A rotary-wing drone

Abstract

This invention discloses a rotary-wing unmanned aerial vehicle (UAV), relating to the field of UAV technology. It includes a UAV body and several rotor arm assemblies, all evenly arranged around the UAV body. Each rotor arm assembly includes a folding arm, a rotor motor, and a retraction / deployment actuator. The first end of the folding arm is hinged to the UAV body, the rotor motor housing is fixedly mounted on the second end of the folding arm, and a rotating wing is fixedly mounted on the power output shaft of the rotor motor. The retraction / deployment actuator is mounted on the UAV body and can drive the folding arm to fold or deploy. The bottom of the UAV body has a suspension area, on which several force sensors are fixedly mounted. A controller is fixedly mounted inside the UAV body, which can control the operation of the rotor motor and the retraction / deployment actuator. This invention can effectively avoid frequent fluctuations in the UAV's attitude, significantly improving the flight stability and operational accuracy of the rotary-wing UAV.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a rotary-wing UAV. Background Technology

[0002] In existing technologies, rotary-wing drones mostly adopt a fixed arm or simple folding arm design.

[0003] Fixed-arm rotor drones: The rotor arm is a solid metal rod that is integrally formed and rigidly connected to the fuselage by welding or high-strength bolts. It has a strong load-bearing capacity, but it cannot be folded and stored. During transportation, it needs to be disassembled into multiple parts such as the fuselage and rotor arm, and relies on special trucks for transportation.

[0004] Simple folding arm rotorcraft drones: Each rotor arm is connected to the fuselage via a rotating hinge made of plastic or ordinary metal. These hinges, along with positioning pins or elastic clips, secure the drone when folded. When folded, the rotor arm can rotate around the hinge towards the fuselage, reducing its size compared to its unfolded state. However, these folding mechanisms have limited connection rigidity and structural strength, resulting in insufficient support when unfolded and limited load-bearing capacity. In industrial operations (such as de-icing of high-altitude cables, hoisting of large equipment, and emergency material transportation), drones often need to carry heavy tools (such as high-frequency vibration de-icers and high-pressure jetting devices) or heavy materials. Traditional simple folding arm rotorcraft drones, due to their insufficient load-bearing capacity, cannot meet the load requirements of such industrial operations. Furthermore, traditional simple folding arm rotorcraft drones can only achieve simple load mounting. In actual flight operations such as high-altitude cable de-icing, airflow disturbances and operational actions (such as robotic arm swinging and jet reaction force) can easily cause the load's center of gravity to shift. When the load's center of gravity deviates from the drone's geometric center, the flight control system needs to continuously output high-intensity correction signals to maintain balance, resulting in frequent fluctuations in the drone's attitude. This can easily reduce operational accuracy (such as the inability to accurately align with cables during de-icing), and may even cause power distribution imbalance due to excessive center of gravity shift, leading to flight instability or even a crash. Summary of the Invention

[0005] The purpose of this invention is to provide a rotary-wing unmanned aerial vehicle (UAV) that solves the problems existing in the prior art, effectively avoids frequent attitude fluctuations of the UAV, and significantly improves the flight stability and operational accuracy of the rotary-wing UAV.

[0006] To achieve the above objectives, the present invention provides the following solution: This invention provides a rotary-wing unmanned aerial vehicle (UAV), comprising a UAV body and several rotor arm assemblies, all of which are evenly arranged around the UAV body. Each rotor arm assembly includes a folding arm, a rotor motor, and a retraction / deployment actuator. The first end of the folding arm is hinged to the UAV body, the housing of the rotor motor is fixedly mounted on the second end of the folding arm, and a rotating wing is fixedly mounted on the power output shaft of the rotor motor. The retraction / deployment actuator is mounted on the UAV body and is tractively connected to the folding arm, enabling the folding arm to fold or deploy. The bottom of the UAV body has a suspension area for suspending a load, and several force sensors are fixedly mounted in the suspension area. A controller is fixedly mounted inside the UAV body, and the controller is communicatively connected to the force sensors, the rotor motor, and the retraction / deployment actuator, enabling the controller to control the operation of the rotor motor and the retraction / deployment actuator.

[0007] Preferably, the retraction and extension execution component includes a telescopic driver and a connecting rod. The housing of the telescopic driver is fixedly mounted on the UAV body. The telescopic end of the telescopic driver is hinged to the first end of the connecting rod, and the second end of the connecting rod is hinged to the folding arm. The extension of the telescopic end can drive the folding arm to unfold outward, and the retraction of the telescopic end can drive the folding arm to fold inward.

[0008] Preferably, the telescopic actuator is an electric telescopic rod.

[0009] Preferably, the UAV body is formed by CNC machining of a single piece of aviation aluminum, and several mounting seats are precision milled on the outer wall of the UAV body. The number of mounting seats is equal to the number of telescopic actuators, and the mounting seats correspond one-to-one with the telescopic actuators. The housing of the telescopic actuator is fixedly mounted on the mounting seats.

[0010] Preferably, the mounting base is welded with reinforcing ribs.

[0011] Preferably, the top surface of the folding arm has two connecting lugs, the second end of the connecting rod extends between the two connecting lugs, and the second end of the connecting rod is hinged to the two connecting lugs.

[0012] Preferably, the retraction and extension execution component further includes a first connecting bolt; a plurality of connecting hinge seats are fixedly provided on the outer wall of the UAV body, the number of connecting hinge seats is equal to the number of folding arms, the connecting hinge seats correspond one-to-one with the folding arms, the connecting hinge seats are provided with connecting hinge holes, the first end of the folding arm is provided with a first mounting hole, the first end of the folding arm can extend into the connecting hinge seat, and the first mounting hole is aligned with the connecting hinge hole; the first connecting bolt can pass through the first mounting hole and the connecting hinge hole, so that the first end of the folding arm is hinged to the connecting hinge seat.

[0013] Preferably, the retraction and extension actuator further includes two mounting supports; the two mounting supports are symmetrically placed on the front and rear sides of the second end of the folding arm, and the two mounting supports are fixedly connected to the second end of the folding arm; the housing of the rotor motor is fixedly mounted on the two mounting supports.

[0014] Preferably, the retraction and extension assembly further includes at least two second connecting bolts; at least two second mounting holes are provided on the second end of the folding arm; at least two third mounting holes are provided on each of the two mounting supports; the second connecting bolts correspond one-to-one with the second mounting holes, and the second connecting bolts can pass through the third mounting holes and the second mounting holes to fix the two mounting supports to the second end of the folding arm.

[0015] Preferably, the folding arm is a carbon fiber arm; the folding arm has a plurality of weight-reducing holes.

[0016] The present invention achieves the following technical effects compared to the prior art: The rotary-wing drone provided by this invention has a folding arm with the first end hinged to the drone body. The housing of the rotor motor is fixedly mounted on the second end of the folding arm. A rotating wing is fixedly mounted on the power output shaft of the rotor motor. When the power output shaft of the rotor motor rotates, it can drive the rotating wing to rotate, thereby obtaining lift. The folding arm is folded or unfolded by the drive of the retraction and extension actuator. By setting a force sensor in the suspension area at the bottom of the drone body, pressure distribution data of the load in three dimensions can be collected in real time. The controller receives the load force distribution data collected by the force sensor and controls the rotor motor and the retraction and extension actuator to work. By precisely controlling the rotation speed of the rotor motor, the weight of the load is dynamically matched to achieve load lift output. The folding or unfolding of the folding arm is controlled by controlling the retraction and extension actuator, so as to switch between the folded storage state and the unfolded working state. Moreover, when flying with a heavy load, if the center of gravity shifts due to airflow disturbance, load operation actions (such as de-icing vibration), etc., the force sensor... It can sense changes in load force in real time and detect pressure distribution deviations in real time. When the deviation reaches a preset threshold, it triggers an adjustment mechanism and transmits the data to the controller. The controller calculates the center of gravity offset and offset direction through a multi-sensor fusion algorithm, and then outputs adjustment commands to drive the corresponding retraction and extension actuators to control the folding arm to rotate precisely. This adjusts the lift distribution of the corresponding rotating wing, enabling active and real-time counteraction of the effects of center of gravity offset. This keeps the center of gravity of the rotorcraft UAV within a stable and reasonable range near the geometric center, reducing the attitude correction pressure on the flight control system, effectively improving endurance, effectively avoiding frequent attitude fluctuations of the UAV, and significantly improving the flight stability and operational accuracy of the rotorcraft UAV. Even under harsh conditions such as airflow disturbances and load vibrations, it can still maintain a stable attitude, greatly reducing the risk of instability. In industrial-grade operations such as de-icing and hoisting, it can accurately aim at the target, meeting the requirements of high-precision operations and achieving the comprehensive goal of high load and high stability. It is especially suitable for high-load and high-precision operation scenarios such as high-altitude cable de-icing. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the rotary-wing unmanned aerial vehicle provided by the present invention; Figure 2 This is a schematic diagram of the rotor arm assembly; Figure 3 This is a schematic diagram of a folding arm; Figure 4This is a schematic diagram of two mounting supports; In the diagram: 11. UAV body; 2. Telescopic actuator; 21. Housing of telescopic actuator; 22. Telescopic end; 3. Connecting rod; 4. Connecting hinge; 5. Folding arm; 51. Connecting ear; 52. First mounting hole; 53. Weight reduction hole; 54. Second mounting hole; 55. Mounting support; 56. Third mounting hole; 6. Rotor motor; 7. Rotary wing. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The purpose of this invention is to provide a rotary-wing unmanned aerial vehicle (UAV) that solves the problems existing in the prior art, effectively avoids frequent attitude fluctuations of the UAV, and significantly improves the flight stability and operational accuracy of the rotary-wing UAV.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figures 1 to 4 As shown, the present invention provides a rotary-wing unmanned aerial vehicle (UAV), including a UAV body 11 and several rotor arm assemblies, all of which are evenly arranged around the UAV body 11. Each rotor arm assembly includes a folding arm 5, a rotor motor 6, and a retraction / deployment actuator. The first end of the folding arm 5 is hinged to the UAV body 11. The housing of the rotor motor 6 is fixedly mounted on the second end of the folding arm 5. A rotating wing 7 is fixedly mounted on the power output shaft of the rotor motor 6. The retraction / deployment actuator is mounted on the UAV body 11 and is connected to the folding arm 5 via a transmission connection. The retraction / deployment actuator can drive the folding arm 5 to fold or unfold. The bottom of the UAV body 11 has a suspension area for suspending loads, and several force sensors are fixedly mounted in the suspension area. A controller is fixedly mounted inside the UAV body 11. The controller is communicatively connected to the force sensors, the rotor motor 6, and the retraction / deployment actuator, and can control the operation of the rotor motor 6 and the retraction / deployment actuator.

[0023] The rotary-wing drone provided by this invention has a folding arm 5, the first end of which is hinged to the drone body 11. The housing of the rotor motor 6 is fixedly mounted on the second end of the folding arm 5. A rotating wing 7 is fixedly mounted on the power output shaft of the rotor motor 6. When the power output shaft of the rotor motor 6 rotates, it can drive the rotating wing 7 to rotate, thereby obtaining lift. The folding arm 5 is folded or unfolded by the drive of the retraction and extension actuator. By setting a force sensor in the suspension area at the bottom of the drone body 11, the pressure distribution data of the load in three dimensions can be collected in real time. The controller receives the load force distribution data collected by the force sensor and controls the rotor motor 6 and the retraction and extension actuator to work. By precisely controlling the rotation speed of the rotor motor 6, the weight of the load is dynamically matched to achieve load lift output. The folding or unfolding of the folding arm 5 is controlled by controlling the retraction and extension actuator, so as to switch between the folded storage state and the unfolded working state. Moreover, when flying with a heavy load, if the center of gravity shifts due to airflow disturbance, load operation actions (such as de-icing vibration), etc., the force sensor will detect the shift in real time. It senses changes in load force and can detect pressure distribution deviations in real time. Using conventional electronic control methods (PID control), when the deviation reaches a preset threshold, it triggers an adjustment mechanism and transmits the data to the controller. The controller calculates the center of gravity offset and offset direction through a multi-sensor fusion algorithm, and then outputs adjustment commands to drive the corresponding retraction and extension actuators to control the folding arm 5 to rotate precisely, thereby adjusting the lift distribution of the corresponding rotating wing 7. This achieves active and real-time countermeasures against the effects of center of gravity offset, keeping the center of gravity of the rotary-wing UAV within a stable and reasonable range near its geometric center. This reduces the attitude correction pressure on the flight control system, effectively improves endurance, effectively avoids frequent attitude fluctuations of the UAV, and significantly improves the flight stability and operational accuracy of the rotary-wing UAV. Even under harsh conditions such as airflow disturbances and load vibrations, it can still maintain a stable attitude, greatly reducing the risk of instability. In industrial-grade operations such as de-icing and hoisting, it can accurately aim at the target, meeting the requirements of high-precision operations and achieving the comprehensive goal of high load and high stability. It is especially suitable for high-load and high-precision operation scenarios such as high-altitude cable de-icing.

[0024] In this embodiment, the force sensor is threadedly connected to the load (or load bracket) suspended in the suspension area to sense changes in the load force in real time.

[0025] The rotary-wing drone provided by this invention can be folded without disassembly and can be directly placed in the trunk of an SUV or the bed of a small pickup truck, eliminating the need to rent large transport vehicles, thus reducing transportation and time costs. It has high deployment efficiency and reduced usage costs. No professional tools are required, and a single person can quickly complete the deployment and storage. The operation process is simple and efficient, while improving the adaptability of the operation scene. It is especially suitable for mobile operation needs in complex road conditions such as mountainous areas and narrow roads.

[0026] In a preferred embodiment of the present invention, the number of rotor arm assemblies is six, and the six rotating wings 7 rotate in opposite pairs in a clockwise + counterclockwise direction, which effectively balances the counter-torque generated when a single rotating wing 7 rotates, thereby achieving stable hovering and attitude control and providing stable flight power.

[0027] In a preferred embodiment of the present invention, the retraction and extension execution component includes a telescopic actuator 2 and a connecting rod 3. The housing 21 of the telescopic actuator is fixedly mounted on the UAV body 11. The telescopic end 22 of the telescopic actuator 2 is hinged to the first end of the connecting rod 3, and the second end of the connecting rod 3 is hinged to the folding arm 5. When the telescopic end 22 extends, it can drive the folding arm 5 to unfold outward. When the telescopic end 22 retracts, it can drive the folding arm 5 to fold inward. The telescopic actuator 2 and the folding arm 5 are connected by the connecting rod 3 to form a multi-link transmission structure. Compared with the traditional single-axis transmission, the stress generated by the load can be distributed to multiple connection points, avoiding stress concentration at a single connection point, significantly improving the load-bearing capacity of the folding arm 5, and meeting the needs of industrial-grade heavy-duty operations such as high-altitude cable de-icing and emergency material transportation.

[0028] In a preferred embodiment of the present invention, the telescopic actuator 2 is an electric telescopic rod. When the rotary-wing UAV provided by the present invention is carrying a heavy load (such as a high-frequency vibration de-icing device), the folding arm 5 will generate an outward "spreading force". The electric telescopic rod can balance this force by locking its own length, so as to avoid deformation or gap at the connection between the folding arm 5 and the UAV body 11 due to excessive force. It can provide stable axial rigid support for the folding arm 5 and improve the load-bearing capacity.

[0029] In a preferred embodiment of the present invention, the UAV body 11 integrates a modular controller and a sensing unit. The controller is based on a high-performance microcontroller and includes a power management module, a motor drive module, a wireless communication module, and an attitude sensing module (which incorporates a three-axis gyroscope, a three-axis accelerometer, and a magnetometer). This enables closed-loop control (PID control) of the rotorcraft's flight attitude, the rotational speed of the rotor blades 7, and the actions of the retraction and extension actuators. The controller communicates with the telescopic actuator 2 via a bus. When deployment is required, the controller sends a deployment command, and the telescopic end 22 of the telescopic actuator 2 extends smoothly. The thrust is transmitted through the connecting rod 3, driving the folding arm 5 to rotate to the preset working position. At this time, the position sensor built into the telescopic actuator 2 sends a position signal, and the controller triggers the self-locking function. The telescopic actuator 2 maintains the current length. Through the rigid support of the multi-link transmission structure, sufficient axial locking force is provided for the folding arm 5 to resist the "spreading force" under heavy load. When the work is completed and storage is required, the controller sends a folding command. The telescopic end 22 of the telescopic actuator 2 retracts at a smooth speed, pulling the connecting rod 3 to drive the folding arm 5 to rotate and fold towards the drone body 11. After folding, the overall volume is greatly reduced and can be directly put into the trunk of a regular family car, greatly improving portability.

[0030] As a preferred embodiment of the present invention, the UAV body 11 is formed by CNC machining of aerospace aluminum, which can achieve high strength load-bearing capacity and rapid folding, improve the load-bearing capacity, ensure the stability of the installation structure under heavy load conditions, and has strong structural durability. It is suitable for industrial-grade high-frequency operation. Several mounting seats are precision milled on the outer wall of the UAV body 11. The mounting seat structure is stable. The number of mounting seats is equal to the number of telescopic actuators 2. The mounting seats and telescopic actuators 2 correspond one-to-one. The housing 21 of the telescopic actuator is fixedly mounted on the mounting seat.

[0031] As a preferred embodiment of the present invention, a reinforcing rib is welded on the mounting base. The thickened reinforcing rib strengthens the stability of the mounting base, improves its load-bearing capacity, and ensures the stability of the installation structure under heavy load conditions. The mounting base has a pre-drilled standard threaded hole for bolt connection with the housing 21 of the telescopic actuator.

[0032] As a preferred embodiment of the present invention, the top surface of the folding arm 5 has two connecting ears 51, the second end of the connecting rod 3 extends between the two connecting ears 51, and the second end of the connecting rod 3 is hinged to the two connecting ears 51, which facilitates manufacturing and use.

[0033] In a preferred embodiment of the present invention, the retraction and extension execution component further includes a first connecting bolt; a plurality of connecting hinge seats 4 are fixedly provided on the outer wall of the UAV body 11, the number of connecting hinge seats 4 being equal to the number of folding arms 5, the connecting hinge seats 4 and the folding arms 5 corresponding one-to-one, the connecting hinge seats 4 having connecting hinge holes, the first end of the folding arm 5 having a first mounting hole 52, the first end of the folding arm 5 being able to extend into the connecting hinge seat 4, and aligning the first mounting hole 52 with the connecting hinge hole; the first connecting bolt can pass through the first mounting hole 52 and the connecting hinge hole, so that the first end of the folding arm 5 is hinged to the connecting hinge seat 4, facilitating manufacturing and use; in a preferred embodiment of the present invention, the connecting hinge seat 4 is made of high-strength aerospace aluminum forging, improving the load-bearing capacity, ensuring the stability of the installation structure under heavy load conditions, the structure is durable, and it is suitable for industrial-grade high-frequency operations.

[0034] In a preferred embodiment of the present invention, the retraction and extension actuator further includes two mounting supports 55; the two mounting supports 55 are symmetrically arranged on the front and rear sides of the second end of the folding arm 5, and the two mounting supports 55 are fixedly connected to the second end of the folding arm 5; the housing of the rotor motor 6 is fixedly mounted on the two mounting supports 55, which can increase the mounting area of ​​the housing of the rotor motor 6, improve the installation stability of the housing of the rotor motor 6, and at the same time, the structure is compact and the additional weight is reduced.

[0035] In a preferred embodiment of the present invention, the retraction and extension actuator further includes at least two second connecting bolts; at least two second mounting holes 54 are provided on the second end of the folding arm 5; at least two third mounting holes 56 are provided on each of the two mounting supports 55; the second connecting bolts correspond one-to-one with the second mounting holes 54, and the second connecting bolts can pass through the third mounting holes 56 and the second mounting holes 54 to fix the two mounting supports 55 to the second end of the folding arm 5, which facilitates manufacturing and use; in another preferred embodiment of the present invention, the two mounting supports 55 and the second end of the folding arm 5 are integrally formed by 3D printing, which can simplify the connection and improve the connection strength.

[0036] In a preferred embodiment of the present invention, the folding arm 5 is a carbon fiber arm, which is wear-resistant, corrosion-resistant, fatigue-resistant, and has a density much lower than that of traditional metal materials. Compared with traditional aluminum alloy arms, its weight is significantly reduced, effectively reducing the overall weight of the rotorcraft drone. It can achieve high-strength load-bearing and rapid folding, improve the load-bearing capacity, ensure the stability of the installation structure under heavy-load conditions, and has strong structural durability, making it suitable for industrial-grade high-frequency operations. The folding arm 5 is provided with several weight-reduction holes 53 to reduce the weight of the folding arm 5.

[0037] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A rotary-wing unmanned aerial vehicle, characterized in that: It includes a drone body and several rotor arm assemblies, all of which are evenly arranged around the drone body; The rotor arm assembly includes a folding arm, a rotor motor, and a retraction / deployment actuator. The first end of the folding arm is hinged to the UAV body. The housing of the rotor motor is fixedly mounted on the second end of the folding arm. A rotating wing is fixedly mounted on the power output shaft of the rotor motor. The retraction / deployment actuator is mounted on the UAV body and is connected to the folding arm via a transmission mechanism. The retraction / deployment actuator can drive the folding arm to fold or unfold. The bottom of the drone body has a suspension area for suspending loads, and several force sensors are fixedly installed in the suspension area. The UAV body is equipped with a controller, which is communicatively connected to the force sensor, the rotor motor and the retraction and extension actuator. The controller can control the rotor motor and the retraction and extension actuator to work.

2. The rotary-wing UAV according to claim 1, characterized in that: The retraction and extension actuator includes a telescopic driver and a connecting rod. The housing of the telescopic driver is fixedly mounted on the UAV body. The telescopic end of the telescopic driver is hinged to the first end of the connecting rod, and the second end of the connecting rod is hinged to the folding arm. When the telescopic end extends, it can drive the folding arm to unfold outward, and when the telescopic end retracts, it can drive the folding arm to fold inward.

3. The rotary-wing UAV according to claim 2, characterized in that: The telescopic actuator is an electric telescopic rod.

4. The rotary-wing UAV according to claim 2, characterized in that: The drone body is formed by CNC machining of a single piece of aviation aluminum. Several mounting seats are precision milled on the outer wall of the drone body. The number of mounting seats is equal to the number of telescopic actuators. Each mounting seat corresponds to one telescopic actuator. The housing of the telescopic actuator is fixedly mounted on the mounting seat.

5. The rotary-wing UAV according to claim 4, characterized in that: The mounting base is welded with reinforcing ribs.

6. The rotary-wing UAV according to claim 2, characterized in that: The top surface of the folding arm has two connecting lugs, and the second end of the connecting rod extends between the two connecting lugs, and the second end of the connecting rod is hinged to the two connecting lugs.

7. The rotary-wing UAV according to claim 1, characterized in that: The retraction and extension execution component further includes a first connecting bolt; a plurality of connecting hinge seats are fixedly provided on the outer wall of the UAV body, the number of connecting hinge seats being equal to the number of folding arms, the connecting hinge seats corresponding one-to-one with the folding arms, the connecting hinge seats having connecting hinge holes, the first end of the folding arm having a first mounting hole, the first end of the folding arm being able to extend into the connecting hinge seat and align the first mounting hole with the connecting hinge hole; the first connecting bolt can pass through the first mounting hole and the connecting hinge hole, so that the first end of the folding arm is hinged to the connecting hinge seat.

8. The rotary-wing UAV according to claim 1, characterized in that: The retraction and extension actuator also includes two mounting supports; the two mounting supports are symmetrically placed on the front and rear sides of the second end of the folding arm, and the two mounting supports are fixedly connected to the second end of the folding arm; the housing of the rotor motor is fixedly mounted on the two mounting supports.

9. The rotary-wing UAV according to claim 8, characterized in that: The retraction and extension assembly further includes at least two second connecting bolts; at least two second mounting holes are provided on the second end of the folding arm; at least two third mounting holes are provided on each of the two mounting supports; the second connecting bolts correspond one-to-one with the second mounting holes, and the second connecting bolts can pass through the third mounting holes and the second mounting holes to fix the two mounting supports to the second end of the folding arm.

10. The rotary-wing UAV according to claim 1, characterized in that: The folding arm is a carbon fiber arm; the folding arm has several weight-reduction holes.

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