, and can be disassembled and replaced. While further simplifying the traditional structure, the reliability of the diffuser casing 100 is improved, and the weight and processing and use costs of the diffuser casing 100 are further reduced.

[0043] The diffuser casing 100 and the diffuser 200 of the present invention are respectively connected to the auxiliary connecting seat 201 and the main connecting seat 202 through the locating pin 107 and the first precision bolt 108, which can further enhance the centering and positioning effect of the diffuser casing 100, improve the stability of the connection between the diffuser casing 100 and the diffuser 200, and effectively suppress the risk of cracks in the diffuser blades due to unstable fixation.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A diffuser casing, characterized in that ； Used to connect a diffuser (200), comprising an auxiliary positioning ring (101), a first air induction ring (102), a main positioning ring (103), a second air induction ring (104) and a mounting ring (105) which are sequentially connected from the inside to the outside, wherein the diffuser (200) is provided with an auxiliary connection seat (201) and a main connection seat (202); A stopper for locating the radial position of the diffuser casing is arranged at the connection between the auxiliary positioning ring (101) and the first air induction ring (102) and at the connection between the main positioning ring (103) and the second air induction ring (104); A detachable auxiliary mounting section (106) is arranged on the mounting ring (105), and the auxiliary mounting section (106) is detachably connected to the mounting ring (105) and the combustion chamber casing (3) via a second precision bolt (112).

2. The diffuser casing according to claim 1, It is characterized by: The auxiliary mounting section (106) is provided with a clamping groove (120), and the clamping groove (120) is clamped on the mounting ring (105) and the combustion chamber casing (3) and is locked by the second precision bolt (112).

3. The diffuser casing according to claim 1, characterized in that ； The stopper comprises a first stopper (109) adapted to the auxiliary connection seat (201) and a second stopper (110) adapted to the main connection seat (202).

4. The diffuser casing according to any one of claims 1 to 3, characterized in that: The auxiliary positioning ring (101) is connected to the auxiliary connecting seat (201) via a positioning pin (107), and the main positioning ring (103) is connected to the main connecting seat (202) via a first precision bolt (108).

5. The diffuser casing according to claim 4, characterized in that: An adjustment pad (113) is arranged between the auxiliary positioning ring (101) and the auxiliary connecting seat (201).

6. The diffuser casing according to claim 4, characterized in that ； It also includes reinforcing ribs (117) for connecting the first air entraining ring (102), the main positioning ring (103) and the second air entraining ring (104), wherein the reinforcing ribs (117) are arranged on the outer wall surface of the diffuser casing in a radial direction.

7. The diffuser casing according to claim 6, It is characterized by: An anti-icing air bleed interface (114) is arranged on the first air bleed ring (102), and the reinforcing ribs (117) are arranged on both sides of the anti-icing air bleed interface (114).

8. The diffuser casing according to claim 6, It is characterized by: A P3 air bleed interface (115) and a cabin air bleed interface (116) are arranged on the second air bleed ring (104), and the reinforcing ribs (117) are arranged on both sides of the P3 air bleed interface (115) and the cabin air bleed interface (116).

9. The diffuser casing according to claim 1, It is characterized by: A through hole (111) is arranged on the mounting ring (105), and a bushing (118) for passing the second precision bolt (112) is arranged in the through hole (111).

10. An aircraft engine, characterized in that: The invention comprises the diffuser casing according to any one of claims 1 to 9.

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