A coaxial drone

Abstract

The application provides a coaxial unmanned aerial vehicle, which comprises a main shaft, a rotor structure, a variable-pitch structure and a landing gear structure, the rotor structure comprises a power assembly, a hub and a plurality of groups of blades, the power assembly drives the hub to rotate to generate centrifugal force to unfold the blades, and a limiting piece is arranged between the hub and the blades to limit the rotation of the unfolded blades to folding; the variable-pitch structure comprises a tilting device and a plurality of groups of steering engines, a total pitch piece is arranged between the tilting device and the blades, a variable-pitch piece connected with the tilting device is arranged on the output end of each group of steering engines, the steering engine drives the variable-pitch piece to move to make the tilting device tilt or move up and down along the main shaft, and the blades rotate along the axial direction of the main shaft; the landing gear structure comprises a plurality of groups of supporting pieces, and the supporting pieces and the main shaft are provided with a reset piece for resetting the supporting pieces from a folded state to a supporting state; the application has the advantages that the take-off mode is suitable for the launching of a cannon barrel, and compared with the existing unmanned aerial vehicle, the take-off mode of the coaxial unmanned aerial vehicle is more diversified.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of unmanned aerial vehicle, more particularly to a coaxial unmanned aerial vehicle. BACKGROUND

[0002] Unmanned aerial vehicle refers to a pilotless aircraft that is controlled by radio remote control equipment and self-provided program control device, including civilian unmanned aerial vehicle and military unmanned aerial vehicle. With the development of technology, the technology of unmanned aerial vehicle is gradually mature, and its specific application is in the fields of aerial photography, agriculture, plant protection, micro-selfie, express delivery, disaster rescue, observation of wild animals, monitoring of infectious diseases, surveying and mapping, news reporting, power patrol, disaster relief, film shooting, romance making, etc.

[0003] The current mainstream unmanned aerial vehicle mainly relies on the rotation of its rotor to generate lift, and the bottom support is fixed on the unmanned aerial vehicle to support. This kind of unmanned aerial vehicle needs to reserve a certain time to make the rotor rotate to a certain speed when taking off, and if the unmanned aerial vehicle needs to take off to a certain height, it takes a long time, which is difficult to meet the take-off purpose in some specific situations. SUMMARY

[0004] In view of the deficiencies in the prior art, the purpose of the present application is to provide a coaxial unmanned aerial vehicle. The rotor part, tilting device linkage part and landing gear structure part of the unmanned aerial vehicle are suitable for the take-off mode of cannon barrel launching, and the take-off mode of the coaxial unmanned aerial vehicle is more diversified compared with the existing unmanned aerial vehicle.

[0005] To achieve the above purpose, the present application provides the following technical scheme:

[0006] A coaxial unmanned aerial vehicle comprises a main shaft, a rotor structure, a variable pitch structure and a landing gear structure. The rotor structure comprises an upper rotor part and a lower rotor part. The upper rotor part and the lower rotor part each comprise a power set, a hub and a plurality of sets of blades. The hub is sleeved on the main shaft, and a plurality of sets of blades are rotationally connected to the hub. The power set drives the hub to rotate to generate centrifugal force to expand the blades. A limiting piece is arranged between the hub and the blades to limit the rotation of the expanded blades to folding.

[0007] The variable pitch structure comprises a tilting device and a plurality of sets of steering machines. A total pitch piece is arranged between the tilting device and the blades. A variable pitch piece connected with the tilting device is arranged on the output end of each set of steering machines. The steering machine drives the variable pitch piece to move to make the tilting device tilt or move up and down along the main shaft, and the blades rotate along the axial direction of the main shaft.

[0008] The landing gear structure comprises a plurality of sets of support members, each of the sets of support members is rotationally connected to the bottom end of the main shaft, so that the landing gear has a folding state and a supporting state, and the support member and the main shaft have a reset member for resetting the support member from the folding state to the supporting state.

[0009] Further, a flap hinge is fixedly arranged on the connecting end of the paddle and the paddle hub, the flap hinge is rotationally connected to the paddle hub, the limiting member is two sets of extension springs, one end of the two sets of extension springs is respectively connected to the two sides of the flap hinge, and the other end is respectively connected to the paddle hub, and when the paddle is switched from the folding state to the extended state, the extension length of the extension spring gradually decreases.

[0010] Further, a total distance adjusting member is rotationally connected to the connecting end of the paddle hub and the flap hinge, the total distance adjusting member comprises a total distance hinge, an adapter and a variable distance shaft, the flap hinge is rotationally connected to the total distance hinge, the total distance hinge is rotationally connected to the adapter, the adapter is fixedly connected to the paddle hub, and one end of the variable distance shaft is fixedly arranged in the adapter and the other end extends into the total distance hinge and is connected to the total distance hinge bearing.

[0011] Further, the inclinator comprises a rotating ring, a fixed ring and a deep groove ball bearing, the fixed ring is sleeved on the main shaft, the rotating ring is rotationally connected to the fixed ring through the deep groove ball bearing, the total distance member is connected to the rotating ring, and the variable distance member is connected to the fixed ring.

[0012] Further, the variable distance member comprises a rotating plate and a variable distance pull rod, one end of the rotating plate is connected to the output end of the rudder machine, the other end is connected to the variable distance pull rod, and the end of the variable distance pull rod away from the rotating plate is connected to the fixed ring.

[0013] Further, the outer side of the fixed ring is provided with a protruding connecting part, and the variable distance pull rod and the connecting part are connected through a ball joint.

[0014] Further, a radial spherical surface sliding bearing is further arranged between the fixed ring and the main shaft.

[0015] Further, a support is further arranged on the main shaft, the rudder machine is arranged on the support, a limiting plate is vertically arranged on the support, a limiting slide is arranged on the limiting plate, and one end of any one set of variable distance pull rods is provided with a sliding rod which is slidingly connected in the limiting slide.

[0016] Further, the total distance member comprises a total distance pull rod and a connecting arm, the total distance pull rod and the connecting arm are rotationally connected, the other end of the total distance pull rod is connected to the fixed ring, and the other end of the connecting arm is connected to the total distance hinge.

[0017] Further, the support piece comprises a support leg and a hinge seat, the upper surface of the hinge seat is fixed on the bottom of the unmanned aerial vehicle body, the reset piece comprises a spring pin, the spring pin is located in the hinge seat, the spring pin comprises a shell and a pin head and a spring located in the shell, the spring applies a spring force to the pin head to make the pin head pop out of the shell, and the pin head pops out the support leg in the folded state to the support state.

[0018] The beneficial effects of the present application are: 1. The paddle is rotationally connected to the hub, which can switch the paddle between the folded state and the stretched state, so as to adapt to the cannon ejection type take-off mode of the unmanned aerial vehicle, and the extension spring is arranged to avoid the paddle switching from the stretched state to the folded state; compared with the existing manual folding paddle mode, the present application switches the folded state of the unmanned aerial vehicle to the stretched state by the centrifugal force generated by the rotation of the hub, which is simple and more suitable for the cannon ejection type take-off mode.

[0019] 2. A plurality of steering gears drive corresponding variable-pitch pull rods to move in the vertical direction, so that the inclinators are inclined to one side or the inclinators are moved up or down as a whole, and the rotating ring on the inclinator and the rotor are provided with a total-pitch pull rod, which rotates relative to the fixed ring of the inclinator with the rotation of the rotor, avoiding the influence of the variable-pitch pull rod due to the rotation of the rotor, and the inclination of the inclinator realizes the periodic variable-pitch of the rotor, and the up and down movement of the inclinator realizes the variable total-pitch of the rotor, which aims to drive two opposite paddles to tilt to one side or to the opposite direction. This structure makes the unmanned aerial vehicle more stable when turning or adjusting the flight angle.

[0020] 3. The support leg is rotationally connected to the bottom of the unmanned aerial vehicle body, and the reset piece is arranged to make the support leg pop from the folded state to the support state when the unmanned aerial vehicle is launched in the cannon to the air, when the reset piece is a spring pin, the support leg is pressed by the pin head after being in the support state, so that the support leg will not rotate even if the unmanned aerial vehicle lands and presses the support leg. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is the overall structure diagram of the coaxial unmanned aerial vehicle;

[0022] Figure 2 It is the structure diagram of the upper rotor part of the present application;

[0023] Figure 3 It is the structure diagram of the lower rotor part of the present application;

[0024] Figure 4 It is the sectional view of the upper rotor part in the present application;

[0025] Figure 5 It is the overall diagram of the inclinator and the steering gear in the present application;

[0026] Figure 6 is a sectional view of the tilting device in the application;

[0027] Figure 7 is a structural view of the support in the application.

[0028] Fig. 1 is a main shaft; Fig. 2 is an upper rotor part; Fig. 3 is a lower rotor part; Fig. 4 is a hub; Fig. 5 is a blade; Fig. 6 is a power group; Fig. 7 is a tilting device; Fig. 7 1 is a rotating ring; Fig. 7 2 is a fixed ring; Fig. 7 3 is a deep groove ball bearing; Fig. 8 is a rudder; Fig. 9 is a total distance piece; Fig. 9 1 is a total distance pull rod; Fig. 9 2 is a connecting arm; Fig. 10 is a variable pitch piece; Fig. 10 1 is a rotating piece; Fig. 10 2 is a variable pitch pull rod; Fig. 11 is a support; Fig. 12 is a flap hinge; Fig. 13 is a tension spring; Fig. 14 is a total distance hinge; Fig. 15 is an adapter; Fig. 16 is a variable pitch shaft; Fig. 17 is a connecting part; Fig. 18 is a radial spherical sliding bearing; Fig. 19 is a bracket; Fig. 21 is a limiting plate; Fig. 22 is a limiting slide; Fig. 23 is a slide rod; Fig. 24 is a supporting leg; Fig. 25 is a hinged seat; Fig. 26 is a supporting part; Fig. 27 is a folding part; Fig. 28 is a spring pin; Fig. 29 is a pin head; Fig. 30 is a first connecting column; Fig. 31 is a second connecting column. DETAILED DESCRIPTION

[0029] The application will be further described in detail below in combination with the drawings and examples. Identical parts are denoted by identical reference numerals in the following description. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings, and the words "bottom surface" and "top surface", "inner" and "outer" refer to the directions towards or away from the geometric center of a particular part.

[0030] The current mainstream unmanned aerial vehicle mainly relies on the rotation of its rotor to generate lift for takeoff, and the bottom supporting leg 24 is fixed on the unmanned aerial vehicle to support it. This kind of unmanned aerial vehicle needs to reserve a certain time to make the rotor rotate to a certain speed when taking off, and if the unmanned aerial vehicle needs to take off to a certain height, it takes a long time, which is difficult to meet the takeoff purpose in some specific situations. Therefore, the application designs this kind of unmanned aerial vehicle which can be applied to the cannon barrel launching takeoff type coaxial unmanned aerial vehicle, as shown in Figure 1 The specific structure includes a main shaft 1, a rotor structure, a variable pitch structure and a landing gear structure. The main shaft 1 includes a plurality of mounting seats from top to bottom, and each component and structure is placed on the mounting seat. The top end of the main shaft 1 is provided with a GPS signal receiver and transmitter for signal transmission with an external control end to control the flight and steering of the unmanned aerial vehicle. The mounting seat above the landing gear structure is also provided with a power supply device for providing power, and the whole is arranged as a vertical cylindrical shape.

[0031] The current mainstream unmanned aerial vehicle rotor part includes two kinds, one is fixed on the four corners of the unmanned aerial vehicle, the other is foldable for storage, but the folded unmanned aerial vehicle needs to be manually folded to the horizontal state before flying, so it is not convenient, and for the barrel launching unmanned aerial vehicle, the rotor part of the unmanned aerial vehicle needs to be designed, therefore, the coaxial unmanned aerial vehicle is designed, and the specific structure is shown in Figures 1-4 The upper rotor part 2 and the lower rotor part 3 are sleeved on the main shaft 1, the upper rotor part 2 and the lower rotor part 3 each include a rotor group and a power group 6 (the power group 6 includes a motor, and an outer rotor of an electronic is sleeved on the outer side of the main shaft 1 and connected with the hub 4), the rotor group includes the hub 4 and a plurality of blade groups 5, each blade group 5 is rotationally connected to the outer side of the hub 4, the blade 5 has a folded state and an extended state, the folded state is that the blade 5 is parallel to the main shaft 1 (the folding of the blade 5 can be horizontal folding or vertical folding, the horizontal folding is that the folding shaft of the blade 5 is a vertical shaft, and the vertical folding is that the folding shaft of the blade 5 is a horizontal shaft, in order to adapt to the barrel launching take-off mode, the vertical folding is selected, and after the vertical folding, the blade 5 also can reduce the occupied space, is convenient for carrying, and is easy to put into the barrel and launch), the extended state is that the blade 5 is perpendicular to the main shaft 1, the power group 6 drives the hub 4 to rotate, so that the centrifugal force generated by the hub 4 switches the blade 5 from the folded state to the extended state, and the hub 4 and the blade 5 are further provided with a limiting piece for limiting the blade 5 from switching from the extended state to the folded state; the advantage of the present application is that the blade 5 is rotationally connected to the hub 4, so that the blade 5 can switch between the folded state and the extended state, so as to adapt to the barrel launching take-off mode, and the stretching spring 13 is arranged to avoid the blade 5 from switching from the extended state to the folded state; compared with the current manual folding blade 5 mode, the unmanned aerial vehicle of the present application switches from the folded state to the extended state through the centrifugal force generated by the rotation of the hub 4 to stretch the blade 5, which is simple and more suitable for the barrel launching take-off mode.

[0032] As Figure 2 And Figure 3As shown, the rotor group further comprises a flapping hinge 12 rotatably connected at one end to the hub 4 and fixedly connected at the other end to the blade 5, the limiting member is a tension spring 13, one end of the tension spring 13 is connected to the hub 4, and the other end is connected to the blade 5, the setting position of the tension spring 13 determines the folding direction of the blade 5, if one end of the tension spring 13 is connected to the upper surface of the hub 4 and the other end is connected to one side of the flapping hinge 12, then the blade 5 is folded downward, if one end of the tension spring 13 is connected to the lower surface of the hub 4 and the other end is connected to one side of the flapping hinge 12, then the blade 5 is folded upward, when the blade 5 is switched from the folded state to the stretched state, the extension length of the tension spring 13 gradually decreases, when the blade 5 is in the folded state, the tension spring 13 is in the maximum extension state, the tension spring 13 has a tension force, when the hub 4 rotates and generates a centrifugal force to throw out the blade 5, then the blade 5 is in the folded state, and the tension spring is tightened, the tension spring 13 is difficult to recover to the stretched state from the tightened state by the gravity of the blade 5, therefore, the blade 5 avoids recovering from the stretched state to the folded state during rotation, another embodiment is that when the blade 5 is between the folded and stretched states, the tension spring 13 is normally not extended, and the tension spring is in the stretched state during folding and unfolding, generates a holding force to keep the blade state.

[0033] As shown in Figure 2 and Figure 3 Since the upper rotor part 2 is located above the overall unmanned aerial vehicle, in order to adapt to the take-off mode of the barrel ejection, and facilitate the storage of the unmanned aerial vehicle, the blade 5 is selected to be folded downward, specifically, a first connecting column 30 is arranged on both sides of the connecting end of the flapping hinge 12 and the hub 4, a second connecting column 31 extending to both sides is arranged on the upper surface of the hub 4, a tension spring 13 is arranged on both sides of the flapping hinge 12, one end of the tension spring 13 is connected to the first connecting column 30, and the other end is connected to the second connecting column 31, the arrangement of the two tension springs 13 can improve the limiting effect and be more stable.

[0034] Since how to adjust the flight direction and flight angle after the current coaxial barrel ejection unmanned aerial vehicle takes off is a difficulty, the variable-pitch structure in the present application comprises a main shaft 1 and a variable-pitch assembly, specifically as Figure 1As shown, the variable pitch assembly includes a tilting device 7 and several groups of rudders 8 (including 3 groups of rudders 8 in the application), the tilting device 7 includes a rotating ring 71, a fixed ring 72 and a deep groove ball bearing 73, the fixed ring 72 is sleeved on the main shaft 1 (the rotating ring 71 can only move up and down and tilt front, back, left and right with the main shaft 1, specifically, the inner ring diameter of the fixed ring 72 can be larger than the diameter of the main shaft 1, or an adjusting structure is arranged), the up and down movement and the front, back, left and right tilt of the fixed ring 72 in the application are realized by the radial spherical sliding bearing 18, the fixed ring 72 is rotationally connected with the rotating ring 71 through the deep groove ball bearing 73, the outer ring of the rotating ring 71 is provided with a total pitch piece 9 connected with the rotor, the output end of each group of rudders 8 is provided with a variable pitch piece 10 connected with the fixed ring 72, the rudders 8 drive the variable pitch piece 10 to move to make the fixed ring 72 tilt or move up and down along the main shaft 1, after the fixed ring 72 tilts or moves, the rotating ring 71 on the fixed ring 72 will also be offset or moved, then the total pitch piece 9 connected with the rotating ring 71 can drive the corresponding paddle 5 to realize deflection, and the effect is that the tilt of the tilting device 7 realizes the cyclic variable pitch of the rotor, and the up and down movement of the tilting device 7 realizes the variable total pitch of the rotor, the purpose is to drive two opposite paddles 5 to cut to one side or tilt to the opposite direction, and the structure makes the unmanned aerial vehicle more stable when turning or adjusting the flight angle.

[0035] As shown in the figure, Figure 5 In the application, there are three groups of variable pitch pieces 10, each group of variable pitch piece 10 includes a rotating piece 101 and a variable pitch pull rod 102, one end of the rotating piece 101 is connected with the output end of the rudder 8, the other end is connected with the variable pitch pull rod 102 through the ball joint, the end of the variable pitch pull rod 102 away from the rotating piece 101 is connected with the fixed ring 72, the outer side of the fixed ring 72 is provided with a protruding connecting part 17, the connecting part 17 includes a first part and a second part which are integrally formed, and the first part and the second part have an included angle, when the included angle is 120°, the fixed ring 72 is most stable when pulled up and down by the variable pitch pull rod 102, and the variable pitch pull rod 102 is connected with the connecting part 17 through the ball joint.

[0036] As shown in the figure, Figure 5 The main shaft 1 is also provided with a support 19, the support 19 is an upper support seat and a lower support seat, the rudders 8 are located between the upper support seat and the lower support seat, a limiting plate 21 is vertically arranged on the upper support seat, a limiting slide 22 is arranged on the limiting plate 21, one end of any one group of variable pitch pull rods 102 is provided with a sliding rod 23 which is slidingly connected in the limiting slide 22, the limiting slide 22 is mainly arranged to limit the variable pitch pull rod 102, when the rudders 8 drive the variable pitch pull rod 102, the variable pitch pull rod 102 can always move in the vertical direction, the limiting plate 21 plays two limiting roles, one is the tilt of the tilting device 7, and the other is to prevent the fixed ring 72 from rotating.

[0037] As shown in the figure, Figure 5 andFigure 6 As shown, the total pitch distance piece 9 comprises a total pitch distance pull rod 91 and a connecting arm 92, the total pitch distance pull rod 91 and the connecting arm 92 are rotationally connected in the application, the total pitch distance pull rod 91 and the connecting arm 92 are perpendicular to each other in the initial state, one end of the total pitch distance pull rod 91 is connected with the rotating ring 71, the other end of the connecting arm 92 is connected with the rotor, in order to realize that the upper rotor can change the rotating speed and can change the total pitch distance and the cyclic pitch distance, therefore the rotor part comprises a total pitch distance hinge 14, a connecting piece 15, a pitch distance shaft 16 and a blade 5, the blade 5 is rotationally connected with the total pitch distance hinge 14, the total pitch distance hinge 14 is rotationally connected with the connecting piece 15 (the rotating direction of the blade 5 and the total pitch distance hinge 14 is the first direction, the rotating direction of the total pitch distance hinge 14 and the connecting piece 15 is the second direction, the first direction and the second direction are perpendicular to each other), the connecting piece 15 is fixedly connected on the hub 4, one end of the pitch distance shaft 16 is fixedly located in the connecting piece 15, the other end extends into the total pitch distance hinge 14 and is bearing connected with the total pitch distance hinge 14, the total pitch distance pull rod 91 is connected on one side of the total pitch distance hinge 14, the pitch distance principle is that the total pitch distance pull rod 91 moves in the vertical direction, the connecting arm 92 rotates relative to the total pitch distance pull rod 91, the connecting arm 92 can drive the total pitch distance hinge 14 to rotate around the pitch distance shaft 16, so as to realize the rotation of the blade 5.

[0038] Since the current mainstream unmanned aerial vehicle mainly relies on the rotation of its rotor to generate lift, the bottom support 24 is fixed on the unmanned aerial vehicle to support, this kind of unmanned aerial vehicle needs to reserve a certain time to make the rotor rotate to a certain rotating speed when taking off, and if the unmanned aerial vehicle needs to take off to a certain height, it takes a long time, therefore for the unmanned aerial vehicle taking off in some special places, the cannon barrel type taking off method is applied, the unmanned aerial vehicle is ejected to a certain height through the cannon barrel, and then taking off, but the setting of the unmanned aerial vehicle landing gear of this kind of method has a certain difficulty, therefore the landing gear structure is designed in the application, and the specific structure is as follows Figure 7As shown, the landing gear includes a plurality of sets of supports 11, the landing gear in the application includes 4 sets of supports 11, each set of supports 11 is evenly distributed on the outer edge of the bottom of the unmanned aerial vehicle body, a plurality of sets of supports 11 and the unmanned aerial vehicle body are rotationally connected to make the landing gear have a folding state and a supporting state, the supports 11 and the unmanned aerial vehicle body have a reset member for resetting the supports 11 from the folding state to the supporting state, the foot 24 is rotationally connected to the bottom of the unmanned aerial vehicle body, and the reset member is further provided to enable the reset member to pop the foot 24 from the folding state to the supporting state when the unmanned aerial vehicle is launched in the barrel to the air. This structure is suitable for barrel launching. Specifically, the support 11 includes a foot 24 and a hinge seat 25, the upper surface of the hinge seat 25 is fixed to the bottom of the unmanned aerial vehicle body, and the foot 24 is hinged to the hinge seat 25. When the landing gear is in the folding state, the foot 24 is tightly attached to the outer side of the unmanned aerial vehicle body. When the landing gear is in the supporting state, the foot 24 has a supporting angle with the unmanned aerial vehicle body, and the supporting angle is between 120°-145°. When the supporting angle is 120°, the unmanned aerial vehicle should be most stable when landing.

[0039] Embodiment 1:

[0040] As shown in Figure 7 , the foot 24 includes a supporting part 26 and a folding part 27, one end of the folding part 27 is hinged to the hinge seat 25, the other end is connected to the supporting part 26, and the reset member includes a spring pin 28 (the specific model of the spring pin 28 is a buckle lock dk634). The spring pin 28 is located in the hinge seat 25, and the spring pin 28 includes a shell, a pin head 29 and a spring located in the shell. The spring applies a spring force to the pin head 29 to make the pin head 29 pop out of the shell, and the pin head 29 pops out the folding part 27 in the folding state to the supporting state. When the unmanned aerial vehicle is located in the launch barrel, the folding part 27 is tightly attached to the outer surface of the unmanned aerial vehicle body in the folding state. At this time, the pin head 29 is compressed inwardly. When the barrel launches the unmanned aerial vehicle to the air, the pin head 29 is pushed outwardly by the spring force to act on the folding part 27, so that the foot 24 is in the supporting state. The limiting torsional spring can play the role of shock absorption and buffering.

[0041] As shown in Figure 7 , when the unmanned aerial vehicle body lands, in order to avoid the rotation of the foot 24, therefore the pin head 29 is a right triangular prism, when the landing gear is in the folding state, the straight side surface of the pin head 29 abuts at the end of the folding part 27, and the inclined side surface of the pin head 29 is parallel to the folding part 27. At this time, the folding part 27 is clamped and cannot rotate.

[0042] Embodiment 2:

[0043] The reset member can also be a limiting torsion spring, the supporting leg 24 is rotatably connected with the hinged seat 25 through the limiting torsion spring, when the unmanned aerial vehicle is located in the barrel, the supporting leg 24 is folded under the action of the limiting torsion spring, when the unmanned aerial vehicle is reflected to the air, the torsion of the limiting torsion spring rotates the supporting leg 24 to the supporting state, the unmanned aerial vehicle lands and presses the supporting leg 24, the limiting torsion spring can play the role of shock absorption and buffering.

[0044] Embodiment 3:

[0045] The coaxial unmanned aerial vehicle can also be a fixed landing gear, the supporting leg 24 is fixedly connected at the bottom of the unmanned aerial vehicle body, and the take-off mode is the traditional bottom surface take-off through the rotation of the rotor.

[0046] The above is only the preferred embodiment of the present application, the protection scope of the present application is not limited to the above-mentioned embodiments, any technical scheme belonging to the idea of the present application is also within the protection scope of the present application. It should be pointed out that, for ordinary skilled in the art, some improvements and decorations without departing from the principle of the present application can also be considered as the protection scope of the present application.

Claims

1. A coaxial drone, characterized by: The utility model provides a kind of multi-rotor unmanned aerial vehicle, including main shaft (1), rotor structure, variable pitch structure and landing gear structure, the rotor structure includes upper rotor part (2) and lower rotor part (3), the upper rotor part (2) and lower rotor part (3) each include power group (6), hub (4) and multiple groups of blades (5), the hub (4) is sleeved on main shaft (1), multiple groups of the blades (5) are rotatably connected on hub (4), the power group (6) drives hub (4) to rotate and generates centrifugal force to make the blades (5) unfold, and the hub (4) and blade (5) are further provided with limiting member for limiting unfolded blade (5) to rotate to fold between the limiting member; The variable pitch structure includes a number of groups of rudders (8), the rudders (7) and the blades (5) are provided with a total pitch member (9) therebetween, the output end of each group of the rudders (8) is provided with a variable pitch member (10) connected with the rudders (7), the rudders (8) drive the variable pitch member (10) to move to make the rudders (7) incline or move up and down along the main shaft (1), and the blades (5) rotate along the axial direction of the main shaft (1); The landing gear structure includes a number of groups of support members (11), the support members (11) are rotatably connected to the bottom end of the main shaft (1) to make the landing gear have a folding state and a supporting state, and the support members (11) and the main shaft (1) have a reset member for resetting the support members (11) from the folding state to the supporting state; The connecting end of the blades (5) and the hub (4) is further fixedly provided with a flapping hinge (12), the flapping hinge (12) is rotatably connected with the hub (4), the limiting member is two groups of extension springs (13), one end of the two groups of extension springs (13) is respectively connected to the two sides of the flapping hinge (12), and the other end is respectively connected to the hub (4), when the blades (5) are switched from the folding state to the unfolded state, the extension length of the extension springs (13) gradually decreases; The connecting end of the hub (4) and the flapping hinge (12) is further rotatably connected with a total pitch adjusting member, the total pitch adjusting member includes a total pitch hinge (14), an adapter (15), and a variable pitch shaft (16), the flapping hinge (12) is rotatably connected with the total pitch hinge (14), the total pitch hinge (14) is rotatably connected with the adapter (15), the adapter (15) is fixedly connected to the hub (4), one end of the variable pitch shaft (16) is fixedly located in the adapter (15), and the other end extends into the total pitch hinge (14) and is bearing-connected with the total pitch hinge (14); The variable pitch member (10) includes a rotating plate (101) and a variable pitch pull rod (102), one end of the rotating plate (101) is connected with the output end of the rudder (8), the other end is connected with the variable pitch pull rod (102), and one end of the variable pitch pull rod (102) away from the rotating plate (101) is connected with a fixed ring (72); The outer side of the fixed ring (72) is provided with a protruding connecting part (17), and the variable pitch pull rod (102) and the connecting part (17) are connected through a ball joint; The main shaft (1) is further provided with a support (19), the steering engine (8) is located on the support (19), the support (19) is further vertically provided with a limiting plate (21), the limiting plate (21) is provided with a limiting slide (22), and one end of any one group of variable-pitch pull rods (102) is provided with a sliding rod (23) which is slidingly connected in the limiting slide (22).

2. The coaxial drone of claim 1, wherein: The inclinator (7) comprises a rotating ring (71), a fixed ring (72) and a deep groove ball bearing (73), the fixed ring (72) is sleeved on the main shaft (1), the rotating ring (71) is rotationally connected with the fixed ring (72) through the deep groove ball bearing (73), the total pitch piece (9) is connected with the rotating ring (71), and the variable-pitch piece (10) is connected with the fixed ring (72).

3. The coaxial unmanned aerial vehicle of claim 1, wherein: The fixed ring (72) and the main shaft (1) are further provided with a radial spherical sliding bearing (18).

4. The coaxial unmanned aerial vehicle of claim 2, wherein: The total pitch piece (9) comprises a total pitch pull rod (91) and a connecting arm (92), the total pitch pull rod (91) is rotationally connected with the connecting arm (92), the other end of the total pitch pull rod (91) is connected with the fixed ring (72), and the other end of the connecting arm (92) is connected with the total pitch hinge (14).

5. The coaxial unmanned aerial vehicle of claim 1, wherein: The support (11) comprises a supporting leg (24) and a hinged seat (25), the upper surface of the hinged seat (25) is fixed on the bottom of the unmanned aerial vehicle body, the reset member comprises a spring pin (28), the spring pin (28) is located in the hinged seat (25), the spring pin (28) comprises a shell, a pin head (29) and a spring in the shell, the spring applies a spring force to the pin head (29) to make the pin head (29) pop out of the shell, and the pin head (29) makes the supporting leg (24) in the folded state pop out to the supporting state.

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