A folding propeller structure with spanwise buffering function

Abstract

The utility model discloses a kind of folding propeller structures with spanwise buffering function, it is related to aerospace technology field, including propeller hub, baffle, the baffle is provided in the end of propeller hub, propeller blade, two the propeller blade is connected with propeller hub, buffer part, the buffer part is set in baffle inside surface, the contact surface of the buffer part and baffle is inclined along the direction of propeller blade rotation unfolding;The folding propeller structure with spanwise buffering function avoids due to mechanical impact too large and causes blade shaking or abnormal folding, guarantees the stability of propeller in high-speed rotating working condition and the security of aircraft operation, and buffer part is realized by pasting rubber pad mode, design flexible, strong applicability, with good popularization and application prospect.

Description

Technical Field

[0001] This utility model relates to the field of aerospace technology, specifically to a folding propeller structure with spanwise buffering function. Background Technology

[0002] In drones, aircraft, and other flight equipment, the propeller is a key power output component, and its performance directly affects the overall flight efficiency, endurance, and operational stability. Traditional propellers typically consist of a hub and blades, employing a fixed structure design. While these fixed propellers are simple in structure and low in manufacturing cost, they occupy a large amount of space during transportation and storage due to the non-foldable blades, causing inconvenience for packaging, warehousing, and logistics, and increasing transportation costs.

[0003] To overcome the space disadvantages of fixed structures, the industry has developed various types of folding propellers. These propellers can fold their blades together against the hub when not in operation, effectively reducing assembly size and improving portability. These folding propellers primarily achieve automatic blade deployment through springs, centrifugal force, or motor drive. However, regardless of the deployment method, the blades must be secured by a locking mechanism after deployment to prevent blade wobbling, misalignment, or even automatic folding during flight due to vibration or airflow disturbances. Currently, the mainstream locking mechanisms can be divided into two categories: one is a snap-fit ​​structure, where the blade has protrusions that automatically snap into grooves in the hub after rotation and deployment; the other is a rigid limiting structure, which restricts the blade's range of motion through metal blocks and relies on centrifugal force generated during flight to stably hold the blade against the limiting component. While these structures achieve reliable blade locking to a certain extent, they generally suffer from significant rigidity and impact. Especially when the blades rapidly transition from a folded state to an operating state, they are often subjected to strong mechanical impacts. Prolonged use can easily lead to fatigue, wear, or even structural damage to the blade root material, thereby shortening the propeller's service life.

[0004] For example, Chinese utility model patent CN209833980U discloses a folding propeller structure that uses a lateral rotational folding method and introduces a rubber sleeve design at the propeller clamp position to form a buffer during the rotation, unfolding, or stopping of the propeller blades, reducing damage from rigid collisions. However, this technology only reduces the impact force during the unfolding process to a certain extent and still fails to completely solve the problem of energy absorption and dispersion during the locking process. Furthermore, the stability of the lateral folding structure under high-speed rotation conditions remains somewhat limited. Utility Model Content

[0005] The purpose of this utility model is to provide a folding propeller structure with spanwise buffering function. By adding baffles and buffer pads at the connection between the propeller hub and the blades, the propeller blades are protected when they are unfolded, rigid impacts are reduced, and the service life of the propeller blades is increased.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a folding propeller structure with spanwise buffering function, comprising: propeller hub; A baffle is provided at the end of the propeller hub; Propeller blades, two of which are connected to the propeller hub; A buffer section is provided on the inner surface of the baffle, and the contact surface between the buffer section and the baffle is inclined in the direction of the propeller blades' rotation and unfolding.

[0007] Preferably, a baffle is fixedly connected to the end of the propeller hub.

[0008] Preferably, the end of the propeller hub facing the baffle is bolted with two propeller blades.

[0009] Preferably, the buffer portion includes a buffer pad, which is adhered to the inner surface of the baffle.

[0010] Preferably, the contact surface between the buffer pad and the baffle is inclined at 8° along the direction of the propeller blades' rotation and unfolding.

[0011] Preferably, the propeller hub and the baffle are integrally formed.

[0012] As can be seen from the above technical solution, this utility model has the following beneficial effects: This folding propeller structure with spanwise buffer function mainly consists of an integrated hub, blades, connecting bolts, and a buffer section. With fewer parts and simpler assembly, it achieves lightweight design, effectively reducing the overall weight of the aircraft. Furthermore, a baffle is installed at the end of the hub, with a buffer section arranged inside. During the unfolding process from the folded state to the working state, the buffer section disperses and absorbs impact along the inclined contact surface, reducing rigid impact and material fatigue at the blade root, enhancing the reliability of the blade-hub connection, and thus extending the propeller's service life. Simultaneously, the buffer section provides cushioning and guidance during unfolding and locking, preventing blade swaying or abnormal folding due to excessive mechanical impact, ensuring propeller stability under high-speed rotation and aircraft operational safety. Moreover, the buffer section is implemented using adhesive pads, making the design flexible, highly adaptable, and with promising prospects for widespread application. Attached Figure Description

[0013] Figure 1This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a cross-sectional view of the overall structure of this utility model; Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0014] In the diagram: 1. Propeller hub; 2. Baffle; 3. Propeller blade; 4. Buffer section; 41. Buffer pad. Detailed Implementation

[0015] 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.

[0016] like Figures 1-3 As shown, this utility model provides a technical solution: a folding propeller structure with spanwise buffering function, including a propeller hub 1, a baffle 2, the end of the propeller hub 1 is provided with the baffle 2, propeller blades 3, two of the propeller blades 3 are connected to the propeller hub 1, and a buffer part 4, which is provided on the inner surface of the baffle 2. The contact surface between the buffer part 3 and the baffle 2 is inclined along the direction of rotation and unfolding of the propeller blades 3.

[0017] The folding propeller structure mainly consists of an integrated propeller hub 1, foldable blades 3, a baffle 2 located at the end of the hub 1, and a buffer section 4 installed inside the baffle 2. The propeller blades 3 are connected to the hub 1 via bolts or hinges, allowing them to fold naturally when the flight stops and unfold under centrifugal force during startup. During unfolding, the ends of the blades 3 come into contact with the buffer section 4 inside the baffle 2. Because the contact surface between the buffer section 4 and the baffle 2 has a certain angle, the impact force on the propeller blades 3 is gradually released along the inclined surface during contact, thereby reducing stress concentration caused by direct collision. The buffer section 4 can be made of elastic rubber or a cushioning pad material, which has good energy absorption characteristics, protecting the propeller blades 3 and stabilizing the unfolding angle.

[0018] This utility model has a simple structure, consisting only of an integrated propeller hub 1, propeller blades 3, connecting bolts, and a buffer part 4, achieving a lightweight design that effectively reduces the overall weight of the aircraft and improves flight efficiency and endurance. By introducing a baffle 2 and a buffer part 4 at the connection between the propeller blades 3 and the propeller hub 1, not only is the connection reliability between the propeller blades 3 and the propeller hub 1 enhanced, but the impact force during deployment is also effectively absorbed, avoiding structural fatigue and damage. This significantly extends the service life of the folding propeller and improves its stability and safety.

[0019] In other feasible solutions, the buffer section 4 can adopt different material structures, such as silicone, foam plastic, and metal spring-loaded bodies, to adapt to the impact resistance and durability requirements of different environments. The inclination angle of the contact surface between the buffer section and the baffle can be optimized according to the blade deployment rate and inertial force, and is usually set between 15° and 45°. The baffle 2 can adopt a segmented structure, which facilitates replacement and maintenance through modularization. In addition, the connection between the propeller blades 3 and the propeller hub 1 can also achieve automatic deployment through magnetic attraction, spring clips, etc., to adapt to different aircraft platforms or installation requirements.

[0020] A baffle 2 is fixedly connected to the end of the propeller hub 1. In this embodiment, the baffle 2 is fixedly installed at the end of the propeller hub 1 to ensure its stability and prevent deformation during structural operation. This fixed connection can be achieved through bolting, welding, gluing, or an embedded structure to ensure the baffle 2's vibration and shear resistance during flight. When the propeller blades 3 unfold under centrifugal force and contact the buffer section 4, the fixedly connected baffle 2 provides a reliable support surface, making the buffering effect of the buffer section 4 more stable and responsive, thereby more effectively absorbing the impact force during blade unfolding and preventing buffering failure due to baffle loosening or displacement.

[0021] The method of fixing the baffle 2 to the propeller hub 1 can be adjusted according to the manufacturing process and application requirements. For example, a high-strength adhesive can be used for structural bonding, or the baffle 2 and the hub 1 can be integrally cast using a one-piece molding process. A slot-locking structure can also be used to achieve quick replacement to adapt to propeller designs with different sizes or material requirements. In addition, depending on the actual installation space and stress requirements, the shape of the baffle 2 can be designed as an arc, an inclined surface, or a multi-faceted structure to further optimize its contact efficiency and buffering capacity with the buffer part 4.

[0022] Two propeller blades 3 are bolted to the end of the propeller hub 1 facing the baffle 2. In this embodiment, the propeller blades 3 are fixed to the end of the propeller hub 1 facing the baffle 2 by bolts, achieving a stable structural connection. The bolted connection facilitates the detachable installation of the blades 3, making maintenance, replacement, or angle adjustment more convenient. During flight, the propeller rotation generates centrifugal force that acts on the blades 3, causing them to rotate from a folded state to an unfolded state, and contact the buffer part 4 located inside the baffle 2 at the unfolded end, thereby achieving a buffering effect. This bolted connection not only provides stable mechanical fixation but also allows for small degrees of freedom within structural tolerances, enabling the blades to undergo slight displacement when subjected to impact, further reducing stress concentration.

[0023] In other embodiments, bolted connections can be replaced with rivets, quick-release pins, or resilient locking mechanisms to meet the connection strength and ease of disassembly requirements of different platforms. The number and specifications of bolts can be adjusted according to blade size, rotational load, and operating environment; for example, high-strength stainless steel bolts or titanium alloy bolts can be used to improve corrosion resistance and lightweight performance. Furthermore, the shock resistance and cushioning effect of the connection can be further improved by adding resilient washers or damping devices to the bolt joints.

[0024] The buffer section 4 includes a buffer pad 41, which is adhered to the inner surface of the baffle 2. In this embodiment, the buffer section 4 is structured as a buffer pad 41 disposed on the inner surface of the baffle 2, which is fixed by adhesive bonding to ensure tight adhesion to the baffle surface. The buffer pad 41 is typically made of elastic rubber, silicone, polyurethane, or other materials with good cushioning properties, possessing excellent compression deformation capacity and energy absorption capacity. During the propeller rotation and deployment process, the blades 3 unfold under centrifugal force and come into contact with the buffer pad 41 at their ends. The impact force during this contact process is absorbed and dispersed by the compression deformation of the pad material, preventing hard contact between the blades and the baffle. Simultaneously, the adhesive bonding method simplifies the assembly process and facilitates later replacement or maintenance.

[0025] In other feasible solutions, the buffer pad 41 can be fixed to the inside of the baffle 2 by screws, clips, or molding to improve peel resistance and suitability for high-temperature or high-load conditions. The material of the buffer pad can be selected with different hardness and thickness according to specific needs, such as using a double-layer composite structure to enhance its cushioning performance and durability. The surface of the pad can also be designed with raised stripes, honeycomb holes, or a wave structure to optimize its energy absorption characteristics. In addition, the bonding position can be precisely matched according to the blade deployment trajectory to achieve a more efficient contact cushioning effect.

[0026] The contact surface between the buffer pad 41 and the baffle 2 is inclined at 8° along the direction of rotation and deployment of the propeller blade 3. In this embodiment, the contact surface between the buffer pad 41 and the baffle 2 is precisely designed to be inclined at 8° along the direction of rotation and deployment of the propeller blade 3, so that when the blade deploys and contacts the buffer pad 41, its impact force is partially converted into sliding friction along the inclined direction. This structural design ensures that the process of the blade 3 contacting the buffer pad 41 is no longer a completely forward impact, but includes a certain amount of tangential sliding, thereby effectively prolonging the impact time and reducing the instantaneous impact load. The setting of this 8° inclination angle was determined after comprehensively considering factors such as blade mass, rotational speed, elasticity of the buffer material, and deployment path, and has good buffering efficiency and structural coordination.

[0027] In other feasible solutions, the contact surface inclination angle can be adjusted according to actual application requirements, such as selecting different angles within the range of 5° to 15° to adapt to different operating conditions of rotational speed, blade mass, or buffer material characteristics; the inclined surface can also be designed as a multi-stage or curved structure to further optimize the impact distribution path. The buffer pad 41 body can also be prefabricated as a wedge-shaped section to naturally form an inclination angle, eliminating the need for special processing on the baffle 2, thereby simplifying the manufacturing process. At the same time, this angle structure can also be combined with sensors or smart materials to achieve monitoring and response control of impact loads.

[0028] The propeller hub 1 and the baffle 2 are integrally formed. In this embodiment, the propeller hub 1 and the baffle 2 are manufactured using an integral forming process, meaning that they are formed as a single structure during manufacturing, without mechanical connections or assembly gaps. This structure can be achieved through processes such as injection molding, metal die casting, CNC machining, or molding of polymer composite materials. The integrally formed structure ensures the coaxiality and structural rigidity between the propeller hub 1 and the baffle 2, avoiding structural fatigue or loosening caused by connection errors, vibration, or stress concentration. During the process of the propeller blade 3 unfolding and contacting the buffer part 4, the baffle 2, as a supporting interface, directly affects the buffering effect due to its stability. The integrally formed structure ensures a more continuous and reliable force transmission path during this contact process.

[0029] 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 structure with spanwise buffering function, characterized in that, include: Propeller hub (1); Baffle (2), the propeller hub (1) is provided with a baffle (2); Propeller blades (3), two of which are connected to the propeller hub (1); The buffer part (4) is provided on the inner surface of the baffle (2), and the contact surface between the buffer part (4) and the baffle (2) is inclined in the direction of the rotation and unfolding of the propeller blade (3).

2. The folding propeller structure with spanwise buffering function according to claim 1, characterized in that: A baffle (2) is fixedly connected to the end of the propeller hub (1).

3. The folding propeller structure with spanwise buffering function according to claim 1, characterized in that: The end of the propeller hub (1) facing the baffle (2) is bolted to two propeller blades (3).

4. A folding propeller structure with spanwise buffering function according to claim 1, characterized in that: The buffer section (4) includes a buffer pad (41), which is attached to the inner surface of the baffle (2).

5. A folding propeller structure with spanwise buffering function according to claim 4, characterized in that: The contact surface between the buffer pad (41) and the baffle (2) is inclined at 8° along the direction of rotation of the propeller blade (3).

6. A folding propeller structure with spanwise buffering function according to claim 1, characterized in that: The propeller hub (1) and the baffle (2) are integrally formed.

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