A passive lift-increasing device for a rotary-wing unmanned aerial vehicle and a rotary-wing unmanned aerial vehicle

Abstract

The present invention discloses a passive lift-enhancing device for a rotary-wing unmanned aerial vehicle, comprising a passive lift-enhancing blade, a fixed shaft, a shaft connector, a fixed ring and a fixed rod, wherein each passive lift-enhancing blade is connected to form a whole through a fixed shaft and a shaft connector, two adjacent fixed shafts are connected through a shaft connector, one end of the fixed rod is connected to the shaft connector, and the other end of the fixed rod is connected to the fixed ring. The present invention also discloses a rotary-wing unmanned aerial vehicle. The purpose of the passive lift-enhancing device for a rotary-wing unmanned aerial vehicle is to solve the problem of low flight efficiency of the rotary-wing unmanned aerial vehicle.

Description

Technical Field

[0001] The invention belongs to the technical field of unmanned aerial vehicles, and in particular relates to a passive lift-increasing device for a rotary-wing unmanned aerial vehicle and the rotary-wing unmanned aerial vehicle. Background Art

[0002] Rotary-wing UAVs are currently widely used in military and civilian fields. Although they can take off and land vertically, they have poor stability and safety. Research and development of special-layout rotary-wing UAVs has been carried out at home and abroad, such as fixed-wing and rotary-wing composite UAVs, tilt-rotor UAVs, coaxial twin-rotor UAVs, etc. However, these special-layout rotary-wing UAVs still have many shortcomings. The additional structure increases the weight of the aircraft, the endurance time is short, and the flight efficiency is low.

[0003] At the same time, after searching, in the Chinese patent application with application number 201410790940.5 and application name "Oil-powered four-rotor unmanned aerial vehicle", there is a record that "due to the use of aircraft engines as power and the addition of four groups of rotors, the control of each group of rotors is achieved through a servo steering gear and a variable pitch system, thus changing the previous unmanned aerial vehicle lift relying on propellers and operation relying on a fixed-pitch variable speed mode, which has the disadvantages of poor maneuverability and weak wind resistance. The present invention adopts a helicopter rotor mode instead, and the control method is a fixed-speed variable pitch mode, which has the advantages of strong wind resistance, large load capacity and good maneuverability." Large power and lift can be provided by aircraft engines and rotors, but it will lead to a complex structure and increased weight of the aircraft, and it will also have a high cost, a high failure rate and difficult maintenance.

[0004] The Chinese patent application with application number 201711331142.6 and application name "A foldable six-rotor agricultural unmanned aerial vehicle" discloses a rotor UAV, which states that "the flight attitude of the aircraft is completed by the four rotors on the main arm, and the two rotors on the secondary arm only provide lift, which improves the load capacity and also realizes the decoupling of attitude control and speed control, reducing the control difficulty." Although lift and load capacity are provided by adding rotors on the secondary arm, the six-rotor agricultural unmanned aerial vehicle is powered by lithium batteries. The two additional rotor systems will increase the weight of the aircraft, consume more electricity, shorten the flight time, and there is no protective structure around the rotors, which will cause certain safety issues.

[0005] The rotor unmanned aerial vehicles disclosed in this type of patent can provide greater lift, but the technologies currently recorded fundamentally have the following problems: changing the power supply mode and adding rotors to provide greater power and lift, but both bring about many problems such as complex structure and increased weight, which will reduce the flight efficiency of the aircraft.

[0006] In view of this, those skilled in the art urgently need to provide a passive lift-enhancing device for a rotary-wing unmanned aerial vehicle and a rotary-wing unmanned aerial vehicle to solve the above-mentioned problems. Summary of the invention

[0007] 1. Technical issues to be resolved

[0008] The technical problem solved by the invention is that the flight efficiency of the rotary-wing unmanned aerial vehicle is low.

[0009] (II) Technical solution

[0010] The present invention provides a passive lift-enhancing device for a rotary-wing unmanned aerial vehicle, comprising a passive lift-enhancing blade, a fixed shaft, a shaft connecting piece, a fixed ring and a fixed rod, wherein each of the passive lift-enhancing blades is connected to form a whole through the fixed shaft and the shaft connecting piece, two adjacent fixed shafts are connected through the shaft connecting piece, one end of the fixed rod is connected to the shaft connecting piece, and the other end of the fixed rod is connected to the fixed ring.

[0011] Furthermore, at least one of the passive lift-enhancing blade, the fixed shaft and the fixed rod is made of carbon fiber.

[0012] Furthermore, two ends of the upper wing surface of the passive lift-enhancing blade are provided with limiting fixing structures, and two ends of the fixing shaft are respectively passed through the corresponding limiting fixing structures.

[0013] Furthermore, the leading and trailing edges of the passive lift-enhancing blade both have curvatures, and the leading edge outer arc diameter and the trailing edge inner arc diameter are determined according to the diameter of the propeller.

[0014] Furthermore, the lateral distance between the inner arc of the trailing edge of the passive lift-enhancing blade and the blade plane of the propeller is 10 mm.

[0015] Furthermore, the installation height of the passive lift-enhancing blade in the propeller flow field is in the same horizontal plane as the wing tip of the propeller.

[0016] Furthermore, a plurality of the fixed shafts are connected to form a hexagonal structure.

[0017] The present invention also provides a rotary-wing unmanned aerial vehicle, comprising a brushless motor, a propeller, a frame and a passive lift-increasing device for the rotary-wing unmanned aerial vehicle, wherein the brushless motor is arranged at the end of the frame, and the passive lift-increasing device for the rotary-wing unmanned aerial vehicle is installed on the frame with the brushless motor as the center.

[0018] Furthermore, the fixed shaft is centered on the brushless motor and is distributed around the propeller at an angle of °, and the fixed ring is sleeved on the brushless motor.

[0019] Furthermore, the rotary-wing unmanned aerial vehicle includes one or more of the propellers.

[0020] (III) Beneficial effects

[0021] The passive lift-enhancing device for a rotor unmanned aerial vehicle provided by the present invention comprises a passive lift-enhancing blade, a fixed shaft, a shaft connector, a fixed ring and a fixed rod, each passive lift-enhancing blade is connected to form a whole through a fixed shaft and a shaft connector, two adjacent fixed shafts are connected through a shaft connector, one end of the fixed rod is connected to the shaft connector, and the other end of the fixed rod is connected to the fixed ring. The passive lift-enhancing blade is installed near the top of the rotor to help improve the flow field and provide additional stability for the rotor unmanned aerial vehicle, and can generate greater thrust compared to an open rotor with the same diameter and equivalent power, so that the rotor aircraft can have higher stability and propulsion efficiency in high-altitude areas where the air is thin. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a structural schematic diagram of a passive lift-enhancing device for a rotary-wing unmanned aerial vehicle provided by an embodiment of the present invention;

[0024] Figure 2 It is a structural schematic diagram of the lower wing surface of a passive lift-increasing blade in a passive lift-increasing device for a rotary-wing unmanned aerial vehicle provided by an embodiment of the present invention;

[0025] Figure 3 It is a structural schematic diagram of an upper wing surface of a passive lift-enhancing blade in a passive lift-enhancing device for a rotary-wing unmanned aerial vehicle provided by an embodiment of the present invention;

[0026] Figure 4 It is an independent installation diagram of a passive lift-enhancing blade in a passive lift-enhancing device for a rotary-wing unmanned aerial vehicle provided by an embodiment of the present invention;

[0027] Figure 5 This is a flight state diagram of a passive lift-enhancing device for a rotary-wing unmanned aerial vehicle provided by an embodiment of the present invention;

[0028] Figure 6 is a free state diagram of a rotary-wing unmanned aerial vehicle provided by an embodiment of the present invention;

[0029] Figure 7 is a flight state diagram of a rotary-wing unmanned aerial vehicle provided by an embodiment of the present invention;

[0030] Figure 8 is a schematic diagram of a passive lift-enhancing blade provided by an embodiment of the present invention;

[0031] Fig. 9 The figure is a relationship diagram between the lift of a passive lift-enhancing blade and the distance between the propeller plane provided by an embodiment of the present invention.

[0032] In the figure:

[0033] 1-passive lift-enhancing blade; 101-limiting fixing structure; 2-fixed shaft; 3-shaft connecting piece; 4-fixed ring; 5-fixed rod; 6-brushless motor; 7-propeller; 8-frame. DETAILED DESCRIPTION

[0034] The following is a further detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments, and covers any modification, replacement and improvement of parts, components and connection modes without departing from the spirit of the present invention.

[0035] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] It should be clear that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. In addition, for the sake of brevity, a detailed description of known methods and technologies is omitted here.

[0037] According to an embodiment of the present invention, a passive lift-enhancing device for a rotary-wing unmanned aerial vehicle is provided. Figure 1-5 As shown, it includes a passive lift-enhancing blade 1, a fixed shaft 2, a shaft connecting member 3, a fixed ring 4 and a fixed rod 5. Each passive lift-enhancing blade 1 is connected into a whole through the fixed shaft 2 and the shaft connecting member 3. Two adjacent fixed shafts 2 are connected through the shaft connecting member 3. One end of the fixed rod 5 is connected to the shaft connecting member 3, and the other end of the fixed rod 5 is connected to the fixed ring 4.

[0038] In the above embodiment, when the rotor unmanned aerial vehicle is not working, the passive lift-enhancing device is in a free state. Figure 8As shown, when the UAV is hovering or descending, the airflow flowing out of the lower wing surface of the propeller 7 passes through the blade tip to form several strong vortices and flows back to the upper wing surface of the propeller 7. The passive lift-enhancing blades 1 installed around the wing tips of the propeller 7 in the same horizontal plane will passively deflect upward and remain parallel to the propeller plane, providing additional lift for the rotary-wing unmanned aerial vehicle.

[0039] The arc-shaped structure of the passive lift-enhancing blade 1 is flexible to disassemble and assemble and is easy to maintain.

[0040] In some optional embodiments, at least one of the passive lift-enhancing blade 1, the fixed shaft 2 and the fixed rod 5 is made of carbon fiber. Specifically, the advantages of using carbon fiber material are light weight, high strength, and little impact on the structure and quality of the original rotor UAV aircraft.

[0041] In some optional embodiments, such as Figure 3-4 As shown, both ends of the upper wing surface of the passive lift-enhancing blade 1 are provided with a limiting fixing structure 101, and both ends of the fixed shaft 2 are respectively passed through the corresponding limiting fixing structures 101. Specifically, both ends of the fixed shaft 2 are respectively passed through the limiting fixing structures 101 and connected to the shaft connector 3, so that the adjacent passive lift-enhancing blades 1 are sequentially connected into an integral structure.

[0042] In some optional embodiments, such as Figure 2 As shown, the leading and trailing edges of the passive lift-enhancing blade 1 both have curvatures, and the leading edge outer arc diameter and the trailing edge inner arc diameter are determined according to the diameter of the propeller 7 .

[0043] Specifically, the curvature range of the leading and trailing edges is 50° to 60°, which enables six identical passive lift-enhancing blades 1 to be evenly distributed around the propeller 7 .

[0044] In some optional embodiments, such as Figure 5 As shown, the lateral distance between the inner arc of the trailing edge of the passive lift-enhancing blade 1 and the blade plane of the propeller 7 is 10 mm. This ensures that the passive lift-enhancing blade 1 has a certain safety distance from the propeller 7, while having a better lift effect.

[0045] In some optional embodiments, the installation height of the passive lift-enhancing blade 1 in the propeller flow field is in the same horizontal plane as the wing tip of the propeller 7 .

[0046] In the above embodiment, the passive lift-enhancing blades 1 and the propeller 7 are in the same horizontal plane, which can improve the forward flight stability and propulsion efficiency of the rotary-wing unmanned aerial vehicle.

[0047] The lift provided by the passive lift-enhancing blade 1 is the largest in the plane of the propeller 7. Fig. 9As shown, the horizontal axis is the longitudinal distance between the lift blade and the propeller plane, and the vertical axis is the lift ratio of the lift blade to the single rotor. It can be seen that when the longitudinal distance between the passive lift blade 1 and the propeller 7 plane is 0 (that is, the passive lift blade 1 and the propeller 7 are in the same horizontal plane), the lift ratio of the passive lift blade 1 to the propeller 7 is the largest, and the maximum lift is about 8% of the lift provided by one propeller 7. A force opposite to the lift direction will be generated above or below the rotor plane. The farther the passive lift blade 1 is from the rotor in the longitudinal direction, the worse the effect.

[0048] In some optional embodiments, a plurality of fixed shafts 2 are connected to form a hexagonal structure. Specifically, the passive lift-enhancing blade 1 is fixed to the hexagonally distributed carbon fiber fixing rods 5 through the carbon fiber fixing rods 5 and the shaft connectors 3, and the passive lift-enhancing blade 1 can be restricted to a horizontal position under the action of the airflow.

[0049] According to a second aspect of an embodiment of the present invention, a rotary wing unmanned aerial vehicle is provided, such as Figure 6-7 As shown, it includes a brushless motor 6, a propeller 7, a frame 8 and the above-mentioned passive lift-increasing device for the rotary-wing unmanned aerial vehicle. The brushless motor 6 is arranged at the end of the frame 8, and the passive lift-increasing device for the rotary-wing unmanned aerial vehicle is installed on the frame 8 with the brushless motor 6 as the center.

[0050] In some optional embodiments, the fixed shaft 2 is centered on the brushless motor 6 and is distributed around the propeller 7 at an angle of 60°, and the fixed ring 4 is sleeved on the brushless motor 6 .

[0051] In some optional embodiments, the rotary-wing UAV includes one or more propellers 7 .

[0052] Specifically, four sets of passive lift-enhancing devices are installed between the brushless motor 6 and the frame 8 of a quad-rotor aircraft, and each lift-enhancing device is equipped with six passive lift-enhancing blades 1, which can make the unmanned aerial vehicle take-off and landing more flexible, and have higher flight stability and flight efficiency.

[0053] It should be clear that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. In addition, for the sake of brevity, a detailed description of known methods and technologies is omitted here.

[0054] The above are only embodiments of the present application and are not limited to the present application. For those skilled in the art, the present application may have various changes and variations without departing from the scope of the present invention. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A passive lift-enhancing device for a rotary-wing unmanned aerial vehicle, characterized in that: The invention comprises a passive lift-enhancing blade (1), a fixed shaft (2), a shaft connecting member (3), a fixed ring (4) and a fixed rod (5); each of the passive lift-enhancing blades (1) is connected to form a whole through the fixed shaft (2) and the shaft connecting member (3); two adjacent fixed shafts (2) are connected through the shaft connecting member (3); one end of the fixed rod (5) is connected to the shaft connecting member (3); and the other end of the fixed rod (5) is connected to the fixed ring (4); The upper wing surface of the passive lift-enhancing blade (1) is provided with position-limiting fixing structures (101) at both ends, and the two ends of the fixing shaft (2) are respectively passed through the corresponding position-limiting fixing structures (101); The installation height of the passive lift-enhancing blade (1) in the propeller flow field is in the same horizontal plane as the wing tip of the propeller (7); When the rotary-wing unmanned aerial vehicle is not in operation, the passive lift-enhancing device is in a free state; when the rotary-wing unmanned aerial vehicle is hovering or descending, the airflow flowing out of the lower wing surface of the propeller (7) passes through the blade tip to form a plurality of strong vortices and flows back to the upper wing surface of the propeller (7), and the passive lift-enhancing blades (1) installed around the wing tips of the propeller (7) in the same horizontal plane will passively deflect upward and remain parallel to the propeller plane, thereby providing additional lift for the rotary-wing unmanned aerial vehicle.

2. The passive lift-enhancing device for a rotary-wing unmanned aerial vehicle according to claim 1, characterized in that: At least one of the passive lift-enhancing blade (1), the fixed shaft (2) and the fixed rod (5) is made of carbon fiber material.

3. The passive lift-enhancing device for a rotary-wing unmanned aerial vehicle according to claim 1, characterized in that: The front and rear edges of the passive lift-enhancing blade (1) both have curvatures, and the outer arc diameter of the front edge and the inner arc diameter of the rear edge are determined according to the diameter of the propeller (7).

4. The passive lift-enhancing device for a rotary-wing unmanned aerial vehicle according to claim 3, characterized in that: The lateral distance between the inner arc of the trailing edge of the passive lift-enhancing blade (1) and the blade plane of the propeller (7) is 10 mm.

5. The passive lift-enhancing device for a rotary-wing unmanned aerial vehicle according to claim 1, characterized in that: A plurality of the fixed shafts (2) are connected to form a hexagonal structure.

6. A rotary wing unmanned aerial vehicle, characterized in that: The invention comprises a brushless motor (6), a propeller (7), a frame (8) and a passive lift-enhancing device for a rotary-wing unmanned aerial vehicle as claimed in any one of claims 1 to 4, wherein the brushless motor (6) is arranged at the end of the frame (8), and the passive lift-enhancing device for a rotary-wing unmanned aerial vehicle is installed on the frame (8) with the brushless motor (6) as the center.

7. The rotary wing unmanned aerial vehicle according to claim 6, characterized in that: The fixed shaft (2) is centered on the brushless motor (6) and is distributed around the propeller (7) at an angle of 60°. The fixed ring (4) is sleeved on the brushless motor (6).

8. The rotary wing unmanned aerial vehicle according to claim 6, characterized in that: Comprising one or more propellers (7).

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