Power device of unmanned aerial vehicle and unmanned aerial vehicle

Abstract

The invention relates to a power device of an unmanned aerial vehicle and the unmanned aerial vehicle. A power device of the unmanned aerial vehicle comprises a main shaft, a motor, a steering engine and a rotor wing assembly. The spindle is fixed to the top of the unmanned aerial vehicle body. The motor is arranged on the main shaft, the steering engine and the rotor wing assembly are both in driving connection with the motor, and the steering engine and the rotor wing assembly can both rotate around the axial direction of the main shaft under driving of the motor. The rotor assembly comprises a propeller hub and blades, the propeller hub is in driving connection with the motor, and the blades are connected with the propeller hub. An output shaft of the steering engine is provided with a first gear, the propeller hub is provided with a second gear, when the flight direction is changed, the steering engine is started and drives the first gear to rotate, and the first gear and the second gear are in meshing transmission, so that the rotor wing assembly rotates by a certain angle, namely, the pitch angle of the propeller blades and the propeller pitch of the rotor wing assembly are adjusted. Thus, a traditional complex and heavy automatic inclinator control system can be replaced, the weight of the unmanned aerial vehicle can be reduced, the control precision of variable pitch is improved, and accurate variable pitch is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of unmanned aerial vehicles, and in particular to a power device of an unmanned aerial vehicle and the unmanned aerial vehicle. Background Art

[0002] A drone is an unmanned aircraft that is controlled by a radio remote control device and a self-contained program control device or is operated completely or intermittently autonomously by an onboard computer.

[0003] The UAV includes a rotor assembly and a control mechanism. The common control mechanism includes a servo, a pull rod and a swash plate. The servo controls the swash plate through the pull rod to control the variable pitch of the rotor assembly. However, the common control mechanism has a complex and bulky structure and low pitch change accuracy. Summary of the invention

[0004] Based on this, it is necessary to provide a power device and a UAV for a UAV, which can reduce the weight of the UAV, improve the control accuracy of the pitch change, and achieve precise pitch change.

[0005] In a first aspect, the present application provides a power device for an unmanned aerial vehicle, comprising:

[0006] Spindle;

[0007] A motor, wherein the motor is arranged on the main shaft;

[0008] A steering gear, the steering gear is drivingly connected to the motor, and driven by the motor, the steering gear can rotate around the axial direction of the main shaft;

[0009] A rotor assembly, the rotor assembly comprising a hub and blades connected to the hub, the hub being drivingly connected to the motor, and driven by the motor, the rotor assembly can rotate around the axial direction of the main shaft; and

[0010] The transmission mechanism includes a first gear and a second gear, the first gear is arranged on the output shaft of the servo, the second gear is arranged on the propeller hub, and the first gear cooperates with the second gear to change the pitch of the rotor assembly.

[0011] In one embodiment, the rotor assembly includes at least two hubs and at least two blades, all of the hubs are connected to the motor drive, all of the hubs are provided with the second gear, and all of the blades are connected to all of the hubs in a one-to-one correspondence.

[0012] In one embodiment, the rotor assembly corresponds to at least two of the servos, all of the servos correspond one-to-one with all of the propeller hubs, all of the servos are provided with a first gear, and all of the first gears are in one-to-one transmission cooperation with all of the second gears.

[0013] In one embodiment, the rotor assembly corresponds to one servo, at least two first gears are provided, all the first gears are coupled to form a gear set, and the gear set is coupled to all the second gears.

[0014] In one embodiment, the motors are provided with two, namely an upper motor and a lower motor, and the upper motor and the lower motor are both provided on the main shaft and spaced apart along the axial direction of the main shaft; the servos are provided with at least two, namely an upper servo and a lower servo, and the upper servo is drivingly connected to the upper motor, and the lower servo is drivingly connected to the lower motor; the rotor assemblies are provided with two, namely an upper rotor assembly and a lower rotor assembly, and the upper rotor assembly is drivingly connected to the upper motor, and the lower rotor assembly is drivingly connected to the lower motor; the transmission mechanisms are provided with two, namely an upper transmission mechanism and a lower transmission mechanism, and the upper servo is connected to the upper rotor assembly via the upper transmission mechanism, and the lower servo is connected to the lower rotor assembly via the lower transmission mechanism.

[0015] In one of the embodiments, the power device of the UAV further includes a propeller chuck, which is drive-connected to the motor, and the servo and the propeller hub are both mounted on the propeller chuck.

[0016] In one embodiment, the power unit of the UAV also includes a posture sensor, which is used to communicate with the flight control system; the posture sensor is arranged on the propeller chuck, and the posture sensor is used to detect the inclination angle and posture of the motor; and / or, the posture sensor is arranged on the propeller hub, and the posture sensor is used to detect the inclination angle and posture of the blade.

[0017] In one embodiment, the motor includes a stator and a rotor cooperating with the stator, the stator is fixed to the main shaft, the rotor is rotatably connected to the main shaft, and the servo and the propeller hub are both connected to the rotor.

[0018] In one embodiment, the setting direction of the rotor assembly is perpendicular to the axial direction of the main shaft, and the setting direction of the servo is parallel to the axial direction of the main shaft; and / or, the first gear and the second gear are one of a helical gear and a bevel gear.

[0019] In a second aspect, the present application also provides a drone, comprising a drone body and the above-mentioned power device, wherein the power device is installed on the drone body.

[0020] In the above-mentioned UAV and its power device, during normal flight, the motor drives the servo and the rotor assembly to rotate around the axial direction of the main shaft. When the flight direction changes, the servo is started, and the servo drives the first gear to rotate, and the first gear and the second gear are meshed and transmitted, so that the rotor assembly rotates a certain angle, that is, the pitch angle of the blade is adjusted, thereby adjusting the pitch of the rotor assembly. In this way, the angle of the rotor assembly is directly controlled by the output of the servo, which can replace the traditional complex and bulky automatic tilt control system, which is conducive to reducing the weight of the UAV, improving the control accuracy of the pitch change, realizing precise pitch change, and improving the flight efficiency of the UAV. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of a drone according to an embodiment of the present application.

[0022] Figure 2 This is a schematic structural diagram of a drone according to another embodiment of the present application.

[0023] Description of Figure Numbers:

[0024] 10. Power unit; 11. Main shaft; 12. Motor; 13. Servo; 14. Rotor assembly; 141. Hub; 142. Blade; 15. Propeller chuck; 20. UAV body. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0026] See also Figure 1 The drone provided by one embodiment of the present application includes a drone body 20 and a power device 10. The power device 10 is disposed on the drone body 20, and the power device 10 is used to provide lift so that the drone can fly.

[0027] In one embodiment, see Figure 1 The power device 10 includes a main shaft 11, a motor 12, a steering gear 13, a rotor assembly 14 and a transmission mechanism.

[0028] See also Figure 1 and Figure 2 , the main shaft 11 is arranged on the top of the drone body 20. Optionally, the main shaft 11 is a hollow cylindrical member, which can reduce the weight of the drone and reduce the cost.

[0029] See also Figure 1 and Figure 2 The motor 12 is provided on the main shaft 11, and the steering gear 13 and the rotor assembly 14 are both drivingly connected to the motor 12. The rotor assembly 14 includes a hub 141 and blades 142, the hub 141 is drivingly connected to the motor 12, and the blades 142 are connected to the hub 141. Under the drive of the motor 12, the steering gear 13 and the rotor assembly 14 can rotate around the axial direction of the main shaft 11.

[0030] The transmission mechanism includes a first gear and a second gear. The first gear is arranged on the output shaft of the steering gear 13, and the second gear is arranged on the propeller hub 141. The first gear and the second gear cooperate with each other to change the pitch of the rotor assembly 14.

[0031] In the above-mentioned power device 10, during normal flight, the motor 12 drives the steering gear 13 and the rotor assembly 14 to rotate around the axial direction of the main shaft 11. When the flight direction changes, the steering gear 13 is started, and the steering gear 13 drives the first gear to rotate, and the first gear and the second gear are meshed and transmitted, so that the rotor assembly 14 rotates a certain angle, that is, the pitch angle of the blade 142 is adjusted, thereby adjusting the pitch of the rotor assembly 14. In this way, the angle of the rotor assembly 14 is directly controlled by the output of the steering gear 13, which can replace the traditional complex and bulky automatic tilt control system, which is conducive to reducing the weight of the UAV, improving the control accuracy of the pitch change, realizing precise pitch change, and improving the flight efficiency of the UAV.

[0032] In one embodiment, see Figure 1 and Figure 2 The rotor assembly 14 includes at least two propeller hubs 141 and at least two propeller blades 142. All propeller hubs 141 are drivingly connected to the motor 12, and all propeller blades 142 are connected to all propeller hubs 141 in a one-to-one correspondence.

[0033] Optionally, see Figure 1 There are two propeller hubs 141, and the two propeller hubs 141 are arranged at 180 degrees. There are two propeller blades 142, and the two propeller blades 142 are connected to the two propeller hubs 141 in a one-to-one correspondence.

[0034] Optionally, there are more than three propeller hubs 141, and all the propeller hubs 141 are arranged at equal intervals around the axial direction of the main shaft 11. There are more than three propeller blades 142, and all the propeller blades 142 are connected to all the propeller hubs 141 in a one-to-one correspondence.

[0035] Furthermore, all the propeller hubs 141 are provided with a second gear, so that the steering engine 13 can drive the propeller hubs 141 to move.

[0036] In one embodiment, see Figure 1One rotor assembly 14 corresponds to at least two steering gears 13, and all steering gears 13 correspond to all propeller hubs 141. All steering gears 13 are provided with first gears, and all first gears correspond to all second gears in a one-to-one transmission manner.

[0037] Understandably, see Figure 1 The number of the servos 13 is the same as the number of the propeller hubs 141 , and one servo 13 drives one propeller hub 141 to move, so that the movements of each propeller hub 141 are independent and do not interfere with each other.

[0038] In another embodiment, see Figure 2 , one rotor assembly 14 corresponds to one steering gear 13. There are at least two first gears, all of which are matched to form a gear set, and the gear set is matched with all of the second gears. In this way, the gear set and all of the second gears corresponding thereto are matched to each other for transmission, which can avoid meshing jump and make the transmission more stable.

[0039] It is understandable that the number of the steering gears 13 is equal to the number of the rotor assemblies 14. One steering gear 13 is matched with all the second gears through the gear set, so that one steering gear 13 can drive all the corresponding propeller hubs 141 to move synchronously.

[0040] In one embodiment, see Figure 1 and Figure 2 There are two motors 12 , and both motors 12 are disposed on the main shaft 11 and spaced apart along the axial direction of the main shaft 11 .

[0041] by Figure 1 and Figure 2 For example, the two motors 12 are an upper motor 12 and a lower motor 12 , wherein the upper motor 12 is disposed at an end of the main shaft 11 away from the drone body 20 , and the lower motor 12 is disposed at an end of the main shaft 11 close to the drone body 20 .

[0042] Further, see Figure 1 and Figure 2 There are two rotor assemblies 14, and the two rotor assemblies 14 are respectively connected to the two motors 12 in a one-to-one driving manner.

[0043] by Figure 1 and Figure 2 For example, the two rotor assemblies 14 are an upper rotor assembly 14 and a lower rotor assembly 14 , wherein the upper rotor assembly 14 is drivingly connected to the upper motor 12 , and the lower rotor assembly 14 is drivingly connected to the lower motor 12 .

[0044] Specifically, the upper rotor assembly 14 includes an upper hub 141 and upper blades 142 . The upper hub 141 is drivingly connected to the upper motor 12 , and the upper blades 142 are connected to the upper hub 141 .

[0045] Specifically, the lower rotor assembly 14 includes a lower propeller hub 141 and lower blades 142 . The lower propeller hub 141 is drivingly connected to the lower motor 12 , and the lower blades 142 are connected to the lower propeller hub 141 .

[0046] It should be noted that the number of the upper propeller hub 141 and the number of the lower propeller hub 141 may be the same or different. The number of the upper propeller blades 142 and the number of the lower propeller blades 142 may be the same or different.

[0047] Further, see Figure 1 and Figure 2 There are at least two steering gears 13 , and each motor 12 is drivingly connected to at least one steering gear 13 .

[0048] by Figure 1 and Figure 2 For example, the servo 13 includes an upper servo 13 and a lower servo 13 , wherein each of the upper servo 13 and the lower servo 13 is provided with at least one, the upper servo 13 is drivingly connected to the upper motor 12 , and the lower servo 13 is drivingly connected to the lower motor 12 .

[0049] Among them, the output ends of the upper servo 13 and the lower servo 13 are both provided with a first gear, the hub 141 of the upper rotor assembly 14 and the hub 141 of the lower rotor assembly 14 are both provided with a second gear, the first gear of the upper servo 13 is matched with the second gear portion of the upper hub, and the first gear of the lower servo 13 is matched with the second gear portion of the lower hub.

[0050] It should be noted that the upper rotor assembly 14 is responsible for lateral cyclic pitch change, that is, the upper rotor assembly 14 controls the forward direction. The lower rotor assembly 14 is responsible for longitudinal cyclic pitch change, that is, the lower rotor assembly 14 provides lift.

[0051] In one embodiment, the direction of rotation of upper rotor assembly 14 is opposite to the direction of rotation of lower rotor assembly 14 .

[0052] Optionally, the upper rotor assembly 14 rotates clockwise around the axial direction of the main shaft 11, and the lower rotor assembly 14 rotates counterclockwise around the axial direction of the main shaft 11. Alternatively, the upper rotor assembly 14 rotates counterclockwise around the axial direction of the main shaft 11, and the lower rotor assembly 14 rotates clockwise around the axial direction of the main shaft 11.

[0053] There is a speed difference between the upper motor 12 and the lower motor 12. In this way, the speed difference between the upper motor 12 and the lower motor 12 is used to achieve yaw control.

[0054] In one embodiment, the first gear and the second gear are both helical gears. In this way, installation interference can be avoided. In addition, the meshing performance is good, the transmission is stable, and the noise is low; the overlap is large. Under the same conditions, the meshing process of the helical gear is longer than that of the spur gear, that is, the overlap is large, which reduces the load of each pair of gears, thereby improving the bearing capacity of the gears, extending the service life of the gears, and making the transmission stable; the structure is compact. When the helical cylindrical gear is cut with a rack-shaped tool, the minimum number of teeth of the non-root-cut gear is less than that of the spur cylindrical gear, so a more compact structure can be obtained.

[0055] Of course, in other embodiments, the first gear and the second gear are both bevel gears, wherein bevel gears have the characteristics of low noise, wear resistance, high transmission efficiency, strong load-bearing capacity, space saving, reliable operation, long life and good wear resistance.

[0056] In one embodiment, see Figure 1 and Figure 2 The power device 10 of the UAV further includes a propeller chuck 15. The propeller chuck 15 is drivingly connected to the motor 12, and the steering engine 13 and the propeller hub 141 are both installed on the propeller chuck 15. In this way, by providing the propeller chuck 15, it is convenient to install the steering engine 13 and the propeller hub 141, and the convenience of installing the steering engine 13 and the propeller hub 141 is improved.

[0057] It should be noted that the paddle chuck 15 is an existing structure and will not be described in detail here.

[0058] In one embodiment, the motor 12 includes a stator and a rotor matched with the stator. The stator is fixed to the main shaft 11, the rotor is rotatably connected to the main shaft 11, and the steering gear 13 and the propeller hub 141 are both connected to the rotor. In this way, the rotor provides an installation position for the steering gear 13 and the propeller hub 141, which facilitates the installation of the steering gear 13 and the propeller hub 141. In addition, when the motor 12 rotates, the rotor rotates around the axial direction of the main shaft 11 to drive the steering gear 13 and the propeller hub 141 to rotate around the axial direction of the main shaft 11.

[0059] In one embodiment, the motor 12 is a brushless motor. The brushless motor 12 has no excitation loss and carbon brush loss, thus eliminating multi-stage deceleration loss and having the characteristic of saving electricity. The brushless motor 12 has no brushes, and the friction during operation is reduced, thereby reducing noise. At the same time, the brushless motor 12 has a simple structure, the parts can be accurately installed, and the operation is relatively stable. The brushless motor 12 does not need to frequently replace the brushes, which can reduce maintenance costs.

[0060] Of course, in other embodiments, the motor 12 may also be a brushed motor.

[0061] In one embodiment, the drone further includes a flight control system, which can stabilize the flight attitude of the drone and can control the drone to fly autonomously or semi-autonomously.

[0062] Furthermore, the power device 10 of the drone also includes a posture sensor. The posture sensor is arranged on the propeller chuck 15, and the posture sensor is connected to the flight control system in communication. Since the propeller chuck 15 is installed on the rotor of the motor 12, the posture sensor can detect the inclination angle and posture of the motor 12, and feed back the inclination angle and posture information of the motor 12 to the flight control system, and the flight control system adjusts the control of the pitch change of the rotor assembly 14 according to the inclination angle and posture of the motor 12. In this way, the posture sensor can detect the attitude of the rotor assembly 14 after the pitch change in real time, which is conducive to improving the accuracy.

[0063] Of course, in other embodiments, the position sensor can also be provided on the hub 141. Since the blade 142 is connected to the hub 141, the position sensor can detect the inclination angle and attitude of the blade 142, and feed back the inclination angle and attitude of the blade 142 to the flight control system. The flight control system adjusts the pitch control of the rotor assembly 14 according to the inclination angle and attitude of the blade 142.

[0064] In one embodiment, see Figure 1 and Figure 2 The setting direction of the rotor assembly 14 is perpendicular to the axial direction of the main shaft 11, and the setting direction of the steering gear 13 is parallel to the axial direction of the main shaft 11. It can be understood that the setting direction of the rotor assembly 14 is perpendicular to the setting direction of the steering gear 13. In this way, the space position can be reasonably utilized, making the power device 10 more compact, which is conducive to reducing the volume of the power device 10.

[0065] In one embodiment, the steering engine 13 is controlled by synchronously outputting PWM, so that high-precision synchronization can be achieved and deviation of the pitch change of the blades 142 can be avoided.

[0066] In this embodiment, the drone uses a PWM signal to control the servo 13. The duty cycle of the PWM signal determines the rotation angle of the servo 13. The motor inside the servo 13 controls the feedback of the position sensor through the PWM signal to adjust the rotation angle of the motor 12, thereby driving the output shaft to rotate.

[0067] The meshing of the first gear and the second gear. The gear type and module determine the reduction ratio and angle transmission relationship of the gear transmission. When the output shaft of the steering gear 13 rotates, the first gear and the second gear mesh, and the angle change can be accurately transmitted.

[0068] The relationship between the angle change and the pitch of the blade 142 is as follows: the servo 13 converts the angle change of the output shaft into the pitch change of the blade 142 through a mechanical structure. Usually, there is a fixed proportional or nonlinear relationship between the pitch change of the blade 142 and the angle of the output shaft of the servo 13 (depending on the design of the mechanical transmission structure).

[0069] Therefore, PWM signal-servo 13 angle-gear transmission-pitch of blade 142 is a complete signal transmission and mechanical control chain. If the servo 13 controls the pitch adjustment device of blade 142 (such as a variable pitch propeller), it is necessary to accurately match the output angle of the servo 13 and the pitch adjustment requirements, and consider parameters such as gear transmission ratio and angle range in mechanical design.

[0070] (1) Relationship between PWM signal and the angle of the servo 13

[0071] The angle of the servo 13 is proportional to the duty cycle of the PWM signal, which can be expressed as:

[0072]

[0073] in, Indicates the output angle of the servo 13 (unit: degree or radian); D indicates the duty cycle of the PWM signal (the duty cycle is usually expressed in 0-100% or pulse width, such as 1000μs-2000μs); Indicates the starting angle corresponding to the minimum duty cycle (usually 1000μs); Indicates the proportional coefficient of duty cycle to angle, which depends on the specifications of the servo 13 (e.g. 500μs corresponds to 90 ° ).

[0074] (2) Relationship between gear transmission

[0075] The angular change of the gear transmission is determined by the gear ratio, which is given by the following formula:

[0076]

[0077] in, Indicates the angle of output after gear transmission (i.e. the angle change of the transmission structure); Indicates the number of teeth of the first gear; Indicates the number of teeth on the second gear, gear ratio It can directly reflect the scaling relationship of angle transfer.

[0078] (3) Relationship between angle change and blade pitch

[0079] The relationship between the pitch change and the angle change of the blade 142 depends on the design of the transmission mechanism and can be expressed by the following formula:

[0080]

[0081] in, represents the pitch of the blade 142 (unit: mm or degree); It represents the proportional coefficient of pitch and angle change, which is determined by the mechanical transmission design; Indicates the initial pitch, that is, the pitch when the servo 13 is in zero position.

[0082] If the transmission mechanism is nonlinear (such as a linkage or cam mechanism), its relationship can be described as:

[0083]

[0084] function Determined by the geometric characteristics of the transmission mechanism, it may be a quadratic or higher-order nonlinear relationship.

[0085] Comprehensive formula:

[0086] Combining the above three processes, the relationship between PWM duty cycle and pitch change can be unified as:

[0087]

[0088] Or further simplified as:

[0089]

[0090] in:

[0091]

[0092] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0093] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0094] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0095] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0096] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0097] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0098] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A power device for an unmanned aerial vehicle, characterized in that: include: Spindle; A motor, wherein the motor is arranged on the main shaft; A steering gear, the steering gear is drivingly connected to the motor, and driven by the motor, the steering gear can rotate around the axial direction of the main shaft; A rotor assembly, the rotor assembly comprising a hub and blades connected to the hub, the hub being drivingly connected to the motor, and under the drive of the motor, the rotor assembly can rotate around the axial direction of the main shaft; as well as The transmission mechanism includes a first gear and a second gear, the first gear is arranged on the output shaft of the servo, the second gear is arranged on the propeller hub, and the first gear cooperates with the second gear to change the pitch of the rotor assembly.

2. The power device of the UAV according to claim 1, characterized in that: The rotor assembly includes at least two hubs and at least two blades, all of the hubs are drivingly connected to the motor, all of the hubs are provided with the second gear, and all of the blades are connected to all of the hubs in a one-to-one correspondence.

3. The power device of the UAV according to claim 2, characterized in that: The rotor assembly corresponds to at least two of the servos, all of the servos correspond to all of the propeller hubs one-to-one, all of the servos are provided with a first gear, and all of the first gears correspond to all of the second gears in a one-to-one transmission manner.

4. The power device of the UAV according to claim 2, characterized in that: The rotor assembly corresponds to one steering gear, at least two first gears are provided, all the first gears are matched to form a gear set, and the gear set is matched with all the second gears.

5. The power device of the UAV according to claim 1, characterized in that: The motors are provided with two, namely an upper motor and a lower motor, and the upper motor and the lower motor are both provided on the main shaft and spaced apart along the axial direction of the main shaft; The steering gear is provided with at least two, namely an upper steering gear and a lower steering gear, the upper steering gear is drivingly connected to the upper motor, and the lower steering gear is drivingly connected to the lower motor; The rotor assembly is provided with two, namely an upper rotor assembly and a lower rotor assembly, the upper rotor assembly is drivingly connected to the upper motor, and the lower rotor assembly is drivingly connected to the lower motor; The transmission mechanism is provided with two, namely an upper transmission mechanism and a lower transmission mechanism. The upper steering gear is connected to the upper rotor assembly via the upper transmission mechanism, and the lower steering gear is connected to the lower rotor assembly via the lower transmission mechanism.

6. The power device of the UAV according to claim 1, characterized in that: The power device of the UAV also includes a propeller chuck, which is drivingly connected to the motor, and the steering gear and the propeller hub are both installed on the propeller chuck.

7. The power device of the UAV according to claim 6, characterized in that: The power device of the UAV also includes a posture sensor, which is used to communicate with the flight control system; The position sensor is arranged on the propeller chuck, and the position sensor is used to detect the inclination angle and posture of the motor; and / or, the position sensor is arranged on the propeller hub, and the position sensor is used to detect the inclination angle and posture of the propeller blade.

8. The power device of the UAV according to any one of claims 1 to 7, characterized in that: The motor comprises a stator and a rotor matched with the stator, the stator is fixed to the main shaft, the rotor is rotatably connected to the main shaft, and the steering gear and the propeller hub are both connected to the rotor.

9. The power device of the UAV according to any one of claims 1 to 7, characterized in that: The rotor assembly is arranged in a direction perpendicular to the axial direction of the main shaft, and the steering gear is arranged in a direction parallel to the axial direction of the main shaft; And / or, the first gear and the second gear are both helical gears and bevel gears.

10. A drone, characterized in that: It comprises a drone body and a power device as described in any one of claims 1 to 9, wherein the power device is installed on the drone body.

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