Contracting duct device

Abstract

The invention belongs to the technical field of aerocar propulsion systems, and particularly relates to a contraction duct device which comprises rotor wings, supporting brackets, fixed skins, movable skins, supporting reinforcing ribs, gear motors, annular racks and shafts. During vertical take-off and landing of the aircraft, the duct is kept complete, and low-speed and high-thrust efficiency is ensured; when the aircraft cruises at a high speed, the duct shrinks, the windward area is reduced, interference of duct walls to airflow is reduced, aerodynamic resistance during high-speed flight is reduced, and flight efficiency is improved. When the duct is in a contraction state, the duct does not need to bear all structural loads, and the overall weight can be optimized by changing the structure and materials, so that the lightweight design of the duct is realized. The vertical take-off and landing and high-speed cruising capabilities are considered, so that the problem that a fixed duct is difficult to consider the contradictory demand of vertical take-off and landing and high-speed flight is solved, the flight scene adaptability is expanded, and the task adaptability is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of flying car propulsion systems, and particularly relates to a retractable duct device. Background Art

[0002] As a representative of a new generation of aircraft, the ducted fan aircraft has an important role for the duct structure which is the main structure of the ducted fan. The ducted fan restricts the airflow through the duct structure, reduces the eddy current loss at the tip of the fan blade, enables more airflow to be accelerated and ejected backward, and improves the thrust efficiency, especially when the aircraft is in a low-speed or hovering state. However, the duct structure will generate additional aerodynamic drag during high-speed flight. When the airflow separates or forms a shock wave in the duct, the efficiency drops significantly and the energy consumption increases.

[0003] Chinese invention patent CN118753500A provides a duct structure, including a telescopic duct, a fixed duct and at least one duct driving device. Its structure is that the duct driving device is fixedly connected to the fixed duct, each duct driving device is connected to the telescopic duct, and the duct driving device can drive the telescopic duct to reciprocate along the central direction of the telescopic duct to achieve the purpose of adjusting the duct length. However, this duct structure can only contract the retractable duct and cannot contract the fixed duct, and the windward area of the duct structure is still large.

[0004] Chinese utility model patent CN209972776U provides a large oil-powered multi-rotor multi-purpose aircraft with a tilt-rotor and foldable ducts. The duct is a foldable two-semicircle structure, and its purpose is to reduce the width of the aircraft. However, it is impossible to reduce the aerodynamic drag during flight through the folding of the duct, which affects the efficiency during high-speed flight. Summary of the Invention

[0005] (1) Technical Problems to be Solved

[0006] The technical problem to be solved by the present invention is: how to solve the problems existing in the prior art, improve the performance of the duct device, and achieve the contraction of the duct device.

[0007] (2) Technical Solutions

[0008] To solve the above technical problems, the present invention provides a retractable duct device, as Figures 1-2 shown, the retractable duct device includes: a rotor 1, a support bracket 2, a fixed skin 3, a moving skin 4, a support stiffener 5, a gear motor 6, an annular rack 7, and a shaft 8;

[0009] The rotor 1 is fixedly connected to the shaft 8 coaxially. The cross-shaped support bracket 2 forms the diameter segments perpendicular to each other within the circular duct, and as a non-rotating component, it is fixedly connected to the shaft 8 coaxially through a bearing. The duct skin is evenly divided into 4 segments, and each segment includes a fixed skin 3 and a movable skin 4. The circumferential lengths of the fixed skin 3 and the movable skin 4 are the same, but the cross-sectional dimension of the movable skin 4 is set to be smaller than that of the fixed skin 3 to ensure that the movable skin 4 can be completely retracted into the fixed skin 3, as Figure 1 shown;

[0010] The cross-shaped support bracket 2 has four outer ends, and each of the outer ends is fixedly connected to a fixed skin 3 through a support reinforcing rib 5;

[0011] A chute for supporting the annular rack 7 is provided on the support reinforcing rib 5. The annular rack 7 can rotate circumferentially along the shaft 8 within the chute, and the annular rack 7 is fixedly connected to the movable skin 4, as Figure 2 shown;

[0012] As Figure 2 , the gear motor 6 is a driving device for the annular rack 7, and the gear motor 6 is arranged inside the support reinforcing rib 5.

[0013] Among them, when the aircraft takes off and lands vertically, the duct is in an open state.

[0014] Among them, when the aircraft is in a high-speed flight state, the duct is in a contracted state.

[0015] Among them, when the duct contracts, the gear motor 6 is powered on, and the annular rack 7 is driven to rotate counterclockwise through gear meshing. Since the annular rack 7 is fixedly connected to the movable skin 4, the movable skin 4 is driven to move into the fixed skin 3. When the movable skin 4 is completely retracted into the fixed skin 3, the duct contraction process is completed; the completed state of the duct contraction is as Figure 3 shown.

[0016] Among them, when the duct opens, the gear motor 6 is powered on, and the annular rack 7 is driven to rotate clockwise through gear meshing, driving the movable skin 4 to rotate clockwise. When the movable skin 4 is stuck into the adjacent support reinforcing rib 5, the duct opening process is completed; the completely open state of the duct is as Figure 1 shown.

[0017] Among them, the middle position inside the support reinforcing rib 5 is a thin plate for providing support, and a chute for supporting the annular rack 7 is provided on the thin plate;

[0018] The gear motor 6 is located inside the support reinforcing rib 5 and is fixedly connected to the thin plate inside the support reinforcing rib 5.

[0019] (III) Beneficial effects

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) When the aircraft takes off and lands vertically, the present invention keeps the duct intact to ensure low-speed and high-thrust efficiency; when the aircraft cruises at high speed, the duct contracts to reduce the windward area and reduce the interference of the duct wall on the airflow, so as to reduce the aerodynamic drag during high-speed flight and improve the flight efficiency.

[0022] (2) In the state where the duct contracts, the duct does not need to bear all the structural loads, and the overall weight can be optimized by changing the structure and materials to achieve the lightweight design of the duct.

[0023] (3) The present invention takes into account both vertical takeoff and landing and high-speed cruise capabilities to solve the contradictory requirements that a fixed duct is difficult to balance vertical takeoff and landing and high-speed flight, expand the adaptability of flight scenarios, and enhance the mission adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a retractable duct device of the present invention;

[0025] Figure 2 It is a schematic diagram of the internal structure of a retractable duct device of the present invention;

[0026] Figure 3 It is a schematic diagram of the fully retracted state of a retractable duct device of the present invention;

[0027] In the figure: 1 rotor, 2 support bracket, 3 fixed skin, 4 moving skin, 5 support reinforcing rib, 6 gear motor, 7 annular rack, 8 shaft. DETAILED DESCRIPTION OF THE INVENTION

[0028] To make the objectives, contents, and advantages of the present invention clearer, the following further describes in detail the specific implementation manners of the present invention with reference to the drawings and embodiments.

[0029] To solve the problems existing in the prior art, improve the performance of the duct device, and realize the contraction of the duct device. The present invention proposes a retractable duct device, which realizes the contraction of the duct by using a gear motor, a rack, and a moving skin.

[0030] To solve the above technical problems, the present invention provides a retractable duct device, as Figures 1-2 shown, the retractable duct device includes: rotor 1, support bracket 2, fixed skin 3, moving skin 4, support reinforcing rib 5, gear motor 6, annular rack 7, shaft 8;

[0031] The rotor 1 is fixedly connected to the shaft 8 coaxially. The cross-shaped support bracket 2 forms the perpendicular diameter segments within the circular duct and is fixedly connected to the shaft 8 coaxially as a non-rotating component through bearings. The duct skin is evenly divided into 4 segments, and each segment includes a fixed skin 3 and a movable skin 4. The circumferential lengths of the fixed skin 3 and the movable skin 4 are the same, but the cross-sectional dimension of the movable skin 4 is set to be smaller than that of the fixed skin 3 to ensure that the movable skin 4 can be fully retracted into the fixed skin 3, as Figure 1 shown;

[0032] The cross-shaped support bracket 2 has four outer ends, and each of the outer ends is fixedly connected to a fixed skin 3 through a support reinforcing rib 5;

[0033] A chute for supporting the annular rack 7 is formed on the support reinforcing rib 5. The annular rack 7 can rotate circumferentially along the shaft 8 within the chute, and the annular rack 7 is fixedly connected to the movable skin 4, as Figure 2 shown;

[0034] As Figure 2 , the gear motor 6 is the driving device for the annular rack 7, and the gear motor 6 is arranged inside the support reinforcing rib 5.

[0035] Among them, when the aircraft takes off and lands vertically, the duct is in the open state.

[0036] Among them, when the aircraft is in the high-speed flight state, the duct is in the contracted state.

[0037] Among them, when the duct contracts, the gear motor 6 is powered on, and the annular rack 7 is driven to rotate counterclockwise through gear meshing. Since the annular rack 7 is fixedly connected to the movable skin 4, the movable skin 4 is driven to move into the fixed skin 3. When the movable skin 4 is completely retracted into the fixed skin 3, the duct contraction process is completed. The fully contracted state of the duct is as Figure 3 shown.

[0038] Among them, when the duct opens, the gear motor 6 is powered on, and the annular rack 7 is driven to rotate clockwise through gear meshing, driving the movable skin 4 to rotate clockwise. When the movable skin 4 is caught in the adjacent support reinforcing rib 5, the duct opening process is completed. The fully open state of the duct is as Figure 1 shown.

[0039] Among them, the middle position inside the support reinforcing rib 5 is a thin plate for providing support, and a chute for supporting the annular rack 7 is formed on the thin plate;

[0040] The gear motor 6 is located inside the support reinforcing rib 5 and is fixedly connected to the thin plate inside the support reinforcing rib 5.

[0041] The structure for realizing the duct contraction by combining the motor and the rack is within the protection scope of the present invention.

[0042] The present invention incorporates a part of the movable duct into the fixed duct to reduce the windward area of the duct, and all are within the protection scope of the present invention.

[0043] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as within the protection scope of the present invention.

Claims

1. A contraction duct device, characterized in that, The described retractable duct device includes: a rotor (1), a support bracket (2), a fixed skin (3), a movable skin (4), a support reinforcing rib (5), a gear motor (6), an annular rack (7), and a shaft (8); The rotor (1) is coaxially and fixedly connected to the shaft (8), and the cross-shaped support bracket (2), as a non-rotating component, is coaxially and fixedly connected to the shaft (8) through a bearing; the duct skin is evenly divided into 4 segments, each segment including a fixed skin (3) and a movable skin (4). The circumferential lengths of the fixed skin (3) and the movable skin (4) are the same, but the cross-sectional dimension of the movable skin (4) is set to be smaller than that of the fixed skin (3) to ensure that the movable skin (4) can be completely retracted into the fixed skin (3); The cross-shaped support bracket (2) has four outer ends, and each of the outer ends is fixedly connected to a fixed skin (3) through a support reinforcing rib (5); A chute for supporting the annular rack (7) is provided on the support reinforcing rib (5), and the annular rack (7) can rotate circumferentially along the shaft (8) within the chute. The annular rack (7) is fixedly connected to the movable skin (4); The gear motor (6) is a driving device for the annular rack (7), and the gear motor (6) is arranged inside the support reinforcing rib (5).

2. The contraction duct device according to claim 1, wherein, When the aircraft takes off and lands vertically, the duct is in an open state.

3. The contraction duct device according to claim 2, wherein When the aircraft is in a high-speed flight state, the duct is in a retracted state.

4. The shrinkage duct device according to claim 3, wherein When the duct retracts, the gear motor (6) is powered on, and the annular rack (7) is driven to rotate counterclockwise through gear meshing. Since the annular rack (7) is fixedly connected to the movable skin (4), the movable skin (4) is driven to move into the fixed skin (3). When the movable skin (4) is completely retracted into the fixed skin (3), the duct retraction process is completed.

5. The contraction duct device according to claim 4, characterized in that, When the duct opens, the gear motor (6) is powered on, and the annular rack (7) is driven to rotate clockwise through gear meshing, driving the movable skin (4) to rotate clockwise. When the movable skin (4) is locked into the adjacent support reinforcing rib (5), the duct opening process is completed.

6. The contraction duct device according to claim 1, characterized in that, The middle position inside the support reinforcing rib (5) is a thin plate for providing support, and a chute for supporting the annular rack (7) is provided on the thin plate; The gear motor (6) is located inside the support reinforcing rib (5) and is fixedly connected to the thin plate inside the support reinforcing rib (5).

7. The retractable duct device according to claim 5, wherein When the aircraft takes off and lands vertically, the retractable duct device keeps the duct intact to ensure low-speed and high-thrust efficiency.

8. The shrinkage duct device according to claim 5, wherein, When the aircraft cruises at high speed, the retractable duct device retracts the duct, reduces the windward area, and reduces the interference of the duct wall on the airflow, so as to reduce the aerodynamic drag during high-speed flight and improve the flight efficiency.

9. The contraction duct device according to claim 5, wherein, In the retracted state of the duct, the duct does not need to bear all the structural loads, and the overall weight is optimized by changing the structure and materials to achieve the lightweight design of the duct.

10. The contraction duct device according to claim 5, wherein, The retractable duct device takes into account both vertical takeoff and landing and high-speed cruise capabilities to solve the contradictory requirements that a fixed duct is difficult to balance vertical takeoff and landing and high-speed flight, expand the flight scenario adaptability, and enhance the mission adaptability.

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