Composite material propeller variable pitch structure of unmanned aerial vehicle

Abstract

The invention discloses an unmanned aerial vehicle composite material propeller variable pitch structure, and relates to the technical field of unmanned aerial vehicles, the device comprises a driving mechanism, a composite head cover, a plurality of composite blades and a propeller hub, the propeller hub is connected with the driving end of the driving mechanism and is driven by the driving mechanism to rotate, and the composite head cover is connected with the driving mechanism through a fixing seat. The adjusting assembly is fixedly arranged on the fixed seat connected with the driving mechanism and the composite head cover, and the driving end of the adjusting assembly directly acts on the rotating assembly connected with the composite blade and the propeller hub, so that the composite blade accurately rotates around the axis of the composite blade to change the propeller pitch; complex mechanical structures such as a cross plate and a swash plate which are essential in a traditional pitch changing mechanism are thoroughly omitted, and a set of pitch changing system which is compact in structure, light in weight and rapid in response is jointly formed through a simple and direct transmission chain composed of the fixing base, the adjusting assembly and the rotating assembly and light weight achieved through the cooperation of the composite head cover and the composite paddles.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and more specifically, to a composite material propeller variable pitch structure for UAVs. Background Technology

[0002] The widespread application of drone technology in logistics, surveying, agriculture, and emergency rescue has placed higher demands on its flight performance. As a key component converting power from the propeller into thrust, its efficiency directly determines the overall performance of the drone. Currently, most small and medium-sized drones use fixed-pitch propellers with a fixed blade angle, requiring adjustments to thrust by changing the motor speed. However, fixed-pitch propellers only achieve optimal efficiency under specific combinations of forward speed and rotational speed. For multi-mode drones (such as VTOL drones), maintaining high efficiency across the entire flight envelope is difficult, resulting in insufficient endurance. Furthermore, thrust adjustment relies entirely on changes in motor speed, and the large rotational inertia of the motor rotor and load leads to sluggish control response, severely limiting the drone's maneuverability and agility, especially in scenarios requiring rapid acceleration and deceleration.

[0003] To address the aforementioned issues, existing technologies have developed variable pitch systems for large drones or helicopters, typically comprising complex hubs, cross discs, swashplates, and hydraulic actuation mechanisms. While these systems achieve pitch adjustment, their complex structure, heavy weight, and high cost contradict the pursuit of lightweight and compact design in small and medium-sized drones. The added weight may offset or even exceed the efficiency gains from variable pitch, and the complex mechanical structure reduces system reliability and increases maintenance costs. Therefore, existing technologies lack a propeller pitch-adjusting mechanism that can balance lightweight design, high reliability, rapid response, and suitability for small and medium-sized drones. Summary of the Invention

[0004] This invention provides a composite material propeller pitch-variable structure for unmanned aerial vehicles (UAVs), which can solve the problem of the lack of a propeller pitch-variable mechanism in the prior art that can take into account lightweight, high reliability, fast response and is suitable for small and medium-sized UAVs.

[0005] A variable-pitch structure for a composite material propeller of an unmanned aerial vehicle (UAV) includes a drive mechanism, a composite helmet, multiple composite blades, and a hub. The hub is connected to and driven to rotate by the drive end of the drive mechanism. The composite helmet is connected to the drive mechanism via a fixed base. The hub is circumferentially connected to each of the composite blades via multiple rotating components. The rotating components allow the composite blades to rotate relative to the hub to change the pitch angle. The fixed base is provided with adjustment components corresponding to the number of rotating components. The drive end of each adjustment component is drively connected to the corresponding rotating component to drive the composite blades to rotate around their own axes.

[0006] The present invention provides a variable pitch structure for a composite material propeller of an unmanned aerial vehicle (UAV), which, compared with the prior art, has, but is not limited to, the following beneficial effects: This composite material propeller pitch-changing structure for UAVs fixes the adjustment component on a fixed base connected to the drive mechanism and composite helmet, and its drive end directly acts on the rotating component connecting the composite blades and the hub. This allows the composite blades to rotate precisely around their own axis to change the pitch, while completely eliminating the complex mechanical structures such as cross discs and swashplates that are indispensable in traditional pitch-changing mechanisms. Through a simple and direct transmission chain consisting of a fixed base, adjustment component, and rotating component, combined with the lightweight design achieved by the composite helmet and composite blades, a compact, lightweight, and fast-responding pitch-changing system is formed. This perfectly solves the problem of the contradiction between traditional complex pitch-changing mechanisms and the core requirements of small and medium-sized UAVs for lightweight, high reliability, and fast response.

[0007] Furthermore, the rotating assembly includes a first connector and a second connector. One end of the first connector is fixedly connected to the composite blade, and the other end of the first connector is rotatably connected to one end of the second connector. The other end of the second connector is connected to the blade hub. The first connector is provided with a transmission part that is connected to the driving end of the adjustment assembly.

[0008] Furthermore, the first connecting member includes a blade clamp for clamping and fixing the composite blade and a rotating column connected to the blade clamp. The rotating column constitutes a rotating connection between the first connecting member and the second connecting member, and the transmission part is a push rod fixed to the outer periphery of the rotating column.

[0009] Furthermore, the second connecting member includes a fixing clamp for fixing to the propeller hub and a rotating cylinder connected to the fixing clamp. The rotating cylinder is sleeved outside the rotating column and rotates with the rotating column through a bushing.

[0010] Furthermore, the adjustment assembly includes an electric push rod, the drive end of which is hinged to the push rod, and a fixing plate is mounted on the electric push rod. The fixing plate is detachably connected to the fixing seat by a third bolt.

[0011] Furthermore, the drive mechanism includes a drive motor and a drive shaft connected thereto. The drive shaft is connected to the propeller hub via bearings, and a clamp is provided on the drive shaft.

[0012] Furthermore, the fixing base includes a base and a fixing plate connected thereto. The base is detachably connected to the composite head cover. The middle part of the fixing plate is connected to the drive shaft, and the circumferential part of the fixing plate is connected to the adjustment component.

[0013] Furthermore, the composite headgear has multiple slots that are adapted to the rotating components.

[0014] Furthermore, the pitch angle adjustment range of the composite blade is -10° to 30°.

[0015] Furthermore, both the composite helmet and the composite blades are made of carbon fiber composite material. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a variable pitch composite material propeller structure for a drone according to an embodiment of the present invention; Figure 2 This is a front view of a variable-pitch composite material propeller structure for an unmanned aerial vehicle according to an embodiment of the present invention; Figure 3 for Figure 1 A schematic diagram of the structure of the adjustment component; Figure 4 for Figure 1 Schematic diagram of the rotating assembly; Figure 5 for Figure 1 Schematic diagram of the middle fixed base; Figure 6 for Figure 4 A schematic diagram of the structure of the first connecting component.

[0017] Explanation of reference numerals in the attached figures: 1. Drive mechanism; 101. Drive motor; 102. Drive shaft; 2. Composite head cover; 3. Composite blade; 4. Hub; 5. Rotating assembly; 51. First connector; 511. Paddle clamp; 512. Rotating column; 513. First bolt; 514. Push rod; 52. Second connector; 521. Fixing clamp; 522. Rotating cylinder; 523. Second bolt; 524. Bushing; 6. Fixing seat; 61. Base; 62. Fixing plate; 7. Adjustment assembly; 71. Electric push rod; 72. Fixing plate; 73. Third bolt; 8. Bearing; 9. Clamp; 10. Groove. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings showing multiple embodiments according to this application. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," etc., in the description, claims, and accompanying drawings of this application are open-ended terms. Therefore, "comprising," "including," or "having" refers to, for example, a method or apparatus having one or more steps or elements, but is not limited to having only these one or more elements. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] It should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, parts, or groups of features, integers, steps, or parts.

[0023] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0024] See Figures 1-3 As shown in the figure, an embodiment of the present invention provides a variable pitch structure for a UAV composite propeller, including a drive mechanism 1, a composite helmet 2, multiple composite blades 3, and a hub 4. The hub 4 is connected to the drive end of the drive mechanism 1 and is driven to rotate by it. The composite helmet 2 is connected to the drive mechanism 1 through a fixed base 6. The hub 4 is circumferentially connected to each composite blade 3 through multiple rotating components 5. The rotating components 5 are used to allow the composite blades 3 to rotate relative to the hub 4 to change the pitch angle. The fixed base 6 is provided with adjustment components 7 corresponding to the number of rotating components 5. The drive end of each adjustment component 7 is connected to the corresponding rotating component 5 to drive the composite blades 3 to rotate around their own axis.

[0025] In this embodiment, by fixing the adjustment component 7 to the fixed base 6 connected to the drive mechanism 1 and the composite head cover 2, and having its drive end directly act on the rotating component 5 connecting the composite blade 3 and the hub 4, the composite blade 3 can be precisely rotated around its own axis to change the pitch, while completely eliminating the complex mechanical structures such as the cross disc and swashplate that are indispensable in traditional pitch-changing mechanisms. This is achieved through a simple and direct transmission chain composed of the fixed base 6, the adjustment component 7, and the rotating component 5. Combined with the lightweight design achieved by the composite head cover 2 and the composite blade 3, this constitutes a compact, lightweight, and rapidly responsive pitch-changing system, perfectly solving the problem of the contradiction between traditional complex pitch-changing mechanisms and the core requirements of small and medium-sized UAVs for lightweight design, high reliability, and rapid response.

[0026] Specifically, the adjustment component 7 on the fixed base 6 corresponds one-to-one with the rotating component 5 circumferentially connected to the rotor hub 4, achieving direct transmission without the need for complex intermediate transmission structures. This efficiently drives the composite blade 3 to rotate rapidly around its own axis to change the pitch angle, solving the slow response problem of fixed-pitch propellers that rely on speed adjustment, and achieving flexible pitch adjustment. With the drive mechanism 1 as the power core, the fixed base 6 securely supports the adjustment component 7, and the rotating component 5 enables reliable rotational engagement between the composite blade 3 and the rotor hub 4. The absence of redundant and complex mechanical structures reduces potential failure points, improves system reliability, and lowers maintenance difficulty and cost. This solves the pain points of low reliability and high maintenance costs in traditional complex variable pitch systems, ultimately forming a propeller-driven variable pitch solution that is lightweight, highly reliable, fast-responding, and fully adaptable to small and medium-sized UAVs, completely breaking the application limitations of existing technologies.

[0027] Preferably, there are three composite blades 3, three rotating components 5, and three adjusting components 7, and the three adjusting components 7 are independently controlled. The three components are evenly distributed circumferentially (i.e., at 120° to each other), forming a dynamically symmetrical rotating system. This symmetry ensures that the propeller has excellent dynamic balance when rotating at high speed, which can effectively reduce vibration and noise, thereby improving flight stability and extending the service life of the entire drive mechanism 1 and the hub 4. Each composite blade 3 is driven and controlled by its own dedicated rotating component 5 and adjusting component 7, which not only ensures that the pitch angle changes of all blades are the same. The precise and accurate control provides the hardware foundation for advanced flight control algorithms. Its symmetrical layout also balances the control torque generated by the system, avoiding additional torsional loads. At the same time, the independent control function of the adjustment component 7 can precisely adjust the pitch of each composite blade 3 individually. This can quickly respond to complex flight environments such as crosswinds and airflow disturbances, correct the UAV's attitude through differentiated pitch adjustment, greatly improve the control accuracy and adaptability to complex scenarios, and realize advanced maneuvers such as single-blade negative pitch braking and multi-attitude switching, making up for the lack of flexibility in the linkage adjustment of traditional variable pitch systems.

[0028] like Figure 1 and Figure 4 As shown, the rotating assembly 5 includes a first connecting member 51 and a second connecting member 52. One end of the first connecting member 51 is fixedly connected to the composite blade 3, and the other end of the first connecting member 51 is rotatably connected to one end of the second connecting member 52. The other end of the second connecting member 52 is connected to the blade hub 4. The first connecting member 51 is provided with a transmission part that is connected to the drive end of the adjustment assembly 7.

[0029] In this embodiment, one end of the first connector 51 is fixedly connected to the composite blade 3, ensuring that the composite blade 3 can move synchronously with the first connector 51 when the pitch is adjusted. The connection is stable and there is no relative displacement, avoiding blade loosening or transmission deviation during pitch change. The other end of the first connector 51 is rotatably connected to the second connector 52, providing a precise and smooth kinematic pair for the rotation of the composite blade 3 relative to the hub 4. The structure is simplified and has no redundant linkage parts, which meets the core requirements of lightweight and compact design for small and medium-sized UAVs, and eliminates the complex cross-plate and swashplate structure of traditional pitch change systems. The other end of the second connector 52 is reliably connected to the hub 4, ensuring that the rotating component 5 rotates synchronously with the hub 4 to obtain the rotational power transmitted by the drive mechanism 1. It can also cooperate with the rotation of the first connector 51 to allow the composite blade 3 to independently complete the pitch change under the drive of the adjustment component 7, achieving no interference between rotational power transmission and pitch adjustment.

[0030] Specifically, the transmission part on the first connecting member 51 is directly connected to the drive end of the adjustment component 7, which shortens the power transmission path, reduces transmission lag, significantly improves the response speed and control accuracy of pitch adjustment, solves the pain points of traditional pitch-changing mechanisms with many transmission links and slow adjustment, and the split structure makes it easy to inspect or replace the first connecting member 51 and the second connecting member 52 separately, reducing maintenance costs and further enhancing the reliability and practicality of the entire pitch-changing structure.

[0031] like Figure 4 and Figure 6 As shown, the first connecting member 51 includes a blade clamp 511 for clamping and fixing the composite blade 3 and a rotating column 512 connected to the blade clamp 511. The rotating column 512 constitutes a rotating connection between the first connecting member 51 and the second connecting member 52. The transmission part is a push rod 514 fixed to the outer periphery of the rotating column 512. The blade clamp 511 is detachably connected to the composite blade 3 by a first bolt 513.

[0032] In this embodiment, the propeller clamp 511 adopts a clamping structure and is detachably connected to the composite blade 3 via the first bolt 513. This ensures the firmness of the composite blade 3 installation, preventing loosening or displacement during pitch changes and flight, while also offering the advantage of convenient assembly and disassembly, significantly reducing the difficulty of maintenance and replacement of the composite blade 3. The rotating column 512 directly forms the rotating connection part with the second connecting member 52, with a simplified and non-redundant structure. This provides a precise and smooth motion foundation for the first connecting member 51 to drive the composite blade 3 to rotate with pitch changes, effectively avoiding the jamming problem caused by the multiple linkage parts in traditional pitch change mechanisms. The push rod 514, fixed to the outer periphery of the rotating column 512, serves as a transmission part and can directly and precisely connect with the drive end of the adjustment component 7, shortening the power transmission path and ensuring that the driving force of the adjustment component 7 can be efficiently transmitted to the composite blade 3, improving the response speed and control accuracy of pitch adjustment.

[0033] Specifically, the entire first connecting component 51 has a compact structure and a high degree of integration, with no unnecessary or complex parts. It perfectly meets the core requirements of small and medium-sized UAVs for lightweight and compact design. Moreover, the functions of each component are clearly defined and work together efficiently, which not only ensures the stability and reliability of pitch-changing actions, but also solves the pain points of traditional pitch-changing mechanisms such as slow transmission, weak connection, and inconvenient maintenance.

[0034] like Figure 4 and Figure 6 As shown, the second connecting member 52 includes a fixing clamp 521 for fixing to the propeller hub 4 and a rotating cylinder 522 connected to the fixing clamp 521. The rotating cylinder 522 is sleeved on the outside of the rotating column 512 and rotates with the rotating column 512 through a bushing 524. The fixing clamp 521 is detachably connected to the propeller hub 4 through a second bolt 523.

[0035] In this embodiment, the fixing clamp 521 is detachably connected to the rotor hub 4 via the second bolt 523. This ensures the stability of the connection between the second connecting member 52 and the rotor hub 4, ensuring no relative displacement when the rotor hub 4 drives the composite blade 3 to rotate. It also has the advantage of convenient disassembly and assembly, reducing the difficulty of later maintenance and component replacement. The rotating cylinder 522 is sleeved on the outside of the rotating column 512 to form a precise concentric rotation fit, providing stable guidance for the variable pitch rotation of the composite blade 3 driven by the first connecting member 51, avoiding off-center loading or jamming. The bushing 524 effectively isolates the direct contact between the rotating cylinder 522 and the rotating column 512, reducing mechanical wear during rotation, improving transmission smoothness and component service life, and reducing operating noise.

[0036] Specifically, the entire second connector 52 consists only of a fixing clamp 521, a rotating cylinder 522, and a bushing 524. The structure is simple and compact with no redundant design, perfectly meeting the core requirements of lightweight and compact design for small and medium-sized UAVs. With the reliable fastening of the second bolt 523 and the wear-resistant protection of the bushing 524, the driving force of the adjustment component 7 can be accurately transmitted to the composite blade 3 through the first connector 51, improving the response accuracy and stability of the pitch adjustment.

[0037] like Figure 1 and Figure 3 As shown, the adjustment assembly 7 includes an electric push rod 71, the drive end of which is hinged to the push rod 514. A fixing plate 72 is mounted on the electric push rod 71, and the fixing plate 72 is detachably connected to the fixing seat 6 by a third bolt 73.

[0038] In this embodiment, the electric push rod 71 is used as the direct drive component, eliminating the complex hydraulic actuation mechanism of the traditional pitch-changing system. The structure is simplified and the response is rapid. It can quickly output driving force to drive the push rod 514 to move, effectively solving the pain points of slow adjustment and lag in power transmission of the traditional pitch-changing mechanism, and ensuring the timeliness of pitch adjustment. The drive end of the electric push rod 71 and the push rod 514 are connected by a hinge, which can flexibly adapt to the angle change of the push rod 514 as the composite blade 3 changes pitch, avoiding jamming and interference problems in the transmission process, ensuring smooth and accurate power transmission, and improving the stability of pitch adjustment. The fixing plate 72 is detachably connected to the fixing seat 6 by the third bolt 73, which not only ensures the stability of the electric push rod 71 installation, so that the adjustment component 7 does not loosen or shift during the flight and pitch-changing action of the UAV, but also has the advantage of convenient disassembly and assembly, which greatly reduces the difficulty and cost of later inspection, maintenance and component replacement.

[0039] Specifically, the entire adjustment component 7 features a compact and non-redundant design, coupled with lightweight material selection, perfectly meeting the core requirements of small and medium-sized UAVs for lightweight and compactness. At the same time, the direct transmission link between the electric push rod 71 and the push rod 514 shortens the power transmission path, reduces energy loss, and further improves the control accuracy of the pitch adjustment.

[0040] like Figure 1 and Figure 3 As shown, the drive mechanism 1 includes a drive motor 101 and a drive shaft 102 connected thereto. The drive shaft 102 is connected to the propeller hub 4 through a bearing 8, and a clamp 9 is provided on the drive shaft 102.

[0041] In this embodiment, the drive motor 101 serves as the power core and is directly connected to the drive shaft 102, forming a streamlined and efficient power transmission link. The drive shaft 102 is connected to the propeller hub 4 through the bearing 8. The bearing 8 effectively isolates the direct rigid contact between the drive shaft 102 and the propeller hub 4, significantly reducing the frictional resistance and mechanical wear during relative rotation, improving the smoothness of power transmission, and extending the service life of the drive shaft 102 and the propeller hub 4. This avoids the frequent failures caused by excessive friction in traditional transmission methods. The clamp 9 set on the drive shaft 102 can accurately position the bearing 8 axially, preventing the bearing 8 from shifting during UAV flight and pitch change, ensuring the coaxiality of the drive shaft 102 and the propeller hub 4, thereby ensuring the stability of the rotation and pitch change of the composite blade 3, and avoiding force imbalance or decreased pitch change accuracy due to coaxiality deviation.

[0042] like Figure 1 and Figure 5 As shown, the fixed base 6 includes a base 61 and a fixed plate 62 connected thereto. The base 61 is detachably connected to the composite head cover 2. The middle part of the fixed plate 62 is connected to the drive shaft 102. The fixed plate 62 is circumferentially connected to the adjustment component 7.

[0043] In this embodiment, the base 61 is detachably connected to the composite head cover 2, which ensures the stability of the composite head cover 2 installation, effectively protecting the internal rotating components 5, adjusting components 7, and other core components from airflow impact and dust and impurity corrosion. It also has the advantage of convenient disassembly and assembly, reducing the difficulty of internal component inspection and maintenance. The middle part of the fixed plate 62 is connected to the drive shaft 102, which can form an auxiliary support for the drive shaft 102, further ensuring the coaxiality of the drive shaft 102 and the propeller hub 4. The fixed plate 62 is circumferentially connected to the adjusting components 7, which can provide a uniform and stable installation reference for the adjusting components 7, ensuring that the force is balanced after the installation of multiple adjusting components 7, thereby ensuring the consistency and accuracy of the pitch adjustment of each composite blade 3, and avoiding transmission lag or uneven pitch caused by installation deviation.

[0044] like Figure 1 and Figure 2 As shown, the composite head cover 2 has multiple slots 10 that are adapted to the rotating component 5. The slots 10 are precisely matched with the shape and movement trajectory of the rotating component 5, providing sufficient and interference-free space for the rotating component 5 to drive the composite blade 3 to rotate with variable pitch. This effectively avoids the composite head cover 2 from obstructing the movement of the rotating component 5 and ensures the smooth swing of the rotating component 5 during the pitch adjustment process.

[0045] Specifically, the pitch angle adjustment range of the composite blade 3 is -10° to 30°. Negative pitch: the blade angle is negative (-10° to 0°), generating a downward pull that allows the drone to descend quickly; zero pitch: the blade angle is 0°, at which point no lift is generated, achieving an "idling" state, where the motor rotates but the drone does not generate lift, similar to a fixed pitch state; positive pitch: the angle range that generates normal lift (0° to 30°), the larger the angle, the greater the lift generated at the same rotational speed.

[0046] Among them, the composite helmet 2 and the composite blade 3 are both made of carbon fiber composite material. Carbon fiber composite material has the outstanding characteristics of high strength and lightweight, which greatly reduces the weight of the composite helmet 2 and the composite blade 3, avoids the extra weight burden brought by traditional metal materials or ordinary composite materials, perfectly matches the ultimate pursuit of lightweight and compactness of small and medium-sized UAVs, and effectively prevents the extra weight of the pitch mechanism from offsetting the efficiency gains brought by pitch.

[0047] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A composite material propeller pitch-variable structure for unmanned aerial vehicles (UAVs), characterized in that, It includes a drive mechanism (1), a composite head cover (2), multiple composite blades (3) and a hub (4). The hub (4) is connected to the drive end of the drive mechanism (1) and is driven to rotate by it. The composite head cover (2) is connected to the drive mechanism (1) through a fixed base (6). The hub (4) is circumferentially connected to each of the composite blades (3) by a plurality of rotating components (5), and the rotating components (5) are used to allow the composite blades (3) to rotate relative to the hub (4) to change the pitch angle. The fixed base (6) is provided with an adjustment component (7) corresponding to the number of the rotating components (5). The driving end of each adjustment component (7) is connected to the corresponding rotating component (5) to drive the composite blade (3) to rotate around its own axis.

2. The variable pitch structure of the UAV composite material propeller as described in claim 1, characterized in that, The rotating assembly (5) includes a first connector (51) and a second connector (52). One end of the first connector (51) is fixedly connected to the composite blade (3), and the other end of the first connector (51) is rotatably connected to one end of the second connector (52). The other end of the second connector (52) is connected to the blade hub (4). The first connector (51) is provided with a transmission part that is connected to the driving end of the adjustment assembly (7).

3. The variable pitch structure of the UAV composite material propeller as described in claim 2, characterized in that, The first connector (51) includes a blade clamp (511) for clamping and fixing the composite blade (3) and a rotating column (512) connected to the blade clamp (511). The rotating column (512) constitutes a rotating connection between the first connector (51) and the second connector (52). The transmission part is a push rod (514) fixed to the outer periphery of the rotating column (512).

4. The variable pitch structure of the UAV composite propeller as described in claim 3, characterized in that, The second connector (52) includes a fixing clamp (521) for fixing to the rotor hub (4) and a rotating cylinder (522) connected to the fixing clamp (521). The rotating cylinder (522) is sleeved on the outside of the rotating column (512) and rotates with the rotating column (512) through a bushing (524).

5. The variable pitch structure of the UAV composite material propeller as described in claim 1, characterized in that, The adjustment assembly (7) includes an electric push rod (71), the drive end of which is hinged to the push rod (514), and a fixing plate (72) is mounted on the electric push rod (71). The fixing plate (72) is detachably connected to the fixing seat (6) by a third bolt (73).

6. The variable pitch structure of the UAV composite material propeller as described in claim 1, characterized in that, The drive mechanism (1) includes a drive motor (101) and a drive shaft (102) connected thereto. The drive shaft (102) is connected to the propeller hub (4) through a bearing (8). A clamp (9) is provided on the drive shaft (102).

7. The variable pitch structure of the UAV composite propeller as described in claim 1, characterized in that, The fixed base (6) includes a base (61) and a fixed plate (62) connected thereto. The base (61) is detachably connected to the composite head cover (2). The middle part of the fixed plate (62) is connected to the drive shaft (102). The fixed plate (62) is circumferentially connected to the adjustment component (7).

8. The variable pitch structure of the UAV composite propeller as described in claim 1, characterized in that, The composite headgear (2) has multiple slots (10) that are compatible with the rotating assembly (5).

9. The variable pitch structure of the UAV composite material propeller as described in claim 1, characterized in that, The pitch angle adjustment range of the composite blade (3) is -10° to 30°.

10. The variable pitch structure of the UAV composite material propeller as described in claim 1, characterized in that, Both the composite headgear (2) and the composite blades (3) are made of carbon fiber composite material.

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