An airfoil assembly

Abstract

The present invention provides a wing assembly, which relates to the technical field of aircraft wings. It includes a driving shaft for driving the wing to rotate. The middle part of the wing mounting bracket is connected to the end of the driving shaft. The first blade is arranged on the wing mounting bracket, and the first blade is rotatably connected to the wing mounting bracket. The second blade is arranged on the wing mounting bracket, and a transmission mechanism is installed on the wing mounting bracket, and the transmission mechanism drives the first blade to rotate. By using wings with different airfoil types, since a steering mechanism is installed inside the first blade, the relative orientation between it and the second blade can be changed online. When performing vertical takeoff and landing, the front and rear edge orientations of the two blades are axisymmetric, and the wing becomes a rotor; when flying horizontally, the front and rear edge orientations of the two blades are face-symmetric, and the wing becomes a fixed wing. It can not only enable the aircraft to perform vertical takeoff and landing, but also improve the cruise performance of the aircraft.

Description

Technical Field

[0001] The present invention relates to the field of aircraft wings, and more particularly, to a wing assembly. Background Art

[0002] Currently, aircraft in the aviation field are generally divided into two categories: fixed-wing aircraft that take off and land by taxiing and cruise horizontally, and helicopters or rotorcraft that take off and land vertically and achieve horizontal forward flight by the projection of the total lift generated by tilting the propeller disk in the forward direction. These two types of aircraft each have their own advantages and disadvantages, and each has its own main uses. Since the invention of the airplane more than 100 years ago, there have been continuous attempts to create a new type of aircraft that combines the advantages of the above two types of aircraft: that is, an all-in-one multifunctional aircraft that can take off and land in place and at the same time has high-efficiency horizontal cruising. However, this goal has not been fully achieved yet. In the past decade or so, with the rapid development of advanced technologies such as automatic control, the Internet, artificial intelligence, new energy, new materials, and intelligent transportation, it has given rise to the development of eVTOL (electric vertical takeoff and landing) aircraft based on the DEP (distributed power) concept and adapted to the development of UAM (modern urban three-dimensional transportation). And so far, many large companies around the world, such as Boeing, Airbus Super Airlines, UBER Transportation Services Company, Internet companies such as Google and Baidu; traditional automobile companies such as Toyota, Honda, Mercedes-Benz, BMW, Geely; new energy vehicle companies such as XPeng and Tesla, etc. have all conducted research on this technology. It almost covers all aspects of modern transportation equipment manufacturing, operation, and service. The main reason is that eVTOL, as a vertical takeoff and landing device in a broad sense, highlights the advantage of environmental protection (electric power). In addition, land is in short supply and expensive in cities, and it is impossible to build airports everywhere, which is also a major factor driving the development of eVTOL. eVTOL just meets the needs of modern urban intelligent three-dimensional transportation. At present, the horizontal flight efficiency of eVTOL is still relatively low. Affected by the battery energy density and restricted by the characteristics of the helicopter motion mode, the application limitations of eVTOL flight devices are still very large, mainly concentrated in their poor horizontal navigation (cruise) performance, and there are still problems such as low speed and short range.

[0003] At present, it is still impossible to develop a dual-purpose aircraft that can meet the high-efficiency flight of "vertical takeoff and landing - horizontal cruise" at the same time. The bottleneck lies in analyzing the root cause of the problem from the special motion mode of the helicopter relying on the rotating wings. The biggest weakness of the helicopter is that its efficiency is very poor when flying horizontally. The reasons are as follows: First, the flight principles of the two types of aircraft are different: The helicopter generates a vertical upward lift through the rotor. When the generated lift is greater than the weight of the aircraft, the helicopter can rise or hover. It has high requirements for the power plant system and a large thrust-to-weight ratio. When the helicopter flies forward horizontally, it relies on tilting the rotor disk to generate a horizontal component force pointing forward, generating horizontal acceleration and obtaining a horizontal flight speed. At the same time, it needs to generate greater power to obtain a greater upward pulling force in the vertical direction to balance the weight of the aircraft. The horizontal speed of the helicopter is limited in various ways. Apart from the power limit of the carried fuel or electricity, it is also limited by the maximum rotational speed to prevent the blade tip from exceeding the speed and generating shock waves. In addition, the configuration of the helicopter and the airflow ejected from under the main rotor blades onto the fuselage will bring a significant additional aerodynamic drag. The sum of these two parts of additional drag and the normal drag of the whole aircraft is much greater than the aerodynamic drag of a fixed-wing aircraft during level flight, which will significantly reduce the forward flight speed of the rotorcraft. The maximum level flight speed of a traditional helicopter is usually 200 - 340 kilometers per hour. The maximum level flight speed of a fixed-wing aircraft with the same engine power can reach 700 - 900 kilometers per hour. Some even break through the sound barrier and fly supersonically. In order to increase the level flight speed of the helicopter, aerospace engineers have designed a hybrid high-speed helicopter, with the maximum level flight speed increased to 436 kilometers per hour, an increase of 28.2%. Later, tilt-rotor vertical takeoff and landing - horizontal flight aircraft such as the V-22 were developed. The maximum level flight speed was further increased to 556 kilometers per hour, a 63.5% increase compared with the helicopter. However, its cruise performance is still not as good as that of a fixed-wing aircraft. Summary of the Invention

[0004] The purpose of the present invention is to provide a wing assembly that can enable an aircraft to perform vertical takeoff and landing and, when flying horizontally, convert the rotating rotor into a fixed wing to improve the cruise performance of the aircraft.

[0005] The embodiments of the present invention are implemented as follows:

[0006] The embodiments of the present application provide a wing assembly, which includes

[0007] A drive shaft, which is used to drive the wing to rotate;

[0008] A wing mounting bracket, the middle part of which is connected to the drive shaft;

[0009] A first blade, which is arranged on one side of the wing mounting bracket and is rotatably connected to the wing mounting bracket;

[0010] The second blade, which is arranged on the other side of the wing mounting bracket;

[0011] The transmission mechanism is installed on the wing mounting bracket, and the transmission mechanism drives the first blade to rotate.

[0012] In some embodiments of the present invention, it further includes a wing automatic balance mechanism, which includes a sensing ring, two inertial balls and two pushing connecting rods; the sensing ring includes a circular outer ring and a transverse axis connected to the inner wall of the circular outer ring. The transverse axis penetrates through the side wall of the driving shaft, and the transverse axis is rotatably connected to the driving shaft. The two inertial balls are symmetrically arranged on the circular outer ring, and the two pushing connecting rods are symmetrically arranged. One end of any pushing connecting rod is hinged to the wing mounting bracket, and the other end of the pushing connecting rod is hinged to the circular outer ring.

[0013] In some embodiments of the present invention, the first blade is sleeved on the wing mounting bracket. The first blade includes a leading edge portion and a trailing edge portion. The trailing edge portion includes a spreading plate and a fixing plate. The spreading plate is hinged to the leading edge portion, and the fixing plate is connected to the leading edge portion.

[0014] In some embodiments of the present invention, it further includes a spreading mechanism, which includes an actuator and a pushing member. The actuator is connected to the leading edge, the output shaft of the actuator is hinged to one end of the pushing member, and the other end of the pushing member is hinged to the spreading plate.

[0015] In some embodiments of the present invention, it further includes a wingtip vortex lift augmentation device arranged at the ends of the first blade and the second blade.

[0016] In some embodiments of the present invention, the projections of the first blade and the second blade on the horizontal plane are both in the shape of a swept wing.

[0017] In some embodiments of the present invention, the transmission mechanism includes a driving motor arranged at one end of the driving shaft close to the wing mounting bracket, a first bevel gear, a second bevel gear, a transmission shaft, an output shaft arranged in the wing mounting bracket, a third bevel gear and a fourth bevel gear arranged in the driving shaft. The end of the output shaft is connected to the first blade, the output shaft is connected to the first bevel gear, the first bevel gear meshes with the second bevel gear, the second bevel gear is connected to one end of the transmission shaft, the other end of the transmission shaft is connected to the third bevel gear, the third bevel gear meshes with the fourth bevel gear, and the fourth bevel gear is connected to the motor shaft of the driving motor.

[0018] In some embodiments of the present invention, the rotation direction vector of the first blade is perpendicular to the horizontal plane of the wing mounting bracket.

[0019] In some embodiments of the present invention, the wing mounting bracket includes an adjusting member and a support frame sleeved on the adjusting member. The adjusting member is hinged to the end of the driving shaft, and the support frame is hinged to the pushing connecting rod.

[0020] In some embodiments of the present invention, it further includes a linear motor disposed on the driving shaft, and the output shaft of the linear motor is hinged to the adjusting member.

[0021] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0022] An airfoil assembly, which includes:

[0023] A driving shaft for driving the airfoil to rotate;

[0024] An airfoil mounting bracket, the middle part of which is connected to the end of the driving shaft;

[0025] A first blade disposed on the airfoil mounting bracket and rotatably connected to the airfoil mounting bracket;

[0026] A second blade disposed on the airfoil mounting bracket;

[0027] A transmission mechanism mounted on the airfoil mounting bracket, and the transmission mechanism drives the first blade to rotate.

[0028] In some embodiments of the present invention, after comparing foreign technologies with each other, the inventor believes that the eagle eye or V-22 and the propeller-wing conversion aircraft are the most successful foreign solutions so far. In these two types of solutions, one uses a tilting engine to achieve vertical takeoff and landing, and it is also equipped with a typical fixed wing for cruising. The other uses an engine that does not tilt, and the rotor becomes a fixed wing for use during forward flight. Especially the latter has a clever concept. And it was inspired after in-depth discussions between the inventor and experts. The inventor believes that the rotorcraft and the fixed-wing aircraft should be fully combined. The main rotor used for vertical takeoff and landing is converted through a mechanical structure so that it becomes a fixed-wing aircraft for cruising. Thus, vertical takeoff and landing are achieved using the rotor, and after rising to a certain height, the converted rotor is used to become a typical fixed-wing aircraft. However, since the wings of the rotorcraft are centrosymmetric, while the wings of the fixed-wing aircraft are axisymmetric, in order to solve the above problems, this embodiment adopts the method of fixing the second blade and rotatably connecting the first fixed wing to the airfoil mounting bracket through a transmission mechanism. When the aircraft rises to a certain height, the transmission mechanism controls the first blade to rotate 180 degrees along the geometric center of the first blade, thereby converting it into a fixed wing for cruising, and thus improving the cruising performance. Description of the Drawings

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0030] Figure 1 Schematic structural diagram of an asymmetric airfoil for a wing assembly of the present invention;

[0031] Figure 2 Schematic diagram of the starting state of the azimuth conversion of the first blade in the present invention;

[0032] Figure 3 Schematic diagram of the state after the azimuth conversion of the first blade in the present invention;

[0033] Figure 4 Schematic structural diagram of the first blade in the present invention;

[0034] Figure 5 Schematic structural diagram of the first blade and the wingtip vortex-induced lift augmentation device in the present invention;

[0035] Figure 6 Comparison diagram of the change in three-dimensional vertical lift after installing the wingtip vortex-induced lift augmentation device in the present invention;

[0036] Figure 7 Schematic structural diagram of the first blade and the second blade in the first form in the present invention;

[0037] Figure 8 Schematic structural diagram of the first blade and the second blade in the second form in the present invention;

[0038] Figure 9 Schematic structural diagram of a transmission mechanism in the present invention;

[0039] Figure 10 Schematic structural diagram of the first blade and the second blade in the third form in the present invention;

[0040] Figure 11 Schematic structural diagram of the first blade and the second blade in the fourth form in the present invention;

[0041] Figure 12 Schematic structural diagram of another transmission mechanism in the present invention;

[0042] Figure 13 Schematic structural diagram of the first blade and the second blade in the fifth form in the present invention;

[0043] Figure 14 Schematic structural diagram of the first blade and the second blade in the sixth form in the present invention;

[0044] Figure 15 It is a schematic projection diagram of the symmetric wing profile in the present invention;

[0045] Figure 16 It is a schematic projection diagram of the asymmetric wing profile in the present invention;

[0046] Figure 17 It is an assembly schematic diagram of the driving shaft, linear motor and wing mounting bracket in the present invention.

[0047] Icon: 1. Driving shaft; 2. Wing mounting bracket; 21. Adjusting part; 22. Support frame; 3. First blade; 31. Leading edge part; 32. Fixed plate; 33. Spreading plate; 4. Second blade; 5. Spreading mechanism; 51. Actuating mechanism; 52. Pushing part; 6. Transmission mechanism; 61. First bevel gear; 62. Second bevel gear; 63. Output shaft; 64. Transmission shaft; 65. Third bevel gear; 66. Fourth bevel gear; 67. Driving motor; 68. Bearing; 69. Rotating shaft; 7. Wingtip vortex lift augmentation device; 8. Linear motor; 9. Wing automatic balance mechanism; 91. Inertia ball; 92. Sensing ring; 93. Pushing connecting rod. Detailed implementation manners

[0048] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0050] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0051] In the description of the embodiments of the present invention, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "horizontal", "inner", "outer", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is usually placed during use. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, terms such as "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0052] In addition, if terms such as "horizontal" are used, it does not mean that the component is required to be absolutely horizontal or hanging, but it can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal. It does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0053] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0054] Embodiment 1

[0055] Please refer to Figure 1 、 Figure 2 and Figure 3 , a wing assembly is provided for this embodiment, which includes:

[0056] The driving shaft 1 is used to drive the wing to rotate;

[0057] The wing mounting bracket 2, the middle part of the wing mounting bracket 2 is connected to the end of the driving shaft 1;

[0058] The first blade 3 is arranged on one side of the wing mounting bracket 2, and the first blade 3 is rotatably connected to the wing mounting bracket 2;

[0059] The second blade 4 is arranged on the other side of the wing mounting bracket 2;

[0060] The transmission mechanism 6 is installed on the wing mounting bracket 2, and the transmission mechanism 6 drives the first blade 3 to rotate.

[0061] In some embodiments of the present invention, in order to enable the "helicopter-plane" to achieve excellent flight performance, the most crucial issue is to properly address the reduction of negative impacts caused by the transition from the vertical takeoff and landing flight mode to the horizontal flight mode, especially the handling of the relatively long helicopter blades during horizontal flight and the handling of the engine. In the history of aviation development, in order to vertically lift an aircraft into the sky, the method of converting the thrust vector by 90 degrees was found. Its principle can be divided into the following stages: First, rotate the entire aircraft so that the nose is facing up and pointing to the sky, and then rotate the engine. During vertical takeoff and landing, adjust the nozzle of the jet engine to change the direction of the jet from horizontal backward to downward. However, this is mostly applied to military aircraft, such as the "Hare Hunter" in the UK and the "F35C" in the US, etc. But the problems brought about by this method are still intractable. The main problem lies in the downward jet, and the thousands-of-degrees-high temperature causes significant damage to the lifespan of the aircraft carrier deck. Therefore, most aircraft use the method of tilting the propeller by 90 degrees and pulling vertically upward. But this is only suitable for aircraft with piston propeller engines. Among them, the V-22 Osprey is the most successful case. And the design idea of this design is: starting from a helicopter, conducting research and development on the propeller / rotor. For a rotorcraft, the greatest difficulty lies not in vertical takeoff and landing, but in horizontal cruise. Directly using the rotor or propeller of a helicopter to fly forward by tilting the blade hub has too much resistance, and the horizontal speed cannot exceed 340 kilometers per hour. While a fixed-wing aircraft is not very good at vertical takeoff, but its performance is extremely excellent during horizontal flight. Therefore, this design first solves the design of a high-lift body fuselage. The key is to invent the lift augmentation technology for a wing with a small aspect ratio, which can be directly used to design the airframe of a new aircraft. The second step is to develop an all-round function that combines the wings of a helicopter and a fixed-wing aircraft. The most important thing is the "Dual-Use Wing Assembly" of the present invention - including the structural design and conversion method. Now, the main results are announced in the following table:

[0062]

[0063]

[0064] The inventor believes that the rotary-wing aircraft and the fixed-wing aircraft should be fully combined. The main rotor for vertical takeoff and landing is converted through a mechanical structure so that it can be used as a fixed-wing aircraft for cruising, thereby realizing vertical takeoff and landing using the rotor. Similar to the small anti-yaw propeller installed on the rear fuselage, an automatic control system for automatically eliminating yaw, which is well-known, is required. For an aircraft with two propulsion propellers, two power devices or two ducted fans installed on the rear fuselage, the differential response of the above devices is controlled based on the error signal sent by the sensor that senses yaw, thereby controlling the yaw error of the aircraft. The principle of the wing assembly in this design is that a wing consists of two parts: the first blade 3 and the second blade 4. A transmission mechanism 6 for driving the first blade 3 to rotate is installed inside the first blade 3. The two blades are installed on both sides of the wing mounting bracket 2 and are vertically centrally symmetric about the center line of the bracket. The first blade 3 is fixedly installed on one side of the wing mounting bracket 2. Usually, the first blade 3 is fixedly connected to the wing mounting bracket 2. However, when the blade needs to change its orientation relative to the fuselage, the fastening connection between the blade and the internal load-bearing beam can be temporarily loosened. After the turning is completed, a reliable fastening connection is made again; as Figure 2 and Figure 3 shown, after rising to a certain height, the converted rotor is used to turn it into a typical fixed-wing aircraft. However, since the wings of the rotary-wing aircraft are centrally symmetric, while the wings of the fixed-wing aircraft are axially symmetric, to solve the above problem, in this embodiment, the second blade 4 is fixed, and the first fixed wing is rotatably connected to the wing mounting bracket 2 through the transmission mechanism 6. When the aircraft rises to a certain height, the transmission mechanism 6 controls the first blade 3 to rotate 180 degrees along the geometric center of the first blade 3, thereby converting it into a fixed wing for cruising, and thus improving the cruising performance.

[0065] Embodiment 2

[0066] Please refer to Figure 1 , this embodiment is proposed based on the technical solution of Embodiment 1 and further includes a wing automatic balance mechanism 9. The wing automatic balance mechanism 9 includes a sensing ring 92, two inertial balls 91 and two push connecting rods 93; the sensing ring 92 includes a circular outer ring and a horizontal axis connected to the inner wall of the circular outer ring. The horizontal axis penetrates through the side wall of the driving shaft 1, and the horizontal axis is rotatably connected to the driving shaft 1. The two inertial balls 91 are symmetrically arranged on the circular outer ring. The two push connecting rods 93 are symmetrically arranged. One end of any push connecting rod 93 is hinged to the wing mounting bracket 2, and the other end of the push connecting rod 93 is hinged to the circular outer ring.

[0067] An aircraft wing automatic balancing mechanism is provided to drive the wing mounting bracket 2 to swing. The middle part of the wing mounting bracket 2 is hinged to the driving shaft 1. The sensing ring 92 of the aircraft wing automatic balancing mechanism is connected to the wing mounting bracket 2 and the driving shaft 1 in a hinged manner. The wing mounting bracket 2 and the sensing ring 92 of the aircraft wing automatic balancing mechanism 9 are rotated simultaneously, and then connected to the output main shaft of the engine through the clutch of the aircraft. Thus, when the rotor is in flight, the inclination of the first blade 3 and the second blade 4 is adjusted, improving the stability of the rotor.

[0068] Embodiment 3

[0069] Please refer to Figure 1 , this embodiment is proposed based on the technical solution of Embodiment 1. The first blade 3 is sleeved on the wing mounting bracket 2. The first blade 3 includes a leading edge portion 31 and a trailing edge portion. The trailing edge portion includes a spreading plate 33 and a fixing plate 32. The spreading plate 33 is hinged to the leading edge portion 31, and the fixing plate 32 is connected to the leading edge portion 31.

[0070] In some embodiments of the present invention, if the wing mounting bracket 2 is connected to the outer wall of the first blade 3, according to the analysis of aerodynamics, at the connection of the blade to the rotor, a large resistance will inevitably be generated under the high-speed rotation of the rotor. Therefore, to avoid the above situation, in this embodiment, the first blade 3 is sleeved on the wing mounting bracket 2. Considering that after the first blade 3 is sleeved on the wing mounting bracket 2, the rotation of the first blade 3 will collide with the wing mounting bracket 2, the trailing edge portion of the first blade 3 is set as a spreading plate 33 hinged to the leading edge portion 31 and a fixing plate 32 connected to the leading edge portion 31. Thus, during rotation, even if a collision occurs, since the spreading plate 33 and the fixing plate 32 are not fixedly connected, after contacting the wing mounting bracket 2, the spreading plate 33 will rotate under the constraint of the hinge, thus successfully passing through the wing mounting bracket 2 and completing a 180-degree rotation of the first blade 3.

[0071] In some embodiments of the present invention, for the second blade 4 to also reduce the influence of air resistance, it is also sleeved on the wing mounting bracket 2 and fixedly connected.

[0072] Embodiment 4

[0073] Please refer to Figure 4 , this embodiment is proposed based on the technical solution of Embodiment 3, and further includes a spreading mechanism 5. The spreading mechanism 5 includes an actuator 51 and a pushing member 52. The actuator 51 is connected to the leading edge. The motor shaft of the actuator 51 is hinged to one end of the pushing member 52, and the other end of the pushing member 52 is hinged to the spreading plate 33.

[0074] In some embodiments of the present invention, when the aircraft is ascending and descending, the first blade 3 and the second blade 4 need to rotate at high speed driven by the main shaft 1. Therefore, the method of pushing open the spreading plate 33 by means of the wing mounting bracket 2 is too material-consuming. To avoid the above problems, in this embodiment, a connecting rod structure is adopted to push the spreading plate 33. The specific implementation method is to set an actuator 51 to push a pushing member 52, and then the pushing member 52 pushes the spreading plate 33, thereby completing the opening of the trailing edge part. In this way, when the first blade 3 needs to be converted, the actuator 51 is controlled in advance to push open the spreading plate 33, and then the first blade 3 rotates 180 degrees. Thus, the first blade 3 will no longer collide with the wing mounting bracket 2 during rotation, improving the service life.

[0075] Embodiment 5

[0076] Please refer to Figure 5 , this embodiment is proposed based on the technical solution of Embodiment 1, and further includes a wingtip vortex lift augmentation device 7 provided at the ends of the first blade 3 and the second blade 4.

[0077] In some embodiments of the present invention, since the use of this wing needs to take into account vertical takeoff and landing and cruise flight, and when applied in the field of flying cars, due to the limitations of roads, the size of the wing needs to be appropriately adjusted, which also reduces its aspect ratio. However, it also has certain advantages, that is, when changing from a larger aspect ratio to a smaller aspect ratio, the stiffness of the wing becomes stronger and the requirements for structural materials are reduced. But the disadvantage is that the line slope of the three-dimensional vertical lift decreases, as Figure 6 shown, thus greatly reducing the lift of the blade and the lift-to-drag ratio. In addition, the blade that can be used as both a rotor and a fixed wing at the same time, its aerodynamic performance, especially the lift-to-drag ratio K, is closely related to the flight performance. The lift-to-drag characteristics of the eVTOL blade and the generated rotor power and the lift-to-drag ratio of horizontal flight are particularly important. Due to various limiting conditions, the eVTOL has a short span and a small aspect ratio, and the lift will not be large enough. Therefore, to solve the above problems, in this embodiment, another wingtip vortex lift augmentation device 7 with a patent number of CN202011258085.5 invented by the inventor is adopted, and the wingtip vortex lift augmentation device 7 is provided at the ends of the first blade 3 and the second blade 4. The purpose is to increase the lift of the small-aspect-ratio wing, reduce the resistance at the same time, and improve the efficiency of the rotor. The calculation method is as follows:

[0078] Using an approximate algorithm: where A is the aspect ratio, R is the three-dimensional effect coefficient, (II) is the two-dimensional lift coefficient, (III) is the three-dimensional lift coefficient.

[0079]

[0080]

[0081] When the wingtip vortex lift augmentation device 7 is installed, the three-dimensional efficiency coefficient R X is:

[0082] R X = 1 - 0.5765·(1 - R)

[0083] The equivalent aspect ratio A X is:

[0084]

[0085] Example 6

[0086] Please refer to Figure 7 and Figure 8 , this example is proposed based on the technical solution of Example 5. The projections of the first blade 3 and the second blade 4 on the horizontal plane are both in the shape of a swept wing.

[0087] In some embodiments of the present invention, during the flight of the aircraft, the planar shape of the wing is also one of the factors affecting flight performance. In this example, the first blade 3 and the second blade 4 are set in the shape of a swept wing. The swept wing shape is beneficial to increasing the critical Mach number during high-speed flight, delaying the moment when shock waves appear on the wing, reducing the drag of the aircraft, and improving the overall performance of the aircraft. Among them, the swept wing shape can be triangular or boomerang-shaped. The purpose is that when the boomerang-shaped first blade 3 and second blade 4 are cruising, the air lift received by the first blade 3 and the second blade 4 is increased by using the airfoil section of the boomerang-shaped strut wing, making the aircraft body stable, thereby improving stability. And due to the special structure of the two wings of the boomerang, when the air flows through both sides of the wing, according to Bernoulli's principle, there will be an upward net force acting on the lower and flatter side of the air, thereby generating buoyancy, thus increasing the lift-to-drag ratio of the aircraft and improving performance.

[0088] Example 7

[0089] Please refer to Figure 9 , this example is proposed based on the technical solution of Example 1. The transmission mechanism 6 includes a drive motor 67 arranged at one end of the drive shaft 1 close to the wing mounting bracket 2, a first bevel gear 61, a second bevel gear 62, a transmission shaft 64, an output shaft 63 arranged in the wing mounting bracket 2, a third bevel gear 65 and a fourth bevel gear 66 arranged in the drive shaft 1. The end of the output shaft 63 is connected to the first blade 3. The output shaft 63 is connected to the first bevel gear 61. The first bevel gear 61 meshes with the second bevel gear 62. The second bevel gear 62 is connected to one end of the transmission shaft 64. The other end of the transmission shaft 64 is connected to the third bevel gear 65. The third bevel gear 65 meshes with the fourth bevel gear 66. The fourth bevel gear 66 is connected to the motor shaft of the drive motor 67.

[0090] In some embodiments of the present invention, when the transmission mechanism 6 drives the first blade 3, if the transmission mechanism 6 is arranged outside the wing mounting bracket 2, during the cruise of the aircraft, the transmission mechanism 6 in the air will increase the air resistance during cruising. Therefore, in this embodiment, the transmission mechanism 6 is arranged inside the rotor. The specific implementation method is that the drive motor 67 is arranged on the top of the drive shaft 1, and its motor shaft is connected to the fourth bevel gear 66. Then the transmission shaft 64 is arranged inside the wing mounting bracket 2. One end of it is connected to the third bevel gear 65, and the other end is connected to the second bevel gear 62, which is used to transmit the kinetic energy of the drive motor 67 through the inside of the wing mounting bracket 2. Then, by using the meshing of the second bevel gear 62 and the first bevel gear 61, the kinetic energy is transmitted to the output shaft 63, thereby driving the first blade 3 to rotate. Since the overall structure of the transmission mechanism 6 is installed inside the wing, there will be no additional air resistance during cruise, improving the performance.

[0091] In some embodiments of the present invention, during the movement of the transmission shaft 64, since the wing mounting bracket 2 is made of high-strength metal material, and because the first blade 3 needs to rotate rapidly, the speed of the transmission shaft 64 is relatively high. As a result, a large friction will be generated between the transmission shaft 64 and the wing mounting bracket 2, which will cause wear, resulting in shaking when the transmission parts rotate, and further affecting the meshing of the first bevel gear 61 and the second bevel gear 62, resulting in a reduction in the kinetic energy transmission efficiency. Long-term wear may even cause mechanical failures, leading to accidents. Therefore, to avoid the above situation, in this embodiment, the transmission shaft 64 is connected to the wing mounting bracket 2 through a bearing 68, thereby avoiding direct friction, reducing the friction between the transmission shaft 64 and the wing mounting bracket 2, and improving the stability.

[0092] Embodiment 8

[0093] Please refer to Figure 10 , Figure 11 , Figure 12 , Figure 13 and Figure 14 , this embodiment is proposed based on the technical solution of Embodiment 1, and the rotation direction vector of the first blade 3 is perpendicular to the horizontal plane of the wing mounting bracket 2.

[0094] In some embodiments of the present invention, for a fully symmetric wing, using the horizontal turning method in the above embodiment will increase the torque. Therefore, in this embodiment, for a fully symmetric wing, vertical rotation is adopted, that is, rotation perpendicular to the wing mounting bracket 2. Among them Figure 10 and Figure 11 are ring wing structures, and this structure has been verified in the paper AIAA-2007-4445-Incremental Ring Wings published by the inventor in AIAA (American Institute of Aeronautics and Astronautics). And Figure 13 and Figure 14, then there are two other shapes of fully symmetric wings, and their cross-sections are both streamlined or water-drop-shaped. And their rotation methods are different from the rotation directions described in the above embodiments, so that after turning, they can become fixed-wing aircraft for cruising. The specific implementation is as Figure 12 shown. The drive motor 67 is used to drive the fourth bevel gear 66, and then the meshing between the fourth bevel gear 66 and the third bevel gear 65 is utilized to drive the transmission shaft 64 to rotate. A rotating shaft 69 is arranged at the end of the transmission shaft 64, thereby driving the first blade 3 to rotate in the vertical direction of the wing mounting bracket 2, so as to achieve the turning function. As the most important load-bearing components of the aircraft - the wings or rotors, both the first blade 3 and the second blade 4 must be reliably and firmly connected to the fuselage. However, due to the need to change the orientation, we set that the connection between the first blade 3 and the fuselage can be fixed. During a specific period, for example, when converting from the takeoff and landing motion mode to the horizontal flight mode, it needs to be unlocked and the relative position of the first blade 3 needs to be changed; the first blade 3 needs to be rotated 180 degrees around the hinge axis that is fixedly connected to the geometric center of the wing and the large beam (i.e., the fuselage). Then, the first blade 3 is locked firmly again to ensure safety.

[0095] Embodiment 9

[0096] Please refer to Figure 1 , this embodiment is proposed based on the technical solution of Embodiment 1. The wing mounting bracket 2 includes an adjusting member 21 and a support frame 22 sleeved on the adjusting member 21. The adjusting member 21 is hinged to the end of the driving shaft 1, and the support frame 22 is hinged to the push link 93.

[0097] In some embodiments of the present invention, after the first blade 3 and the second blade 4 are converted into the fixed-wing type, due to the need to adjust the fixation for the direction conversion of the fixed wing, especially the left and right adjustment directions, in order to achieve the ability to adjust the left and right directions, in this embodiment, the wing mounting bracket 2 is hinged to the end of the driving shaft 1, and its structure is similar to a seesaw. The included angle between the first blade 3 and the second blade 4 relative to the water surface is adjusted through the adjusting mechanism, so that the aircraft turns left and right.

[0098] Embodiment 10

[0099] Please refer to Figure 17 , this embodiment is proposed based on the technical solution of Embodiment 9, and further includes a linear motor 8 arranged on the driving shaft 1. The output shaft of the linear motor 8 is hinged to the adjusting member 21.

[0100] In some embodiments of the present invention, when adjusting the wing mounting bracket 2, since the wing mounting bracket 2 is hinged to the driving shaft 1, only a thrust or a pulling force needs to be applied to the wing mounting bracket 2 to cause the wing mounting bracket 2 to tilt, thereby changing the gas flow on the fixed wing, resulting in a lift force to the left or right, enabling the aircraft to turn left and right. Therefore, in this embodiment, a linear motor 8 is arranged on the driving shaft 1, and its output shaft 63 is hinged to the wing mounting bracket 2, and the pulling force of the linear motor 8 on the wing mounting bracket 2 is utilized to drive the wing mounting bracket 2 to deflect.

[0101] 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, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An airfoil assembly, characterized in that, comprising: a driving shaft for driving the airfoil to rotate; an airfoil mounting bracket, the middle of which is connected to the driving shaft; a first blade disposed on one side of the airfoil mounting bracket, and the first blade is rotatably connected to the airfoil mounting bracket; a second blade disposed on the other side of the airfoil mounting bracket; a transmission mechanism mounted on the airfoil mounting bracket, and the transmission mechanism drives the first blade to rotate; further comprising an airfoil automatic balancing mechanism, which includes a sensing ring, two inertia balls and two pushing linkages; the sensing ring includes a circular outer ring and a transverse shaft connected to the inner wall of the circular outer ring, the transverse shaft penetrates through the side wall of the driving shaft, the transverse shaft is rotatably connected to the driving shaft, the two inertia balls are symmetrically arranged on the circular outer ring, the two pushing linkages are symmetrically arranged, one end of any one of the pushing linkages is hinged to the airfoil mounting bracket, and the other end of the pushing linkage is hinged to the circular outer ring.

2. The airfoil assembly according to claim 1, characterized in that, the first blade is sleeved on the airfoil mounting bracket, the first blade includes a leading edge portion and a trailing edge portion, the trailing edge portion includes a spreading plate and a fixing plate, the spreading plate is hinged to the leading edge portion, and the fixing plate is connected to the leading edge portion.

3. The airfoil assembly according to claim 2, characterized in that, further comprising a spreading mechanism, which includes an actuating mechanism and a pushing member, the actuating mechanism is connected to the leading edge, the output shaft of the actuating mechanism is hinged to one end of the pushing member, and the other end of the pushing member is hinged to the spreading plate.

4. The airfoil assembly according to claim 1, characterized in that, further comprising a wingtip vortex enhancement device provided at the ends of the first blade and the second blade.

5. The airfoil assembly according to claim 4, characterized in that, the projections of the first blade and the second blade on the horizontal plane are both in the shape of a swept wing.

6. The airfoil assembly according to claim 1, characterized in that, the transmission mechanism includes a driving motor provided at one end of the driving shaft close to the airfoil mounting bracket, a first bevel gear, a second bevel gear, a transmission shaft, an output shaft provided in the airfoil mounting bracket, a third bevel gear and a fourth bevel gear provided in the driving shaft, the end of the output shaft is connected to the first blade, the output shaft is connected to the first bevel gear, the first bevel gear meshes with the second bevel gear, the second bevel gear is connected to one end of the transmission shaft, the other end of the transmission shaft is connected to the third bevel gear, the third bevel gear meshes with the fourth bevel gear, and the fourth bevel gear is connected to the motor shaft of the driving motor.

7. The airfoil assembly according to claim 1, characterized in that, the rotation direction vector of the first blade is perpendicular to the horizontal plane of the airfoil mounting bracket.

8. The airfoil assembly according to claim 1, characterized in that, The wing mounting bracket includes an adjusting member and a support frame sleeved on the adjusting member. The adjusting member is hinged to the end of the driving shaft, and the support frame is hinged to the push link.

9. The wing assembly according to claim 8, wherein, it further includes a linear motor disposed on the driving shaft, and an output shaft of the linear motor is hinged to the adjusting member.

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