A large bypass engine fan post-intermediate gearbox and test structure thereof

Abstract

This application belongs to the field of high-bypass engine fan design, specifically relating to a rear intermediate casing for a high-bypass engine fan and its experimental structure. The rear intermediate casing includes an outer ring casing, an inner ring casing, a support plate, and a thrust hanger. The front end of the outer ring casing connects to the rear end of the fan casing, and the rear end connects to the front end of the thrust reverser casing. The inner ring casing is disposed within the outer ring casing, with its front end connected to the fan booster stage outlet and its rear end connected to the core engine inlet. Multiple support plates are provided circumferentially between the outer and inner ring casings. The thrust hanger includes a hanger head connected to the aircraft structure. Below the hanger head is a hanger section that passes through the space between the outer and fan casings to form an opening. Below the hanger section is a forward-bending section that rests against the inner side of the outer ring casing. Below this section is a connecting section that connects to the rear edge of the support plate. Below this section is an arc-shaped section that separates to both sides, with connecting pieces at the ends of the arc-shaped sections that connect to the outer side of the inner ring casing.

Description

Technical Field

[0001] This application belongs to the field of high-bypass engine fan design, specifically relating to a rear intermediate casing for a high-bypass engine fan and its test structure. Background Technology

[0002] Small bypass engines can hardly produce more than 18 tons of thrust, but large bypass engines can produce up to 50 tons of thrust. In the future, large bypass engines may be able to withstand even higher thrust-to-weight ratios. More than 70% of the thrust of a large bypass engine is generated by the fan.

[0003] Compared to small-bypass engines, large-bypass engines have larger fan rotor blades and outer bypass ducts, with diameters reaching up to 1.8 meters and a maximum of 3.5 meters. The diameter of the fan components is usually over 2 meters. Therefore, an intermediate casing needs to be designed between the fan and the core engine to transfer the thrust generated by the fan and the thrust transmitted by the core engine to the aircraft.

[0004] In the design of traditional small-bypass engine fan components, the study of load-bearing and force-transmitting structures under large-size external bypass conditions has not been emphasized. Designing a lightweight, high-strength intermediate casing is a technical problem that urgently needs to be solved in the design of current large-bypass engines.

[0005] In addition, during the design of high-bypass turbine engines, not only the aerodynamic performance of the fan must be considered, but the design of the mechanical frame and load-bearing structure is also a critical technical indicator. Therefore, it is necessary to develop a lightweight and high-strength load-bearing frame to construct the fan test structure. If the traditional design method is followed, the design cycle of the high-bypass turbine fan test structure is long and the verification cost is high, which is not conducive to short-term iterative research.

[0006] In view of the above, this application is hereby filed. Summary of the Invention

[0007] The purpose of this application is to provide a rear intermediate casing for a high-bypass engine fan and its test structure, so as to provide a lightweight and high-strength load-bearing structure for high-bypass engines, realize the force transmission layout of the load-bearing frame, shorten the design cycle of the high-bypass fan test structure, reduce the high verification cost, and promote the test research of the fan.

[0008] The technical solution of this application is:

[0009] On the one hand, a large bypass engine fan rear intermediate casing is provided, including an outer ring casing, an inner ring casing, a support plate, and a thrust hanger;

[0010] The front end of the outer ring casing is connected to the rear end of the fan casing, and the rear end is connected to the front end of the thrust reverser casing.

[0011] The inner ring casing is located inside the outer ring casing, with its front end connected to the fan booster stage outlet and its rear end connected to the core engine inlet.

[0012] There are multiple support plates, which are circumferentially supported between the outer ring casing and the inner ring casing;

[0013] Each support plate is welded to the inner ring casing;

[0014] The contact surfaces between each support plate and the outer ring casing are palm-shaped structures with lace trim;

[0015] The thrust pylon includes a pylon head that connects to the aircraft structure. Below the pylon head is a pylon section that forms an opening between the outer ring casing and the fan casing. Below the pylon section is a forward-bending section that rests against the inner side of the outer ring casing. Below the forward-bending section is a connecting section that connects to the rear edge of the support plate. Below the connecting section is an arc-shaped section that separates to both sides. The ends of the arc-shaped sections have connecting plates that connect to the outer side of the inner ring casing.

[0016] Optionally, in the aforementioned high-bypass engine fan rear intermediate casing, the outer ring casing diameter is 2~3.5m;

[0017] The inner ring casing diameter is within 1.2m;

[0018] The number of support plates is 6 to 12, the height is 0.5 to 1.3m, and it is a titanium alloy conical shell structure with a wall thickness of 3 to 5mm;

[0019] Thrust hangers can be multiple, with their connecting sections attached to the rear edges of different support plates.

[0020] Optionally, in the aforementioned high-bypass engine fan rear intermediate casing, the welding method between each support plate and the inner ring casing is argon arc welding or electron beam welding, and the weld seam on the welding surface is U-shaped or anti-misalignment runway type.

[0021] In the thrust suspension, the suspension head is welded or bolted to the aircraft structure, the connecting section is bolted to the rear edge of the support plate, and the connecting piece is bolted to the outer side of the inner ring casing.

[0022] Optionally, in the aforementioned high-bypass engine fan rear intermediate casing, the fan booster stage is located inside the fan casing, behind the fan inlet rotor blades, forming the fan outer bypass duct with the fan booster stage, and forming the fan inner bypass duct inside.

[0023] The outer ring casing and the inner ring casing form an intermediate casing outer bypass duct, which connects to the fan outer bypass duct. The interior of the inner ring casing forms an intermediate casing inner bypass duct, which connects to the fan inner bypass duct.

[0024] The core machine is connected in sequence to components such as the high-pressure turbine and the low-pressure turbine, which together form the inner channel of the intermediate casing and are connected to the inner channel of the intermediate casing.

[0025] The core engine, high-pressure turbine, and low-pressure turbine are located inside the thrust reverser casing, forming an intermediate casing rear bypass duct with the thrust reverser casing, and connecting to the intermediate casing outer bypass duct.

[0026] The fan outer bypass duct, the intermediate casing outer bypass duct, and the intermediate casing rear outer bypass duct constitute the engine outer bypass duct, while the fan inner duct, the intermediate casing inner duct, and the intermediate casing rear inner duct constitute the engine outer bypass duct.

[0027] Optionally, in the aforementioned high-bypass engine fan rear intermediate casing, an intermediate casing is provided inside the engine's outer bypass duct, with the front end of the intermediate casing connected to the outside of the fan turbocharger inlet and the rear end connected to the outside of the low-pressure turbine outlet.

[0028] Optionally, in the aforementioned high-bypass engine fan rear intermediate casing, the fan inlet rotor blades, the rotor components of the fan booster stage, and the low-pressure turbine are connected via an internal low-pressure shaft, and the rotor components of the core engine are connected to the high-pressure turbine via a high-pressure shaft, with the high-pressure shaft sleeved around the outer periphery of the low-pressure shaft.

[0029] Optionally, in the aforementioned high-bypass engine fan rear intermediate casing, the front end of the inner ring casing is supported on the low-pressure shaft by a single-point bearing, the rear end of the inner ring casing and the front end of the high-pressure shaft are supported on the low-pressure shaft by two-point bearings, and the rear end of the high-pressure shaft is supported on the low-pressure shaft by three-point bearings.

[0030] On the other hand, a test structure for a high-bypass engine fan is provided, in which the rear intermediate casing of the high-bypass engine fan serves as a load-bearing unit, with the front end connected to the fan unit and the rear end connected to the exhaust unit.

[0031] The fan unit includes a fan casing, fan inlet rotor blades and a fan booster stage disposed within the fan casing. The fan booster stage is located behind the fan inlet rotor blades. The fan booster stage and the fan booster stage together form a fan outer bypass duct, and the fan inner duct inside forms a fan inner duct. The fan outer bypass duct connects to the intermediate casing outer bypass duct, and the fan inner duct connects to the intermediate casing inner duct.

[0032] The exhaust unit includes an outer bypass exhaust volute and an inner exhaust volute, wherein the outer bypass exhaust volute is connected to the outer bypass duct of the intermediate casing.

[0033] The outer exhaust volute and the inner exhaust volute are equipped with a drive shaft with a drive motor. The drive shaft is connected to the fan inlet rotor blades and the rotor components of the fan booster stage.

[0034] Optionally, in the above-mentioned high-bypass engine fan test structure, the inner exhaust volute is connected to the inner duct of the casing and is located behind the outer exhaust volute.

[0035] Optionally, in the above-mentioned high-bypass engine fan test structure, the front and rear ends of the inner ring casing are supported on the drive shaft by bearings, and the inner exhaust volute is supported on the drive shaft by two bearings. Attached Figure Description

[0036] Figure 1 This is an application schematic diagram of the intermediate casing behind the fan of a high-bypass engine provided in the embodiments of this application;

[0037] Figure 2 This is a schematic diagram of the inner ring casing provided in an embodiment of this application;

[0038] Figure 3 This is a schematic diagram of the support plate provided in an embodiment of this application;

[0039] Figure 4 This is a schematic diagram of the inner ring casing and support plate provided in an embodiment of this application;

[0040] Figure 5 This is a cross-sectional view of the outer ring casing, inner ring casing, and support plate provided in the embodiments of this application;

[0041] Figure 6 This is a view of the thrust suspension provided in an embodiment of this application at an angle;

[0042] Figure 7 This is a view of the thrust suspension provided in the embodiment of this application from another angle;

[0043] Figure 8 This is a schematic diagram of the high-bypass engine fan test structure provided in the embodiments of this application;

[0044] Figure 9 This is an assembly drawing of the high-bypass engine fan test structure provided in the embodiments of this application;

[0045] in:

[0046] 1-Outer ring casing; 2-Inner ring casing; 3-Support plate; 4-Thrust hanger; 5-Fan casing; 6-Thrust reverser casing; 7-Fan booster stage; 8-Core engine; 9-Fan inlet rotor blade; 10-High pressure turbine; 11-Low pressure turbine; 12-Intermediate casing; 13-Low pressure shaft; 14-High pressure shaft; 15-Single-point bearing; 16-Double-point bearing; 17-Triple-point bearing; 18-Inner exhaust volute; 19-Drive shaft; 20-Outer bypass exhaust volute.

[0047] 41-Hanging head; 42-Hanging section; 43-Forward bending section; 44-Connecting section; 45-Arc-shaped section; 46-Connecting piece.

[0048] To better illustrate this embodiment, some content in the accompanying drawings may be omitted, enlarged, or reduced. They are for illustrative purposes only and should not be construed as limiting the scope of this application. Detailed Implementation

[0049] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, and other related parts can be referred to the general design.

[0050] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The word "comprising" as used in this application description indicates that the concept preceding the word encompasses the concepts listed following the word and their equivalents, without excluding other related concepts.

[0051] Furthermore, the terms indicating location used in the description of this application are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation" and "connection" used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0052] A high-bypass turbine fan rear intermediate casing includes an outer ring casing 1, an inner ring casing 2, a support plate 3, and a thrust hanger 4, such as... Figure 1 As shown.

[0053] The outer ring casing 1 has a diameter of 2~3.5m, and its front end is connected to the rear end of the fan casing 5, while its rear end is connected to the front end of the thrust reverser casing 6.

[0054] The inner ring casing 2 is housed within the outer ring casing 1, forming a double-layer casing structure, such as... Figure 2 As shown, the diameter is within 1.2m, the front end is connected to the outlet of the fan booster stage 7, and the rear end is connected to the inlet of the core machine 8.

[0055] The fan booster stage 7 is located inside the fan casing 5, behind the fan inlet rotor blades 9, and forms the fan outer bypass duct with the fan booster stage 7, and forms the fan inner bypass duct inside.

[0056] The outer ring casing 1 and the inner ring casing 2 form an intermediate casing outer bypass duct, which connects to the fan outer bypass duct. The inner ring casing 2 forms an intermediate casing inner bypass duct, which connects to the fan inner bypass duct.

[0057] The core machine 8 is connected in sequence to components such as the high-pressure turbine 10 and the low-pressure turbine 11, which together form the inner channel of the intermediate casing and are connected to the inner channel of the intermediate casing.

[0058] The core engine 8, high-pressure turbine 10, and low-pressure turbine 11 are located inside the thrust reverser casing 6, forming an intermediate casing rear bypass duct with the thrust reverser casing 6, and connecting to the intermediate casing outer bypass duct.

[0059] The fan outer bypass duct, the intermediate casing outer bypass duct, and the intermediate casing rear outer bypass duct constitute the engine outer bypass duct. The fan inner duct, the intermediate casing inner duct, and the intermediate casing rear inner duct constitute the engine outer bypass duct. An intermediate casing 12 can be installed inside the engine outer bypass duct. The front end of the intermediate casing 12 is connected to the outside of the inlet of the fan booster stage 7, and the rear end is connected to the outside of the outlet of the low-pressure turbine 11.

[0060] The airflow entering the fan casing 5 flows through the fan inlet rotor blades 9, and then part of it flows out through the engine outer bypass duct and part of it flows out through the engine inner bypass duct.

[0061] The rotor blades 9 of the fan inlet and the rotor components of the fan booster stage 7 are connected to the low-pressure turbine 11 through the internal low-pressure shaft 13. The rotor components of the core machine 8 are connected to the high-pressure turbine 10 through the high-pressure shaft 14, and the high-pressure shaft 14 is sleeved on the outer periphery of the low-pressure shaft 13.

[0062] The front end of the inner ring casing 2 is supported on the low-pressure shaft 13 by a single-point bearing 15. The rear end of the inner ring casing 2 and the front end of the high-pressure shaft 14 are supported on the low-pressure shaft 13 by a double-point bearing 16. The rear end of the high-pressure shaft 14 is supported on the low-pressure shaft 13 by a triple-point bearing 17.

[0063] Support plate 3 Figure 3 As shown, there are multiple support plates, typically 6 to 12, with a height of 0.5 to 1.3m. They are circumferentially supported between the outer ring casing 1 and the inner ring casing 2. To ensure the flow of air in the engine's external bypass duct, the support plate 3 can be designed as a titanium alloy conical shell structure, which has high load-bearing capacity and relatively light weight.

[0064] The intermediate casing is the main load-bearing frame of the engine and is often cast as a whole. Unlike small ducted engines, large ducted engines usually have a diameter of more than 2 meters, and the traditional integral casting method cannot meet the design requirements.

[0065] Each support plate 3 is welded to the inner ring casing 2. The welding method can be argon arc welding or electron beam welding. To ensure welding accuracy, the weld seam on the welding surface is U-shaped or anti-misalignment runway-shaped. Each support plate 3 and the inner ring casing 2 bear the radial and axial loads of the engine. The wall thickness of each support plate 3 is designed according to strength requirements and can be between 3 and 5 mm.

[0066] After each support plate 3 is welded to the inner ring casing 2 to form a radial structure, as... Figure 4 As shown, it is assembled with the outer ring casing 1, as follows. Figure 5 As shown, each support plate 3 can be welded to the outer ring casing 1, and the contact surface between them is a palm-shaped structure with lace, which mainly transmits axial load to the outer ring casing 1.

[0067] Thrust suspension 4 Figures 6-7 As shown, it includes a sling head 41 that connects to the aircraft structure. The sling head 41 is welded or bolted to the aircraft structure. Below it is a sling section 42 that forms an opening between the outer ring casing 1 and the fan casing 5. Below the sling section 42 is a forward-bending section 43 that abuts against the inner side of the outer ring casing 1. Below it is a connecting section 44 that connects to the rear edge of the support plate 3, which can be bolted. Below it is an arc-shaped section 45 that splits to both sides. At the end of the arc-shaped section 45 is a connecting piece 46 that connects to the outer side of the inner ring casing 2, which can be bolted.

[0068] The thrust hanger 4 may have multiple sections, with its connecting section 44 connected to the rear edge of different support plates 3.

[0069] The high-bypass engine fan rear intermediate casing disclosed in the above embodiments is designed to bear the axial load and impact load from the first-point bearing 15 and the second-point bearing 16 through the front and rear ends of the inner ring casing 2, and transmit the axial thrust load through the support plate 3 and the outer ring casing 1, and transmit it to the aircraft through the thrust hanger 4.

[0070] The high-bypass engine fan rear intermediate casing disclosed in the above embodiments mainly bears the thrust and load from the outside, the inside and the rotor through multiple annular surfaces, and transmits them mainly through three paths.

[0071] Force transmission path 1: The fan supercharger stage 7 and core engine 8 casing transmit the internal force to the inner ring casing 2, and the inner ring casing 2 transmits the core engine 8 thrust to the aircraft through the thrust sling 4.

[0072] Force transmission path 2: The high and low pressure rotor's mechanical and vibration loads, borne by the first-point bearing 15 and the second-point bearing 16, are transmitted to the inner ring casing 2.

[0073] Force transmission path 3: The fan casing 5 and thrust reverser casing 6 transmit external forces to the outer ring casing 1. The outer ring casing 1 transmits the force to the inner ring casing 2 and its thrust hanger 4 through the support plate 3, and then transmits it to the aircraft through the thrust hanger 4.

[0074] The high-bypass engine rear intermediate casing disclosed in the above embodiments constructs three force transmission paths with the inner ring casing 2 as the core load-bearing point and the support plate 3 assisting in centripetal force transmission. Through the fan casing → outer ring casing support plate → inner casing → thrust hanger, the force is transmitted to the aircraft via the core force transmission point and the thrust hanger support and force transmission frame. The transmitted thrust can reach more than 70% of the total thrust of the engine. It integrates aerodynamic design, structural load-bearing and other technologies to form a lightweight thin-walled shell structure, which meets the load-bearing and frame support requirements of high-bypass engines. It solves the force transmission problem of high-bypass engines under lightweight structure, and can develop high-bypass fan components with larger bypass ratios, increasing the maximum diameter of the engine to more than 3 meters and expanding the market space of the engine.

[0075] A test structure for a high-bypass engine fan, using the rear intermediate casing of the high-bypass engine fan disclosed in the above embodiments as a load-bearing unit, with the fan unit connected to the front end and the exhaust unit connected to the rear end, as shown below. Figures 8-9 As shown.

[0076] The fan unit includes a fan housing 5, a fan inlet rotor blade 9 and a fan booster stage 7 disposed within the fan housing 5, wherein the fan booster stage 7 is located behind the fan inlet rotor blade 9, the fan booster stage 7 and the fan booster stage 7 together form a fan outer bypass duct, and the fan inner duct inside forms a fan inner duct, the fan outer bypass duct is connected to the intermediate housing outer bypass duct, and the fan inner duct is connected to the intermediate housing inner duct.

[0077] The exhaust unit includes an outer bypass exhaust volute 20 and an inner bypass exhaust volute 18. The outer bypass exhaust volute 20 is connected to the outer bypass duct of the intermediate casing, and the inner bypass exhaust volute 18 is connected to the inner bypass duct of the intermediate casing and is located behind the outer bypass exhaust volute 20.

[0078] The outer exhaust volute 20 and the inner exhaust volute 18 are equipped with a drive shaft 19 with a drive motor. The drive shaft 19 is connected to the fan inlet rotor blades 9 and the rotor components of the fan booster stage 7. The front and rear ends of the inner ring casing 2 are supported on the drive shaft 19 by bearings, and the inner exhaust volute 18 is supported on the drive shaft 19 by two bearings.

[0079] With the high-bypass engine fan test structure disclosed in the above embodiment, when conducting fan tests, the drive motor can drive the fan inlet rotor blades 9 and the rotor components of the fan booster stage 7 to rotate through the drive shaft 19, simulating the working state of the fan unit. The airflow of the fan outer bypass and the fan inner bypass is collected and discharged through the outer bypass exhaust volute 20 and the inner exhaust volute 18, and the aerodynamic performance of the fan is tested to verify the aerodynamic performance of the fan.

[0080] The high-bypass engine fan test structure disclosed in the above embodiments uses the rear intermediate casing of the high-bypass engine fan as a fixed module. It adopts a modular and fixed design concept of load-bearing structure and constructs a low-cost fan booster stage test structure by adding a double-bypass exhaust volute with a single rotor shaft. The fan test structure is designed in a low-cost mode for the rapid iterative verification of fan modification design and performance testing. Compared with the current fan aerodynamic performance test components, it can save 30%-50% of the cost.

[0081] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A high-bypass engine fan rear intermediate casing, characterized in that, Includes outer ring casing (1), inner ring casing (2), support plate (3), and thrust hanger (4); The front end of the outer ring casing (1) is connected to the fan casing (5) and the rear end is connected to the thrust reverser casing (6). The inner ring casing (2) is installed inside the outer ring casing (1), with its front end connected to the outlet of the fan booster stage (7) and its rear end connected to the inlet of the core machine (8); There are multiple support plates (3), which are circumferentially supported between the outer ring casing (1) and the inner ring casing (2); Each support plate (3) is welded to the inner ring casing (2); The contact surface between each support plate (3) and the outer ring casing (1) is a palm-shaped structure with lace trim; The thrust sling (4) includes a sling head (41) that connects to the aircraft structure. Below the sling head (41) is a sling section (42) that forms an opening between the outer ring casing (1) and the fan casing (5). Below the sling section (42) is a forward bending section (43) that abuts against the inner side of the outer ring casing (1). Below the sling head (41) is a connecting section (44) that connects to the rear edge of the support plate (3). Below the sling is an arc-shaped section (45) that separates to both sides. At the end of the arc-shaped section (45) is a connecting piece (46) that connects to the outer side of the inner ring casing (2). The fan booster stage (7) is located inside the fan casing (5), behind the fan inlet rotor blades (9), forming the fan outer bypass duct between the fan booster stage (7) and the fan inner bypass duct inside. The outer ring casing (1) and the inner ring casing (2) form an intermediate casing outer bypass duct, which connects to the fan outer bypass duct. The inner ring casing (2) forms an intermediate casing inner bypass duct, which connects to the fan inner bypass duct. The core machine (8) is connected in sequence to the high-pressure turbine (10) and the low-pressure turbine (11), which form the inner channel of the intermediate casing and are connected to the inner channel of the intermediate casing. The core engine (8), high-pressure turbine (10), and low-pressure turbine (11) are located inside the thrust reverser casing (6), forming an intermediate casing rear bypass duct with the thrust reverser casing (6), and connecting to the intermediate casing outer bypass duct; The fan outer bypass duct, the intermediate casing outer bypass duct, and the intermediate casing rear outer bypass duct constitute the engine outer bypass duct, while the fan inner duct, the intermediate casing inner duct, and the intermediate casing rear inner duct constitute the engine outer bypass duct. An intermediate casing (12) is installed inside the outer bypass duct of the engine. The front end of the intermediate casing (12) is connected to the outside of the inlet of the fan booster stage (7), and the rear end is connected to the outside of the outlet of the low-pressure turbine (11).

2. The intermediate casing behind the fan of a high-bypass engine according to claim 1, characterized in that, The outer ring casing (1) has a diameter of 2~3.5m; The inner ring casing (2) has a diameter of less than 1.2m; The number of support plates (3) is 6 to 12, the height is 0.5 to 1.3m, and they are titanium alloy conical shell structures with a wall thickness of 3 to 5mm. The thrust hanger (4) has multiple sections, and its connecting section (44) is connected to the rear edge of different support plates (3).

3. The intermediate casing behind the fan of a high-bypass engine according to claim 2, characterized in that, The welding method between each support plate (3) and the inner ring casing (2) is argon arc welding or electron beam welding, and the weld seam of the welding surface is U-shaped or anti-misalignment runway type; In the thrust sling (4), the sling head (41) is welded or bolted to the aircraft structure, the connecting section (44) is bolted to the rear edge of the support plate (3), and the connecting piece (46) is bolted to the outside of the inner ring casing (2).

4. The intermediate casing behind the fan of a high-bypass engine according to claim 3, characterized in that, The fan inlet rotor blades (9) and the rotor components of the fan booster stage (7) are connected to the low-pressure turbine (11) via an internal low-pressure shaft (13). The rotor components of the core machine (8) are connected to the high-pressure turbine (10) via a high-pressure shaft (14). The high-pressure shaft (14) is sleeved on the outer periphery of the low-pressure shaft (13).

5. The intermediate casing behind the fan of a high-bypass engine according to claim 4, characterized in that, The front end of the inner ring casing (2) is supported on the low-pressure shaft (13) by a single-point bearing (15). The rear end of the inner ring casing (2) and the front end of the high-pressure shaft (14) are supported on the low-pressure shaft (13) by a double-point bearing (16). The rear end of the high-pressure shaft (14) is supported on the low-pressure shaft (13) by a triple-point bearing (17).

6. A test structure for a high-bypass engine fan, characterized in that, The high-bypass engine fan rear intermediate casing as described in claim 5 is used as a load-bearing unit, with the front end connected to the fan unit and the rear end connected to the exhaust unit. The fan unit includes a fan housing (5), a fan inlet rotor blade (9) and a fan booster stage (7) disposed inside the fan housing (5). The fan booster stage (7) is located behind the fan inlet rotor blade (9). The fan booster stage (7) and the fan booster stage (7) form a fan outer bypass duct and an internal fan inner duct. The fan outer bypass duct is connected to the intermediate housing outer bypass duct, and the fan inner duct is connected to the intermediate housing inner duct. The exhaust unit includes an outer bypass exhaust volute (20) and an inner bypass exhaust volute (18), wherein the outer bypass exhaust volute (20) is connected to the outer bypass duct of the intermediate casing; The outer exhaust volute (20) and the inner exhaust volute (18) are equipped with a drive shaft (19) with a drive motor. The drive shaft (19) is connected to the fan inlet rotor blades (9) and the rotor components of the fan booster stage (7).

7. The high-bypass engine fan test structure according to claim 6, characterized in that, The inner exhaust volute (18) is connected to the inner channel of the casing and is located behind the outer exhaust volute (20).

8. The high-bypass engine fan test structure according to claim 7, characterized in that, The front and rear ends of the inner ring casing (2) are supported on the drive shaft (19) by bearings, and the inner exhaust volute (18) is supported on the drive shaft (19) by two bearings.

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