Power clutch for unmanned aerial vehicle

Abstract

The invention discloses a power clutch for an unmanned aerial vehicle, which belongs to the technical field of aircraft power transmission and comprises a power output mechanism, an output flange, an actuating mechanism, a driving disc and a driven disc. And the output flange can rotate relative to the main shaft sleeve for power output. And the actuating mechanism is used for driving the driving disc to axially move on the main shaft sleeve. The driven disc is arranged in the output flange, and a clamping piece is arranged between the driven disc and the driving disc. The driving disc is driven by the executing mechanism to move axially, and the driven disc and the driving disc are pushed to be mechanically locked through a clamping piece. The relative rotation design of the main shaft sleeve and the output flange allows dynamic separation of power output and a load end. The clamping piece maintains the state through physical occlusion after being closed, continuous energy input of the executing mechanism is not needed, and energy consumption is remarkably reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft power transmission, and in particular to a power clutch for an unmanned aerial vehicle. Background Art

[0002] With the widespread use of drones in logistics, emergency rescue, agricultural plant protection, and other fields, their power systems are facing demands for higher reliability, longer flight time, and adaptability to multiple operating conditions. Traditional drones mostly use a direct-drive engine-propeller power structure, but this direct-drive power transmission layout suffers from insufficient power redundancy, limited energy efficiency optimization, and significant response delays. For example, when a single engine fails, there is no mechanism to quickly disconnect the faulty unit and switch to backup power, resulting in a crash risk. Furthermore, during the aircraft's gliding or low-power cruising phases, non-essential power units cannot be actively disconnected, resulting in energy waste.

[0003] Therefore, installing a clutch between the engine and propeller allows for flexible control of power transmission. When the clutch is closed, a torque transmission channel is established between the engine output shaft and the propeller, and when it is disconnected, the power is physically isolated. Traditional mechanical clutches are often driven hydraulically, but the engagement and disengagement times are generally long, which cannot meet the real-time requirements of high-speed UAV attitude adjustment. Electromagnetic clutches use electromagnetic force to drive friction plates, magnetic powder, or eddy current fields to transmit torque, which has the advantage of rapid response. However, maintaining the electromagnetic force requires continuous power supply, which reduces the UAV's endurance performance.

[0004] Patent publication number CN117401203A discloses a clutch mechanism for controlling the rotation and starting of drone propellers. The centrifugal shoe clutch is fixedly connected to the engine and rotates synchronously with the engine. This clutch mechanism operates by allowing the shoe of the centrifugal shoe clutch to expand outward under the influence of centrifugal force and contact the inner wall of the outer shell. The resulting friction creates torque, which drives the propeller through the outer shell. While this structure achieves clutching, the clutching action is controlled solely by the centrifugal force acting on the clutch, making power transmission impossible at low speeds. Summary of the Invention

[0005] The object of the present invention is to provide a power clutch for a drone to solve the problems raised in the above-mentioned prior art.

[0006] Provided is a power clutch for a drone, comprising:

[0007] A power output mechanism, comprising a main shaft sleeve for outputting power;

[0008] Output flange, which can rotate relative to the main shaft sleeve;

[0009] an actuator, which is arranged on a housing of the power output mechanism;

[0010] A driving disc having only axial movement freedom in the main shaft sleeve, and the actuator is drivingly connected to the driving disc;

[0011] The driven disc is arranged inside the output flange, and a clamping piece is provided between the driven disc and the driving disc.

[0012] As a further embodiment of the present invention: the clamping member includes a clamping slot and a plurality of deformable contact fingers, and the deformable contact fingers have a deformation action and a recovery action under the limitation of the clamping slot during the movement process.

[0013] The deformable contact finger elastically deforms during axial movement, restrained by the retaining groove. Once locked, it returns to its original shape, forming a rigid connection. This elastic deformation provides both a flexible cushion during engagement and a mechanically secure connection to the retaining groove through its restoring force. The elastic preload of the deformable contact finger counteracts the drive plate's tendency to slip due to its own weight and high-frequency vibrations during flight, preventing accidental clutch disengagement.

[0014] As a further embodiment of the present invention: the cavity wall where the snap-fit groove contacts the deformable contact finger forms a stopper and a cavity from the outside to the inside, and the deformable contact finger has a slope that can be in contact with and squeezed by the stopper and a root that is forced to deform during the squeezing process.

[0015] When the slope contacts the stop, a radial force component is generated, forcing the base to contract inward. Once inside the cavity, the base expands and locks. The stop acts as a mechanical limiter, preventing the deformed finger from slipping back out. The slope's guiding design ensures a smooth deformation process, concentrating stress at the base and preventing overall plastic deformation and failure of the finger.

[0016] As a further embodiment of the present invention: some of the roots are provided with strain gauges.

[0017] Strain gauges monitor the deformation stress at the root in real time and provide feedback to the control system. When the clutch is closed and the actuator detects excessive deformation of the contact finger, it triggers the anti-disengagement mechanism, outputting emergency power to the drive plate to restore close contact with the driven plate, thus completing the control logic closed loop.

[0018] As a further embodiment of the present invention: a rib is provided between adjacent roots, and the rib is recessed in the axial direction of the driving disc away from the driven disc.

[0019] The ribs are used to constrain lateral deformation at the root. The recessed design of the ribs enhances the lateral bending moment resistance of the deformable contact finger at the root, providing structural strength to resist lateral deformation while not significantly affecting the vertical deformation of the deformable contact finger at the root, thereby improving the structural stability of the deformable contact finger for long-term use.

[0020] As a further embodiment of the present invention: the driving disc is provided with a plurality of first meshing teeth along the circumference, and the driven disc is provided with a plurality of second meshing teeth along the circumference, and the first meshing teeth and the second meshing teeth can contact each other.

[0021] The driving and driven discs transmit torque through direct engagement between the first and second meshing teeth, forming a rigid mechanical connection. This rigid meshing virtually eliminates relative slip, preventing frictional heat generation that can lead to coupling failure and energy waste, significantly improving transmission efficiency.

[0022] As a further embodiment of the present invention: an arc-shaped guide surface is formed on a side of the first meshing tooth and the second meshing tooth away from the torque transmission surface.

[0023] The curved guide surface is located on the non-torque transmission side of the meshing teeth. When the driving and driven discs engage, if there is axial or circumferential misalignment between the teeth, the curved surface first contacts and generates a tangential sliding guide force, prompting the teeth to automatically adjust their position and avoid hard collisions. This reduces tooth tip collisions caused by misalignment and lowers the chance of engagement failure, making it particularly suitable for dynamic meshing scenarios during high-speed rotation.

[0024] As a further embodiment of the present invention: the normal line of the torque transmission surface of the first meshing tooth extends in a direction away from the driven disc, and the normal line of the torque transmission surface of the second meshing tooth extends in a direction away from the driving disc.

[0025] The normal directions of the torque transmission surfaces of the first meshing tooth and the second meshing tooth are designed to extend away from the other disc body. When the torque is transmitted and there is a tendency for the tooth surfaces to disengage, the contact force between the meshing teeth can be decomposed to form a tangential friction force. The greater the torque, the stronger the tangential friction force between the meshing teeth, forming a "torque-friction force" positive feedback, which significantly reduces the load on the clamping parts.

[0026] As a further embodiment of the present invention: the actuator includes an electromagnetic coil winding, and a magnet assembly is provided in the driving disk.

[0027] The actuator utilizes electromagnetic coil windings and a built-in magnet assembly on the drive disc. When the coil is energized, a controllable magnetic field is generated, interacting with the magnet assembly to produce axial electromagnetic thrust, rapidly moving the drive disc. This electromagnetic force operates without intermediate transmission links, resulting in minimal operational latency. Because the closed state is maintained by the mechanical self-locking of the clip, the electromagnetic drive consumes energy only during the switching instant, significantly reducing overall energy consumption compared to electromagnetic friction clutches that require continuous power.

[0028] As a further embodiment of the present invention: a first bearing is provided between the main shaft sleeve and the actuator.

[0029] After establishing a clutch between the main shaft sleeve and the output flange, there is a dynamic response process and vibration risk. Therefore, a bearing connection is established between the main shaft sleeve and the actuator. The fixation of the actuator and the engine housing is used to provide radial constraints to the main shaft sleeve, which significantly improves the rotational stability of the main shaft sleeve. This allows the actuator to have the function of executing clutch and improves the stability of the entire propeller drive mechanism.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The actuator drives the driver disc to move axially, forcing the driven disc to mechanically lock with the driver disc via a snap-fit mechanism. The relative rotation of the spindle sleeve and output flange allows dynamic decoupling of the power output and load. Once closed, the snap-fit mechanism maintains this position through physical engagement, eliminating the need for continuous energy input from the actuator and significantly reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present drawings or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present drawings. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0033] Figure 1 This is a schematic diagram of the cross-sectional structure of a power clutch for a UAV;

[0034] Figure 2 A partial three-dimensional structural diagram of the clutch provided by the present invention;

[0035] Figure 3 for Figure 2 Enlarged view of area A in the middle;

[0036] Figure 4 This is a partial cross-sectional structural diagram of the clutch provided by the present invention.

[0037] In the figure: 1. power output mechanism; 11. spindle sleeve; 2. output flange; 3. actuator; 4. driving plate; 41. first meshing tooth; 5. driven plate; 51. second meshing tooth; 6. clamping member; 61. clamping groove; 611. stop portion; 612. cavity portion; 62. deformation contact finger; 621. slope portion; 622. root portion; 623. strain gauge; 624. rib plate; 7. arc-shaped guide surface; 8. first bearing. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0039] Obviously, the drawings described below are merely examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios based on these drawings without inventive effort. Furthermore, it is understood that while the effort involved in such a development process may be complex and lengthy, for those skilled in the art related to the disclosure of the present invention, any design, manufacturing, or production changes based on the technical content disclosed in the present invention are merely conventional technical means and should not be construed as an inadequacy of the disclosure of the present invention.

[0040] However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of substantially identical structures may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Furthermore, the drawings and the following description are provided to facilitate a thorough understanding of the present invention by those skilled in the art and are not intended to limit the subject matter recited in the claims.

[0041] See also Figure 1-Figure 2 As shown, the power clutch for a drone in an embodiment of the present invention includes a power output mechanism 1, an output flange 2, an actuator 3, a drive disc 4, and a driven disc 5. The power output mechanism 1 includes a main shaft sleeve 11 for outputting power. The output flange 2 is rotatable relative to the main shaft sleeve 11. The actuator 3 is disposed on the housing of the power output mechanism 1. The drive disc 4 has only axial freedom of movement within the main shaft sleeve 11, and the actuator 3 is transmission-connected to the drive disc 4. The driven disc 5 is disposed within the output flange 2, with a clamping member 6 disposed between the driven disc 5 and the drive disc 4.

[0042] The main shaft sleeve 11 is connected to the engine to form the overall structure of the power output mechanism 1. The power output mechanism 1, the output flange 2 and the actuator 3 constitute the core structural framework of the clutch. The torque power is transmitted through the main shaft sleeve 11 of the power output mechanism 1, and the relative rotation of the output flange 2 and the main shaft sleeve 11 realizes power separation. The drive disc 4 can only move axially relative to the main shaft sleeve 11 and can be connected to the main shaft sleeve 11 through a spline. The driven disc 5 is fixed inside the output flange 2 and is arranged opposite to the drive disc 4. The drive disc 4 is driven by the actuator 3, which pushes the drive disc 4 to combine with the driven disc 5 and locks it through the clamping part 6 to form a rigid connection or separation. The clutch realizes dynamic control of power transmission. After the clamping part 6 is mechanically locked, no continuous energy input is required, the energy consumption is low, the structure is compact, and it is suitable for the long-term endurance requirements of drones.

[0043] In one embodiment, the clamping member 6 performs a locking action by magnet attraction, and ensures that the driving disk 4 and the driven disk 5 are always stably combined through magnetic attraction.

[0044] In one embodiment, see Figure 2 and Figure 4 As shown, the clamping member 6 includes a clamping slot 61 and a plurality of deformable contact fingers 62. The clamping member 6 achieves engagement through the deformation and recovery of the deformable contact fingers 62 within the clamping slot 61. The deformable contact fingers 62 elastically deform under compression during axial movement and restore their shape after entering the locked position, forming a rigid connection within the structural constraints. The elastic cushioning of the deformable contact fingers 62 reduces the impact of the engagement between the drive disc 4 and the driven disc 5. The rigid connection after recovery ensures efficient torque transmission. The elastic preload of the clamping member 6 offsets the self-weight slip and vibration of the drive disc 4, preventing accidental clutch disengagement.

[0045] Specifically, the cavity wall where the engaging groove 61 contacts the deformable contact finger 62 forms a stopper 611 and a cavity 612 from the outside to the inside. The deformable contact finger 62 has a slope 621 that can be pressed against the stopper 611 and a root 622 that is forced to deform during the pressing process. When the driving disc 4 moves toward the driven disc 5 to perform the engagement action, the stopper 611 of the engaging groove 61 contacts the slope 621 of the deformable contact finger 62 to generate a radial component of force, forcing the root 622 to deform radially until the slope 621 enters the cavity 612 and then resumes its expansion to complete the locking. After locking, the slope 621 adapts to the shape of the cavity 612, forming a structural limit between the slope 621 and the stopper 611. If the clutch tends to disengage, the root 622 needs to overcome the elastic restoring force to deform, thereby providing a locking force to prevent disengagement. In addition, the front arc-shaped guiding surface of the slope portion 621 makes the deformation smooth, and the stop portion 611 provides reverse limiting to prevent slipping.

[0046] It should be noted that, in the illustration of this application, after the clutch is engaged, the stop portion 611 is arranged on the inner ring relative to the slope portion 621, and the slope portion 621 is located on the outer ring to form a fit. The present invention only provides an arrangement embodiment, and does not limit the arrangement direction of the snap-in groove 61 and the deformation contact finger 62.

[0047] Furthermore, strain gauges 623 are simultaneously deployed at multiple bases 622 of the deformable contact finger 62, forming a multi-point detection network that can monitor the stress distribution and deformation differences at each base 622 in real time. This deformation monitoring system, comprised of multiple strain gauges 623, can identify localized overloads or uneven deformation. For example, if a strain gauge 623 at a particular base 622 displays significantly higher stress than at other points, this could indicate eccentricity of the connector 6 or a foreign object being trapped. This multi-point arrangement creates a redundant sensor array. Even if a single strain gauge 623 fails, the overall condition can still be inferred from data at other points.

[0048] In a specific use case, the sensing signal from strain gauge 623 is fed back to the control system in real time, dynamically adjusting the drive parameters of actuator 3. Specifically, when the clutch is closed, if the stress at root 622 exceeds a safety threshold, there is a risk of driver plate 4 and driven plate 5 separating. In this case, actuator 3 immediately triggers a propulsion action, re-strengthening the bond between driver plate 4 and driven plate 5, ensuring stable torque transmission and preventing the risk of a crash caused by power separation.

[0049] Further, see Figure 3 and Figure 4 As shown, ribs 624 are provided between adjacent roots 622, and the ribs 624 are recessed in the axial direction of the driving disc 4 away from the driven disc 5. The ribs 624 connect adjacent roots 622, so that each deformable contact finger 62 is connected in the circumferential direction to form a whole. When the root 622 is subjected to a lateral force, the ribs 624 increase the sectional moment of inertia of the root 622 to enhance the lateral bending resistance of the deformable contact finger 62, thereby preventing the deformable contact finger 62 from producing non-functional deformation and causing failure. This lateral force may be generated by aircraft vibration or by structural processing errors. The middle part of the rib 624 is recessed in the axial direction, so that the deformable contact finger 62 can maintain low bending stiffness in the radial direction and will not interfere with the normal elastic deformation of the root 622.

[0050] See also Figure 1 and Figure 2As shown, the drive disc 4 is circumferentially provided with a plurality of first meshing teeth 41, and the driven disc 5 is circumferentially provided with a plurality of second meshing teeth 51. The first meshing teeth 41 and the second meshing teeth 51 can contact each other. When the actuator 3 is de-energized, the drive disc 4 is in its initial position away from the driven disc 5, and the first meshing teeth 41 and the second meshing teeth 51 are completely disengaged. At this time, the main shaft sleeve 11 of the power output mechanism 1 is idling, the output flange 2 has no power output, and the UAV is in a free-gliding or power-off state. After the actuator 3 is activated, it pushes the drive disc 4 along the main shaft sleeve 11 toward the driven disc 5. The first meshing teeth 41 and the second meshing teeth 51 come into contact, assuming the torque transmission function. The complete meshing of the meshing teeth forms a rigid mechanical connection, and power is transmitted sequentially through the main shaft sleeve 11, the drive disc 4, the first meshing teeth 41, the second meshing teeth 51, the driven disc 5, the output flange 2, and finally to the propeller.

[0051] Further, see Figure 2 and Figure 3 As shown, the first meshing teeth 41 and the second meshing teeth 51 form an arcuate guide surface 7 on the side facing away from the torque transmission surface. If the tooth tips of the first meshing teeth 41 and the second meshing teeth 51 collide, the arcuate guide surface 7 converts the radial force between the first meshing teeth 41 and the second meshing teeth 51 into a tangential sliding force, automatically correcting the circumferential phase deviation between the driving plate 4 and the driven plate 5, and avoiding hard collisions of the tooth tips, especially during dynamic meshing during high-speed rotation.

[0052] Furthermore, the normal line of the torque transmission surface of the first meshing tooth 41 extends away from the driven disc 5, while the normal line of the torque transmission surface of the second meshing tooth 51 extends away from the driving disc 4. This structure allows the normal component of the contact force (perpendicular to the tooth surface) to be decomposed into a tangential component and an axial component when there is a tendency for the driving disc 4 and the driven disc 5 to disengage. The tangential component is the friction force in the opposite direction of the disengagement of the driving disc 4, resisting relative sliding; the axial component presses the two meshing teeth toward each other, enhancing contact tightness. This means that clutch disengagement requires overcoming the mechanical locking force of the clamping member 6 and the self-locking friction of the meshing teeth.

[0053] Actuator 3 includes electromagnetic coil windings, and a magnet assembly is located within drive disc 4. When energized, the electromagnetic coil windings of actuator 3 instantly generate a strong magnetic field, which interacts with the magnet assembly (e.g., permanent magnets or soft magnetic material) within drive disc 4 to generate axial electromagnetic thrust. This electromagnetic force acts directly on drive disc 4, eliminating the need for hydraulic transmission or gear linkage required in traditional clutches. This results in a fast response, and high-speed electromagnetic drive allows for real-time dynamic adjustment.

[0054] See also Figure 1As shown, a first bearing 8 is provided between the output flange 2 and the main shaft sleeve 11. Similarly, a first bearing 8 is provided between the main shaft sleeve 11 and the actuator 3. The first bearing 8 is installed between the main shaft sleeve 11 and the actuator 3, forming a rigid radial support point. When the main shaft sleeve 11 rotates, the first bearing 8 absorbs radial runout through the cooperation of the raceway and the rolling element. During drone maneuvering flight, the gyroscopic effect of the propeller and aerodynamic loads may cause the main shaft sleeve 11 to deflect. The first bearing 8 provides lateral stiffness to limit the radial displacement of the sleeve. The actuator 3 is rigidly connected to the engine through the housing. The first bearing 8 transfers the vibration energy of the main shaft sleeve 11 to the fuselage frame for dissipation, rather than feeding it back into the clutch.

[0055] It should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the technical solution of the present invention are all included in the technical scope of the present invention. In addition, without departing from the scope of the present invention, other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A power clutch for a drone, characterized in that: include: A power output mechanism (1) comprising a main shaft sleeve (11) for outputting power; An output flange (2) rotatable relative to the spindle sleeve (11); An actuator (3) is arranged on a housing of the power output mechanism (1); A driving disc (4) having only axial movement freedom in the main shaft sleeve (11), wherein the actuator (3) is in driving connection with the driving disc (4); A driven disc (5) is arranged inside the output flange (2), and a clamping member (6) is provided between the driven disc (5) and the driving disc (4).

2. A power clutch for a drone according to claim 1, characterized in that: The clamping member (6) comprises a clamping slot (61) and a plurality of deformable contact fingers (62), wherein the deformable contact fingers (62) have a deformation action and a recovery action under the limitation of the clamping slot (61) during the movement process.

3. The power clutch for a drone according to claim 2, characterized in that: The cavity wall where the clamping groove (61) contacts the deformable contact finger (62) forms a stopper (611) and a cavity (612) from the outside to the inside, and the deformable contact finger (62) has a slope (621) that can be in contact with and squeezed by the stopper (611) and a root (622) that is forced to deform during the squeezing process.

4. The power clutch for a drone according to claim 3, characterized in that: Several of the roots (622) are provided with strain gauges (623).

5. The power clutch for a drone according to claim 3, characterized in that: A rib plate (624) is provided between adjacent roots (622), and the rib plate (624) is recessed in the axial direction of the driving disc (4) in a direction away from the driven disc (5).

6. The power clutch for a drone according to claim 1, characterized in that: The driving disc (4) is provided with a plurality of first meshing teeth (41) along the circumference, and the driven disc (5) is provided with a plurality of second meshing teeth (51) along the circumference. The first meshing teeth (41) and the second meshing teeth (51) can contact each other.

7. The power clutch for a drone according to claim 6, characterized in that: The first meshing teeth (41) and the second meshing teeth (51) form an arc-shaped guide surface (7) on the side facing away from the torque transmission surface.

8. The power clutch for a drone according to claim 6, characterized in that: The normal line of the torque transmission surface of the first meshing tooth (41) extends in a direction away from the driven disc (5), and the normal line of the torque transmission surface of the second meshing tooth (51) extends in a direction away from the driving disc (4).

9. The power clutch for a drone according to claim 1, characterized in that: The actuator (3) comprises an electromagnetic coil winding, and a magnet assembly is arranged in the driving disc (4).

10. The power clutch for a drone according to claim 1, characterized in that: A first bearing (8) is provided between the main shaft sleeve (11) and the actuator (3).

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