Turbofan engine

Abstract

The present invention discloses a turbofan engine, which includes a compressor, a combustion chamber, a turbine fan assembly and a speed reducer; the combustion chamber is sleeved outside the compressor and communicated with the compressor, the turbine fan assembly is sleeved outside the speed reducer, and the turbine fan assembly drives the compressor through the speed reducer; the turbine fan assembly includes a first propeller fan and a turbine blade assembly fixedly arranged at the blade tip of the first propeller fan; the first propeller fan is sleeved outside the ring gear of the speed reducer and is drivingly connected with the ring gear, and the sun gear of the speed reducer is drivingly connected with the rotating structure of the compressor. By setting a differential planetary speed reducer in this engine, the turbine fan assembly is sleeved outside the speed reducer, the original output ring gear is used as the input end, and the original input sun gear is used as the output end. The turbine fan assembly drives the sun gear through the input of the ring gear and then drives the compressor, greatly shortening the axial distance of the engine while meeting the high thrust requirement of the engine.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and particularly to a turbofan engine. Background Art

[0002] In a conventional turbofan engine, a fan, a high-pressure compressor, a combustor, a high-pressure turbine, and a low-pressure turbine are arranged along an axis. The high-speed rotating fan compresses air to a certain pressure. After passing through a flow splitting device, the air is divided into two parts. One part of the air enters the outer bypass duct, and the other part of the air enters the inner bypass duct. The compressed air entering the inner bypass duct is compressed to a higher pressure by the high-pressure compressor rotating at a higher speed. After the high-pressure air enters the combustor, it is quickly mixed with fuel and ignited to form high-temperature and high-pressure gas. The gas is accelerated by the high-pressure turbine nozzle guide vane and drives the rotor of the high-pressure turbine to rotate rapidly. The high-pressure turbine is connected to the high-pressure compressor through a turbine shaft and drives the rotor of the high-pressure compressor to rotate at the same speed. The temperature and pressure of the gas decrease. The gas leaving the high-pressure turbine continues to expand and do work in the low-pressure turbine. After being accelerated by the low-pressure turbine guide vane, it drives the rotor of the low-pressure turbine to rotate at a high speed. The rotor of the low-pressure turbine is connected to the fan through a turbine shaft, and the fan and the low-pressure turbine rotate at the same speed. The gas after the low-pressure turbine is mixed with the air in the outer bypass and then continues to accelerate and is discharged from the engine to generate thrust.

[0003] To increase the thrust and reduce the fuel consumption of a conventional turbofan engine, it is achieved by improving the thermodynamic cycle parameters of the engine, such as increasing the pressure ratio, increasing the turbine inlet temperature, and increasing the bypass ratio. Increasing the temperature at the front end of the turbine is limited by the material properties and cooling capacity. Increasing the pressure ratio will lead to an increase in the axial length dimension of the engine, etc. Increasing the bypass ratio is also restricted by conditions such as the turbine inlet temperature and the tip speed. Therefore, it is becoming increasingly difficult to improve the performance of a conventional turbofan engine based on the existing technology.

[0004] In the prior art, various technical solutions of tip turbines have been disclosed at home and abroad. Although they can solve the problem of the overly complex overall structure caused by the complex compression system, multi-rotor, and long-span layout of traditional turbofans, for a single integrated turbine / fan configuration, the turbine work is transmitted only by one fan. When the engine is operating at a low state, the cycle parameters of the core flow (compressor pressure ratio, combustion chamber outlet temperature) are relatively low, resulting in a low cycle efficiency, a low fan work driven by the turbine, a low thrust, and a high specific fuel consumption. For a dual integrated turbine / fan configuration, since the turbine work is transmitted through two rows of fans, and one row of turbines only drives the compressor, when the other row of turbines drives the fan, it also needs to drive the compressor through a speed-increasing gear. When the engine is operating at a low state, similar to the tip turbine engine with a single integrated turbine / fan configuration, there is also a problem of relatively low cycle parameters of the core flow, resulting in a low fan work driven by the turbine, a low thrust, and a high specific fuel consumption. Moreover, due to the adoption of a dual integrated turbine / fan configuration, a post-stage strut structure needs to be set as a support, which increases the axial dimension of the engine, affects the engine performance, and is not conducive to the compact layout of the engine. Summary of the Invention

[0005] The present invention provides a turbofan engine to solve the technical problem that while improving the performance of the existing engine, the axial dimension is increased.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A turbofan engine includes a compressor, a combustion chamber, a turbine fan assembly, and a reducer.

[0008] The combustion chamber is sleeved outside the compressor and communicated with the compressor. The turbine fan assembly is sleeved outside the reducer, and the turbine fan assembly drives the compressor through the reducer.

[0009] The turbine fan assembly includes a first propeller fan and a turbine blade assembly fixedly arranged at the tip of the first propeller fan.

[0010] The reducer includes a sun gear, an annular gear, a planetary gear, and a planet carrier. The sun gear and the annular gear are coaxially arranged. The planetary gear is located between the sun gear and the annular gear and meshes with both of them respectively. The planet carrier is connected to the planetary gear and is used to rotate coaxially with the sun gear as the planetary gear moves circumferentially. The first propeller fan is sleeved outside the annular gear and is drivingly connected to the annular gear. The sun gear is drivingly connected to the rotating structure of the compressor.

[0011] As a further improvement of the above technical solution, the turbine blade assembly includes a first turbine blade and a second turbine blade coaxially arranged along the air flow direction, and the first turbine blade and the second turbine blade are respectively radially fixed to the blade tips of the first paddle fan.

[0012] As a further improvement of the above technical solution, the turbine fan assembly further includes turbine guide vanes, the turbine guide vanes are fixedly arranged on the inner wall of the outer casing of the engine and are located between the air outlet end of the combustion chamber and the air inlet end of the turbine fan assembly, and a plurality of the turbine guide vanes are evenly distributed circumferentially on the inner wall of the outer casing of the engine.

[0013] As a further improvement of the above technical solution, the turbine fan assembly further includes a second paddle fan, and the second paddle fan is sleeved outside the planet carrier and is drivingly connected to the planet carrier.

[0014] As a further improvement of the above technical solution, an angle adjustment structure is provided between the second paddle fan and the planet carrier, which is used to change the angle of the second paddle fan relative to the oncoming flow direction so as to adjust the torque of the second paddle fan.

[0015] As a further improvement of the above technical solution, the engine further includes a control module, and the control module is drivingly connected to the angle adjustment structure, and is used to adjust the angle adjustment structure according to the change of the fuel flow rate of the engine so as to change the angle of the second paddle fan.

[0016] As a further improvement of the above technical solution, the engine further includes an inner support structure, the inner support structure includes an inner support casing arranged at the air inlet end of the compressor, and the inner support casing is coaxially arranged with the compressor; the inner support casing is formed with an air inlet structure, the formation position of the air inlet structure is adapted to the air inlet end position of the rotating structure of the compressor, and the width of the air inlet structure is adapted to the radial dimension of the air inlet end of the rotating structure of the compressor; the inner support structure further includes inner air inlet plates, and a plurality of the inner air inlet plates are evenly arranged circumferentially in the air inlet structure.

[0017] As a further improvement of the above technical solution, a roller bearing is arranged between the outer wall of the air inlet end of the rotating structure of the compressor and the inner air inlet plate, or a roller bearing is arranged between the outer wall of the air inlet end of the rotating structure of the compressor and the inner support casing; the rotating structure of the compressor axially extends towards the air outlet end direction of the rotating structure to form a support structure, and the support structure is drivingly connected to the sun gear.

[0018] As a further improvement of the above technical solution, the engine further includes an external support structure, which includes an external air inlet support plate. The external air inlet support plate is arranged radially between the internal support casing and the external casing of the engine. A plurality of the external air inlet support plates are evenly arranged circumferentially between the internal support casing and the external casing. The external air inlet support plate is a hollow plate with a diversion cavity. Openings communicating with the diversion cavity are respectively arranged at both ends of the external air inlet support plate. One opening at one end of the external air inlet support plate communicates with the air outlet end of the compressor, and the other opening at the other end of the external air inlet support plate communicates with the air inlet end of the combustion chamber.

[0019] As a further improvement of the above technical solution, the planet carrier is arranged in the direction towards the exhaust end of the engine; an extension section is formed on one side of the planet carrier towards the air inlet end of the engine; a roller bearing is arranged between the extension section of the planet carrier and the external air inlet support plate.

[0020] The present invention has the following beneficial effects: The air entering the engine is divided into two paths, namely the core air flow path and the bypass air flow path. Among them, the air flow in the core air flow path is pressurized by the compressor and then enters the combustion chamber arranged on the outer ring to mix and burn with the fuel. The high-temperature and high-pressure combustion gas drives the turbine fan assembly to rotate through the turbine blade assembly and is then discharged through the engine tail nozzle; the air flow in the bypass air flow path is pressurized by the first paddle fan and then mixed with the gases of different pressures and temperatures discharged from the core air flow path in the tail nozzle and discharged into the atmosphere; compared with the structure of the traditional engine where components such as the fan, compressor, combustion chamber, and turbine are arranged in series axially, in this engine, the combustion chamber is arranged outside the compressor, the turbine and paddle fan structures are integrated into an integrated structure, and the turbine blade assembly is circumferentially arranged at the tip of the paddle fan as a whole, thereby greatly shortening the axial distance of the engine; by setting a differential planetary reducer, the turbine fan assembly is sleeved outside the reducer, the ring gear originally used as the output end is used as the input end, and the sun gear originally used as the input end is used as the output end. The turbine fan assembly drives the sun gear through the ring gear input and then drives the compressor, greatly shortening the axial distance of the engine while meeting the high-thrust requirements of the engine, making the engine structure more compact, and further improving the engine performance to a greater extent on this basis.

[0021] In addition to the purposes, features, and advantages described above, the present invention has other purposes, features, and advantages. The following will refer to the accompanying drawings to further elaborate on the present invention in detail. Description of the Drawings

[0022] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0023] Figure 1 It is a schematic diagram of the engine part structure of the preferred embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of the flow of the inner and outer ducts of the engine of the preferred embodiment of the present invention;

[0025] Figure 3 It is a simplified structural diagram of the differential planetary accelerator of the preferred embodiment of the present invention.

[0026] 1. Inner air intake strut 2. Compressor 21. Support structure 3. Outer air intake strut 31. Flow guiding cavity 4. Combustion chamber 5. First turbine guide vane 6. First turbine blade 7. Turbine outlet strut 8. Reducer 9. Second propeller fan 91. Angle adjustment structure 10. Tail nozzle 11. Ring gear 12. Planet carrier 121. Extension section 13. Planet gear 14. Sun gear 15. First propeller fan 16. Bearing 17. Inner support casing 18. Second turbine guide vane 19. Second turbine blade Specific embodiments

[0027] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0028] Referring to Figures 1 to 3 , the preferred embodiment of the present invention provides a turbofan engine, including a compressor 2, a combustion chamber 4, a turbine fan assembly, and a reducer 8;

[0029] The combustion chamber 4 is sleeved outside the compressor 2 and communicated with the compressor 2. The turbine fan assembly is sleeved outside the reducer 8, and the turbine fan assembly drives the compressor 2 through the reducer 8; It should be understood that, since the combustion chamber 4 is arranged on the outer ring of the compressor 2, the compressor 2 used in this embodiment is preferably a single-stage centrifugal compressor 2, and the rotating structure is the centrifugal impeller of the compressor 2.

[0030] The turbine fan assembly includes a first propeller fan 15 and a turbine blade assembly fixedly arranged at the tip of the first propeller fan 15;

[0031] The reducer 8 includes a sun gear 14, a ring gear 11, a planet gear 13, and a planet carrier 12. The first propeller fan 15 is sleeved outside the ring gear 11 and is drivingly connected to the ring gear 11. The sun gear 14 is drivingly connected to the rotating structure of the compressor 2;

[0032] It can be understood that the speed reducer 8 of the present invention is a differential planetary speed reducer 8, the sun gear 14 and the ring gear 11 (i.e., the external gear ring) are coaxially arranged, and the planetary gears 13 are located between the sun gear 14 and the ring gear 11 and mesh with both; the planet carrier 12 is connected to the planetary gears 13 and rotates coaxially with the sun gear 14 as the planetary gears 13 move.

[0033] The working principle of this turbofan engine: The air entering the engine is divided into two paths, namely the core air flow path and the bypass air flow path. Among them, the air flow in the core air flow path is pressurized by the compressor 2 and then enters the combustion chamber 4 arranged on the outer ring to be mixed with fuel and burned. The high-temperature and high-pressure gas after combustion drives the turbofan assembly to rotate through the turbine blade assembly and is discharged through the engine tail nozzle 10; the air flow in the bypass air flow path is pressurized by the first propeller fan 15 and then mixed with the gases of different pressures and temperatures discharged from the core air flow path in the tail nozzle 10 and discharged into the atmosphere; compared with the structure in which components such as the fan, compressor 2, combustion chamber 4, and turbine of a traditional engine are arranged in series along the axial direction, in this engine, the combustion chamber 4 is arranged outside the compressor 2, the turbine and propeller fan structures are integrated into an integrated structure, and the turbine blade assembly is fixedly arranged circumferentially as a whole at the tip of the propeller fan, thereby greatly shortening the axial distance of the engine; by setting the differential planetary speed reducer 8 in this engine, the turbofan assembly is sleeved outside the speed reducer 8, the ring gear 11 that was originally the output end is used as the input end, and the sun gear 14 that was originally the input end is used as the output end. The turbofan assembly drives the sun gear 14 through the ring gear 11 and then drives the compressor 2. While meeting the high thrust requirements of the engine, the axial distance of the engine is greatly shortened, making the engine structure more compact, and further improving the engine performance to a greater extent on this basis.

[0034] Specifically, the turbine blade assembly includes a first turbine blade 6 and a second turbine blade 19 coaxially arranged along the air flow direction, and both the first turbine blade 6 and the second turbine blade 19 are fixedly arranged at the tip of the first propeller fan 15;

[0035] Specifically, the turbofan assembly further includes a first turbine guide vane 5, and the first turbine guide vane 5 is fixedly arranged on the inner wall of the outer casing of the engine and is located between the gas outlet end of the combustion chamber 4 and the gas inlet end of the first turbine blade 6. The high-temperature and high-pressure gas flowing out of the combustion chamber 4 is expanded and accelerated by the first turbine guide vane 5 to provide a suitable air flow pre-whirl angle for the first turbine blade 6; the turbofan assembly further includes a second turbine guide vane 18, and the second turbine guide vane 18 is fixedly arranged on the inner wall of the outer casing of the engine and is located between the gas outlet end of the first turbine blade 6 and the gas inlet end of the second turbine blade 19, and its function is the same as that of the first turbine guide vane 5;

[0036] Among them, a turbine outlet strut 7 located at the outlet end of the second turbine blade 19 is fixedly arranged on the inner wall of the outer casing of the engine to direct the discharged air flow and reduce the flow loss at the same time.

[0037] Furthermore, the turbofan assembly further includes a second paddle fan 9. The second paddle fan 9 is sleeved outside the planet carrier 12 and is drivingly connected to the planet carrier 12. By arranging the first paddle fan 15, the second paddle fan 9, and the differential planetary reducer 8 in this engine, and setting the turbofan assembly outside the reducer 8, the ring gear 11 that was originally the output end is used as the input end and is driven by the first paddle fan 15, the planet carrier 12 is used as the input end and is driven by the second paddle fan 9, and the sun gear 14 that was originally the input end is used as the output end. The turbofan assembly drives the sun gear 14 through the input of the ring gear 11 and then drives the compressor 2, developing a new driving method (double input and single output method) by using the differential planetary reducer 8 to drive the sun gear 14 as the power output end in a speed-increasing manner. Under the condition of meeting the high thrust requirement of the engine, the axial distance of the engine is greatly shortened, making the engine structure more compact; through the combined application of the differential planetary reducer 8, the first paddle fan 15, and the second paddle fan 9, the axial path of the air flow through the turbofan assembly is relatively long, and the axial velocity difference between the inlet and outlet air flows is relatively large. Under the same flow geometry conditions of the fan (i.e., the same flow area and flow rate conditions), the tip tangential velocity of the paddle fan of this engine is lower, the rotational speed of the first paddle fan 15 is lower than that of the second paddle fan 9, and it has a higher strength reserve; on the other hand, based on the combined application of the two paddle fans and the differential planetary reducer 8, the two paddle fans operate in a contra-rotating manner, and the first paddle fan 15 provides pre-rotation for the inlet air flow of the second paddle fan 9, thereby improving the compression efficiency and reducing the rotational speed requirement of the reducer 8 and the gear load.

[0038] Furthermore, an angle adjustment structure 91 is provided between the second paddle fan 9 and the planet carrier 12 for changing the angle of the second paddle fan 9 so as to adjust the torque of the second paddle fan 9. When the engine is operating at a low rotational speed, the engine cycle parameters (compression ratio of the centrifugal compressor 2 and total temperature at the outlet of the combustion chamber 4) decrease due to the reduction in the engine rotational speed. By adjusting the angle of the second paddle fan 9 through the angle adjustment structure 91, the torque of the second paddle fan 9 is increased, that is, the angle of the second paddle fan 9 is adjusted towards the feathering direction (the paddle fan blades tend to be flat with the oncoming flow direction). At this time, the speed increase of the second paddle fan 9 decreases, and the absorbed power decreases, so that the power of the turbine fan assembly transmitted to the single-stage centrifugal compressor 2 through the differential planetary reducer 8 device increases, thereby increasing the rotational speed and compression ratio of the single-stage centrifugal compressor 2. When the angle of the second paddle fan 9 is adjusted to the fan feathering position, the second paddle fan 9 is at the position with the maximum torque, its rotational speed is the minimum, the flow area is the largest and thus the flow capacity increases, and the absorbed power is the minimum, enabling the paddle fan section of the turbine fan assembly and the single centrifugal compressor 2 to obtain more power, and the air flow rate, rotational speed and compression ratio all increase. Based on the working principle of the aeroengine, under the given fuel condition, increasing the compression ratio of the compression component can increase the cycle work of the engine. At the same time, since the air flow rates of the inner and outer bypasses both increase, the engine thrust can be further increased and the fuel consumption rate can be reduced. At this time, it can be approximately considered that the single-input double-output function of the differential planetary reducer 8 degenerates into a single-input single-output function. When the second paddle fan 9 is between the positive pitch position (design point) and the fuel flow rate corresponding to the feathering position, at different engine fuel flow rates, by adjusting the angle of the second paddle fan 9 through the angle adjustment structure 91, the maximum thrust and the lowest fuel consumption rate can be obtained, thereby obtaining a turbofan engine with the optimal thrust under each rotational speed condition.

[0039] Based on the above technical solution, the engine is further provided with a control module, which is drivingly connected to the angle adjustment structure 91 and is used to adjust the angle adjustment structure 91 to change the angle of the second paddle fan 9 according to the change in the fuel flow rate of the engine, so that its angle adapts to the current fuel quantity and maintains the lowest fuel consumption rate under each thrust.

[0040] Furthermore, the engine includes an inner support structure. The inner support structure includes an inner support casing 17 arranged at the air inlet end of the compressor 2, and the inner support casing 17 is coaxially arranged with the compressor 2. The inner support casing 17 is formed with an air inlet structure, and the formation position of the air inlet structure is adapted to the air inlet end position of the rotating structure of the compressor 2, and the width of the air inlet structure is adapted to the radial dimension of the air inlet end of the rotating structure of the compressor 2, so that the airflow in the core duct can be led into the compressor 2 through the air inlet structure of the inner support casing 17. The inner support structure further includes inner air inlet struts 1 arranged radially along the inner support casing 17, and a plurality of inner air inlet struts 1 are evenly arranged circumferentially within the air inlet structure to guide and expand-accelerate the oncoming airflow.

[0041] In this embodiment, a roller bearing 16 is provided between the toroidal surface formed by the inner ends of the respective inner air intake support plates 1 and the outer wall of the intake end of the rotating structure of the compressor 2 to support and radially position the rotating structure of the compressor 2, further shortening the support span, enabling the air flow guiding structure and the support structure at the front end of the compressor 2 to be located at the same axial position, further reducing the axial distance of the engine, and making the engine structure compact;

[0042] In some embodiments, it may also be that a roller bearing 16 is provided between the inner support casing 17 and the outer wall of the intake end of the rotating structure of the compressor 2 to achieve the above effects.

[0043] In this embodiment, a cylindrical support structure 21 is axially extended from the rotating structure of the compressor 2 toward the outlet end of the rotating structure. The support structure 21 is drivingly connected to the sun gear 14, and the speed reducer 8 drives the support structure 21 through the sun gear 14 to drive the operation of the rotating structure of the compressor 2.

[0044] In this embodiment, the engine further includes an outer support structure. The outer support structure includes an outer air intake support plate 3. The outer air intake support plate 3 is radially arranged between the inner support casing 17 and the outer casing of the engine. A plurality of outer air intake support plates 3 are circumferentially and evenly arranged between the inner support casing 17 and the outer casing. The outer air intake support plate 3 is a hollow plate with a flow guiding cavity 31. Openings communicating with the flow guiding cavity 31 are respectively provided at both ends of the outer air intake support plate 3. The opening at the first end of the outer air intake support plate 3 communicates with the outlet end of the compressor 2, and the opening at the second end of the outer air intake support plate 3 communicates with the intake end of the combustion chamber 4. By providing the outer air intake support plate 3, the core air flow path enters the combustion chamber 4 through the intake structure, the compressor 2, and the flow guiding cavity 31, and the bypass air flow path enters the tail nozzle 10 of the engine after passing through the gaps between the respective outer air intake support plates 3, the first propeller fan 15, and the second propeller fan 9 in sequence.

[0045] In this embodiment, the size of the flow guiding cavity 31 gradually increases from the intake end to the outlet end to decelerate and expand the high-pressure gas entering the combustion chamber 4 and reduce the flow loss. Similarly, a tail nozzle 10 is provided at the outlet end of the turbine propeller fan assembly of this engine. The size of the tail nozzle 10 gradually increases from the inlet end to the outlet end to achieve the purpose of decelerating and expanding the pressure and reduce the flow loss.

[0046] It should be understood that the second propeller fan 9 is located at the tail end, and the planet carrier 12 connected thereto is arranged in the direction toward the exhaust end of the engine. An extension section 121 is formed on one side of the planet carrier 12 toward the intake end of the engine. The extension section is a cylindrical structure coaxial with the sun gear 14 and rotates coaxially with the planet carrier 12. A roller bearing 16 is provided as a support between the outer air intake support plate 3 and the extension section 121 of the planet carrier 12 to further shorten the support span and make the structure compact;

[0047] The inner support structure and the outer support structure of this engine are based on the coaxial setting structure of the turbine fan assembly and the reducer 8. By means of the support method of arranging a bearing 16 at the front end of the compressor 2 for inner support and arranging a bearing 16 at the front end of the turbine for outer support, the inter-stage splint structure and the post-stage support structure are cancelled, the layout is compact, and it has good rigidity. Compared with the existing support structure, the support span is further shortened, and thus the axial distance of the engine is shortened.

[0048] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A turbofan engine, characterized in that, it includes a compressor (2), a combustion chamber (4), a turbofan assembly, and a speed reducer (8); the combustion chamber (4) is sleeved outside the compressor (2) and communicates with the compressor (2), the turbofan assembly is sleeved outside the speed reducer (8), and the turbofan assembly drives the compressor (2) through the speed reducer (8); the turbofan assembly includes a first paddle fan (15) and a turbine blade assembly fixedly arranged at the blade tips of the first paddle fan (15); the speed reducer (8) includes a sun gear (14), an annular gear (11), a planetary gear (13), and a planet carrier (12). The sun gear (14) and the annular gear (11) are coaxially arranged. The planetary gear (13) is located between the sun gear (14) and the annular gear (11) and meshes with both of them respectively. The planet carrier (12) is connected to the planetary gear (13) and is used to rotate coaxially with the sun gear (14) as the planetary gear (13) moves circumferentially; the first paddle fan (15) is sleeved outside the annular gear (11) and is drivingly connected to the annular gear (11), and the sun gear (14) is drivingly connected to the rotating structure of the compressor (2); the turbofan assembly further includes a second paddle fan (9). The second paddle fan (9) is sleeved outside the planet carrier (12) and is drivingly connected to the planet carrier (12), and the planet carrier (12) is used as an input end to be driven by the second paddle fan (9).

2. The turbofan engine according to claim 1, characterized in that, the turbine blade assembly includes a first turbine blade (6) and a second turbine blade (19) coaxially arranged along the air flow direction. The first turbine blade (6) and the second turbine blade (19) are respectively radially and fixedly arranged at the blade tips of the first paddle fan (15).

3. The turbofan engine according to claim 2, characterized in that, the turbofan assembly further includes turbine guide vanes. The turbine guide vanes are fixedly arranged on the inner wall of the outer casing of the engine and are located between the air outlet end of the combustion chamber (4) and the air inlet end of the turbofan assembly. A plurality of the turbine guide vanes are evenly distributed circumferentially on the inner wall of the outer casing of the engine.

4. The turbofan engine according to claim 1, characterized in that, an angle adjustment structure (91) is provided between the second paddle fan (9) and the planet carrier (12), which is used to change the angle of the second paddle fan (9) relative to the oncoming flow direction so as to adjust the torque of the second paddle fan (9).

5. The turbofan engine according to claim 4, characterized in that, the engine further includes a control module. The control module is drivingly connected to the angle adjustment structure (91) and is used to adjust the angle adjustment structure (91) according to the change of the fuel flow rate of the engine so as to change the angle of the second paddle fan (9).

6. The turbofan engine according to claim 1, characterized in that, The engine further includes an inner support structure, which includes an inner support casing (17) disposed at the air inlet end of the compressor (2), and the inner support casing (17) is coaxially arranged with the compressor (2); the inner support casing (17) is formed with an air inlet structure, and the formation position of the air inlet structure is adapted to the air inlet end position of the rotating structure of the compressor (2), and the width of the air inlet structure is adapted to the radial dimension of the air inlet end of the rotating structure of the compressor (2); the inner support structure further includes inner air inlet support plates (1), and a plurality of the inner air inlet support plates (1) are circumferentially and uniformly arranged inside the air inlet structure.

7. The turbofan engine according to claim 6, wherein, a roller bearing (16) is disposed between the outer wall of the air inlet end of the rotating structure of the compressor (2) and the inner air inlet support plate (1), or a roller bearing (16) is disposed between the outer wall of the air inlet end of the rotating structure of the compressor (2) and the inner support casing (17); a support structure (21) is axially extended from the rotating structure of the compressor (2) towards the air outlet end direction of the rotating structure, and the support structure (21) is drivingly connected to the sun gear (14).

8. The turbofan engine according to claim 6, wherein, the engine further includes an outer support structure, which includes outer air inlet support plates (3), and the outer air inlet support plates (3) are radially arranged between the inner support casing (17) and the outer casing of the engine, and a plurality of the outer air inlet support plates (3) are circumferentially and uniformly arranged between the inner support casing (17) and the outer casing; the outer air inlet support plates (3) are hollow plates having a flow guiding cavity (31), and openings communicating with the flow guiding cavity (31) are respectively disposed at both ends of the outer air inlet support plate (3), one end opening of the outer air inlet support plate (3) communicates with the air outlet end of the compressor (2), and the other end opening of the outer air inlet support plate (3) communicates with the air inlet end of the combustion chamber (4).

9. The turbofan engine according to claim 8, wherein, the planet carrier (12) is arranged towards the exhaust end direction of the engine; an extension section (121) is formed on one side of the planet carrier (12) towards the air inlet end of the engine; a roller bearing (16) is disposed between the extension section (121) of the planet carrier (12) and the outer air inlet support plate (3).

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