A folding propeller blade hinge anti-locking connecting structure

Abstract

The utility model discloses a folding propeller paddle clamp hinge prevents locking connecting structure relates to propeller structure technical field, including propeller hub, limiting mechanism, this limiting mechanism is connected with propeller hub, propeller blade, fixed establishment, propeller hub is connected with propeller blade through limiting mechanism and fixed establishment, this folding propeller paddle clamp hinge prevents locking connecting structure, aims at solving the low assembly accuracy, big rotation resistance or operation vibration problem that the bolt fastening force is difficult to control in the process of connecting paddle and hub of existing folding propeller, through setting limiting mechanism and fixed establishment between hub and paddle, makes paddle after assembly can be steady connection, can realize flexible rotation.

Description

Technical Field

[0001] This utility model relates to the field of propeller structure technology, specifically to a folding propeller clamp hinge anti-locking connection structure. Background Technology

[0002] In drones, aircraft, and other flight equipment, the propeller, as its core power component, mainly consists of a hub and blades. Its performance directly affects the equipment's endurance, operational efficiency, and flight safety. To improve portability, folding propellers are widely used. Compared to traditional fixed propellers, folding propellers can fold the blades to one side of the hub when not in use, thus significantly reducing the propeller's size, facilitating transportation and storage, and lowering packaging and shipping costs.

[0003] In existing folding propellers, the blades are typically connected to the hub using bolts during installation. The tightness of the bolts directly determines the clearance between the blades and the hub. However, this structure presents certain problems in practical applications: the bolt tightness is difficult to control precisely. If the bolts are too tight, the clearance between the blades and the hub may decrease, preventing the blades from folding and unfolding smoothly; if the bolts are too loose, the blades may wobble and vibrate during operation, affecting flight stability and propeller lifespan. Furthermore, individual hubs vary during manufacturing, resulting in different bolt tightening torques, making it difficult to guarantee assembly consistency. To address these issues, Chinese utility model patent CN207712288U proposes a folding propeller clamp with positioning posts. This solution uses positioning and limiting posts on a split hub to structurally limit the clearance between the blades and the hub, improving assembly stability and operational reliability. However, this structural design is only applicable to split-type propeller hubs and not to the increasingly popular integrated propeller hub structures. Therefore, its application scope is limited and its versatility is insufficient, making it difficult to meet the current market demand for multi-model, highly versatile folding propellers. Utility Model Content

[0004] The purpose of this utility model is to provide a foldable propeller clamp hinge anti-locking connection structure to solve the problems existing in the prior art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a folding propeller clamp hinge anti-locking connection structure, comprising: propeller hub; A limiting mechanism, which is connected to the propeller hub; Propeller blades; The propeller hub and propeller blades are connected by a limiting mechanism and a fixing mechanism.

[0006] Preferably, the limiting mechanism includes limiting grooves, and limiting grooves are provided on both sides of the propeller hub facing the propeller blade end.

[0007] Preferably, the propeller blades have a connection hole at one end facing the propeller hub.

[0008] Preferably, the limiting mechanism further includes a limiting cylinder inserted into the connecting hole.

[0009] Preferably, both ends of the limiting shaft are fitted with the limiting groove.

[0010] Preferably, the propeller hub has two mounting holes at one end facing the propeller blades, and the centers of the two mounting holes are located on the same axis.

[0011] Preferably, the center of the limiting shaft and the center of the two mounting holes are located on the same axis.

[0012] Preferably, the fixing mechanism includes a fixing bolt, which passes through the mounting hole and the limiting shaft, and the fixing bolt is threadedly connected to the mounting hole.

[0013] As can be seen from the above technical solution, this utility model has the following beneficial effects: This folding propeller clamp hinge anti-locking connection structure aims to solve the problems of low assembly accuracy, high rotational resistance, or operational vibration caused by the difficulty in controlling bolt tightening force during the connection of blades and hub in existing folding propellers. By setting a limiting mechanism and a fixing mechanism between the hub and the blade, the blade can be securely connected while still allowing for flexible rotation after assembly. Specifically, during propeller blade installation, the limiting shaft is first inserted into the connecting hole of the blade, then the two ends of the limiting shaft are slid into the limiting grooves on both sides of the hub, and finally, it is tightened with fixing bolts. This structure effectively avoids jamming caused by overtightening or shaking caused by loosening the bolts, improving assembly accuracy and operational stability. The close fit design of the limiting shaft and the limiting groove improves the stability of blade positioning, while the fixing bolts passing through the mounting hole and the limiting shaft achieve reliable fixing while preventing locking. Furthermore, the two mounting holes on the rotor hub are centered on the same axis, and the center of the limiting shaft is coaxial with the center of the mounting holes, ensuring coaxiality and rotational balance after assembly. This structure is suitable for integrated rotor hubs, featuring high reliability, good assembly consistency, and wide adaptability, effectively overcoming the limitation of existing technologies that can only be applied to split rotor hubs. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is an exploded view of the overall structure of this utility model; Figure 3This is an enlarged view of the propeller hub facing the end of the propeller blades.

[0015] In the diagram: 1. Propeller hub; 2. Limiting mechanism; 21. Limiting groove; 22. Limiting shaft; 3. Propeller blade; 4. Fixing mechanism; 41. Fixing bolt; 5. Connecting hole; 6. Mounting hole. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] like Figure 1 , Figure 2 and Figure 3 As shown, this utility model provides a technical solution: a folding propeller clamp hinge anti-locking connection structure, including a propeller hub 1, a limiting mechanism 2, a propeller blade 3, and a fixing mechanism 4, wherein the limiting mechanism 2 is connected to the propeller hub 1, and the propeller blade 3 is connected to the propeller hub 1 through the limiting mechanism 2 and the fixing mechanism 4.

[0018] In this embodiment, the propeller hub 1 serves as the core connecting component, supporting and fixing the position of each blade 3. A limiting mechanism 2 is positioned between the hub 1 and the blades 3, providing angle limitation and rotational guidance during blade folding and unfolding. Through the structural design of the limiting mechanism 2, mechanical limiting is provided when the blades 3 are folded to their limit positions, preventing excessive rotation or swaying. A fixing mechanism 4 is used to achieve detachable fixing between the blades 3 and the hub 1. Its design ensures connection strength while allowing the blades 3 to fold and unfold smoothly around the limiting mechanism 2. The overall structure achieves coordination between its parts through bolts, pins, or bushings, ensuring sufficient rigidity and stability in the working state, while allowing free folding in the retracted state, ensuring ease of use and reliability.

[0019] This embodiment effectively solves the problem of difficulty in controlling the bolt tightening degree in existing folding propellers through the coordinated design of the limiting mechanism 2 and the fixing mechanism 4. The limiting mechanism 2 restricts the angle range of the blade 3 when folding and unfolding, structurally preventing the blade from jamming or locking; the fixing mechanism 4 provides uniform connection torque, making the assembly process more controllable and consistent, and avoiding blade wobbling or frictional obstruction caused by differences in tightening force. In addition, this structure is compatible with the integrated hub 1 design, which has stronger versatility and adaptability compared to solutions that are only applicable to split hubs. It can be applied to drone propellers of different models and sizes, improving product standardization and market competitiveness.

[0020] In other possible implementations, the limiting mechanism 2 can adopt various structural forms, such as double limiting shoulders, elastic blocks, or embedded stop sleeves, to achieve limiting control at different angles. The fixing mechanism 4 can be selected from different materials and manufacturing processes, using connection methods such as screws, pins, quick-release pins, or wedge-shaped locking blocks to adapt to different strength and maintenance requirements. The propeller hub 1 can be made of different materials such as aluminum alloy, carbon fiber composite materials, or high-strength engineering plastics, and prepared by CNC machining or molding to improve strength and reduce weight. In special applications, a wear-resistant coating or low-friction lining can also be applied to the contact surface of the limiting mechanism 2 to further reduce rotational resistance and extend service life.

[0021] The limiting mechanism 2 includes limiting grooves 21, and limiting grooves 21 are provided on both sides of the propeller hub 1 facing the propeller blade 3. In this embodiment, the limiting grooves 21 are a key structural feature of the limiting mechanism 2 and are provided on both sides of the hub 1. The limiting grooves 21 are used to accommodate the limiting shaft cylinder 22.

[0022] A connecting hole 5 is provided at the end of the propeller blade 3 facing the propeller hub 1. In this embodiment, the connecting hole 5 is located at the root of the blade 3 and is used to achieve a rotatable connection with the limiting mechanism 2 and the fixing mechanism 4 on the propeller hub 1. The central axis of the connecting hole 5 forms a specific angle with the axis of the blade 3 to ensure that the blade can form a reasonable angle of attack in the unfolded state, thereby improving aerodynamic efficiency. Through the connecting hole 5, the limiting pin or connecting shaft can pass through the blade 3 and the hub 1 to achieve a pivotal installation, allowing the blade 3 to rotate smoothly within the limiting groove 21. During folding and unfolding, the connecting hole 5 acts as a rotation fulcrum, and its geometric accuracy directly affects the motion stability and limiting accuracy of the blade. By designing a suitable fit clearance between the hole wall and the connecting pin, stability can be maintained while avoiding blade jamming or wobbling due to tolerance accumulation, thereby ensuring the flexible and reliable operation of the folding structure.

[0023] By setting a connecting hole 5 at the root of the propeller blade 3, a clear rotational hinge relationship is formed between the blade and the hub 1, achieving high-precision rotational control of the folding propeller. This design avoids the instability of traditional structures that rely on bolt tightening to control the gap, making the assembly process more consistent and repeatable. The setting of the connecting hole 5 further improves the fitting accuracy between the limiting mechanism 2 and the blade 3, reduces rotational resistance, and extends the service life of the rotating connecting components. In addition, this structure can meet the assembly requirements of blades and hubs of different specifications by optimizing the diameter, position, and fitting tolerance of the connecting hole 5, improving the versatility and standardization of the propeller system. For lightweight equipment such as drones, this solution reduces the number of connecting components while ensuring structural strength, thereby reducing the overall weight and improving the endurance.

[0024] In other possible implementations, the shape of the connecting hole 5 can be designed as a circle, ellipse, or an irregularly shaped hole structure with guide grooves to meet different hinge forms. The hole wall can be embedded with a copper sleeve, stainless steel bushing, or polymer bushing to improve wear resistance and reduce rotational friction. For applications requiring quick assembly and disassembly, the connecting hole 5 can be used with quick-release pins or elastic pins to achieve tool-less replacement of the blade structure. In high-load applications, torsional stiffness can be improved by adding reinforcing ribs or thickening the area around the connecting hole 5. Furthermore, the connecting hole 5 can be fabricated using CNC machining or laser drilling technology to ensure hole diameter accuracy and surface roughness, thereby further improving connection accuracy and operational stability.

[0025] The limiting mechanism 2 also includes a limiting cylinder 22 inserted into the connecting hole 5. In this embodiment, the limiting cylinder 22 is disposed inside the connecting hole 5 of the propeller blade 3 to realize the rotational connection and limiting guidance between the blade 3 and the propeller hub 1. One end of the limiting cylinder 22 is inserted into the connecting hole 5 of the blade 3, and the other end cooperates with the limiting groove 21 of the hub 1, so that the blade 3 can rotate smoothly around the limiting cylinder 22. This structure acts as a hinge during the movement of the folding propeller: when the blade 3 unfolds, the limiting cylinder 22 drives the blade to rotate to the unfolded limit position and contact the end of the limiting groove 21 to form a stop; when the blade folds, the limiting cylinder 22 rotates in the opposite direction to the other end of the groove to form a folding limit. With the presence of the limiting cylinder 22, the rotation center is more fixed, the force is more uniform, and the wear and excessive rotational resistance caused by direct metal contact are avoided, thereby ensuring the smoothness and repeatability of the folding action.

[0026] This embodiment, by incorporating a limiting sleeve 22 within the connecting hole 5, makes the connection between the propeller blade 3 and the hub 1 more stable and durable. The limiting sleeve 22 serves both as a rotational axis and as a preventative locking mechanism, effectively controlling the rotational freedom of the blades during folding and unfolding, and preventing structural jamming or motion obstruction caused by over-tightening. Compared to the traditional method of direct bolt fastening, this solution significantly improves the service life and assembly consistency of the connecting components. The limiting sleeve 22 also shares some of the radial and axial forces when the blade 3 rotates, thereby reducing the vibration amplitude of the propeller during operation and improving flight stability and power efficiency. Furthermore, the modular design of this structure allows for independent replacement and maintenance of the limiting sleeve 22, facilitating later maintenance and standardized parts production, further enhancing product reliability and economy.

[0027] In other possible implementations, the limiting shaft 22 can be made of different materials and have different structural forms depending on the application requirements. For example, stainless steel, titanium alloy, or oil-impregnated nylon can be used to improve wear resistance and corrosion resistance.

[0028] The two ends of the limiting shaft cylinder 22 are fitted with the limiting grooves 21. In this embodiment, the two ends of the limiting shaft cylinder 22 are respectively fitted with the limiting grooves 21 provided on both sides of the propeller hub 1, realizing stable positioning and precise rotational guidance of the blade 3 within the hub 1. Specifically, when the blade 3 is installed on the limiting shaft cylinder 22 through the connecting hole 5, the two ends of the limiting shaft cylinder 22 are respectively embedded in the limiting grooves 21, forming reliable positioning and support through the fitting surface, thereby ensuring that the blade 3 maintains a stable axial position during rotation, folding, or unfolding. This fitting design allows the limiting shaft cylinder 22 to form surface contact with the limiting grooves 21 rather than point contact during rotation, thereby significantly reducing local stress concentration and improving rotational balance and smoothness of movement. The gap control of the fitting area can be achieved through high-precision machining, enabling the limiting shaft cylinder 22 to obtain excellent guiding effect without affecting rotational flexibility, ensuring that the blade 3 can still maintain a stable posture under dynamic loads.

[0029] By fitting the two ends of the limiting shaft cylinder 22 into the limiting groove 21, this embodiment achieves multi-point support and high-precision guidance for the blades 3 in the hub 1, significantly improving the structural stability and durability of the folding propeller. The fitting structure effectively avoids blade swaying, wear, and locking problems caused by unilateral support or excessive gaps. Since the limiting shaft cylinder 22 forms a stable support surface in the limiting groove 21, the frictional force during rotation is evenly distributed, thereby reducing mechanical noise and operational vibration, and improving flight balance and power efficiency. In addition, this structural design enables the blades 3 to have higher repeatability during folding and unfolding, ensuring that the angles of each blade are consistent in the working state, and improving the overall aerodynamic consistency and reliability of the propeller.

[0030] In other possible implementations, the fitting form between the limiting shaft 22 and the limiting groove 21 can adopt various structural designs. For example, the two ends of the limiting shaft 22 can be designed as hemispherical, conical, or with guide rounded corners to achieve an automatic centering effect during rotation. The bottom of the limiting groove 21 can be machined into a corresponding concave or V-shaped groove structure according to the fitting method to enhance contact stability. To further reduce friction and wear, wear-resistant pads, ball bearings, or a polytetrafluoroethylene low-friction layer can be placed between the fitting surfaces. Under different operating conditions, the depth and angle of the limiting groove 21 can be finely adjusted to achieve fine-tuning and adaptation of the blade 3 deployment angle. In addition, in lightweight applications, the limiting shaft 22 can be manufactured using carbon fiber or high-strength composite materials and integrated with the limiting groove 21 through insert molding process to further improve strength and reduce weight.

[0031] Two mounting holes 6 are provided at the end of the propeller hub 1 facing the propeller blade 3, and the centers of the two mounting holes 6 are located on the same axis. In this embodiment, one mounting hole 6 is provided at each of the two ends of the hub 1, and the centers of the two mounting holes 6 are arranged along the same straight line to ensure the coaxiality and rotational balance of the blade 3 when connected through the limiting shaft sleeve 22. The two ends of the limiting shaft sleeve 22 can be inserted into the corresponding mounting holes 6 respectively, thereby forming a precise coaxial hinge structure between the connecting hole 5 of the blade 3, the limiting shaft sleeve 22, and the mounting holes 6. This design ensures that the blade 3 rotates smoothly around the fixed axis when folding and unfolding, avoiding tilting or eccentricity caused by installation deviation. The positional accuracy of the two mounting holes 6 on the hub 1 directly determines the synchronization of the blade movement and the cooperation effect of the limiting mechanism 2. Therefore, they are generally prepared by CNC machining or precision mold forming to ensure the consistency of the hole axis and the stability of the fitting clearance.

[0032] This implementation achieves high-precision symmetrical installation of the folding propeller hinge structure by setting two coaxial mounting holes 6 on the hub 1, significantly improving overall assembly consistency and rotational stability. This structure effectively distributes the force during propeller blade 3 rotation, ensuring uniform force distribution at both ends of the limiting shaft cylinder 22, reducing localized wear, and extending the lifespan of the connecting components. Simultaneously, the coaxial mounting holes 6 ensure dynamic balance during propeller rotation, reducing vibration and noise during flight. Compared to traditional structures using only a single hole for installation, this dual-hole coaxial design makes the connection more robust and reliable, adaptable to high-speed, high-load UAV or aircraft applications, thereby enhancing the overall safety and reliability of the system.

[0033] The center of the limiting shaft cylinder 22 is located on the same axis as the centers of the two mounting holes 6. In this embodiment, the center of the limiting shaft cylinder 22 is collinear with the centers of the two mounting holes 6 on the rotor hub 1, thus forming a unified axis of rotation that runs through the rotor hub 1, the limiting shaft cylinder 22, and the blade 3 connecting hole 5. This structure ensures that the blade 3 rotates around a precise axis during folding and unfolding, avoiding blade wobbling, uneven force, or jamming caused by coaxiality deviation. During assembly, the limiting shaft cylinder 22 achieves self-positioning through the cooperation of its two ends with the mounting holes 6, keeping the entire folding structure balanced during rotation. During rotation, the limiting shaft cylinder 22 forms a high-precision sliding fit with the inner wall of the mounting holes 6, thereby providing a good guiding effect while maintaining an appropriate clearance. Through this coaxial arrangement, the blade 3 can achieve a stable angle of attack consistency when unfolded and can accurately return to the predetermined position when folded, improving the coordination and repeatability of the folding propeller's movements.

[0034] This implementation achieves high-precision coaxial connection of the entire folding structure by ensuring that the centers of the limiting shaft cylinder 22 and the mounting hole 6 are on the same axis, fundamentally eliminating the problem of eccentric installation of the blade 3. This design ensures symmetrical force on the blade during rotation, significantly reducing mechanical vibration and imbalance during operation, and improving the dynamic stability and aerodynamic efficiency of the aircraft. The coaxial design also effectively prevents deflection wear during folding or unfolding, extending the service life of the limiting shaft cylinder 22, mounting hole 6, and blade 3 connection. While this solution requires high assembly precision, once completed, it allows for modular assembly and interchangeability, improving production consistency and maintenance convenience. Compared to traditional non-coaxial designs, this solution maintains structural balance under high speed and high load conditions, exhibiting excellent fatigue resistance and long-term operational reliability.

[0035] The fixing mechanism 4 includes a fixing bolt 41, which passes through the mounting hole 6 and the limiting shaft 22, and is threadedly connected to the mounting hole 6. In this embodiment, the fixing bolt 41 serves as the main fastening element of the fixing mechanism 4, used to achieve a reliable connection between the limiting shaft 22 and the propeller hub 1. The fixing bolt 41 enters the mounting hole 6 from the outside of the hub 1, passes through the hollow channel of the limiting shaft 22 in sequence, and is then threadedly connected to the mounting hole 6 at the other end, forming a complete through-locking structure. Through the axial preload of the fixing bolt 41, the limiting shaft 22 can be firmly positioned inside the hub 1, while allowing the blade 3 to rotate freely around the limiting shaft 22. When the blade 3 is folded or unfolded, the limiting shaft 22, as the hinge center, is only allowed to rotate without axial displacement under the constraint of the fixing bolt 41. The tightening degree of the fixing bolt 41 can be precisely adjusted by controlling the tightening torque, so that the blade 3 obtains appropriate axial constraint while maintaining rotational flexibility, preventing wobbling and loosening.

[0036] This implementation achieves a high-strength adjustable hinge connection for the folding propeller through a structural design where the fixing bolt 41 passes through the mounting hole 6 and connects to the limiting shaft 22. The fixing bolt 41 provides a stable axial clamping force, preventing axial displacement of the limiting shaft 22 during operation, thereby maintaining the stability and concentricity of the blade 3's rotation axis. The threaded connection makes assembly and maintenance more convenient. Users can adjust the bolt torque to change the blade rotation damping according to different models or operating environments, achieving optimal folding sensitivity and unfolding stability. Compared to traditional direct clamping connections, this structure effectively avoids blade locking caused by over-tightening, while improving the reassembleability and overall durability of the connecting components. Furthermore, this solution is compatible with various bolt standard specifications, facilitating standardized production and subsequent maintenance, and reducing manufacturing and maintenance costs.

[0037] In other possible implementations, the fixing bolt 41 can adopt various structural forms depending on different working conditions. For example, an anti-loosening structure with locking washers, self-locking nuts, or elastic washers can be used to improve vibration resistance; the fixing bolt 41 can also be designed as a quick-release structure or with a torque limiting device to achieve tool-based precise assembly. The threaded connection can be located inside or outside the propeller hub 1 to adapt to different spatial layouts. The material of the fixing bolt 41 can be stainless steel, titanium alloy, or nickel-plated steel to improve strength and corrosion resistance. The through hole inside the limiting shaft sleeve 22 can be designed as a stepped hole or a matching guide hole to optimize bolt installation accuracy and reduce frictional resistance. In some lightweight or automated assembly scenarios, embedded threaded bushings or tightening structures can be used to replace traditional threaded holes to achieve efficient batch assembly and improved maintainability.

[0038] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A folding propeller clamp hinge anti-locking connection structure, characterized in that, include: Propeller hub (1); A limiting mechanism (2) is connected to the propeller hub (1); Propeller blades (3); The propeller hub (1) and the propeller blade (3) are connected by a limiting mechanism (2) and a fixing mechanism (4).

2. The anti-locking connection structure of the folding propeller clamp hinge according to claim 1, characterized in that: The limiting mechanism (2) includes a limiting groove (21), and the propeller hub (1) has limiting grooves (21) on both sides facing the end of the propeller blade (3).

3. The anti-locking connection structure of the folding propeller clamp hinge according to claim 2, characterized in that: The propeller blade (3) has a connecting hole (5) at one end facing the propeller hub (1).

4. The anti-locking connection structure of the folding propeller clamp hinge according to claim 3, characterized in that: The limiting mechanism (2) also includes a limiting cylinder (22) inserted into the connecting hole (5).

5. The anti-locking connection structure of the folding propeller clamp hinge according to claim 4, characterized in that: The two ends of the limiting shaft (22) are fitted with the limiting groove (21).

6. The anti-locking connection structure of the folding propeller clamp hinge according to claim 4, characterized in that: The propeller hub (1) has two mounting holes (6) at one end facing the propeller blade (3), and the centers of the two mounting holes (6) are located on the same axis.

7. The anti-locking connection structure of the folding propeller clamp hinge according to claim 6, characterized in that: The center of the limiting shaft (22) and the center of the two mounting holes (6) are on the same axis.

8. The anti-locking connection structure of the folding propeller clamp hinge according to claim 6, characterized in that: The fixing mechanism (4) includes a fixing bolt (41), which passes through the mounting hole (6) and the limiting cylinder (22), and the fixing bolt (41) is threadedly connected to the mounting hole (6).

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