WO2024093476A1

WO2024093476A1 - Coaxial dual-rotor unmanned aerial vehicle

Info

Publication number: WO2024093476A1
Application number: PCT/CN2023/115496
Authority: WO
Inventors: 王玉林; 董斌; 李东达
Original assignee: 苏州览众科技有限公司
Priority date: 2022-11-01
Filing date: 2023-08-29
Publication date: 2024-05-10
Also published as: CN115535228A

Abstract

The present invention provides a coaxial dual-rotor unmanned aerial vehicle, comprising a main shaft, an upper rotor assembly, a lower rotor assembly, an upper motor, a lower motor, and a rotor control device. The upper rotor assembly is pivotably arranged on the main shaft; the lower rotor assembly is pivotably arranged on the main shaft; the upper motor is in driving connection with the upper rotor assembly; the lower motor is in driving connection with the lower rotor assembly; the rotation directions of the upper rotor assembly and of the lower rotor assembly are opposite; and the rotor control device is in driving connection with the lower rotor assembly to perform periodic variable-pitch control on the lower rotor assembly. By applying the technical solution of the present invention, a transmission mechanism of an unmanned aerial vehicle is simplified by means of motor direct drive, so that the structure of the coaxial dual-rotor unmanned aerial vehicle is more simplified, and thus the following three advantages are obtained: firstly, weight reduction design is facilitated; secondly, the probability of part damage is reduced, thereby improving the reliability of the coaxial dual-rotor unmanned aerial vehicle and prolonging the service life thereof; and thirdly, machining and assembling can be facilitated, and the coaxial dual-rotor unmanned aerial vehicle is suitable for mass production.

Description

Coaxial twin-rotor drone

Technical Field

The present invention relates to the field of aircraft, and in particular to a coaxial twin-rotor UAV.

Background technique

According to the "Regulations on the Management of Flight Dynamic Data of Light and Small Civilian UAVs", drones with an empty weight of less than 0.25kg are classified as micro drones. Drones with an empty weight of no more than 4kg and a maximum take-off weight of no more than 7kg are classified as light drones. Drones with an empty weight of no more than 15kg or a maximum take-off weight of no more than 25kg are classified as small drones (excluding micro and light drones). Drones with a maximum take-off weight between 25kg and 150kg are classified as medium drones. Drones with a maximum take-off weight of more than 150kg are classified as large drones.

Coaxial helicopters have the advantages of small size, no tail rotor, high hovering efficiency, etc., and are the most suitable layout form for lightweight and miniaturized unmanned helicopters. Lightweight and miniature coaxial drones have certain advantages over multi-rotor drones in terms of endurance and portability, both in civil and military applications.

Generally, the operating mechanism and transmission mechanism of a coaxial helicopter are complicated, which makes the coaxial helicopter difficult to assemble on the one hand, and also affects the reliability of the coaxial helicopter on the other hand.

Summary of the invention

The main purpose of the present invention is to provide a coaxial twin-rotor UAV to solve the problem of complex structure of the coaxial twin-rotor UAV in the prior art.

In order to achieve the above-mentioned purpose, the present invention provides a coaxial twin-rotor UAV, comprising: a main shaft; an upper rotor assembly, which is pivotally arranged on the main shaft; a lower rotor assembly, which is pivotally arranged on the main shaft; an upper motor, which is arranged on the main shaft and is drivingly connected to the upper rotor assembly; a lower motor, which is arranged on the main shaft and is drivingly connected to the lower rotor assembly, and the rotation directions of the upper rotor assembly and the lower rotor assembly are opposite; a rotor control device, which is arranged on the main shaft and is drivingly connected to the lower rotor assembly to perform cyclic pitch control on the lower rotor assembly.

In one embodiment, the upper motor includes: an upper motor body; a first stator seat, fixedly arranged On the main shaft, the upper motor body is fixed on the first stator seat; the upper motor rotor, the first stator seat supports the upper motor rotor, the upper motor rotor cooperates with the main shaft through the first bearing, and the upper motor rotor is drivingly connected to the upper rotor assembly.

In one embodiment, the lower motor includes: a lower motor body; a second stator seat, fixedly disposed on the main shaft, and the lower motor body is fixed on the second stator seat; a lower motor rotor, matched with the main shaft through a second bearing, and the lower motor rotor is drivingly connected to the lower rotor assembly.

In one embodiment, when the upper motor includes a first stator seat, the upper motor and the lower motor are located between the upper rotor assembly and the lower rotor assembly, and the first stator seat and the second stator seat are the same common stator seat.

In one embodiment, the coaxial twin-rotor UAV further includes: a motor cover, which is arranged outside the upper motor and the lower motor, and the motor cover is fixed on the common stator seat.

In one embodiment, the lower rotor assembly includes a lower rotor assembly body disposed on the lower motor rotor and a needle bearing, wherein the needle bearing is located between the lower rotor assembly body and the main shaft.

In one embodiment, the rotor control device includes: an automatic tilt device, which is arranged on the main shaft and connected to the lower rotor assembly; and a driving device, which drives the lower rotor assembly to move through the automatic tilt device.

In one embodiment, the automatic tilt device includes from the inside to the outside: a central ball joint, a fixed ring, a third bearing and a dynamic ring, the main shaft is passed through the central ball joint, the driving device includes a first servo and a second servo, and the coaxial twin-rotor UAV also includes: a bracket, which is arranged on the main shaft, the first servo and the second servo are fixed on the bracket, a limiting structure is arranged on the bracket, and a vertical slide groove is arranged on the limiting structure; a pitch rod connecting the dynamic ring and the lower rotor assembly; a first connecting rod, which is connected between the first servo and the fixed ring; a second connecting rod, which is connected between the second servo and the fixed ring, and the fixed ring is provided with a limiting protrusion that cooperates with the slide groove.

In one embodiment, the first steering gear is a pitch steering gear, the second steering gear is a roll steering gear, and the upper rotor assembly includes: an upper hinge seat, the main shaft is passed through the upper hinge seat, and the upper hinge seat is connected to the upper motor drive; an upper propeller hub extends along a first horizontal direction, and the upper propeller hub is hinged to the upper hinge seat through a central hinge pin, and the central hinge pin Extending along the second horizontal direction, the first horizontal direction is perpendicular to the second horizontal direction; the fourth bearing is arranged between the upper hinge seat and the central hinge pin; the upper rotor blade is connected to the upper hub.

In one embodiment, the stationary ring includes a stationary ring body and a first extension arm, a second extension arm and a third extension arm which are arranged on the stationary ring body and extend outward, the first connecting rod is connected to the first extension arm, the second connecting rod is connected to the second extension arm, and the limiting boss is arranged on the third extension arm. The position of the limiting boss is 0° of the UAV azimuth angle Ψ, the first extension arm extends in the direction of 135° of the UAV azimuth angle Ψ, and the second extension arm extends in the direction of 225° of the UAV azimuth angle Ψ. The longitudinal section where the UAV azimuth angle Ψ is 0° is taken as the reference plane, and the first servo and the second servo are symmetrically arranged on both sides of the reference plane.

In one embodiment, a first ball head is provided at the end of the first extension arm, and a second ball head is provided at the end of the second extension arm. The driving device also includes a first rocker arm and a second rocker arm. The first rocker arm and the second rocker arm are respectively connected to the first servo and the second servo through splines. The first connecting rod connects the first rocker arm and the first ball head, and the second connecting rod connects the second rocker arm and the second ball head.

In one embodiment, the coaxial twin-rotor UAV further includes: a pressure ring, the main shaft is inserted into the pressure ring, the pressure ring is fixed on the main shaft, and the automatic inclinator is clamped between the pressure ring and the bracket.

In one embodiment, the coaxial twin-rotor UAV further includes: a fuselage, which is arranged on the main shaft; and an automatic tilt device cover, which is arranged outside the automatic tilt device and fixed to the fuselage.

In one embodiment, the upper rotor assembly includes: an upper hinge seat, on which the main shaft is passed, and the upper hinge seat is drive-connected to the upper motor; an upper hub, extending along a first horizontal direction, the upper hub and the upper hinge seat are hinged through a center hinge pin, the center hinge pin extends along a second horizontal direction, and the first horizontal direction is perpendicular to the second horizontal direction; a fourth bearing, arranged between the upper hinge seat and the center hinge pin; and an upper rotor blade, which is hinged to the upper hub through a vertically extending screw.

In one embodiment, the upper propeller hub includes an upper connecting frame, two upper extension handles and two first propeller clamps, the upper connecting frame includes two first frame frames arranged opposite to each other and two second frame frames arranged opposite to each other between the two first frame frames, the main shaft is passed through a central hole surrounded by the first frame frames and the second frame frames, and the two The upper extension handles are respectively connected to the two first frame frames, there are two center hinge pins, and the two center hinge pins are respectively arranged on the second frame frames. The two first propeller clamps are respectively hinged to the ends of the two upper extension handles through the first folding pins, and the first folding pins extend along the second horizontal direction. The upper rotor blades are hinged to the first propeller clamps through screws.

In one embodiment, the lower rotor assembly includes: a lower hinge seat, a main shaft is passed through the lower hinge seat, and the lower hinge seat is drivingly connected to the lower motor; a lower hub, extending along a third horizontal direction, the lower hub and the lower hinge seat are hinged through a transverse axis, the transverse axis extends along the third horizontal direction, and the automatic tilt device is drivingly connected to the lower hub; a fifth bearing is arranged between the lower hinge seat and the transverse axis; and a lower rotor blade is hinged to the lower hub through a vertically extending screw.

In one embodiment, the lower hub includes a lower connecting frame and two lower extending handles, the lower connecting frame includes two third frame frames arranged opposite to each other and two fourth frame frames arranged opposite to each other between the two third frame frames, the main shaft is passed through a center hole surrounded by the third frame frame and the fourth frame frame, the two lower extending handles are respectively connected to the two third frame frames, there are two transverse axes, and the two transverse axes are respectively arranged on the third frame frames, the automatic inclinator includes from the inside to the outside: a central ball joint, a fixed ring, a third bearing and a dynamic ring, the main shaft is passed through the central ball joint, the driving device includes a first servo and a second servo, and the coaxial twin-rotor UAV also It includes: a bracket, which is arranged on the main shaft, the first servo and the second servo are fixed on the bracket, the bracket is provided with a limiting structure, and the limiting structure is provided with a vertically extending slide groove; a first connecting rod, which is connected between the first servo and the fixed ring; a second connecting rod, which is connected between the second servo and the fixed ring, and the fixed ring is provided with a limiting convex column that cooperates with the slide groove, two fourth frame frames are provided with cylindrical hinges, and the position of the movable ring corresponding to the cylindrical hinge is provided with a third ball head; two variable pitch pull rods, the first ends of the two variable pitch pull rods are respectively hinged to the two cylindrical hinges, and the second ends of the two variable pitch pull rods are respectively connected to the two third ball heads.

In one embodiment, the lower rotor assembly includes: a lower hinge seat, the main shaft is passed through the lower hinge seat, the lower hinge seat is connected to the lower motor drive; a lower propeller hub extends along the third horizontal direction, the lower propeller hub and the lower hinge seat are hinged through a transverse axis, the transverse axis extends along the third horizontal direction, and the rotor control device is connected to the lower propeller hub drive; a fifth bearing is arranged between the lower hinge seat and the transverse axis; the lower rotor blade is connected to the lower rotor blade by a vertically extending screw The lower propeller hub is hinged.

In one embodiment, the lower propeller hub includes: a lower propeller hub body and two second propeller clamps arranged at opposite ends of the lower propeller hub body, the second propeller clamps are hinged to the lower hub body through second folding pins, the second folding pins extend along a fourth horizontal direction, the fourth horizontal direction is perpendicular to the third horizontal direction, and the lower rotor blades are hinged to the second propeller clamps through screws.

In one embodiment, the coaxial twin-rotor UAV further includes: a battery module, which is arranged on the main shaft; a fuselage, which is arranged on the main shaft; and a pod module, including a camera, which is arranged on the fuselage.

In one embodiment, the coaxial twin-rotor UAV further includes: a fuselage, which is arranged on the main shaft; and a landing gear, which is arranged on the fuselage.

In one embodiment, the main shaft is a hollow shaft, and the coaxial twin-rotor UAV also includes: a fuselage, which is arranged on the main shaft, and the inner hole of the main shaft extends to the fuselage, and a wire entry hole connected to the inner hole of the main shaft is arranged on the side wall of the main shaft, and the wire entry hole is located between the upper motor and the lower motor.

By applying the technical solution of the present invention, the upper motor and the lower motor drive the upper rotor assembly and the lower rotor assembly to rotate in the form of direct drive. The upper rotor assembly rotates counterclockwise (clockwise), and the lower rotor assembly rotates clockwise (counterclockwise). The rotor control device performs cyclic pitch-changing operations on the lower rotor assembly in the lateral, longitudinal, and longitudinal and lateral linkages. The cyclic pitch-changing motion of the lower rotor assembly can realize the flight of the UAV left and right, front and back, and in any direction. The acceleration and deceleration of the upper rotor assembly and the lower rotor assembly driven by the upper motor and the lower motor can realize the climbing, descending, and maneuvering of the UAV. One of the upper motor and the lower motor accelerates and the other decelerates, providing a torque for heading control while the total lift remains unchanged. In this way, the UAV realizes omnidirectional flight, climbing, descending, maneuvering, and heading control. The above structure simplifies the transmission mechanism of the UAV by direct motor drive, thereby making the structure of the coaxial twin-rotor UAV simpler, thereby achieving the following three advantages: first, it is conducive to weight reduction design; second, it reduces the probability of damage to components and can improve the reliability and life of the coaxial twin-rotor UAV; third, it can be easily processed and assembled, and is suitable for mass production.

In addition to the objects, features and advantages described above, the present invention also has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

FIG1 is a schematic diagram showing a three-dimensional structure of an embodiment of a coaxial twin-rotor UAV according to the present invention;

FIG2 is a schematic diagram showing a three-dimensional structure of the upper rotor blades and the lower rotor blades of the coaxial twin-rotor UAV of FIG1 after being folded;

FIG3 shows a schematic diagram of the exploded structure of the coaxial twin-rotor UAV of FIG1 ;

FIG4 is a schematic diagram showing a three-dimensional structure of a part of the coaxial twin-rotor UAV of FIG2 ;

FIG5 is a schematic diagram showing an enlarged structure of the coaxial twin-rotor UAV at A in FIG4 ;

FIG6 shows an enlarged structural schematic diagram of the coaxial twin-rotor UAV at B in FIG4 ;

FIG. 7 shows an enlarged structural schematic diagram of the coaxial twin-rotor UAV at C in FIG. 4 ;

FIG8 shows a schematic longitudinal section structure diagram of the coaxial twin-rotor UAV of FIG4 ;

FIG9 shows an enlarged structural schematic diagram of a portion D of the coaxial twin-rotor UAV of FIG8 ;

FIG10 is a schematic diagram showing an enlarged structure of the coaxial twin-rotor UAV at position E in FIG8 ;

FIG11 is a schematic diagram showing an enlarged structure of the coaxial twin-rotor UAV at F in FIG8 ;

FIG12 is a schematic diagram showing the three-dimensional structure of the automatic tilt device of the coaxial twin-rotor UAV of FIG1 ;

FIG. 13 is a schematic top view of the coaxial twin-rotor UAV of FIG. 1 , wherein FIG. 13 shows the forward flight direction and azimuth angle Ψ of the coaxial twin-rotor UAV; and

FIG. 14 is a schematic top view showing a partial structure of the coaxial twin-rotor UAV of FIG. 1 , wherein FIG. 14 shows the azimuth angle Ψ at which the extension arm of the automatic tilter is located.

The above drawings include the following reference numerals:
10. Main shaft; 11. Cable entry hole; 20. Upper rotor assembly; 21. Upper hinge seat; 22. Upper propeller hub;
221, upper connecting frame; 2211, first frame; 2212, second frame; 222, upper extension handle; 223, first blade clamp; 224, first folding pin; 23, center hinge pin; 24, fourth bearing; 25, upper rotor blade; 30, lower rotor assembly; 31, lower hinge seat; 32, lower hub; 321, lower connecting frame; 3211, third frame; 3212, fourth frame; 3213, cylindrical hinge; 322, lower extension handle; 323, horizontal axis; 324, lower hub body; 325, second blade clamp; 326, second folding pin; 33, fifth bearing; 34, lower rotor blade; 40, upper motor; 42, upper motor rotor; 43, first bearing; 50, lower motor; 52, lower motor rotor; 53, second bearing; 60, rotor control device; 61, automatic tilt device; 6 11. Center ball joint; 612. Immovable ring; 6121. Immovable ring body; 6122. First extension arm; 6123. Second extension arm; 6124. Third extension arm; 6125. First ball head; 6126. Second ball head; 613. Third bearing; 614. Moving ring; 615. Limiting boss; 616. Third ball head; 62. Driving device; 621. First servo; 622. Second servo; 623. First rocker arm; 624. Second rocker arm; 70. Common stator seat; 80. Motor cover; 90. Bracket; 91. Slide; 100. Pitch rod; 110. First connecting rod; 120. Second connecting rod; 130. Pressure ring; 140. Battery module; 150. Fuselage; 160. Nacelle module; 170. Landing gear; 180. Automatic tilter cover; 190. Needle bearing.

Detailed ways

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

In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or priority. It should be understood that the terms used in this manner are interchangeable where appropriate to facilitate the embodiments of the invention described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or inherent to these processes, methods, products, or apparatuses.

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and/or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and/or combinations thereof.

As shown in Figures 1 to 4 and Figure 8, the coaxial twin-rotor drone of this embodiment includes: a main shaft 10, an upper rotor assembly 20, a lower rotor assembly 30, an upper motor 40, a lower motor 50, and a rotor control device 60. Among them, the upper rotor assembly 20 is pivotally arranged on the main shaft 10. The lower rotor assembly 30 is pivotally arranged on the main shaft 10. The upper motor 40 is arranged on the main shaft 10, and the upper motor 40 is driven and connected to the upper rotor assembly 20. The lower motor 50 is arranged on the main shaft 10, and the lower motor 50 is driven and connected to the lower rotor assembly 30, and the rotation direction of the upper rotor assembly 20 is opposite to that of the lower rotor assembly 30. The rotor control device 60 is arranged on the main shaft 10, and the rotor control device 60 is driven and connected to the lower rotor assembly 30 to perform cyclic pitch control on the lower rotor assembly 30.

By applying the technical solution of this embodiment, the upper motor 40 and the lower motor 50 drive the upper rotor assembly 20 and the lower rotor assembly 30 to rotate in a direct drive manner. The upper rotor assembly 20 rotates counterclockwise (clockwise), and the lower rotor assembly 30 rotates clockwise (counterclockwise). The rotor control device 60 controls the lower rotor assembly 30. The cyclic pitch-changing operation of the horizontal, vertical and vertical and horizontal linkage. The cyclic pitch-changing movement of the lower rotor assembly 30 can realize the flight of the drone left and right, front and back, and in any direction. The upper motor 40 and the lower motor 50 drive the acceleration and deceleration of the upper rotor assembly 20 and the lower rotor assembly 30 to realize the climbing, descending and maneuvering of the drone. The upper motor 40 and the lower motor 50 accelerate one and decelerate the other, and provide the torque for heading control under the condition that the total lift remains unchanged. In this way, the drone realizes omnidirectional flight, climbing, descending, maneuvering and heading control. The above structure simplifies the transmission mechanism of the drone by direct motor drive, thereby making the structure of the coaxial twin-rotor drone more simplified, thereby obtaining the following three advantages: first, it is conducive to weight reduction design; second, it reduces the probability of damage to components and can improve the reliability and life of the coaxial twin-rotor drone; third, it can be easily processed and assembled, and is suitable for mass production.

In addition, it should be noted that in this embodiment, the drone is arranged in a longitudinal structure, and the structure is basically arranged around the main axis 10.

As shown in Figures 4 and 8, in this embodiment, the upper motor 40 includes: an upper motor body, a first stator seat and an upper motor rotor 42. Among them, the first stator seat is fixedly arranged on the main shaft 10, and the upper motor body is fixed on the first stator seat. The first stator seat supports the upper motor rotor 42, and the upper motor rotor 42 cooperates with the main shaft 10 through the first bearing 43 (two ball bearings arranged at intervals up and down), and the upper motor rotor 42 is connected to the upper rotor assembly 20. The above structure allows the upper motor 40 that drives the upper rotor assembly 20 to be arranged around the main shaft 10, thereby ensuring that the rotational inertia of the entire machine in the heading direction is small, and improving the control efficiency of controlling the heading using the rotor speed difference.

As shown in FIG. 4 and FIG. 8 , in this embodiment, the lower motor 50 includes: a lower motor body, a second stator seat, and a lower motor rotor 52. The second stator seat is fixedly arranged on the main shaft 10, and the lower motor body is fixed on the second stator seat. The lower motor rotor 52 is connected to the lower motor body by a second bearing 53 (arranged in an upper and lower interval). The lower motor 50 driving the lower rotor assembly 30 is arranged around the main shaft 10, thereby ensuring that the rotational inertia of the whole machine in the heading direction is small, and improving the control efficiency of controlling the heading using the rotor speed difference.

As shown in FIG8 , in this embodiment, when the upper motor 40 includes a first stator seat, the upper motor 40 and the lower motor 50 are located between the upper rotor assembly 20 and the lower rotor assembly 30, and the first stator seat and the second stator seat are the same common stator seat 70. The above structure allows the upper motor 40 and the lower motor 50 to share the same stator seat, thereby reducing the number of parts and components, and facilitating processing, production, disassembly and maintenance.

As shown in FIGS. 1 to 3 , in this embodiment, the coaxial twin-rotor UAV further includes: a motor cover 80, which is arranged outside the upper motor 40 and the lower motor 50, and the motor cover 80 is fixed on the common stator seat 70. The above structure can prevent external moisture and dust from contacting the upper motor 40 and the lower motor 50 inside, thereby increasing the service life of the upper motor 40 and the lower motor 50. In addition, two motors can be protected by one motor cover 80, reducing parts, thereby reducing production costs and facilitating assembly.

As shown in Figures 4, 8 and 10, in this embodiment, the lower rotor assembly 30 includes a lower rotor assembly body and a needle bearing 190 disposed on the lower motor rotor 52, and the needle bearing 190 is located between the lower rotor assembly body and the main shaft 10. Specifically, the outer ring of the needle bearing 190 is interference fit with the lower rotor assembly body, and the needle of the needle bearing 190 is in contact with the main shaft. Since the lower rotor assembly 30 has active control and swinging, most of its alternating loads are borne by the needle bearing 190. It protects the second bearing 53 of the lower motor 50 and increases the service life of the lower motor 50. It should be noted that in this embodiment, the second bearing 53 is a hinged ball bearing. It should also be noted that in this embodiment, the needle bearing 190 plays an auxiliary supporting role for the lower rotor assembly 30.

As shown in FIGS. 4 , 7 , 8 , 11 and 12 , in this embodiment, the rotor control device 60 It includes: an automatic inclinometer 61 and a driving device 62. Among them, the automatic inclinometer 61 is arranged on the main shaft 10 and connected to the lower rotor assembly 30. The driving device 62 drives the lower rotor assembly 30 to move through the automatic inclinometer 61. It should be noted that the present embodiment uses the automatic inclinometer 61 to control a vice rotor (the lower rotor assembly 30) to perform periodic pitch change to control the UAV to achieve omnidirectional flight. Although the control torque is reduced compared to the automatic inclinometer controlling the two vice rotors, the rotor control mechanism is simplified. In addition, the inertia of the micro or small coaxial twin-rotor UAV itself is relatively small, and its control performance has not been significantly reduced.

As shown in Figures 4, 7, 8, 11 and 12, in this embodiment, the automatic tilt device 61 includes from the inside to the outside: a central ball joint 611 (radial spherical bearing), a fixed ring 612, a third bearing 613 (preferably a ball bearing) and a dynamic ring 614, the main shaft 10 is inserted into the central ball joint 611, the drive device 62 includes a first servo 621 and a second servo 622, and the coaxial twin-rotor drone also includes: a bracket 90, a pitch-changing pull rod 100, a first connecting rod 110 and a second connecting rod 120. Among them, the bracket 90 is arranged on the main shaft 10, the first servo 621 and the second servo 622 are fixed on the bracket 90, and a limiting structure is arranged on the bracket 90, and a vertically extending slide groove 91 is arranged on the limiting structure. The pitch-changing pull rod 100 connects the dynamic ring 614 and the lower rotor assembly 30. The first connecting rod 110 is connected between the first servo 621 and the fixed ring 612; the second connecting rod 120 is connected between the second servo 622 and the fixed ring 612, and the fixed ring 612 is provided with a limiting boss 615 that cooperates with the slide groove 91. Specifically, the outer ring of the center ball joint 611 is interference fit with the inner ring of the fixed ring 612, and the upper end face of the outer ring of the center ball joint 611 is in close contact with the inner end face of the fixed ring 612. The inner ring of the third bearing 613 is interference fit with the outer ring of the fixed ring 612, and the inner ring end face of the third bearing 613 is in close contact with the step of the fixed ring 612. The inner ring of the movable ring 614 is interference fit with the outer ring of the third bearing 613, and the inner end face of the movable ring 614 is in close contact with the outer ring end face of the third bearing 613. In addition, since the bracket 90 is provided with a vertically extending slide groove 91, the limiting boss 615 on the fixed ring 612 is slidably matched with the slide groove 91, thereby limiting the swing of the automatic tilt device 61. In this way, the automatic tilt device 61 is automatically tilted. The device 61 has only two degrees of freedom, roll and pitch. It should be noted that the coaxial twin-rotor drone in this embodiment has only two servo steering gears to drive the control mechanism. Its automatic tilter and connecting rod mechanism are relatively simple, which improves reliability and service life, and is conducive to weight reduction design.

As shown in Figures 4 to 9, in this embodiment, the first servo 621 is a pitch servo, the second servo 622 is a roll servo, and the upper rotor assembly 20 includes: an upper hinge seat 21, an upper propeller hub 22, a fourth bearing 24 (sliding or ball bearing) and an upper rotor blade 25. Among them, the main shaft 10 is penetrated on the upper hinge seat 21, and the upper hinge seat 21 is driven and connected to the upper motor 40. The upper propeller hub 22 extends along the first horizontal direction, and the upper propeller hub 22 is hinged to the upper hinge seat 21 through the central hinge pin 23, and the central hinge pin 23 extends along the second horizontal direction, and the first horizontal direction is perpendicular to the second horizontal direction. The fourth bearing 24 is arranged between the upper hinge seat 21 and the central hinge pin 23. The upper rotor blade 25 is connected to the upper propeller hub 22. The hinge structure of the upper rotor assembly 20 is a center hinge for the upper rotor to swing, and the automatic tilt device 61 only performs cyclic pitch control on the lower rotor assembly 30. In the forward flight state, the upper rotor assembly 20 is in a free blowing and swinging state, maintaining the aerodynamic symmetry of the coaxial helicopter. In addition, when the forward flight state is transferred to the hovering state, since the upper rotor assembly 20 is swinging with a center hinge, the normal of the rotor cone surface has a forward component, which has a certain hindering effect on the backward flight, reduces the control pressure of the autopilot, and improves the stability of the flight.

It should be noted that, in this embodiment, the upper hinge seat 21 is fixed to the upper motor rotor 42 by screws.

As shown in Figures 4, 7, 12 to 14, in this embodiment, the immovable ring 612 includes an immovable ring body 6121 and a first extension arm 6122, a second extension arm 6123 and a third extension arm 6124 arranged on the immovable ring body 6121 and extending outward, the first connecting rod 110 is connected to the first extension arm 6122, the second connecting rod 120 is connected to the second extension arm 6123, and the limiting boss 615 is arranged on the third extension arm 6124. The position of the limiting boss 615 is 0° of the azimuth angle Ψ of the drone, and the first extension arm 6122 is connected to the second extension arm 6123. The second extension arm 6123 extends in the direction of 135° azimuth angle Ψ of the drone, and the second extension arm 6123 extends in the direction of 225° azimuth angle Ψ of the drone. The longitudinal section of the drone azimuth angle Ψ is 0° as the reference plane, and the first servo 621 and the second servo 622 are symmetrically arranged on both sides of the reference plane. Specifically, in this embodiment, the first servo 621 and the second servo 622 are symmetrically arranged on the left and right, and the first extension arm 6122 and the second extension arm 6123 of the fixed ring 612 are distributed at 90 degrees, respectively located at 135 degrees and 225 degrees of the azimuth angle of the drone. Since only the lower rotor assembly 30 is subjected to periodic pitch change, a coupling effect is generated with the free swinging of the upper rotor assembly 20. The arrangement of the positions of the first extension arm 6122 and the second extension arm 6123 of the fixed ring 612 just makes the first servo 621 a pitch servo and the second servo 622 a roll servo. The coupling of pitch and roll control is minimized, which reduces the decoupling control pressure of the autopilot. It should be noted that, in other embodiments, the angle between the first extension arm and the second extension arm may be any angle between 90° and 120°.

As shown in Fig. 4 and Fig. 7, in this embodiment, a first ball head 6125 is provided at the end of the first extension arm 6122, a second ball head 6126 is provided at the end of the second extension arm 6123, the driving device 62 further comprises a first rocker arm 623 and a second rocker arm 624, the first rocker arm 623 and the second rocker arm 624 are respectively connected to the first steering gear 621 and the second steering gear 622 through splines, the first connecting rod 110 connects the first rocker arm 623 and the first ball head 6125, and the second connecting rod 120 connects the second rocker arm 624 and the second ball head 6126. The above structure is simple and easy to connect.

As shown in Figures 4, 7, 8 and 11, in this embodiment, the coaxial twin-rotor UAV also includes: a pressure ring 130, the main shaft 10 is inserted into the pressure ring 130, the pressure ring 130 is fixed on the main shaft 10, and the automatic tilt device 61 is clamped between the pressure ring 130 and the bracket 90. Specifically, during assembly, the lower rotor assembly 30 is first connected to the lower motor rotor 52 with screws. The pressure ring 130 is inserted from the lower end face of the main shaft 10, and then the automatic tilt device 61 is inserted from the lower end face of the main shaft 10. Finally, the bracket 90 is inserted from the lower end face of the main shaft 10, and the automatic tilt device 61 is inserted from the lower end face of the main shaft 10. The nail is fixed on the main shaft 10. The lower end face of the center ball joint 611 of the automatic recliner 61 is in close contact with the upper end face of the bracket 90, and the upper end face of the center ball joint 611 is in close contact with the pressure ring of the automatic recliner 61. The pressure ring 130 is fixed with a set screw, so that the position of the center ball joint 611 is fixed. It should be noted that a pressure ring 130 is provided on the upper part of the automatic recliner 61. From the functional realization, the original function can still be realized without using the pressure ring 130. However, the use of the pressure ring 130 completely fixes the center ball joint 611 of the automatic recliner 61, thereby improving the rigidity and periodic pitch accuracy of the operating mechanism.

As shown in Figures 1 to 3, in this embodiment, the coaxial twin-rotor UAV further includes: a fuselage 150 and an automatic tilting device cover 180. The fuselage 150 is arranged on the main shaft 10; the automatic tilting device cover 180 is arranged outside the automatic tilting device 61 and fixed to the fuselage 150. The above structure can protect the automatic tilting device 61 from damage, and prevent water vapor and dust from contacting the automatic tilting device 61, thereby improving the reliability and life of the twin-rotor UAV. Preferably, in this embodiment, the fuselage 150 is connected to the main shaft 10 through a bracket 90.

As shown in Figures 4 and 6, in this embodiment, the upper rotor blade 25 is hinged to the upper hub 22 through a vertically extending screw. The hinge structure is an upper rotor swing hinge, which enables the upper rotor blade 25 to swing and improve the flight performance of the drone.

As shown in Figures 2 and 4 to 9, the upper hub 22 includes an upper connecting frame 221, two upper extension handles 222 and two first paddle clips 223. The upper connecting frame 221 includes two first frame frames 2211 arranged opposite to each other and two second frame frames 2212 arranged opposite to each other between the two first frame frames 2211. The main shaft 10 is passed through a central hole surrounded by the first frame frame 2211 and the second frame frame 2212. The two upper extension handles 222 are respectively connected to the two first frame frames 2211. There are two central hinge pins 23, and the two central hinge pins 23 are respectively arranged on the second frame frame 2212. The two first paddle clips 223 are respectively hinged to the ends of the two upper extension handles 222 through the first folding pin 224. The first folding pin 224 extends along the second horizontal direction. The upper rotor blade 25 is connected to the rotor blade 25 through the first folding pin 224. The first folding pin 224 is hinged to the first blade clamp 223 by a screw. The first folding pin 224 is a folding hinge when the blade is stored. The above structure enables the drone to fold down when the upper rotor blade 25 is not in use, thereby reducing the storage space occupied by the drone.

As shown in Figures 4 to 8 and 10, in this embodiment, the lower rotor assembly 30 includes: a lower hinge seat 31, a lower hub 32, a fifth bearing 33 (two ball bearings) and a lower rotor blade 34. Among them, the main shaft 10 is passed through the lower hinge seat 31, and the lower hinge seat 31 is drivingly connected to the lower motor 50. The lower hub 32 extends along the third horizontal direction, and the lower hub 32 is hinged to the lower hinge seat 31 through a transverse axis 323, and the transverse axis 323 extends along the third horizontal direction. The automatic tilt device 61 is drivingly connected to the lower hub 32. The fifth bearing 33 is arranged between the lower hinge seat 31 and the transverse axis 323. The lower rotor blade 34 is hinged to the lower hub 32 through a vertically extending screw. Specifically, the transverse axis 323 serves as a lower rotor pitch hinge.

As shown in Figures 4 to 8 and 10, in this embodiment, the lower hub 32 includes a lower connecting frame 321 and two lower extension handles 322, the lower connecting frame 321 includes two third frames 3211 arranged opposite to each other and two fourth frames 3212 arranged opposite to each other between the two third frames 3211, the main shaft 10 is passed through the center hole surrounded by the third frame 3211 and the fourth frame 3212, the two lower extension handles 322 are respectively connected to the two third frames 3211, there are two transverse axes 323, and the two transverse axes 323 are respectively arranged on the third frames 3211, and the automatic tilt device 61 From inside to outside, it includes: a central ball joint 611, a fixed ring 612, a third bearing 613 and a dynamic ring 614. The main shaft 10 is inserted into the central ball joint 611. The drive device 62 includes a first servo 621 and a second servo 622. The two fourth frames 3212 are each provided with a cylindrical hinge 3213. The dynamic ring 614 is provided with a third ball head 616 at a position corresponding to the cylindrical hinge 3213. There are two pitch rods 100, and the first ends of the two pitch rods 100 are respectively hinged to the two cylindrical hinges 3213, and the second ends of the two pitch rods 100 are respectively connected to the two third ball heads 616. Specifically, in the present embodiment, one end of the pitch rod 100 is hinged to the third ball head 616, and the other end is hinged to the lower hub 32 using a cylindrical hinge. In this way, The dynamic ring 614 of the automatic tilt device 61 will rotate together with the lower rotor assembly 30. Due to the cylindrical hinge effect of the pitch change rod 100, the pitch change mechanism will not be torsionally deformed.

As shown in Figures 4 and 8, in this embodiment, the lower rotor blade 34 is hinged to the lower hub 32 via a vertically extending screw. The hinge structure is a lower rotor swing hinge, which enables the lower rotor blade 34 to swing and improve the flight performance of the drone.

As shown in FIG. 4 and FIG. 8 , in this embodiment, the lower propeller hub 32 includes: a lower propeller hub body 324 and two second propeller clamps 325 arranged at opposite ends of the lower propeller hub body 324, the second propeller clamps 325 are hinged to the lower propeller hub body 324 through a second folding pin 326, the second folding pin 326 extends along a fourth horizontal direction, the fourth horizontal direction is perpendicular to the third horizontal direction, and the lower rotor blade 34 is hinged to the second propeller clamp 325 through a screw. The second folding pin 326 is a folding hinge when the blade is stored. The above structure enables the drone to fold downward when the lower rotor blade 34 is not in use, thereby reducing the storage space occupied by the drone.

It should be noted that the first servo 621 and the second servo 622 drive the automatic tilt device 61 through the first rocker arm 623, the second rocker arm 624, the first connecting rod 110 and the second connecting rod 120, and the automatic tilt device 61 drives the pitch change pull rod 100 to perform cyclic pitch change operations in the horizontal, vertical and longitudinal and horizontal and longitudinal linkage on the lower rotor assembly 30. The cyclic pitch change motion of the lower rotor can realize the flight of the drone left and right, front and back, and in any direction.

As shown in Figures 1 to 3, in this embodiment, the coaxial twin-rotor drone also includes: a battery module 140, a fuselage 150, and a pod module 160. Among them, the battery module 140 is arranged on the main shaft 10. The fuselage 150 is arranged on the main shaft 10. The pod module 160 includes a camera, and the pod module 160 is arranged on the fuselage 150. The above structure makes the battery and the pod form a modular design, which is easier to assemble and maintain. It should be noted that the battery module 140 and the pod module 160 are connected to the fuselage 150 in a modular design. connections, including structural and electrical connections.

It should be noted that, in this embodiment, the battery module 140 includes a battery body and a battery bracket. The battery bracket is fixed to the main shaft 10 by screws, and its lower end surface is tightly attached to the inner ring of the upper motor rotor 42 of the upper motor 40 to prevent the upper motor rotor 42 from axial movement.

As shown in Figures 1 to 3, in this embodiment, the coaxial twin-rotor UAV further includes: a landing gear 170, which is arranged on the fuselage 150. The above structure enables the coaxial twin-rotor UAV to land smoothly when landing. Preferably, the landing gear 170 is a rear three-point type, fixed on the fuselage 150.

As shown in Figure 8, in this embodiment, the main shaft 10 is a hollow shaft, the inner hole of the main shaft 10 extends to the fuselage 150, and the side wall of the main shaft 10 is provided with a wire entry hole 11 connected to the inner hole of the main shaft 10, and the wire entry hole 11 is located between the upper motor 40 and the lower motor 50. Specifically, both ends of the main shaft 10 are through holes, and side holes are provided thereon. The power supply cable passes through the hollow main shaft 10 to the fuselage 150 to supply power to the entire machine and onboard equipment. The motor wiring harness passes through the wire entry hole 11 and the bottom hole of the main shaft 10 to the fuselage 150 to connect the motor driver. The above structure is simple, convenient for threading, and the wires are not easily damaged.

It should be noted that the UAV in this embodiment is a micro or light coaxial biplane UAV.

Unless otherwise specifically stated, the relative arrangement of the components and steps, the numerical expressions and numerical values described in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for ease of description, the dimensions of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be regarded as part of the authorized specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain If an item is defined in one figure, it need not be discussed further in subsequent figures.

For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

A coaxial twin-rotor UAV, characterized by comprising:

Spindle (10);

An upper rotor assembly (20) is pivotally mounted on the main shaft (10);

A lower rotor assembly (30) is pivotally mounted on the main shaft (10);

An upper motor (40) is arranged on the main shaft (10), and the upper motor (40) is drivingly connected to the upper rotor assembly (20);

A lower motor (50) is arranged on the main shaft (10), the lower motor (50) is drivingly connected to the lower rotor assembly (30), and the upper rotor assembly (20) and the lower rotor assembly (30) rotate in opposite directions;

A rotor control device (60) is arranged on the main shaft (10), and the rotor control device (60) is drivingly connected to the lower rotor assembly (30) to perform cyclic pitch control on the lower rotor assembly (30).
The coaxial twin-rotor UAV according to claim 1, characterized in that the upper motor (40) comprises:

Upper motor body;

A first stator seat is fixedly arranged on the main shaft (10), and the upper motor body is fixed on the first stator seat;

An upper motor rotor (42), wherein the first stator seat supports the upper motor rotor (42), the upper motor rotor (42) cooperates with the main shaft (10) via a first bearing (43), and the upper motor rotor (42) is drivingly connected to the upper rotor assembly (20).
The coaxial twin-rotor UAV according to claim 1 or 2, characterized in that the lower motor (50) comprises:

Lower motor body;

A second stator seat is fixedly arranged on the main shaft (10), and the lower motor body is fixed on the second stator seat;

The lower motor rotor (52) is matched with the main shaft (10) through a second bearing (53), and the lower motor rotor (52) is drivingly connected to the lower rotor assembly (30).
The coaxial twin-rotor UAV according to claim 3 is characterized in that, when the upper motor (40) includes the first stator seat, the upper motor (40) and the lower motor (50) are located between the upper rotor assembly (20) and the lower rotor assembly (30), and the first stator seat and the second stator seat are the same common stator seat (70).
The coaxial twin-rotor UAV according to claim 4, characterized in that the coaxial twin-rotor UAV further comprises:

A motor cover (80) is arranged outside the upper motor (40) and the lower motor (50), and the motor cover (80) is fixed on the common stator seat (70).
The coaxial twin-rotor UAV according to claim 3 is characterized in that the lower rotor assembly (30) includes a lower rotor assembly body arranged on the lower motor rotor (52) and a needle bearing (190), and the needle bearing (190) is located between the lower rotor assembly body and the main shaft (10).
The coaxial twin-rotor UAV according to claim 1, characterized in that the rotor control device (60) comprises:

An automatic tilt device (61) is arranged on the main shaft (10) and connected to the lower rotor assembly (30);

The driving device (62) drives the lower rotor assembly (30) to move via the automatic tilt device (61).
The coaxial twin-rotor UAV according to claim 7 is characterized in that the automatic tilt device (61) comprises, from inside to outside: a central ball joint (611), a fixed ring (612), a third bearing (613) and a dynamic ring (614), the main shaft (10) is inserted into the central ball joint (611), the driving device (62) comprises a first steering gear (621) and a second steering gear (622), and the coaxial twin-rotor UAV further comprises:

A bracket (90) is arranged on the main shaft (10); the first steering gear (621) and the second steering gear (622) are fixed on the bracket (90); a limiting structure is arranged on the bracket (90); and a vertical slide groove (91) is arranged on the limiting structure;

A pitch-changing pull rod (100) connecting the dynamic ring (614) and the lower rotor assembly (30);

A first connecting rod (110) connected between the first steering gear (621) and the stationary ring (612);

The second connecting rod (120) is connected between the second steering gear (622) and the fixed ring (612), and the fixed ring (612) is provided with a limiting protrusion (615) that cooperates with the sliding groove (91).
The coaxial twin-rotor UAV according to claim 8, characterized in that the first steering gear (621) is a pitch steering gear, the second steering gear (622) is a roll steering gear, and the upper rotor assembly (20) comprises:

An upper hinge seat (21), the main shaft (10) is passed through the upper hinge seat (21), and the upper hinge seat (21) is drivingly connected to the upper motor (40);

The upper propeller hub (22) extends along a first horizontal direction, the upper propeller hub (22) is hinged to the upper hinge seat (21) via a central hinge pin (23), the central hinge pin (23) extends along a second horizontal direction, and the first The horizontal direction is perpendicular to the second horizontal direction;

A fourth bearing (24) is disposed between the upper hinge seat (21) and the central hinge pin (23);

The upper rotor blade (25) is connected to the upper hub (22).
The coaxial twin-rotor drone according to claim 9 is characterized in that the stationary ring (612) includes a stationary ring body (6121) and a first extension arm (6122), a second extension arm (6123) and a third extension arm (6124) which are arranged on the stationary ring body (6121) and extend outward, the first connecting rod (110) is connected to the first extension arm (6122), the second connecting rod (120) is connected to the second extension arm (6123), and the limiting boss ( 615) is arranged on the third extension arm (6124), the position of the limiting boss (615) is taken as 0° of the UAV azimuth angle Ψ, the first extension arm (6122) extends in the direction of 135° of the UAV azimuth angle Ψ, the second extension arm (6123) extends in the direction of 225° of the UAV azimuth angle Ψ, the longitudinal section of the UAV azimuth angle Ψ of 0° is taken as the reference plane, and the first steering gear (621) and the second steering gear (622) are symmetrically arranged on both sides of the reference plane.
The coaxial twin-rotor UAV according to claim 10 is characterized in that a first ball head (6125) is provided at the end of the first extension arm (6122), and a second ball head (6126) is provided at the end of the second extension arm (6123), and the driving device (62) also includes a first rocker arm (623) and a second rocker arm (624), and the first rocker arm (623) and the second rocker arm (624) are respectively connected to the first steering gear (621) and the second steering gear (622) through splines, the first connecting rod (110) connects the first rocker arm (623) and the first ball head (6125), and the second connecting rod (120) connects the second rocker arm (624) and the second ball head (6126).
The coaxial twin-rotor UAV according to claim 8 is characterized in that the coaxial twin-rotor UAV also

include:

A pressure ring (130), the main shaft (10) is inserted into the pressure ring (130), the pressure ring (130) is fixed on the main shaft (10), and the automatic tilt device (61) is clamped between the pressure ring (130) and the bracket (90).
The coaxial twin-rotor UAV according to claim 7, characterized in that the coaxial twin-rotor UAV further comprises:

A body (150) is arranged on the main shaft (10);

An automatic tilting device cover (180) is arranged outside the automatic tilting device (61) and is connected to the body (150). fixed.
The coaxial twin-rotor UAV according to claim 1, characterized in that the upper rotor assembly (20) comprises:

An upper hinge seat (21), the main shaft (10) is passed through the upper hinge seat (21), and the upper hinge seat (21) is drivingly connected to the upper motor (40);

An upper propeller hub (22) extends along a first horizontal direction, the upper propeller hub (22) is hinged to the upper hinge seat (21) via a central hinge pin (23), the central hinge pin (23) extends along a second horizontal direction, and the first horizontal direction is perpendicular to the second horizontal direction;

A fourth bearing (24) is disposed between the upper hinge seat (21) and the central hinge pin (23);

The upper rotor blade (25) is hinged to the upper hub (22) via a vertically extending screw.
The coaxial twin-rotor drone according to claim 14 is characterized in that the upper hub (22) comprises an upper connecting frame (221), two upper extension handles (222) and two first blade clamps (223), the upper connecting frame (221) comprises two first frame borders (2211) arranged opposite to each other and two second frame borders (2212) arranged opposite to each other between the two first frame borders (2211), and the main shaft (10) is passed through a central hole surrounded by the first frame border (2211) and the second frame border (2212). The two upper extension handles (222) are respectively connected to the two first frame frames (2211); there are two central hinge pins (23), and the two central hinge pins (23) are respectively arranged on the second frame frames (2212); the two first paddle clamps (223) are respectively hinged to the ends of the two upper extension handles (222) through first folding pins (224); the first folding pins (224) extend along the second horizontal direction; and the upper rotor blade (25) is hinged to the first paddle clamp (223) through the screw.
The coaxial twin-rotor UAV according to claim 7, characterized in that the lower rotor assembly (30) comprises:

A lower hinge seat (31), the main shaft (10) is passed through the lower hinge seat (31), and the lower hinge seat (31) is drivingly connected to the lower motor (50);

A lower propeller hub (32) extends along a third horizontal direction, the lower propeller hub (32) is hinged to the lower hinge seat (31) via a transverse axis (323), the transverse axis (323) extends along the third horizontal direction, and the automatic tilt device (61) is drivingly connected to the lower propeller hub (32);

a fifth bearing (33), disposed between the lower hinge seat (31) and the transverse axis (323);

The lower rotor blade (34) is hinged to the lower hub (32) via a vertically extending screw.
The coaxial twin-rotor drone according to claim 16, characterized in that the lower propeller The hub (32) comprises a lower connecting frame (321) and two lower extending handles (322), the lower connecting frame (321) comprises two third frame frames (3211) arranged opposite to each other and two fourth frame frames (3212) arranged opposite to each other between the two third frame frames (3211), the main shaft (10) is passed through a central hole surrounded by the third frame frames (3211) and the fourth frame frames (3212), the two lower extending handles (322) are respectively connected to the two third frame frames (3211) and the fourth frame frames (3212). ), there are two transverse axes (323), and the two transverse axes (323) are respectively arranged on the third frame (3211), the automatic tilt device (61) comprises from the inside to the outside: a central ball joint (611), a fixed ring (612), a third bearing (613) and a dynamic ring (614), the main shaft (10) is inserted into the central ball joint (611), the driving device (62) comprises a first steering gear (621) and a second steering gear (622), and the coaxial twin-rotor UAV further comprises:

A bracket (90) is arranged on the main shaft (10); the first steering gear (621) and the second steering gear (622) are fixed on the bracket (90); a limiting structure is arranged on the bracket (90); and a vertically extending slide groove (91) is arranged on the limiting structure;

A first connecting rod (110) connected between the first steering gear (621) and the stationary ring (612);

A second connecting rod (120) is connected between the second steering gear (622) and the fixed ring (612); a limiting convex column (615) cooperating with the slide groove (91) is provided on the fixed ring (612); a cylindrical hinge (3213) is provided on the two fourth frames (3212); and a third ball head (616) is provided at a position of the movable ring (614) corresponding to the cylindrical hinge (3213);

Two variable distance pull rods (100), wherein the first ends of the two variable distance pull rods (100) are respectively hinged to the two cylindrical hinges (3213), and the second ends of the two variable distance pull rods (100) are respectively connected to the two third ball heads (616).
The coaxial twin-rotor UAV according to claim 1, characterized in that the lower rotor assembly (30) comprises:

A lower hinge seat (31), the main shaft (10) is passed through the lower hinge seat (31), and the lower hinge seat (31) is drivingly connected to the lower motor (50);

A lower propeller hub (32) extends along a third horizontal direction, the lower propeller hub (32) is hinged to the lower hinge seat (31) via a transverse axis (323), the transverse axis (323) extends along the third horizontal direction, and the rotor control device (60) is drivingly connected to the lower propeller hub (32);

a fifth bearing (33), disposed between the lower hinge seat (31) and the transverse axis (323);

The lower rotor blade (34) is hinged to the lower hub (32) via a vertically extending screw.
The coaxial twin-rotor drone according to claim 18, characterized in that the lower propeller The hub (32) includes: a lower propeller hub body (324) and two second propeller clamps (325) arranged at opposite ends of the lower propeller hub body (324), the second propeller clamps (325) being hinged to the lower propeller hub body (324) via a second folding pin (326), the second folding pin (326) extending along a fourth horizontal direction, the fourth horizontal direction being perpendicular to the third horizontal direction, and the lower rotor blade (34) being hinged to the second propeller clamps (325) via the screw.
The coaxial twin-rotor UAV according to claim 1, characterized in that the coaxial twin-rotor UAV further comprises:

A battery module (140) is arranged on the main shaft (10);

A body (150) is arranged on the main shaft (10);

The pod module (160) comprises a camera, and the pod module (160) is arranged on the fuselage (150).
The coaxial twin-rotor UAV according to claim 1, characterized in that the coaxial twin-rotor UAV further comprises:

A body (150) is arranged on the main shaft (10);

The landing gear (170) is arranged on the fuselage (150).
The coaxial twin-rotor UAV according to claim 1, characterized in that the main shaft (10) is a hollow shaft, and the coaxial twin-rotor UAV further comprises:

A body (150) is arranged on the main shaft (10), and the inner hole of the main shaft (10) extends to the body (150). A wire inlet hole (11) connected to the inner hole of the main shaft (10) is arranged on the side wall of the main shaft (10), and the wire inlet hole (11) is located between the upper motor (40) and the lower motor (50).