Variable pitch propeller assembly, unmanned aerial vehicle and aerial vehicle system

Abstract

The present invention provides a variable pitch screw assembly, an unmanned aerial vehicle and an aircraft system. The aircraft system includes the unmanned aerial vehicle, which is provided with the variable pitch screw assembly. The variable pitch screw assembly includes at least two propeller assemblies, a base, a conductive member, a drive assembly and a transmission assembly. The at least two propeller assemblies are arranged on the base, and the drive assembly drives the at least two propeller assemblies to tilt through the transmission assembly. The conductive member is arranged on the base, and the conductive member includes a fixed end and a rotating end. The fixed end is connected to the rotating end, and the rotating end rotates relative to the fixed end. The fixed end is electrically connected to the drive assembly, and the rotating end is used to connect to the control unit of the aircraft. With the above structure, the propeller assembly is driven by the drive assembly and the transmission assembly to achieve tilting, so that the variable pitch screw assembly is directly applied to the outer rotor motor without changing the structure of the outer rotor motor itself, thereby providing the applicability of the variable pitch screw assembly.

Description

Technical Field

[0001] The present invention relates to the field of unmanned aerial vehicles, and in particular to a variable pitch propeller assembly, an unmanned aerial vehicle and an aerial vehicle system. Background Art

[0002] Among the existing aircraft, most of the fixed-wing drones and multi-rotor drones that use brushless motors as power use fixed-pitch propellers, that is, the propellers can only rotate during flight and cannot tilt. When fixed-pitch propellers are used on fixed-wing aircraft, when the aircraft is flying at low speed, the pitch of the propeller is too small when flying at high speed, and the push-pull force required for takeoff and cruising is also different. The use of fixed-pitch propellers makes it impossible to improve the flight efficiency, increasing power loss. On multi-rotor aircraft, since the air density at different flight altitudes is also different, the air density at low altitudes is large, and the power that can be satisfied by a small pitch will be greatly reduced at high altitudes due to the thin air. At this time, a large-pitch propeller is needed to improve the rotation efficiency of the propeller, but the pitch of the propeller of the existing multi-rotor drone cannot be changed, making the multi-rotor drone poor in environmental and flight adaptability.

[0003] The variable pitch structures currently used in aircraft, such as the variable pitch structures on coaxial counter-propeller helicopters, use a drive device to drive the push rod to move, and the movement of the push rod drives the propeller to tilt. However, this type of variable pitch structure requires a structural change in the motor that drives the propeller to rotate. This type of variable pitch structure requires a corresponding drive device, which makes the implementation of the aircraft's propeller pitch change complicated and costly. Summary of the invention

[0004] A first object of the present invention is to provide a variable pitch propeller assembly for achieving propeller pitch change.

[0005] A second object of the present invention is to provide an unmanned aerial vehicle comprising the variable pitch propeller assembly.

[0006] A third object of the present invention is to provide an aircraft system including an unmanned aerial vehicle.

[0007] In order to achieve the above-mentioned first purpose, the variable pitch propeller assembly provided by the present invention includes at least two propeller assemblies, a base, a conductive member, a drive assembly and a transmission assembly, at least two propeller assemblies are arranged on the base, and the drive assembly drives at least two propeller assemblies to tilt through the transmission assembly; the conductive member is arranged on the base, the conductive member includes a fixed end and a rotating end, the fixed end is connected to the rotating end, the rotating end rotates relative to the fixed end, the fixed end is electrically connected to the drive assembly, and the rotating end is used to connect to the control unit of the aircraft.

[0008] It can be seen from the above scheme that the drive assembly drives the transmission assembly to work and drives the propeller assembly to tilt, thereby realizing the pitch change of the blades in the propeller assembly; and the propeller assembly, the conductive member, the drive assembly and the control assembly in the variable pitch helical assembly are respectively arranged on the base, and the base is used to connect with the outer rotor motor that drives the propeller assembly to rotate. The base is used as a connecting medium, and the propeller assembly is driven by the drive assembly and the transmission assembly to achieve tilting, so that the variable pitch helical assembly is directly applied to the outer rotor motor without making changes to the structure of the outer rotor motor itself, thereby providing the applicability of the variable pitch helical assembly; because the variable pitch helical assembly rotates with the outer rotor of the outer rotor motor, the base is provided with a conductive member, wherein the fixed end of the conductive member is connected to the drive assembly, and the rotating end is connected to the control unit of the aircraft, so that when the variable pitch helical assembly rotates, the electrical connection line on the variable pitch helical assembly is not broken due to entanglement.

[0009] A further solution is that the conductive member is an electric slip ring, the base includes a bottom plate, the bottom plate is used to connect an outer rotor motor that drives at least two propeller assemblies to rotate, and the electric slip ring is arranged on the bottom plate and located between the at least two propeller assemblies.

[0010] It can be seen that the electric slip ring as a conductive member is arranged between at least two propeller assemblies, so that the connecting wires on the electric slip ring are closer to the hollow center shaft of the outer rotor motor, which facilitates the connecting wires on the electric slip ring to pass through the hollow center shaft of the outer rotor motor and connect to the control unit of the aircraft.

[0011] A further solution is that the drive assembly includes a drive device and a first bevel gear, the drive device drives the first bevel gear to rotate, the transmission assembly includes multiple second bevel gears, each propeller assembly is connected to a second bevel gear, and the first bevel gear is meshed with multiple second bevel gears.

[0012] It can be seen that since the first bevel gear connected to the driving device is respectively meshed with multiple second bevel gears, the driving device drives the multiple second bevel gears to rotate through the first bevel gear, thereby driving each two relatively arranged propeller assemblies to tilt synchronously in opposite directions. The transmission structure has a simple structure and high transmission efficiency.

[0013] A further solution is that the drive assembly includes a drive motor, the axial direction of the drive shaft of the drive motor is perpendicular to the rotation center axis of at least two propeller assemblies, the drive assembly includes a first spur gear, and the drive motor drives the first spur gear to rotate; the variable pitch screw assembly includes an angle measuring assembly and a control assembly, the control assembly is electrically connected to the conductive member, the angle measuring assembly includes a second spur gear, a connecting rod and an angle detector, the angle detector is connected to the control assembly, the second spur gear is connected to the axial first end of the connecting rod, the axial second end of the connecting rod is connected to the angle detector, the first spur gear is meshed with the second spur gear, and the axial direction of the connecting rod is parallel to the axial direction of the drive shaft of the drive motor.

[0014] It can be seen that since the driving motor and the transmission assembly are connected through the first spur gear, there is an intermediate transmission structure between the driving motor and the transmission assembly, and the second spur gear in the angle measuring assembly is connected to the first spur gear, and is connected to the angle measuring assembly through the intermediate transmission structure. The angle measuring assembly realizes the detection of the inclination angle of the propeller assembly, which facilitates the aircraft control unit to adjust the inclination angle of the propeller assembly.

[0015] A further solution is that the angle detector is a potentiometer.

[0016] It can be seen that the potentiometer, as an angle detector, can directly output voltage, and the rotational displacement of the second spur gear can be obtained through the output voltage, thereby obtaining the pitch angle.

[0017] A further solution is that the drive assembly includes a drive motor, the axial direction of the drive shaft of the drive motor is perpendicular to the rotation center axis of at least two propeller assemblies, the drive assembly includes a first spur gear, and the drive motor drives the first spur gear to rotate; the variable pitch screw assembly includes a self-locking assembly, the self-locking assembly includes a worm wheel, a worm and a third spur gear, the axial direction of the worm is parallel to the axial direction of the drive shaft of the drive motor, the axial first end of the worm is connected to the third spur gear, the first spur gear is meshed with the third spur gear, the axial second end of the worm is fixed on the base, the worm wheel is meshed with the worm, and the worm wheel is used to be coaxially connected to the first bevel gear of the drive assembly.

[0018] It can be seen that the matching structure of the worm wheel and the worm gear has reverse self-locking. When the driving shaft of the motor is parallel to the axial direction of the worm gear, self-locking can be achieved through the matching structure of the worm wheel and the worm gear. As an intermediate transmission component between the drive device and the transmission component, the self-locking component can maintain the stability after the pitch is changed after adjusting the large-diameter propeller assembly, and eliminate the reverse torque on the outer rotor drive motor on the aircraft. Even if the aircraft is powered off, it will not affect the pitch under the influence of air resistance.

[0019] A further solution is that the driving assembly includes a steering gear, and the steering gear is connected to the transmission assembly.

[0020] It can be seen that since the servo itself is an angle servo driver, using the servo as a driving device for the variable pitch of the propeller assembly makes the structure of the variable pitch drive assembly of the propeller assembly simpler and easier to install.

[0021] To achieve the above second purpose, the unmanned aerial vehicle provided by the present invention comprises: an outer rotor motor and a variable pitch screw assembly as described above, wherein the outer rotor of the outer rotor motor is connected to the base.

[0022] A further solution is that the outer rotor motor includes a hollow center shaft and a control unit, the connecting wire of the conductive member passes through the hollow center shaft, and the conductive member is connected to the control unit.

[0023] To achieve the third purpose mentioned above, the aircraft system provided by the present invention includes: a drone, a tether rope and a ground control tether box, the drone is the unmanned aerial vehicle as mentioned above, one end of the tether rope is connected to the drone, and the other end of the tether rope is connected to the ground control tether box. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a stereoscopic diagram of an embodiment of a variable pitch spiral assembly of the present invention.

[0025] Figure 2 It is a stereoscopic diagram of the variable pitch spiral assembly embodiment of the present invention with the protective cover removed.

[0026] Figure 3 It is a cross-sectional view of the variable pitch spiral assembly embodiment of the present invention with the protective cover removed.

[0027] Figure 4 It is an exploded view of the variable pitch spiral assembly embodiment of the present invention with the protective cover removed.

[0028] Figure 5 This is a structural diagram of another drive assembly implementation method in the variable pitch screw assembly embodiment of the present invention.

[0029] The present invention is further described below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0030] The variable pitch helical assembly of the present invention realizes the variable pitch of the propeller assembly through the drive assembly and the gear transmission, and the drive assembly, the transmission assembly and the propeller assembly are respectively arranged on the base, and the base serves as an intermediate medium for connecting the outer rotor motor of the aircraft with the variable pitch helical assembly. The base can be directly mounted on the outer rotor motor of the aircraft to realize the rotation of the variable pitch helical assembly, and the propeller assembly is driven by the drive assembly and the transmission assembly to realize the tilt, so that the variable pitch helical assembly is directly applied to the outer rotor motor without changing the structure of the outer rotor motor itself, thereby providing the applicability of the variable pitch helical assembly, and then by setting a conductive member with a rotating end and a fixed end, it is realized that when the variable pitch helical assembly rotates, the electrical connection line on the variable pitch helical assembly is not broken due to winding. The variable pitch helical assembly of the present invention is applied to an aircraft, and the aircraft can be a multi-rotor unmanned aerial vehicle, and the multi-rotor unmanned aerial vehicle can include at least one of a free flight mode and a tethered mode.

[0031] See also Figure 1 , Figure 2 , Figure 3 and Figure 4The variable pitch propeller assembly of the present invention comprises a protective cover 10, a base 1, at least two propeller assemblies 2, a conductive member 3, a drive assembly 4, a transmission assembly 5, an angle measuring assembly 6, a self-locking assembly 7 and a control assembly 8. The at least two propeller assemblies 2, the conductive member 3, the drive assembly 4, the transmission assembly 5 and the control assembly 8 are respectively arranged on the base 1. The base 1 comprises a bottom plate 11, a first support plate 12, a second support plate 13 and a third support plate 14. The first support plate 12, the second support plate 13 and the third support plate 14 are respectively arranged on the side wall of the base 1 away from the outer rotor motor. The first support plate 12 is arranged opposite to the second support plate 13, the third support plate 14 is arranged opposite to the bottom plate 11, and the third support plate 14 is connected between the first support plate 12 and the second support plate 13, so that the first support plate 12, the second support plate 13, the third support plate 14 and the bottom plate 11 form a placement grid 15, and the transmission assembly 5 is located in the placement grid 15. Multiple support plates are used to install the propeller assembly 2, the transmission assembly 5 and the drive assembly 4 respectively; when the base plate 11 serves as the bottom of the variable pitch propeller assembly, starting from the base 1, from bottom to top, at least two propeller assemblies 2, transmission assemblies 5 and drive assemblies 4 are sequentially arranged on the base plate 11.

[0032] The propeller assembly 2 includes a blade and a propeller clamp, and the blade is connected to the propeller clamp. The variable pitch propeller assembly includes at least two propeller assemblies 2, and the number of propeller assemblies 2 is two, three, four or five. In this embodiment, the number of propeller assemblies 2 is two, one propeller assembly 2 is arranged on the first support plate 12, and the other propeller assembly 2 is arranged on the second support plate 13; based on the bottom plate 11, the two propeller assemblies 2 are arranged at the same height.

[0033] Since the driving assembly 4 drives the propeller assembly 2 to tilt through the transmission assembly 5, the transmission assembly 5 is arranged between the driving assembly 4 and the propeller assembly 2, which can shorten the transmission distance and improve the transmission effect. The driving assembly 4 includes a driving device 41 and a first bevel gear 42. The driving device 41 drives the first bevel gear 42 to rotate. The driving device 41 is arranged on the side wall of the third support plate 14 away from the placement grid 15, and the first bevel gear 42 is arranged in the placement grid 15. The transmission assembly 5 includes a plurality of second bevel gears 51, and the first bevel gear 42 is arranged between the plurality of second bevel gears 41. The number of the second bevel gears 41 is the same as the number of the propeller assemblies 2. Each propeller assembly 2 is connected to a second bevel gear 41 respectively, and the first bevel gear 42 is meshed with at least two second bevel gears 41. Since the first bevel gear 42 connected to the driving device 41 is meshed with the plurality of second bevel gears 41 respectively, the driving device 41 drives the plurality of second bevel gears 41 to rotate through the first bevel gear 42, thereby driving each two relatively arranged propeller assemblies 2 to tilt synchronously in the opposite direction, and realizing the synchronous change of the pitch of the plurality of propeller assemblies 2. The transmission structure is simple and the transmission efficiency is high; wherein the driving device 41 and the first bevel gear 42 can be directly connected, or an intermediate transmission member is further provided between the driving device 41 and the first bevel gear 42. In this embodiment, an angle measuring assembly 6 and a self-locking assembly 7 are further connected between the driving assembly 4 and the transmission assembly 5.

[0034] In this embodiment, the self-locking assembly 7 can be used as an intermediate transmission member between the driving device 41 and the first bevel gear 42. Based on the bottom plate 11, the self-locking assembly 7 is arranged between the driving assembly 4 and the transmission assembly 5. The driving device 41 is a driving motor 41. The axial direction of the driving shaft of the driving motor 41 is perpendicular to the rotation center axis of at least two propeller assemblies 2. The driving assembly 4 includes a first spur gear 43, and the first spur gear 43 is connected to the driving motor 41; the driving motor 41 is arranged on the side wall of the third support plate 14 away from the placement grid 15 through two motor fixing seats 411, and the self-locking assembly 7 is arranged between the driving motor 41 and the third support plate 14. The self-locking assembly 7 includes a worm wheel 71, a worm 72 and a third spur gear 73. The worm wheel 71 is meshedly connected with the worm 72. The axial first end of the worm 72 passes through one of the motor fixing seats 411 and is connected to the third spur gear 73. The axial second end of the worm 72 is fixed on the other motor fixing seat 411. In this embodiment, the axial direction of the worm 72 is parallel to the axial direction of the driving shaft of the driving motor 41 , the first spur gear 43 is meshed with the third spur gear 73 , and the worm gear 72 is coaxially connected with the first bevel gear 42 . The matching structure of the worm wheel 71 and the worm 72 has reverse self-locking. When the axial direction of the driving shaft of the driving motor 41 is parallel to the axial direction of the worm 72, the self-locking can be achieved through the matching structure of the worm wheel 71 and the worm 72 and serve as an intermediate transmission component 5 between the driving device 41 and the transmission component 5, so that the driving motor 41 drives the first spur gear 43 to rotate, driving the third spur gear 73 to rotate, and the rotation of the worm 72 of the third spur gear 73 and the matching connection of the worm wheel 71 are rotated, thereby realizing the rotation of the first bevel gear 42 and driving the propeller assembly 2 to tilt; a self-locking component 7 is set between the driving motor 41 and the first bevel gear 42 to maintain the stability after the pitch is changed after adjusting the large-diameter propeller, and eliminate the counter-torque on the outer rotor driving motor 41 on the aircraft. Even if the aircraft is powered off, it will not affect the pitch under the influence of air resistance, and realize the transmission between the driving motor 41 and the first bevel gear 42.

[0035] The angle measuring assembly 6 and the control assembly 8 are respectively arranged on the side wall of the third support plate 14 away from the placement grid 15. The angle measuring assembly 6 is used to detect the pitch change angle of the propeller assembly 2. The control assembly 8 cooperates with the control unit of the aircraft to adjust the pitch change angle of the propeller assembly 2 so that it meets the requirements of the control signal output by the control unit. The angle measuring assembly 6 includes a second spur gear 61, a connecting rod 62 and an angle detector 63. The angle detector 63 can be an angle sensor or a potentiometer. In this embodiment, the angle detector 63 is a potentiometer. The second spur gear 61 is connected to the axial first end of the connecting rod 62, and the axial second end of the connecting rod 62 is connected to the angle detector 63. The first spur gear 43 is meshed with the second spur gear 61. The axial direction of the connecting rod 62 is parallel to the axial direction of the driving shaft of the driving motor 41, so that the axial direction of the connecting rod 62 is parallel to the axial direction of the worm 72. The connecting rod 62 and the worm 72 can be respectively located on two opposite sides of the worm wheel 71, so that the component layout is more reasonable. When the driving motor 41 drives the first spur gear 43 to rotate, it drives the second spur gear 61 and the connecting rod 62 to rotate, so that the angle detector 63 detects the rotation angle of the connecting rod 62, and the angle detector 63 outputs the angle signal to the aircraft control unit through the control component 8. The control unit determines whether to output a control signal to the driving motor 41 based on the angle signal to adjust the inclination angle of the propeller assembly 2.

[0036] In this embodiment, the conductive member 3 is an electric slip ring, which is arranged on the base 1. The conductive member 3 includes a fixed end 31 and a rotating end 32. The fixed end 31 is electrically connected to the rotating end 32, and the rotating end 32 rotates relative to the fixed end 31. The fixed end 31 is connected to the driving assembly 4 through the control assembly 8, and the rotating end 32 is used to connect the control unit of the aircraft. In this embodiment, a through hole 111 is arranged on the bottom plate 11, and the electric slip ring 3 is located in the through hole 111. The through hole 111 is arranged between multiple propeller assemblies 2. The through hole 111 can be connected to the hollow central shaft on the outer rotor motor of the aircraft, and is arranged in a colinear manner along the rotation center axis of the propeller assembly 2, so that the connection line on the electric slip ring 3 can shorten the distance and pass through the hollow central shaft of the outer rotor motor to connect with the control unit and power supply of the aircraft. When the electric slip ring 3 is arranged, the electric connection line on the variable pitch screw assembly will not break due to winding when the variable pitch screw assembly rotates.

[0037] Three electrical connection lines are arranged on the control component 8, which are respectively power positive and negative connection lines and signal transmission lines. The power positive and negative connection lines are correspondingly connected to the positive and negative poles of the drive motor 41 and the electric slip ring, so that the control component 8 is arranged near the positive and negative pole connection of the drive motor 41, and the signal transmission lines are respectively connected to the drive motor 41 and the electric slip ring.

[0038] The transmission assembly 5 is driven by the driving assembly 4 to drive the propeller assembly 2 to tilt, thereby realizing the pitch change of the blades; the propeller assembly 2, the conductive member 3, the driving assembly 4 and the control assembly 8 in the variable pitch screw assembly are respectively arranged on the base 1, and the base 1 is used to connect with the outer rotor motor that drives the propeller assembly 2 to rotate. The base 1 is used as a connecting medium, and the propeller is driven by the driving assembly 4 and the transmission assembly 5 to achieve tilting, so that the variable pitch screw assembly is directly applied to the outer rotor motor, without changing the structure of the outer rotor motor itself, thereby providing the applicability of the variable pitch screw assembly.

[0039] As another embodiment, see Figure 5 , the steering gear 9 can be used to replace the driving assembly 4, and the steering gear 9 directly drives the first bevel gear 42 to rotate, thereby driving the propeller assembly 2 to tilt and change the pitch through the second bevel gear 41 meshing with the first bevel gear 42. Since the steering gear 9 itself is an angle servo driver, the steering gear 9 is used as the propeller pitch drive device 41, and there is no need to set the angle measurement assembly 6, the self-locking assembly 7 and the control assembly 8. The connecting wire on the steering gear 9 is directly connected to the electric slip ring 3, so that the structure of the propeller pitch drive assembly 4 is simpler and the installation is simpler.

[0040] In this embodiment, the protection cover 10 is disposed on the third support plate 14 , the protection cover 10 covers the components disposed on the third support plate 14 , and the protection cover 10 is in a conical shape.

[0041] The unmanned aerial vehicle of the present invention may be a multi-rotor unmanned aerial vehicle, and the unmanned aerial vehicle includes an outer rotor motor, the above-mentioned variable pitch propeller assembly and a control unit, the outer rotor of the outer rotor motor is connected to the base 1, and the outer rotor motor is used to drive the variable pitch propeller assembly to rotate, thereby driving the propeller assembly 2 to rotate. The control unit is connected to the conductive member 3. The multi-rotor unmanned aerial vehicle can have a free flight state or a tethered flight state. The aircraft system of the present invention includes an unmanned aerial vehicle, a tethering rope and a ground control tethering box, and the unmanned aerial vehicle is the above-mentioned unmanned aerial vehicle, one end of the tethering rope is connected to the unmanned aerial vehicle, and the other end of the tethering rope is connected to the ground control tethering box.

[0042] Finally, it should be emphasized that the above 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 changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A variable pitch screw assembly, characterized in that: It comprises at least two propeller assemblies, a base, a conductive member, a driving assembly and a transmission assembly, wherein at least two of the propeller assemblies are arranged on the base, and the driving assembly drives the at least two propeller assemblies to tilt through the transmission assembly; The conductive member is disposed on the base, and includes a fixed end and a rotating end, wherein the fixed end is connected to the rotating end, the rotating end rotates relative to the fixed end, the fixed end is electrically connected to the driving assembly, and the rotating end is used to connect to a control unit of the aircraft; The drive assembly comprises a drive motor, the axial direction of the drive shaft of the drive motor is perpendicular to the rotation center axis of at least two of the propeller assemblies, the drive assembly comprises a first spur gear, and the drive motor drives the first spur gear to rotate; The variable pitch screw assembly includes an angle measuring assembly and a control assembly, wherein the control assembly is electrically connected to the conductive member, and the angle measuring assembly includes a second spur gear, a connecting rod and an angle detector, wherein the angle detector is connected to the control assembly, the second spur gear is connected to an axial first end of the connecting rod, and an axial second end of the connecting rod is connected to the angle detector, the first spur gear is meshed with the second spur gear, and the axial direction of the connecting rod is parallel to the axial direction of the driving shaft of the driving motor.

2. The variable pitch screw assembly according to claim 1, characterized in that: The conductive member is an electric slip ring, the base includes a bottom plate, the bottom plate is used to connect an outer rotor motor that drives at least two of the propeller assemblies to rotate, the electric slip ring is arranged on the bottom plate, and the electric slip ring is located between at least two of the propeller assemblies.

3. The variable pitch screw assembly according to claim 1, characterized in that: The driving assembly includes a driving device and a first bevel gear, wherein the driving device drives the first bevel gear to rotate. The transmission assembly includes a plurality of second bevel gears, each of the propeller assemblies is respectively connected to one of the second bevel gears, and the first bevel gear is respectively meshed with the plurality of second bevel gears.

4. The variable pitch screw assembly according to claim 1, characterized in that: The angle detector is a potentiometer.

5. The variable pitch screw assembly according to claim 3, characterized in that: The drive assembly comprises a drive motor, the axial direction of the drive shaft of the drive motor is perpendicular to the rotation center axis of at least two of the propeller assemblies, the drive assembly comprises a first spur gear, and the drive motor drives the first spur gear to rotate; The variable pitch screw assembly includes a self-locking assembly, which includes a worm wheel, a worm and a third spur gear. The axial direction of the worm is parallel to the axial direction of the driving shaft of the driving motor. The axial first end of the worm is connected to the third spur gear, and the first spur gear is meshed with the third spur gear. The axial second end of the worm is fixed on the base, and the worm wheel is meshed with the worm. The worm wheel is used to be coaxially connected to the first bevel gear of the driving assembly.

6. An unmanned aerial vehicle, characterized in that: include: An outer rotor motor and a variable pitch screw assembly as claimed in any one of claims 1 to 5, wherein the outer rotor of the outer rotor motor is connected to the base.

7. The unmanned aerial vehicle according to claim 6, characterized in that: The outer rotor motor comprises a hollow central shaft and a control unit, the connecting wire of the conductive member passes through the hollow central shaft, and the conductive member is connected to the control unit.

8. An aircraft system, characterized in that include: A drone, a tether rope and a ground control tether box, wherein the drone is an unmanned aerial vehicle as described in claim 6 or 7, one end of the tether rope is connected to the drone, and the other end of the tether rope is connected to the ground control tether box.

Images