Coaxial propeller pair structure of unmanned aerial vehicle and unmanned aerial vehicle

Abstract

The utility model relates to the technical field of unmanned aerial vehicles, in particular to an unmanned aerial vehicle coaxial opposite propeller structure and an unmanned aerial vehicle. The two propellers are connected to the opposite ends of the two motor assemblies correspondingly; and the shaft assembly penetrates through and is connected with the two motor assemblies. The double propellers are arranged between the two motors in the middle, the distance between the power plane of the propellers and the gravity center plane of the unmanned aerial vehicle can be shortened, and the flying stability of the unmanned aerial vehicle is improved; and the shaft assembly is arranged to connect the two motor assemblies, so that the Z-axis strength and stability can be effectively improved. The whole unmanned aerial vehicle is compact in structure and tight in connection, high-frequency vibration of the unmanned aerial vehicle during flight can be effectively reduced, and then the load of an unmanned aerial vehicle flight control system is reduced. In addition, the whole device is simple in structure, convenient to assemble, quite convenient to disassemble, assemble and maintain and high in practicability.

Description

Technical Field

[0001] The utility model relates to the technical field of unmanned aerial vehicles, in particular to a coaxial propeller structure of an unmanned aerial vehicle and an unmanned aerial vehicle. Background Art

[0002] A multi-rotor drone is a special unmanned helicopter with three or more rotor shafts. The motors on each shaft rotate to drive the rotors, thereby generating lift thrust. Multi-rotor drones are small in size, light in weight, and have good concealment. They are widely used in aerial photography, reconnaissance, environmental monitoring and other fields.

[0003] The twin propellers of current coaxial twin-propeller multi-rotor drones are generally arranged on the same side of the motor, such as a vector coaxial twin-propeller drone disclosed in publication number CN111169630 A, in which the first rotor and the second rotor are both installed at the output end of the counter-rotating motor, the first rotor is located above the second rotor, and the rotation direction of the first rotor is opposite to that of the second rotor. However, when a drone with this structure is flying, the propeller power plane and the center of gravity plane of the drone deviate greatly, affecting the stability during flight, and this structure requires complex mechanical transmission to realize the forward and reverse rotation of the two rotors, which is complicated to assemble and has poor maintainability.

[0004] Another part of the UAV has twin propellers installed on the upper and lower sides of the motor, such as a UAV with a coaxial twin-propeller structure disclosed in publication number CN 105947207B, in which the rotor power assembly includes a cooling seat, and the upper and lower sides of the cooling seat are respectively fixed with a first motor and a second motor, and the output ends of the first motor and the second motor are respectively connected to the first rotor and the second rotor, and finally the first rotor and the second rotor are symmetrically distributed on both sides of the rotor shaft. However, when a UAV with this structure is flying, the twin propellers are prone to collision with the external structure, affecting the safety of the flight. In addition, the twin propellers under this structure are spaced relatively large, which affects the efficiency of the UAV propellers.

[0005] In addition, both of these UAV dual propeller structures have problems such as insufficient compactness, insufficient connection between structures, and insufficient Z-axis strength. When the UAV flies at high speed, high-frequency vibration will occur between the frame and the propeller structure and between the internal structures of the propeller structure, which will increase the load of the flight control system, easily cause the chip to overload, and increase the instability of the entire system. In view of this, we propose a UAV coaxial propeller structure and a UAV. Utility Model Content

[0006] The purpose of the embodiments of the utility model is to provide a coaxial propeller structure for a UAV and a UAV, which solves the problems of low stability, insufficient Z-axis strength, and insufficient safety of the current UAV double-propeller structure.

[0007] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0008] A first aspect of an embodiment of the utility model provides a coaxial propeller structure of a drone, comprising two symmetrically arranged motor assemblies;

[0009] Two propellers, the two propellers are respectively connected to opposite ends of the two motor assemblies;

[0010] The shaft assembly passes through and connects the two motor assemblies.

[0011] Preferably, the motor assembly comprises:

[0012] A base, used to connect with the drone;

[0013] inner stator and outer rotor;

[0014] A driving shaft, fixedly connected to the axis of the outer rotor;

[0015] One end of the driving shaft passes through the inner stator and the base in sequence, and a through hole is opened at the axis center of the driving shaft for the shaft assembly to pass through.

[0016] Preferably, the shaft assembly comprises:

[0017] A central axis rod, passing through the two through holes;

[0018] Two end covers, inner walls of which are respectively threadedly connected to the two ends of the central axis rod to limit the relative movement between the central axis rod and the machine base.

[0019] Preferably, a groove is formed at one end of the base, and the inner peripheral wall of the groove is threadedly connected to the outer peripheral wall of the end cover.

[0020] Preferably, a screwing groove is provided on one end surface of the end cover, and a hexagonal groove is provided on one end surface of the central axis rod.

[0021] Preferably, the central axis comprises:

[0022] A first shaft rod, wherein a threaded hole is formed on one end surface of the first shaft rod;

[0023] A second shaft rod, one end surface of which is fixedly connected with a threaded rod, which is threadedly connected with the threaded hole.

[0024] Preferably, the propeller is sleeved on the driving shaft, and a limit nut is threadedly connected to the outer peripheral wall of the driving shaft to limit the relative movement between the driving shaft and the propeller.

[0025] Preferably, the central axis rod and the limiting nut are connected via a first bearing.

[0026] A second aspect of an embodiment of the utility model provides a drone, comprising a frame, characterized in that four drone coaxial propeller structures are arranged on the frame, and the four drone coaxial propeller structures are distributed in a cross shape;

[0027] Wherein, the base is fixed on the frame by screws.

[0028] Preferably, a foot is fixedly connected to the bottom of the frame.

[0029] By means of the above technical scheme, the utility model provides a coaxial propeller structure of a UAV and a UAV. It has at least the following beneficial effects: by arranging the double propellers centrally between the two motors, the distance between the propeller power plane and the center of gravity plane of the UAV can be shortened, thereby improving the stability of the UAV during flight; at the same time, the distance between the two propellers can be shortened, thereby improving the propeller efficiency. By setting a shaft assembly to connect the two motor assemblies, the Z-axis strength and stability can be effectively improved. The entire UAV has a compact structure and is tightly connected, which can effectively reduce high-frequency vibrations during flight of the UAV, thereby reducing the load on the UAV flight control system. In addition, the entire device has a simple structure and is easy to assemble, making disassembly and maintenance very convenient and highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application:

[0031] Figure 1 This is a schematic diagram of the overall structure of the first embodiment of the utility model;

[0032] Figure 2 This is an exploded view of the overall structure of the first embodiment of the utility model;

[0033] Figure 3 A schematic diagram of a motor assembly from one perspective in an embodiment of the utility model;

[0034] Figure 4 It is a schematic diagram of a motor assembly in an embodiment of the utility model;

[0035] Figure 5 This is a schematic diagram of an end cover in an embodiment of the utility model;

[0036] Figure 6 It is a schematic diagram of the first shaft rod and the second shaft rod in the embodiment of the utility model;

[0037] Figure 7 It is a schematic diagram of the overall structure of the second embodiment of the utility model.

[0038] In the figure: 1. motor assembly; 11. base; 111. groove; 12. inner stator; 13. outer rotor; 14. drive shaft; 15. retaining ring; 16. second bearing; 2. propeller; 3. shaft assembly; 31. middle shaft rod; 311. hexagonal groove; 312. second shaft rod; 3121. threaded rod; 313. first shaft rod; 3131. threaded hole; 32. end cover; 321. screw groove; 32. end cover; 4. limit nut; 5. first bearing; 6. frame; 7. screw; 8. foot. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0040] Embodiment 1

[0041] See also Figure 1-Figure 6 The utility model provides a coaxial propeller structure for a drone, comprising two motor assemblies 1 symmetrically arranged in an upper and lower direction, the output ends of the two motor assemblies 1 are close to each other, and propellers 2 are connected to both output ends. In this way, a double-rotor propeller structure is formed, which can change the power position of the propeller structure of a traditional drone, making the propeller power plane more centered, thereby shortening the distance between the propeller power plane and the drone's center of gravity plane, and improving the stability of the drone during flight. At the same time, the distance between the two propellers is shortened, and the propeller efficiency is improved. In addition, since the double-propeller structure is centered, the probability of collision between the propeller 2 and the external structure during drone flight can be effectively reduced, thereby improving the safety of flight.

[0042] Among them, the two motor assemblies 1 have the same structure, and both are outer rotor brushless motors. Specifically, each motor assembly 1 includes a base 11, and the base 11 is provided with four reserved holes for connecting to the drone frame 6. An inner stator 12 is fixedly connected to the base 11, and an outer rotor 13 is rotatably connected to the inner stator 12. A drive shaft 14 is fixedly connected to the center of the outer rotor 13. In this embodiment, the two drive shafts 14 are respectively located at the opposite ends of the two motor assemblies 1, and the two bases 11 are respectively located at the opposite ends of the two motor assemblies 1.

[0043] Combination Figure 2As shown, one end of the drive shaft 14 extends to the outside of the outer rotor 13 and is provided with an external thread, and the drive shaft 14 is connected to the limit nut 4 through the external thread. When in use, the propeller 2 is sleeved on the drive shaft 14, and then the limit nut 4 is threadedly connected to the drive shaft 14 to fix the propeller 2. The propeller 2 is fixed by the limit nut 4, which is convenient for the disassembly and assembly of the propeller 2.

[0044] Combination Figure 3 , Figure 4 As shown, the other end of the drive shaft 14 passes through the inner stator 12 and the base 11, and the drive shaft 14 is connected to the base 11 through a second bearing 16. An annular groove is provided on the outer peripheral wall of the drive shaft 14, and a shaft retaining ring 15 is engaged in the annular groove to improve the stability of the connection.

[0045] In order to improve the stability of the propeller structure, the device also includes a shaft assembly 3, which runs through the axes of the two motor assemblies 1, connecting the two motor assemblies 1 into a whole, thereby improving the stability of the propeller structure.

[0046] Combination Figure 2 , Figure 3 As shown, the shaft assembly 3 in this embodiment includes a central shaft rod 31, and a through hole is opened at the axis center of the drive shaft 14, and both ends of the through hole are penetrated for the central shaft rod 31 to pass through. The two ends of the central shaft rod 31 respectively penetrate the through holes on the two drive shafts 14, and the outer peripheral walls at both ends are provided with external threads, and the two sections of the external threads are connected with end covers 32. The two ends of the shaft assembly 3 are respectively fixed to the two motor assemblies 1 through the two end covers 32, so as to improve the bearing capacity and stability of the propeller structure in the Z-axis direction. The material of the central shaft rod 31 is titanium alloy to ensure its strength.

[0047] Combination Figure 4 , Figure 5 As shown, a groove 111 is provided at the end of the base 11, an inner wall of the groove 111 is provided with an internal thread, and an outer wall of the end cover 32 is provided with an external thread, so that the end cover 32 can be threadedly connected to the inner wall of the base 11, so that the end cover 32 can be retracted into the base 11, thereby improving the compactness of the structure.

[0048] In addition, a flat screw groove 321 is provided on one end of the end cap 32, so that a flat screwdriver can be used to screw the end cap 32. A hexagonal groove 311 is provided on one end surface of the central shaft 31, so that a hexagonal screwdriver can be used to screw the central shaft 31, thereby facilitating the disassembly and assembly of the structure.

[0049] Combination Figure 1 , Figure 2As shown, one end of the limit nut 4 extends out of the drive shaft 14 and is connected to the central shaft rod 31 through the first bearing 5, thereby providing a fulcrum for the middle section of the central shaft rod 31 and improving the strength of the Z axis. The first bearing 5 is assembled through the limit nut 4, making installation more convenient and making the structure more compact.

[0050] As one embodiment, the middle axis rod 31 includes a first axis rod 313 and a second axis rod 312. A threaded hole 3131 and a threaded rod 3121 are respectively provided on the opposite ends of the first axis rod 313 and the second axis rod 312. The threaded rod 3121 is threadedly connected to the threaded hole 3131. By setting the threaded rod 3121 and the threaded hole 3131, the length of the middle axis rod 31 can be adjusted, thereby improving the adaptability of the coaxial propeller structure to the drone frame 6, and facilitating the installation of the coaxial propeller structure on the drone frame 6 of different heights.

[0051] The coaxial propeller structure of the drone is compact and tightly connected, which can effectively reduce the high-frequency vibration of the drone during flight and reduce the load of the drone flight control system. The two motor assemblies 1 are connected by the shaft assembly 3, which can effectively improve the Z-axis strength and stability, making it easier for the drone to perform tasks such as transportation, videography and reconnaissance. The entire device has a simple structure, obvious effects, and is easy to assemble, making disassembly and maintenance very convenient, highly practical, and can reduce production costs.

[0052] Embodiment 2

[0053] See also Figure 7 On the basis of the first embodiment, a UAV includes a frame 6, on which four UAV coaxial propeller structures are arranged, and the four UAV coaxial propeller structures are distributed in a cross shape.

[0054] The frame 6 has eight arms, and the four UAV coaxial propeller structures have eight machine seats 11 . The eight machine seats 11 are fixedly mounted on the eight arms on the frame 6 by screws 7 .

[0055] The drone adopts four coaxial propeller structures, which improves the stability and safety of the drone during flight. At the same time, the upper and lower surfaces of the drone are flatter, so that the drone frame 6 can have a larger and flatter load-bearing surface, improving the carrying capacity and transportation efficiency.

[0056] With this structure, when the drone lands, the propeller 2 will not come into contact with the ground, so there is no need to configure an additional landing bracket, making the drone structure simpler and lighter.

[0057] In addition, a foot 8 is fixedly connected to the bottom of the frame 6. The foot 8 is made of rubber material and is used to contact the external structure. When the drone lands, the foot 8 first contacts the ground to play a buffering role, thereby improving the safety of the drone's landing.

[0058] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0059] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A coaxial propeller structure for a drone, characterized in that: include: Two symmetrically arranged motor assemblies (1); Two propellers (2), the two propellers (2) being respectively connected to opposite ends of the two motor assemblies (1); A shaft assembly (3) passing through and connecting the two motor assemblies (1); The shaft assembly (3) comprises a central shaft rod (31) and two end covers (32), wherein the inner walls of the two end covers (32) are respectively threadedly connected to the two ends of the central shaft rod (31); The central axis rod (31) comprises: A first shaft rod (313), wherein a threaded hole (3131) is formed on one end surface of the first shaft rod (313); A second shaft rod (312), one end surface of which is fixedly connected with a threaded rod (3121), and the threaded rod (3121) is threadedly connected with the threaded hole (3131).

2. The coaxial propeller structure of the UAV according to claim 1 is characterized in that: The motor assembly (1) comprises: A base (11), used for connecting to the drone; An inner stator (12) and an outer rotor (13); A drive shaft (14) is fixedly connected to the axis of the outer rotor (13); One end of the driving shaft (14) passes through the inner stator (12) and the machine base (11) in sequence, and a through hole is provided at the axis center of the driving shaft (14) for the shaft assembly (3) to pass through.

3. The coaxial propeller structure of the UAV according to claim 2 is characterized in that: The central axis rod (31) passes through the two through holes.

4. The coaxial propeller structure of the UAV according to claim 2 is characterized in that: A groove (111) is formed at one end of the machine base (11), and an inner peripheral wall of the groove (111) is threadedly connected to an outer peripheral wall of the end cover (32).

5. The coaxial propeller structure of the UAV according to claim 2 is characterized in that: A screwing groove (321) is provided on one end surface of the end cover (32), and a hexagonal groove (311) is provided on one end surface of the central shaft rod (31).

6. The coaxial propeller structure of the UAV according to claim 2 is characterized in that: The propeller (2) is sleeved on the driving shaft (14), and a limit nut (4) is threadedly connected to the outer peripheral wall of the driving shaft (14) for limiting the relative movement between the driving shaft (14) and the propeller (2).

7. The coaxial propeller structure of the UAV according to claim 6 is characterized in that: The central shaft rod (31) and the limiting nut (4) are connected via a first bearing (5).

8. An unmanned aerial vehicle, comprising a frame (6), characterized in that: The frame (6) is provided with four coaxial propeller structures for the UAV according to any one of claims 2 to 7, and the four coaxial propeller structures for the UAV are distributed in a cross shape; Wherein, the base (11) is fixedly mounted on the frame (6) by means of screws (7).

9. The drone according to claim 8, characterized in that: A foot base (8) is fixedly connected to the bottom of the frame (6).

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