Lightning protection device, electric propulsion device and aircraft

Abstract

The invention provides a lightning protection device, an electric propulsion device and an aircraft, and relates to the technical field of aircrafts. The lightning protection device comprises a lapping wire, a discharge electrode and at least one lightning receiving assembly, the lightning receiving assembly is used for receiving lightning, and the lapping wire is conductively connected with the lightning receiving assembly; the first end of the discharge electrode is conductively connected with the lapping wire, and the second end extends towards the machine body and has a discharge gap with the machine body; the discharge electrode is configured to receive the lightning current of the lapping wire and conduct the lightning current to the machine body through the discharge gap. The initial lightning is actively captured by arranging the lightning receiving assembly and conducted to the discharge electrode through the lapping wire, and the discharge gap between the discharge electrode and the engine body is an extremely non-uniform field and is easily broken down by lightning current to form a conductive path, so that the lightning current is conducted to the engine body by bypassing a core area of the electric engine; and the protection effect of the electric engine is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aircraft technology, in particular to a lightning protection device, an electric propulsion device and an aircraft. BACKGROUND

[0002] An electric vertical take-off and landing (eVTOL) aircraft is an aircraft that uses electric power as a source of flight power and has the function of vertical take-off and landing, and has the characteristics of vertical take-off and landing, intelligent operation, low noise, low emission, easy maintenance, high safety, etc. The electric vertical take-off and landing aircraft includes an electric propulsion device, which is a system for providing lift or thrust for the electric vertical take-off and landing aircraft (hereinafter referred to as an aircraft).

[0003] The electric propulsion device includes a fairing, a propeller, an electric motor, etc. During flight of the aircraft, the fairing and the propeller are potential attachment points for lightning and are easily struck by lightning to generate an electric current, which affects the use stability of the electric propulsion device. In the related art, a carbon brush or a slip ring is arranged between the rotor and the stator of the electric motor to serve as a lightning grounding path to guide the electric current; or a rolling bearing is installed between the propeller and the electric motor to guide the electric current of lightning from the propeller to the electric motor housing and finally to the aircraft frame.

[0004] However, when the electric current passes through the above lightning grounding path, the electric current is easy to enter the electric motor, thereby affecting the operation of the electric motor and resulting in poor protection effect. SUMMARY

[0005] Therefore, the present application provides a lightning protection device, an electric propulsion device and an aircraft, which can reasonably guide the electric current generated on the electric propulsion device due to lightning and improve the protection effect of the electric motor.

[0006] To achieve the above-mentioned purpose, the lightning protection device, the electric propulsion device and the aircraft provided by the present application adopt the following technical solutions:

[0007] In a first aspect, the present application provides a lightning protection device, comprising:

[0008] At least one lightning receiving component for receiving lightning, the lightning receiving component being arranged on a blade of a propeller and / or a fairing;

[0009] A lap joint wire arranged on the propeller and electrically connected with the lightning receiving component;

[0010] A discharge electrode, a first end of the discharge electrode being electrically connected with the lap joint wire, a second end of the discharge electrode extending towards a machine body, and a discharge gap being formed between the second end of the discharge electrode and the machine body.

[0011] The discharge electrode is configured to receive a lightning current of the jumper wire and conduct the lightning current to the machine body through the discharge gap.

[0012] In a possible implementation, the lightning protection device provided in the present application, the second end of the discharge electrode is provided in a conical shape, and the top end of the conical second end of the discharge electrode is used to face the machine body.

[0013] In a possible implementation, the lightning protection device provided in the present application, the airfoil and / or the top end portion of the spinner are configured to be subjected to a metalization treatment, and the metalized area is determined by a ball rolling method, and an insulating layer is arranged between the metalized area and the airfoil and / or the spinner.

[0014] In a possible implementation, the lightning protection device provided in the present application, the airfoil and / or the top end portion of the spinner are configured to be subjected to a metalization treatment, and the metalized area is determined by a ball rolling method, and an insulating layer is arranged between the metalized area and the airfoil and / or the spinner.

[0015] The airfoil and / or the spinner are coated with the metal conductive material.

[0016] The busbar is arranged on one side of the airfoil and is electrically connected to the jumper wire.

[0017] In a possible implementation, the lightning protection device provided in the present application, the airfoil and / or the top end portion of the spinner are configured to be subjected to a metalization treatment, and the metalized area is determined by a ball rolling method, and an insulating layer is arranged between the metalized area and the airfoil and / or the spinner.

[0018] The first air terminal assembly is arranged on the airfoil, and is spaced and insulated from the blade root of the airfoil on the side close to the rotation axis of the propeller.

[0019] The second air terminal assembly is arranged on the spinner, and is spaced and insulated from the blade root of the airfoil on the side close to the machine body.

[0020] In a possible implementation, the lightning protection device provided in the present application, the first air terminal assembly is arranged on the airfoil, and is spaced and insulated from the blade root of the airfoil on the side close to the rotation axis of the propeller.

[0021] In a possible implementation, the lightning protection device provided in the present application, the second air terminal assembly is arranged on the spinner, and is spaced and insulated from the blade root of the airfoil on the side close to the machine body.

[0022] In a possible implementation, the lightning protection device provided in the present application, the overlap line is sleeved with an insulating sleeve.

[0023] In a possible implementation, the lightning protection device provided in the present application, the discharge gap is greater than or equal to 10 millimeters and less than or equal to 20 millimeters.

[0024] In a second aspect, the present application provides an electric propulsion device, comprising:

[0025] A propeller, comprising a spinner, a hub and a plurality of blades arranged on the hub, the spinner covering the hub;

[0026] The lightning protection device as described above, the lightning protection device is connected with the propeller.

[0027] In a possible implementation, the electric propulsion device provided in the present application further comprises an electric motor, the electric motor comprising an outer rotor, the outer rotor being fixedly connected with the hub of the propeller;

[0028] The overlap line of the lightning protection device is conformally solidified with the surface of the spinner and / or the outer rotor, and matches the aerodynamic shape of the electric propulsion device;

[0029] And / or, the discharge electrode of the lightning protection device is conformally solidified with the surface of the spinner and / or the outer rotor, and matches the aerodynamic shape of the electric propulsion device.

[0030] In a possible implementation, the electric propulsion device provided in the present application further comprises a pitch changing mechanism, the pitch changing mechanism being connected to the blade root of the blade and the hub;

[0031] The connection of the pitch changing mechanism with the blade root and the connection of the pitch changing mechanism with the hub are both insulatively arranged.

[0032] In a third aspect, the present application provides an aircraft, comprising:

[0033] A body, an outer covering skin of the body, the skin being a conductive member;

[0034] The electric propulsion device as described above;

[0035] The electric propulsion device is connected with the body.

[0036] In a possible implementation, the aircraft provided in the present application, the side of the body facing the discharge electrode is provided with a sawtooth-shaped tip structure.

[0037] The lightning protection device, the electric propulsion device and the aircraft provided by the application, wherein the lightning protection device comprises a bridging wire, a discharge electrode and at least one lightning receptor, the lightning receptor is used for receiving lightning, and the lightning receptor is arranged on a blade and / or a spinner of a propeller; the bridging wire is arranged on the propeller and is in conductive connection with the lightning receptor; the first end of the discharge electrode is in conductive connection with the bridging wire; the second end of the discharge electrode extends towards a machine body, and the second end of the discharge electrode has a discharge gap with the machine body; the discharge electrode is configured to receive lightning current of the bridging wire and conduct the lightning current to the machine body through the discharge gap.

[0038] By arranging the lightning receptor to actively capture initial lightning and conduct the lightning current to the discharge electrode through the bridging wire, since the discharge gap between the discharge electrode and the machine body is an extremely non-uniform field, the discharge gap is easily broken down by the lightning current to form a conductive path, so that the lightning current is conducted to the machine body by bypassing the core area of the electric motor, thereby improving the protection effect of the electric motor.

[0039] In addition to the technical problems solved by the embodiments of the application described above, the technical features constituting the technical solutions and the beneficial effects brought by these technical features, other technical problems solved by the technical solutions of the application, other technical features included in the technical solutions and the beneficial effects brought by these technical features will be further described in detail in the specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0040] The specific embodiments of the application will be described in detail below with reference to the accompanying drawings, and it should be understood that the specific embodiments described herein are only used to illustrate and explain the application, and the application is not limited to the specific embodiments described below.

[0041] Figure 1 A schematic diagram of an aircraft provided by an embodiment of the application;

[0042] Figure 2 A schematic diagram of part of the structure of the lightning protection device and the electric propulsion device provided by an embodiment of the application Figure 1 ;

[0043] Figure 3 A schematic diagram of part of the structure of the lightning protection device and the electric propulsion device provided by an embodiment of the application Figure 2 ;

[0044] Figure 4 A schematic diagram of a metallization processing area determined by a rolling ball method;

[0045] Figure 5 A schematic diagram of the structure of the lightning receptor and / or the bridging wire conformally solidified with the surface of the propeller provided by an embodiment of the application.

[0046] REFERENCE SIGNS

[0047] 11, fuselage; 12, wing; 13, tail; 14, arm; 15, nacelle; 20, electric propulsion device; 20a, fixed electric propulsion device; 20b, tilting electric propulsion device; 22, propeller; 23, protective layer; 100, electric motor; 200, blade; 300, hub; 400, pitch mechanism; 500, skin; 600, lap joint; 601, insulating sleeve; 700, discharge electrode; 800, lightning receptor assembly; 800a, first lightning receptor assembly; 800b, second lightning receptor assembly; 810, lightning receptor; 820, busbar; 900, spinner.

[0048] The specific embodiments of the present application have been shown through the above drawings, and will be described in more detail hereinafter. The drawings and the written description are not intended to restrict the scope of the present application in any way, but to explain the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below in combination with the drawings of the preferred embodiments of the present application. In the drawings, the same or similar notations represent the same or similar components or components with the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, not all the embodiments. The embodiments described below by referring to the drawings are exemplary, and are intended to explain the present application, and cannot be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below in combination with the drawings.

[0050] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms “mounting”, “connection”, “connecting” should be understood in a broad sense, for example, can be fixed connection, can be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0051] In the description of the embodiments of the present application, it should be understood that the terms “up”, “down”, “front”, “back”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only intended to facilitate the description of the present application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0052] In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more than two, unless otherwise specified precisely and specifically.

[0053] The terms "first", "second", "third", "fourth" and the like in the description of the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not have to be used to describe a particular order or sequence.

[0054] In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0055] An electric vertical take-off and landing (eVTOL) aircraft is an aircraft that uses electricity as a flight power source and has a vertical take-off and landing function, and has the characteristics of vertical take-off and landing, intelligent operation, low noise, low emission, easy maintenance, high safety, etc. The electric propulsion device refers to a system that converts electrical energy into mechanical energy to provide lift or thrust for the electric vertical take-off and landing aircraft (hereinafter referred to as the aircraft). The electric propulsion device includes an electric motor (also known as an electric motor), a propeller, and its accessories, etc.

[0056] Electric motors have been mainly used in ground industrial products such as new energy vehicles, etc. Compared with ground products, the electric motor in the eVTOL needs to meet various environmental safety flight requirements while meeting the power demand.

[0057] During the flight of the aircraft, the fairing and the propeller are potential attachment points for lightning and are easily struck by lightning to generate current. The above-mentioned current affects the use stability of the electric propulsion device. Because lightning is an uncontrollable natural phenomenon, and lightning often has characteristics such as high voltage and large current, after the aircraft is struck by lightning, it may cause structural damage, destruction, and equipment failure or degradation due to high voltage and large current, and in severe cases, the aircraft struck by lightning may have catastrophic consequences. Lightning protection is an important measure for the aircraft to avoid being struck by lightning.

[0058] Because part of the lightning is difficult to predict, whether it is an aircraft that only flies in an expected thunderstorm-free flight environment or an all-weather aircraft, the aircraft needs to consider lightning protection, and the all-weather aircraft must consider the impact of lightning.

[0059] Compared with traditional propeller aircraft, eVTOL using electric propulsion device is more sensitive to lightning damage or damage effect after lightning strike, especially for electric propulsion device with motor directly driving propeller; in traditional setting mode, electric motor is the only path for lightning current to flow through. As the core unit, electric propulsion device may fail directly under high voltage and large current if lightning protection is not performed, and even high voltage and large current may form a channel in the aircraft, causing temporary or permanent failure of more electrical equipment and structural failure, thereby causing catastrophic consequences of the aircraft when it is struck by lightning.

[0060] The electromagnetic environment of the electronic equipment on the aircraft when the aircraft is struck by lightning may be more severe due to the small structure space of the eVTOL, and the electric propulsion electric motor as the main power output component may become the only path for lightning current to adhere to the blade, so the lightning electromagnetic environment of the electric propulsion electric motor is extremely severe. The consequence of failure of the electric propulsion electric motor is unacceptable, which directly relates to the safety of the aircraft. Therefore, the electric propulsion electric motor that bears the lightning current flow must have the ability to withstand the severe lightning electromagnetic environment, and lightning protection must be performed.

[0061] If an effective current conduction and discharge channel is not built for the propeller blade, and the current on the blade cannot be discharged in time, when the blade rotates with the propeller, an electric spark discharge will occur at the small gap between the blade tip or hub and the motor when the voltage on the blade reaches a certain value. The electromagnetic pulse generated may interfere with the onboard communication, navigation and control systems; or due to the electrical isolation of the motor stator and rotor for the motor bearing, the potential difference between the blade and the motor rotor and the motor stator is conducted to the motor stator through the electric propulsion electric motor bearing, which may cause electrical erosion of the electric propulsion electric motor bearing over a long period of time.

[0062] At the same time, due to the lack of effective conduction path between the blade and the aircraft body, the blade will reduce the breakdown voltage of the aircraft and the surrounding air, attract lightning, and the blade tip of the propeller may become the preferred path of lightning due to its large curvature and high charge density, increasing the probability of lightning adhering to the blade, and thereby increasing the probability of the motor bearing the lightning current flow path.

[0063] Currently, in the related art, a carbon brush or slip ring is arranged between the rotor and the stator of the electric motor to guide the current as a lightning grounding path; the carbon brush is suitable for low linear speed, large space, easy maintenance and easy collection of carbon brush wear powder; and the large-current conductive slip ring is also suitable for low-speed working conditions. However, the electric motor in the electric propulsion device has high speed, small space and large influence of carbon brush wear powder on the motor, and the wear carbon powder needs to be treated and frequently maintained.

[0064] Or install a rolling bearing between the propeller and the electric motor to add a lightning grounding path, so that after the lightning current enters the propeller, part of the lightning current will be conducted from the rolling bearing to the motor shell, and the other part of the lightning current will still enter the motor system from the motor shaft. The prior art solution can only disperse part of the lightning current entering the propeller to the motor shell, but cannot block the lightning current from entering the motor system.

[0065] In addition, in the related art, the lightning grounding path element is installed in contact with the motor shell, and the motor shell is fixedly connected with the machine frame (indicated as an internal rotor motor), so that the lightning current can be guided to the machine frame.

[0066] However, for an external rotor motor, the motor shell is not fixedly connected with the aircraft frame, which means that the motor shell and the aircraft frame are in a disconnected state, and cannot be electrically connected through fixed lapping. Due to high speed and wear and tear, measures such as brushes and carbon brushes cannot be used. If the above setting method is still used, the lightning current cannot be effectively conducted to the aircraft frame, resulting in a failed solution.

[0067] For an external rotor motor, the electromagnetic field environment inside the motor is complex and the electromagnetic environment is harsh, and the temperature of the lightning current plasma channel is high. The arc heat and large current of the uncertain lightning channel in the small gap may demagnetize the magnetic steel; due to manufacturing and other reasons, the lightning current path is also uncertain, and the protection of the external rotor motor poses higher challenges. Therefore, the methods currently used are not suitable for the protection of the external rotor motor of the direct-drive propeller.

[0068] For an electromechanical integrated electric motor for aviation, it contains strong and weak electrical components inside, and its working conditions and environment are subject to lightning strikes. How to solve the problems of motor structure failure, even more temporary or permanent failure of electrical equipment, and structural failure caused by high voltage and large current breakdown of the motor caused by lightning, avoid the interference of lightning current on weak electrical components inside the electric motor, and ensure the safety of all-weather flight and avoid catastrophic accidents caused by lightning are the technical problems to be solved by the present application.

[0069] Specifically, for the lightning protection of the external rotor motor direct-drive propeller electric propulsion device for all-weather flight, no lightning protection or improper lightning protection may cause the motor structure to directly fail under high voltage and large current of lightning; it may also form a plasma discharge channel in the process of lightning current flowing due to high voltage breakdown of small gaps in the motor, thereby generating arc heat or Joule heat to demagnetize the magnetic steel in the motor and burn the winding, causing the electric propulsion device to fail; or it may cause high voltage and large current to enter the machine from the motor end to form a channel in the machine, causing more electrical equipment to be temporarily or permanently damaged and the structure to fail.

[0070] To solve the above technical problems, the lightning protection device, the electric propulsion device and the aircraft are provided in the technical scheme. The lightning protection device provided in the technical scheme includes a bridging wire, a discharge electrode and at least one lightning receptor. The lightning receptor is configured to receive lightning. The lightning receptor is arranged on a blade and / or a fairing of a propeller. The bridging wire is arranged on the propeller and is electrically connected to the lightning receptor. The first end of the discharge electrode is fixed to the propeller and is electrically connected to the bridging wire. The second end of the discharge electrode extends towards a machine body, and the second end of the discharge electrode has a discharge gap with the machine body. The discharge electrode is configured to receive lightning current of the bridging wire and conduct the lightning current to the machine body through the discharge gap.

[0071] The lightning receptor is configured to actively capture initial lightning, and the lightning current is conducted to the discharge electrode through the bridging wire. Since the discharge gap between the discharge electrode and the machine body is a very uneven field, it is easy to be struck by lightning current to form a conductive path, so as to realize the conduction of lightning current around the core area of the electric motor to the machine body, thereby improving the protection effect of the electric motor.

[0072] The above arrangement forms a lightning current conduction path of the lightning receptor-bridging wire-discharge electrode-machine body. The path is away from the electric motor, and the conduction of the lightning current is realized outside the electric motor, so as to avoid random discharge of the current in the electric motor, thereby protecting the core components of the electric motor from damage and significantly improving the protection effect.

[0073] It should be noted that, Figures 1 to 5 The schematic diagram of the lightning protection device, the electric propulsion device and the aircraft is shown, and the specific structure of the remaining components of the lightning protection device, the electric propulsion device and the aircraft is not limited to Figures 1 to 5 The example.

[0074] The present application will be described in detail below in combination with the drawings and specific embodiments:

[0075] The present application provides an aircraft, which can be an electric vertical take-off and landing (eVTOL) aircraft. Of course, it can also be other aircraft.

[0076] Figure 1 The schematic diagram of the aircraft provided in the present application is shown. Among them, Figure 1 The aircraft shown in the figure is only used for illustration and does not constitute a limitation on the specific structure and shape of the aircraft.

[0077] As Figure 1As shown, the aircraft includes a fuselage 11, wings 12, and a tail 13. The fuselage 11 has a symmetrical structure; the remaining structure and shape of the fuselage 11 are not limited and can refer to the structure of the fuselage 11 of existing aircraft. The wings 12 are fixedly connected to the fuselage 11, and the structure of the wings 12 can also refer to the structure of the fixed wings 12 of existing aircraft, which will not be described in detail here. The tail 13 is fixedly located at the tail of the fuselage 11, and the tail 13 is integrally formed with the fuselage 11 or mechanically connected, and has a symmetrical structure. The structure of the tail 13 can also refer to the structure of the tail 13 of existing aircraft, which will not be described in detail here.

[0078] It should be noted that in some scenarios, the aircraft may also include the fuselage 11 and wings 12, that is, the aircraft does not include the tail 13.

[0079] like Figure 1 As shown, the aircraft also includes an electric propulsion unit 20, which can be used to provide power to the aircraft. The number of electric propulsion units 20 can be one or more, for example... Figure 1 As shown, the aircraft includes eight electric propulsion units 20.

[0080] The electric propulsion device 20 is disposed on the fuselage 11 and / or wings 12 and / or tail 13, for example Figure 1 As shown, electric propulsion devices 20 are symmetrically mounted on both the wings 12 and the tail 13. However, in some scenarios, the electric propulsion devices 20 are mounted on the fuselage 11, while those on the wings 12 and tail 13 are not. In other scenarios, the electric propulsion devices 20 are mounted on the wings 12, while those on the fuselage 11 and tail 13 are not. In still other scenarios, the electric propulsion devices 20 are mounted on the tail 13, while those on the fuselage 11 and wings 12 are not.

[0081] See also Figure 1 As shown, the aircraft also includes an arm 14 and a nacelle 15, both of which are used to connect to the electric propulsion unit 20 to mount the electric propulsion unit 20 on the fuselage 11, wing 12, or tail 13. Of course, in some scenarios, the aircraft may also include only one of the arms 14 and the nacelle 15.

[0082] In some embodiments, such as Figure 1 As shown, the electric propulsion device 20 is mounted on the wing 12 via the arm 14. In other embodiments, the electric propulsion device 20 may also be mounted on the wing 12 via a nacelle 15 (not shown in the figure).

[0083] In some embodiments, such as Figure 1As shown, the electric propulsion devices 20 are arranged on the tail 13 through the nacelles 15. In other embodiments, the electric propulsion devices 20 can also be arranged on the tail 13 through the arms 14 (not shown in the figure).

[0084] In some examples, the electric propulsion devices 20 arranged on the aircraft can include fixed electric propulsion devices 20a, which are fixedly connected with any one of the fuselage 11, the wings 12 and the tail 13.

[0085] In some examples, the electric propulsion devices 20 arranged on the aircraft can include tilting electric propulsion devices 20b, which are provided with a tilting mechanism between any one of the fuselage 11, the wings 12 and the tail 13, the tilting mechanism being used to adjust the tilting angle of the tilting electric propulsion devices 20b.

[0086] In some examples, all the electric propulsion devices 20 arranged on the aircraft are fixed electric propulsion devices 20a.

[0087] In other examples, all the electric propulsion devices 20 arranged on the aircraft are tilting electric propulsion devices 20b.

[0088] In yet other examples, part of the electric propulsion devices 20 arranged on the aircraft are fixed electric propulsion devices 20a, and part of the electric propulsion devices 20 are tilting electric propulsion devices 20b, for example Figure 1 As shown, of the eight electric propulsion devices 20, four are fixed electric propulsion devices 20a, and the remaining four are tilting electric propulsion devices 20b, the fixed electric propulsion devices 20a being arranged outside the tilting electric propulsion devices 20b.

[0089] As shown in Figure 1 The electric motor 100 is arranged on the arm 14 or the nacelle 15, the electric motor 100 is in transmission connection with the propeller 22, and the electric motor 100 is used to drive the propeller 22 to rotate to provide power for the aircraft.

[0090] As shown in Figure 2 and Figure 3 In the embodiments of the present application, the electric motor 100 can be arranged on the fuselage 11 and / or the wings 12 and / or the tail 13 through the mounting seat.

[0091] The propeller 22 can be arranged on one side of the electric motor 100, the electric motor 100 is in transmission connection with the propeller 22, and the electric motor 100 is used to drive the propeller 22 to rotate.

[0092] With reference to Figure 2 and Figure 3As shown, in one possible implementation, the application provides a lightning protection device, including a bonding wire 600, a discharge electrode 700 and at least one lightning receptor 800.

[0093] The lightning receptor 800 is used to receive lightning, and the lightning receptor 800 is arranged on the propeller blade 200 and / or the fairing 900 of the propeller 22; here, only one lightning receptor 800 can be arranged on the propeller blade 200 or the fairing 900, or multiple lightning receptors 800 can be arranged on the fairing 900 and multiple propeller blades 200; the lightning receptor 800 is arranged as a metal conductor and can actively receive lightning.

[0094] The bonding wire 600 is arranged on the propeller 22 and is in conductive connection with the lightning receptor 800; it can be understood that the propeller 22 provides support and mounting position for the bonding wire 600, for example, the bonding wire 600 can be bonded to the surface of the propeller 22, or can also be fixedly embedded in the material coating of the propeller 22. Here, the bonding wire 600 can be made of metal to facilitate the reception of lightning, for example, the bonding wire 600 can be an iron wire, and can also be a copper wire.

[0095] The first end of the discharge electrode 700 is fixed on the propeller 22 and is in conductive connection with the bonding wire 600; the second end of the discharge electrode 700 extends towards the machine body 11, and the discharge electrode 700 has a discharge gap between the second end and the machine body 11; the discharge electrode 700 is configured to receive lightning current of the bonding wire 600 and conduct the lightning current to the machine body 11 through the discharge gap.

[0096] In the above embodiment, the lightning receptor 800 is arranged to actively receive the initial lightning, and the lightning receptor 800 can actively receive the lightning current at the position of the propeller blade 200 and the fairing 900. The lightning current is conducted to the discharge electrode 700 through the bonding wire 600, and the lightning current is converged at the position of the discharge electrode 700.

[0097] The discharge gap between the discharge electrode 700 and the machine body 11 is a very uneven field, which is easy to be struck by lightning current to form a conductive path, so as to realize the conduction of lightning current around the core area of the electric motor 100 to the machine body 11, and finally discharge the lightning current to the atmosphere or the ground through structures such as landing gear, tail fin and wing tip, so as to achieve the purpose of protecting the electric propulsion device 20. It is ensured that the lightning current only conducts on the outer surface of the electric propulsion device 20 and the machine body 11, and does not enter the inside of the electric motor 100.

[0098] Or it can be understood that the lightning current only conducts on the outer surface of the aircraft, and does not enter the inside of the electric motor 100, thereby improving the protection effect of the electric motor 100.

[0099] In the above embodiment, the discharge gap can be broken down by the transient high voltage. Since the voltage in lightning is usually as high as millions of volts, and the instantaneous current exceeds 100,000 amperes, a strong discharge phenomenon can be generated in the discharge gap. In turn, the current on the discharge electrode 700 is conducted to the machine body 11.

[0100] In a specific embodiment, the first end of the discharge electrode 700 is fixedly connected to the spinner 900 of the propeller 22. The first end of the discharge electrode 700 can be fixed on the outer surface of the spinner 900, or can be embedded in the interior of the spinner 900.

[0101] In a possible implementation, referring to FIG. 6, the second end of the discharge electrode 700 is provided in a conical shape, and the tip of the conical second end of the discharge electrode 700 is used to direct towards the machine body 11. Figure 2

[0102] In the above embodiment, the conical tip has a natural electric field distortion characteristic, which can sharply enhance the electric field intensity in a local space, and significantly reduce the voltage threshold of air breakdown of the discharge gap. When the lightning current is transmitted to the discharge electrode 700 through the jumper 600, the conical tip preferentially initiates air ionization, forming a stable arc channel; the ionized air becomes a conductive channel, allowing the lightning current to be introduced into the machine body 11 with minimal loss; the conical tip is clearly directed towards the machine body 11, avoiding the diffusion of the current to unintended areas. The arc in the discharge gap is strictly developed along the axial direction, avoiding lateral jumping.

[0103] In a possible implementation, the lightning arrestor assembly 800 is configured to perform a metalization treatment on the top end portion of the blade 200 and / or the spinner 900, and the metalized area is determined by the rolling sphere method. The metalized area is provided with an insulating layer between the blade 200 and / or the spinner 900.

[0104] In the above embodiment, the blade 200 and the spinner 900 of the electric propulsion device 20 are both potential lightning attachment positions. In this embodiment, the lightning attachment area and the non-attachment area of the spinner 900 and the blade 200 are first determined according to the rolling sphere method. The blade 200 and the spinner 900 in the lightning attachment area are subjected to a metalization treatment for lightning arrest.

[0105] It should be noted that in the related art, due to the demand for high strength and lightweight design, the blade 200 and the spinner 900 are mostly made of carbon fiber composite material, which is a non-metallic material. The carbon fiber composite material has a certain conductivity, but the conductivity is poor, and the carbon fiber composite material cannot effectively conduct lightning.

[0106] ​The internationally standardized rolling sphere method was used to simulate the spatial electric field distribution during the development stage of a lightning leader, quantifying the most vulnerable areas on the aircraft surface. Metallization was applied only to the calculated lightning attachment areas, i.e., the high-probability lightning strike zones, to avoid the weight redundancy caused by full coverage.

[0107] In specific implementation, refer to Figure 4 As shown, for example, using a lightning strike distance of 10 meters (R) for the rolling sphere method, the point of tangency between the rolling sphere and the fairing 900 and the blade 200 is the boundary of the lightning attachment area. The lightning attachment area extends from the top of the fairing 900 or the blade 200 to the point of tangency. The aforementioned lightning attachment area is metallized to enhance its conductivity. The metallization process can be any of the following methods: flame-sprayed metal, application of a metal mesh, or a metal film.

[0108] Furthermore, an insulating layer is provided between the metallized area and the blade 200 and / or fairing 900, so that lightning current can only flow on the surface metal layer of the blade 200 and / or fairing 900 and cannot penetrate into the internal composite material or engine compartment. The insulating layer can be one or more layers of epoxy fiberglass cloth.

[0109] In one possible implementation, refer to Figure 2 and Figure 3 As shown, the lightning arresting assembly 800 includes a lightning arresting part 810 and a current collector 820 electrically connected to the lightning arresting part 810; the lightning arresting part 810 is configured as a conductive metal material, and the conductive metal material covers the blade 200 and / or the fairing 900; the current collector 820 is configured as a metal strip, the metal strip is disposed on one side of the lightning arresting part 810, and the metal strip is electrically connected to the overlap line 600.

[0110] In the above embodiment, a continuous conductive layer is formed by completely covering the critical areas of the blade 200 / fairing 900 with a conductive metallic material (such as copper alloy, aluminum alloy, etc.). By setting a metal strip extending longitudinally along the edge of the lightning arrester 810, the dispersed lightning current is converged to the collector 820 and then connected to the connection cable 600. This combines multiple incident lightning points into a single cable for transmission, reducing the number of interfaces on the connection cable 600 and lowering the risk of poor contact.

[0111] Furthermore, the large cross-sectional area of ​​the metal strip effectively reduces the Joule heating effect, preventing structural deformation caused by instantaneous high temperatures. Specifically, the width of the metal strip is set to 20 mm to 40 mm, and the thickness to 1 mm to 1.5 mm, ensuring that the cross-sectional area of ​​the metal strip is above 20 square millimeters. Ensuring a cross-sectional area above 20 square millimeters guarantees that the metal strip can effectively conduct lightning current.

[0112] In a possible implementation, the lightning arresting assembly 800 includes a first lightning arresting assembly 800a and a second lightning arresting assembly 800b; the first lightning arresting assembly 800a is arranged on the blade 200 and is spaced apart and insulated from the blade root of the blade 200 on the side close to the rotation axis of the propeller 22.

[0113] The second lightning arresting assembly 800b is arranged on the spinner 900 and is spaced apart and insulated from the blade root of the blade 200 on the side close to the aircraft body 11.

[0114] In the above embodiment, the lightning arresting assembly 800 is provided in at least two, which can simultaneously protect the blade 200 and the spinner 900 from lightning, further improving the protection effect. In actual application, the blade 200 of the aircraft is usually provided with a plurality of blades, and the number of the first lightning arresting assembly 800a can be adaptively set according to the number of the blade 200 to ensure that the spinner 900 and each blade 200 are effectively protected.

[0115] The first lightning arresting assembly 800a and the second lightning arresting assembly 800b are both physically spaced apart from the blade root and completely isolated by the insulating material. The traditional invasion path of lightning current through the blade 200, the blade root to the electric motor 100 is completely cut off, and the lightning current directly reaches the core components of the electric motor 100.

[0116] The above insulating material can be an insulating material layer coated with a modified material with good insulating performance such as glass fiber reinforced plastic material and SiO2 epoxy resin composite material, and the thickness of the insulating material layer is set to be greater than or equal to 2 mm to ensure the insulating performance.

[0117] In a possible implementation, continuing to refer to Figure 4 As shown in FIG. 8A, the lightning arresting portion 810 of the first lightning arresting assembly 800a extends inward from the tip of the blade 200 by a distance greater than or equal to one half of the length of the blade 200 and less than or equal to three fourths of the length of the blade 200; for example, the length of the blade 200 is L, and the lightning arresting portion 810 of the first lightning arresting assembly 800a extends inward from the tip of the blade 200 to the blade root by a distance of 1L / 2-3L / 4. Figure 4 As shown in FIG. 8B, the lightning arresting portion 810 of the first lightning arresting assembly 800a extends inward from the tip of the blade 200 to the bottom by a distance of 3L / 4.

[0118] As shown in FIG. 8B, the lightning arresting portion 810 of the first lightning arresting assembly 800a extends inward from the tip of the blade 200 to the bottom by a distance of 3L / 4. Figure 4The distance from the top end to the bottom end of the lightning receiving part 810 of the second lightning receiving assembly 800b shown in the middle is 1h / 2.

[0119] In the above embodiment, through the above setting mode, sufficient lightning receiving area is ensured to ensure the sufficiency of lightning protection, and redundant material is avoided.

[0120] In a possible implementation, the lap joint wire 600 is sleeved with an insulating sleeve 601. In specific implementation, the diameter of the lap joint wire 600 is set to 5-6 mm, and can be any one of 5.0 mm, 5.1 mm, 5.5 mm and 6 mm. The lap joint wire 600 and the metal strip can be connected in a stable and conductive manner by welding or screwing.

[0121] The insulating sleeve 601 covers the outer surface of the lap joint wire 600. By setting the insulating sleeve 601, the path of the lap joint wire 600 conducting current to the propeller 22 is physically blocked, and the lap joint wire 600 is ensured to stably conduct lightning current to the discharge electrode 700.

[0122] In a possible implementation, the discharge gap is greater than or equal to 10 mm and less than or equal to 20 mm. The discharge gap can be set to any one of 10.0 mm, 10.1 mm, 11.0 mm, 15.0 mm, 19.1 mm and 20.0 mm. The size of the discharge gap directly determines the breakdown voltage threshold of the air medium. Through the above setting mode, the gap range of 10-20 mm can stably trigger an arc under a typical lightning impulse voltage, while avoiding self-excited discharge. It can be ensured that the air is quickly broken down under the lightning peak voltage to form a stable conductive channel.

[0123] Optionally, as shown in Figure 5 The lap joint wire 600 and the surface of the propeller 22 are conformally solidified to smooth the outer surface of the propeller 22.

[0124] Here, as Figure 5 In the related art, the blades 200 of the propeller 22 and the outer surface of the fairing 900 are coated with a protective layer 23. The lap joint wire 600 is embedded in the protective layer 23, or understood as being pressed to the protective layer 23, so that the outer surface of the protective layer 23 is a smooth surface, avoiding the lap joint wire 600 protruding and affecting the aerodynamic shape and aerodynamic performance of the electric propulsion device 20. Further, the lightning receiving assembly 800 can also be conformally solidified with the surface of the propeller 22 to further avoid affecting the aerodynamic performance.

[0125] In a possible implementation, the embodiment of the application further provides an electric propulsion device 20, comprising a propeller 22 and the lightning protection device described above, the propeller 22 comprising a spinner 900, a hub 300 and a plurality of blades 200 arranged on the hub 300, and the spinner 900 is arranged on the hub 300. The lightning protection device is connected with the propeller 22. The plurality of blades 200 are evenly arranged on the circumferential side of the hub 300. Among them, the lightning arresting assembly 800 is arranged on the blades 200 and / or the spinner 900 of the propeller 22, and here, the number of lightning arresting assemblies 800 is set to be multiple, at least one lightning arresting assembly 800 is arranged on the spinner 900, and at least one lightning arresting assembly 800 is arranged on each blade 200.

[0126] In the embodiment, one lightning arresting assembly 800 is arranged on the spinner 900, and one lightning arresting assembly 800 is arranged on each blade 200. The bottom end of the spinner 900 of the propeller 22 is provided with a lap joint wire 600, and each lightning arresting assembly 800 is in conductive connection with the lap joint wire 600. The current collected from each lightning arresting assembly 800 is guided to the lap joint wire 600, the lap joint wire 600 is in conductive connection with the discharge electrode 700, and the lightning current is conducted to the machine body 11 through the discharge electrode 700 and the discharge gap.

[0127] The electric propulsion device 20 provided by the embodiment of the application further comprises an electric motor 100, the electric motor 100 comprising an outer rotor, and the outer rotor is fixedly connected with the propeller 22. Specifically, the outer rotor of the electric motor 100 is fixedly connected with the hub 300 of the propeller 22. The electric motor 100 further comprises an electric motor body, the electric motor body is arranged on the machine body 11, and the electric motor body is in insulating connection with the machine body 11.

[0128] The electric motor drives the hub 300 to rotate, and then drives the blades 200 to rotate, so as to realize power transmission. The lap joint wire 600 can also be conformally solidified with the surface of the outer rotor, and matched with the aerodynamic shape of the electric propulsion device 20.

[0129] In a possible implementation, the lap joint wire 600 can also be conformally solidified with the surface of the spinner 900, and matched with the aerodynamic shape of the electric propulsion device 20.

[0130] In a possible implementation, the discharge electrode 700 can be connected to the spinner 900 or the outer rotor. When the discharge electrode 700 is connected to the spinner 900, the discharge electrode 700 is conformally solidified with the surface of the spinner 900. When the discharge electrode 700 is connected to the outer rotor, the discharge electrode 700 is conformally solidified with the outer surface of the outer rotor. Of course, when the discharge electrode 700 is connected to the spinner 900 and the outer rotor at the same time, the discharge electrode 700 is conformally solidified with the surfaces of the spinner 900 and the outer rotor at the same time.

[0131] In a possible implementation, the lap joint line 600 is solidified conformally with the portion of the structure connecting the blade 200 and / or the blade root of the blade 200, and the outer surface of the blade 200 and / or the blade root of the blade 200, to match the aerodynamic shape of the electric propulsion device 20.

[0132] In the embodiment of the application, the lap joint line 600 can also be connected with the fairing 900, and the lap joint line 600 is solidified conformally with the surface of the fairing 900. Of course, the lap joint line 600 can also be connected with the fairing 900 and the outer rotor at the same time, so that the lap joint line 600 is solidified conformally with the surface of the fairing 900 and the outer rotor at the same time, thereby avoiding affecting the aerodynamic effect of the electric propulsion device 20 or the aircraft.

[0133] In the above embodiment, the lightning current on the blade 200 is guided to the machine body 11 through the lightning protection device, so as to avoid the lightning current affecting the electric motor 100 of the electric propulsion device 20. The structure of the lightning protection device has been described above, and will not be repeated here. The electric propulsion device 20 provided with the lightning protection device can reasonably guide the current generated on the electric propulsion device 20 due to lightning, and improve the protection effect.

[0134] Especially for the outer rotor electric motor 100, the shell of the electric motor 100 is not fixedly connected with the machine body 11, and the shell of the outer rotor electric motor 100 is in an electrically disconnected state with the machine body 11, so that the lightning current cannot be effectively conducted to the machine body 11. By using the scheme of the application, the discharge gap between the discharge electrode 700 of the lightning protection device and the machine body 11 is used as a conduction path of lightning, the lightning current received by the blade 200 and / or the fairing 900 is guided to the machine body 11, the lightning current is blocked from entering the system inside the electric motor 100, and the outer rotor electric motor 100 system is prevented from being damaged.

[0135] Compared with the small resistance requirement of the traditional low-voltage electrical conduction path, the discharge gap has an infinite resistance, but when the high voltage of lightning is applied to the discharge electrode 700, the tip of the discharge electrode 700 makes the electric field at the discharge gap be an extremely non-uniform field, and the discharge gap is easily broken down to form a path under the voltage, thereby achieving the purpose of lightning conduction.

[0136] In a possible implementation, as shown in Figure 3 The electric propulsion device 20 further includes a pitch mechanism 400 connected to the blade root of the blade 200 and the hub 300.

[0137] The connection between the pitch changing mechanism 400 and the blade root, and the connection between the pitch changing mechanism 400 and the hub 300 are insulated. The number of blades 200 driven by the pitch changing mechanism 400 can be set according to requirements, for example, only part of the blades 200 can be driven to rotate and change pitch, or all of the blades 200 can be simultaneously driven to change pitch synchronously. By setting the pitch changing mechanism 400, the pitch changing or tilting function of the propeller 22 can be realized.

[0138] In the above embodiment, the connection between the pitch changing mechanism 400 and the hub 300 is insulated, for example, an insulating coating material is used, or an insulating structure is used, to avoid lightning conduction from the blade root and the hub 300 to the pitch changing mechanism 400.

[0139] In a possible implementation, the embodiment of the application provides an aircraft, which includes a body 11 and the above-mentioned electric propulsion device 20. The electric motor 100 of the electric propulsion device 20 is located inside the body 11. The structure of the electric propulsion device 20 has been described above and will not be repeated here. The body 11 is covered with a skin 500, which is a conductive member.

[0140] By setting the skin 500 on the body 11, the current conducted to the body 11 by the discharge electrode 700 can be further conducted to the skin 500, forming a discharge path, to prevent high voltage and large current from breaking sensitive components inside the motor.

[0141] In a possible implementation, the skin 500 herein can be a metal conductive member, and can also be a conductive member made of a composite material. For example, the skin 500 can be made of a traditional mainstream material, aluminum alloy, which has the characteristics of light weight, moderate strength, low cost, and easy processing. The skin 500 can also be made of titanium alloy, which has a very high strength-to-weight ratio, high temperature resistance (supersonic flight), and corrosion resistance.

[0142] The skin 500 can also be a composite material, for example, a skin 500 integrated with a metal mesh. It has the characteristics of light weight, high strength, fatigue resistance, and strong designability. For example, a skin 500 integrated with a carbon fiber reinforced polymer and a metal mesh.

[0143] In a possible implementation, the side of the body 11 facing the discharge electrode 700 is provided with a sawtooth-shaped or other pointed structure (not shown in the figure), to strengthen the extremely uneven electric field between the body 11 and the discharge electrode 700, and to promote the effectiveness of the discharge gap discharge.

[0144] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein.

[0145] Embodiments of the application are intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice in the art to which the application pertains or can pertain. The teachings of the specification and the examples are intended to be exemplary only and not limiting of the true scope and spirit of the application, which is indicated by the following claims.

[0146] It should be understood that the application is not limited to the precise construction and compositions described above and shown in the attached drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is indicated by the claims appended hereto.

Claims

1. A lightning protection device, characterized in that, The utility model relates to a lightning protection device for a rotorcraft, comprising: at least one lightning receptor (800) for receiving lightning, the lightning receptor (800) being arranged on a blade (200) and / or a spinner (900) of a propeller (22); a bonding wire (600) arranged on the propeller (22) and electrically connected to the lightning receptor (800); a discharge electrode (700) having a first end electrically connected to the bonding wire (600) and a second end extending towards a fuselage (11) with a discharge gap between the second end of the discharge electrode (700) and the fuselage (11); the discharge electrode (700) being configured to receive a lightning current of the bonding wire (600) and to conduct the lightning current to the fuselage (11) through the discharge gap.

2. The lightning protection apparatus of claim 1, wherein, the second end of the discharge electrode (700) being conical, the tip of the conical second end of the discharge electrode (700) being directed towards the fuselage (11).

3. The lightning protection apparatus of claim 1, wherein, the lightning receptor (800) being configured to be formed by a metallization of a tip portion of the blade (200) and / or the spinner (900), the metallization being separated from the blade (200) and / or the spinner (900) by an insulating layer, and / or the metallization being determined by a balling method.

4. The lightning protection apparatus of claim 1, wherein, the lightning receptor (800) comprising a lightning receptor portion (810) and a busbar portion (820) electrically connected to the lightning receptor portion (810); the lightning receptor portion (810) being configured as a metal conductive material, the metal conductive material covering the blade (200) and / or the spinner (900); the busbar portion (820) being configured as a metal strip arranged on one side of the lightning receptor portion (810) and electrically connected to the bonding wire (600).

5. The lightning protection apparatus of claim 4, wherein, the lightning receptor (800) comprising a first lightning receptor (800a) and a second lightning receptor (800b); the first lightning receptor (800a) being arranged on the blade (200) and being spaced apart and insulated from a blade root of the blade (200) on a side of the first lightning receptor (800a) close to a rotation axis of the propeller (22); the second lightning receptor (800b) being arranged on the spinner (900) and being spaced apart and insulated from the blade root of the blade (200) on a side of the second lightning receptor (800b) close to the fuselage (11).

6. The lightning protection apparatus of claim 5, wherein, the lightning receptor portion (810) of the first lightning receptor (800a) extending from a tip of the blade (200) to the blade root by a distance greater than or equal to one half of a length of the blade (200) and less than or equal to three thirds of the length of the blade (200); and / or the lightning receptor portion (810) of the second lightning receptor (800b) extending from a tip of the spinner (900) to a bottom portion of the spinner (900) by a distance greater than or equal to one third of a length of the spinner (900) and less than or equal to one half of the length of the spinner (900).

7. The lightning protection device according to any one of claims 1 to 6, characterized in that An insulating sleeve (601) is sleeved on the overlap line (600).

8. The lightning protection device according to any one of claims 1 to 6, characterized in that The discharge gap is greater than or equal to 10 mm and less than or equal to 20 mm.

9. An electric propulsion device, characterized by Comprise: A propeller (22) comprising a spinner (900), a hub (300) and a plurality of blades (200) disposed on the hub (300), the spinner (900) covering the hub (300); The lightning protection device according to any one of claims 1 to 8, wherein the lightning protection device is connected to the propeller (22).

10. The electric propulsion device according to claim 9, characterized in that Further comprising an electric motor (100), the electric motor (100) comprising an outer rotor fixedly connected to the hub (300) of the propeller (22); The overlap line (600) of the lightning protection device is conformally solidified with the surface of the spinner (900) and / or the outer rotor, matching the aerodynamic shape of the electric propulsion device (20); And / or, the discharge electrode (700) of the lightning protection device is conformally solidified with the surface of the spinner (900) and / or the outer rotor, matching the aerodynamic shape of the electric propulsion device (20).

11. The electric propulsion device according to claim 9 or 10, characterized in that Further comprising a pitch changing mechanism (400) connected to the blade root of the blade (200) and the hub (300); The connection between the pitch changing mechanism (400) and the blade root, and the connection between the pitch changing mechanism (400) and the hub (300) are both insulated.

12. An aircraft, characterized in that Comprise: A machine body (11), an outer covering skin (500) of the machine body (11), the skin (500) being an electrically conductive member; The electric propulsion device (20) according to claim 10 or 11; Wherein, the electric propulsion device (20) is connected to the machine body (11).

13. The aircraft of claim 12, wherein, The machine body (11) is provided with a sawtooth-shaped tip structure on the side facing the discharge electrode (700).

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