A large pitch high pulling force propeller and mounting assembly for a drone

Abstract

The utility model relates to propeller technical field discloses a big pitch high pulling force propeller for unmanned plane and installation assembly, including hub, the hole is vertically penetrated to the center of hub, propeller blade, propeller blade is fixed in the both sides of hub, and the central symmetry distribution is shown, the propeller blade outer surface is the structure of gradually changing torsion, and the chord length and maximum thickness parameter of propeller blade change with torsion angle, propeller blade with the hub is integrally formed structure, and the connecting place is equipped with arc transition surface. In the utility model, through the gradually changing torsion angle and specific chord length thickness distribution of propeller blade, the effect that makes blade each airfoil always be in the best angle of attack state is reached, solves the efficiency loss problem caused by local airflow slip, provides the adaptability for big pitch design, enhances the effect of air delivery capacity and pulling force output.

Description

Technical Field

[0001] This utility model relates to the field of propeller technology, and in particular to a large-pitch, high-tension propeller for unmanned aerial vehicles and its mounting components. Background Technology

[0002] In the application of human-machine interfaces in many fields, the requirements for load, endurance and efficiency are increasing. Large-pitch propellers are the key to improving thrust. The drag and noise characteristics of propellers and mounting components affect endurance and environmental adaptability. Therefore, the development of related components that are adapted to large pitch, high thrust and low drag and low noise is an important requirement for the optimization of drone power. Most existing drone propellers employ blade structures with uniform or segmented fixed twist angles. The blade chord length and thickness distribution are typically uniform or simply linear. The propeller is driven by a motor, and lift (i.e., thrust) is generated by the relative motion between the blades and the air, enabling the drone to take off and fly. The mounting components usually consist of cylindrical or simple block-shaped connectors, serving only to fix the propeller and motor shaft, relying on the rigid structure of the connectors to ensure stable power transmission. Existing propellers suffer from unreasonable design of twist angle, chord length and thickness, which cannot guarantee the optimal angle of attack for each airfoil, are prone to airflow slippage, have large efficiency losses, are difficult to adapt to large pitches, and limit thrust. The non-streamlined connecting parts generate large parasitic drag, affecting endurance, and lack noise reduction design, which cannot disrupt vortex synchronization and generate harsh narrow-frequency noise. To address these issues, a large-pitch, high-thrust propeller and mounting components for UAVs are proposed. Utility Model Content

[0003] To overcome the above shortcomings, this utility model provides a large-pitch, high-tension propeller and mounting assembly for unmanned aerial vehicles, aiming to improve the efficiency loss caused by local airflow slippage around the propeller blades and the problem of high pressure differential drag affecting the endurance.

[0004] To achieve the above objectives, this utility model adopts the following technical solution: a large-pitch, high-tension propeller for unmanned aerial vehicles, comprising: The propeller hub has a vertical hole running through its center; The propeller blades are fixed on both sides of the hub and are centrally symmetrically distributed. The outer surface of the propeller blades has a gradually twisted structure, and the chord length and maximum thickness parameters of the propeller blades vary with the twist angle. The propeller blades and the hub are integrally formed, and the connection is provided with an arc-shaped transition surface.

[0005] As a further description of the above technical solution: This utility model also provides a mounting assembly for a large-pitch, high-tension propeller for unmanned aerial vehicles (UAVs). The mounting assembly includes a connector, the top of which is fixed to the bottom of the propeller hub. The outer surface of the connector has an oval streamlined structure that is larger at the top and smaller at the bottom.

[0006] As a further description of the above technical solution: A fixing ring is fixedly connected to the bottom edge of the connector, and the outer surface of the fixing ring has a wave structure.

[0007] As a further description of the above technical solution: The surface of the connector has grooves and is coated with a smooth coating.

[0008] As a further description of the above technical solution: A label plate is provided on the outer surface of the connector. The label plate is attached to the inner wall of the groove and has the same thickness as the inner wall of the groove.

[0009] As a further description of the above technical solution: The surface of the label plate has a rectangular structure and matches the curvature of the surface of the connector.

[0010] As a further description of the above technical solution: The connector has an insertion hole inside, an electric motor is provided at the bottom of the connector, a fixing pin is sleeved on the surface of the electric motor output rod, a locking ring is provided at the bottom of the outer wall of the fixing pin, and the locking ring is in contact with the bottom of the fixing ring.

[0011] As a further description of the above technical solution: The outer wall of the fixing pin passes through the insertion hole inside the connector and extends to the top of the propeller hub. The top of the fixing pin is threaded with a bullet head, and the bullet head has a circular hole on its surface. The bullet head fits into the top of the propeller hub.

[0012] This utility model has the following beneficial effects: 1. In this utility model, by using the gradual twist angle and specific chord thickness distribution of the propeller blades, the airfoil of each blade is always in the optimal angle of attack state, which solves the efficiency loss problem caused by local airflow slippage, provides adaptability for large pitch, and enhances the air exhaust volume and thrust output.

[0013] 2. In this utility model, the smooth oval streamlined structure of the connector reduces the parasitic resistance in the central area, solves the problem of high pressure differential resistance affecting the range, and the wavy fixing ring disrupts the vortex synchronization at the bottom of the connector, enhancing the effect of converting harsh tone noise into broadband noise. Attached Figure Description

[0014] Figure 1 This is a perspective view of a large-pitch, high-tension propeller for unmanned aerial vehicles and its mounting assembly proposed in this utility model. Figure 2 This is a schematic diagram of the propeller blades of a large-pitch, high-tension propeller and its mounting assembly for a drone, as proposed in this utility model. Figure 3 This is a schematic diagram of a connector for a large-pitch, high-tension propeller and mounting assembly for unmanned aerial vehicles (UAVs) proposed in this utility model. Figure 4 for Figure 3 Enlarged structural diagram at point A in the diagram; Figure 5 This is a schematic diagram of a smooth coating for a large-pitch, high-tension propeller and its mounting assembly for unmanned aerial vehicles (UAVs) proposed in this utility model.

[0015] Legend: 1. Propeller blade; 2. Connector; 3. Retaining ring; 4. Marking plate; 5. Mounting hole; 6. Hub; 7. Groove; 8. Smooth coating; 9. Electric motor; 10. Fixing pin; 11. Locking ring; 12. Bullet head. 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] Reference Figure 1 and Figure 2 One embodiment of this utility model is a large-pitch, high-tension propeller for unmanned aerial vehicles (UAVs), comprising: The hub 6 has a vertical hole running through its center. The hub 6 is preferably made of lightweight and high-strength carbon fiber composite material. Its main function is to serve as the structural center between the connector 2 and the propeller blade 1, ensuring that power is efficiently transmitted to the propeller blade 1. Propeller blades 1 are fixed on both sides of the hub 6 and are centrally symmetrically distributed. The outer surface of propeller blade 1 has a gradually twisted structure, and the chord length and maximum thickness parameters of propeller blade 1 vary with the twist angle. Propeller blade 1 and hub 6 are integrally formed, and the connection has an arc-shaped transition surface. Propeller blade 1 adopts a streamlined airfoil design to generate lift by utilizing the pressure difference formed by its upper and lower surfaces. Its gradually twisted angle design, for example, the twist angle at the radial position r1 is 56.52 degrees, at the position r2 it is 43.92 degrees, at the position r3 it is 33.93 degrees, and at the position r4 it is 28.8 degrees, is used to ensure that the airfoil at each radius of blade 1 is always in the optimal angle of attack state for adapting to the large pitch, avoiding efficiency loss caused by local airflow slippage. At the same time, its chord length, maximum thickness, and distance parameters from the rotation center to the airfoil are specific. The distribution of the rotor blades is as follows: at position r1, the chord length is 17.9 mm, the maximum thickness is 3.401 mm, and the distance from the rotation center to the airfoil is 25.3 mm; at position r2, the chord length is 19.4 mm, the maximum thickness is 2.716 mm, and the distance from the rotation center to the airfoil is 42.4 mm; at position r3, the chord length is 13.3 mm, the maximum thickness is 1.596 mm, and the distance from the rotation center to the airfoil is 62.2 mm; and at position r4, the chord length is 8.4 mm, the maximum thickness is 1.008 mm, and the distance from the rotation center to the airfoil is 84 mm. This design aims to reduce air resistance and weight while ensuring structural strength. The propeller blade 1 is made of high-toughness engineering plastic. This structure, combined with the large pitch design, can move more volume of air at the same rotation speed, directly increasing the air displacement per unit time and thus enhancing the thrust output.

[0018] Reference Figures 3-5Another embodiment of this utility model is provided: a large-pitch, high-tension propeller mounting assembly for drones. The assembly includes a connector 2, the top of which is integrally fixed to the bottom of the rotor hub 6. The outer surface of the connector 2 has an oval streamlined structure, wider at the top and narrower at the bottom. This structure allows the connector 2 to gently separate horizontally and tangentially superimposed spiral airflow, enabling the airflow to adhere tightly to its smooth surface and form a stable adhering flow. This fundamentally reduces pressure drag, the main source of wind resistance. The connector 2 is injection molded from high-rigidity ABS material. This design reduces parasitic drag in the propeller's central region, allowing more of the motor's output energy to be used for lift generation. A retaining ring 3 is integrally fixed to the bottom edge of connector 2. The outer surface of the retaining ring 3 has a wave-like structure. This wave-like retaining ring 3 actively disrupts the conditions for the formation of tonal noise. It forces the airflow to detach in different ways at different wave crests and troughs, forcibly breaking up and recombining the periodically detached vortices into countless tiny vortices. Acoustically, this transforms harsh tonal noise into broadband noise distributed over a wide frequency range, significantly reducing flight noise. The connector 2 has a groove 7 on its surface and is coated with a smooth paint 8 made of polytetrafluoroethylene (PTFE). This smooth paint reduces friction on the surface of the connector 2 and better guides airflow. A marking plate 4 is fixedly connected to the outer surface of the connector 2. The marking plate 4 is coated with a specific color of paint. This marking plate 4 is used to easily align the rotor hub 6 to the correct position using different colors, avoiding installation errors. Existing drones have two types of rotor blades: A-blade and B-blade. If the two types of rotor blades are installed in the wrong position, it can easily affect the flight of the drone. Plate 4 is pasted on the inner wall of groove 7 and has the same thickness as the inner wall of groove 7. Connector 2 has an insertion hole 5 inside. Electric motor 9 is provided at the bottom of connector 2. Fixed pin 10 is sleeved on the surface of the output rod of electric motor 9. Locking ring 11 is provided at the bottom of the outer wall of fixed pin 10. Locking ring 11 fits with the bottom of fixed ring 3. The outer wall of fixed pin 10 passes through the insertion hole 5 inside connector 2 and extends to the top of propeller hub 6. Bullet head 12 is threaded to the top of fixed pin 10. Bullet head 12 has a circular hole on its surface and fits with the top of propeller hub 6.

[0019] Working principle: First, the fixing pin 10 is interference-fitted onto the rotating shaft surface at the top of the electric motor 9, so that the top of the rotating shaft at the top of the electric motor 9 fits against the top of the groove on the inner wall of the fixing pin 10. At this time, there is a certain gap between the bottom of the fixing pin 10 and the electric motor 9 to avoid friction. Then, the locking ring 11 is fitted onto the outer surface of the fixing pin 10, so that the locking ring 11 fits against the bottom of the fixing pin 10. Then, the connecting piece 2 and the propeller hub 6 are fitted onto the outer wall of the fixing pin 10. If a large gap occurs between the connecting piece 2 and the propeller hub 6 and the fixing pin 10 during the fitting process, rubber gaskets can be installed on the top of the inner wall of the propeller hub 6 and the bottom of the insertion hole 5 inside the connecting piece 2 to ensure that the inner wall of the connecting piece 2 and the propeller hub 6 fits fully with the fixing pin 10. Then, the bullet head 12 is screwed to the top of the fixing pin 10, which can remove the outer cylindrical hard metal strip (now A propeller blade installation tool is inserted into the bullet head 12. The cylindrical hard metal strip is consistent with the size of the hole inside the bullet head 12, making it easy to tighten the bullet head 12. This allows the hub 6 and the connector 2 to push the locking ring 11 to press the skirt structure at the bottom of the fixing pin 10, achieving a secondary lock between the fixing pin 10 and the top output rod of the electric motor 9. This connects and fixes the propeller blade 1 to the electric motor 9. When the electric motor 9 drives the propeller blade 1 and the hub 6 located at its center to rotate around the rotation center, the streamlined airfoil of the propeller blade 1 results in a high air velocity and low air pressure on its upper surface, and a slow air velocity and high air pressure on its lower surface. The lift generated by this air pressure difference is decomposed into a tangential component to overcome air resistance and a tensile component along the axial direction of the equipment under the action of the preset installation angle of the blade, providing power for the flight of the equipment. The propeller blade 1 adopts a gradually varying twist angle design. Its radial twist angles are 56.52 degrees at position r1, 43.92 degrees at position r2, 33.93 degrees at position r3, and 28.8 degrees at position r4. This design ensures that the airfoil at each radius of the blade is at its optimal angle of attack. The blade's chord length, maximum thickness, and distance from the rotation center to the airfoil also exhibit specific distributions with the twist angle. For example, at position r1, the chord length is 17.9 mm, the maximum thickness is 3.401 mm, and the distance from the rotation center to the airfoil is 25.3 mm; at position r2, the chord length is 19.4 mm, the maximum thickness is 2.716 mm, and the distance from the rotation center to the airfoil is 42.4 mm; and at position r3, the chord length is 13.3 mm, the maximum thickness is 1.596 mm, and the distance from the rotation center to the airfoil is 25.3 mm. The airfoil has a pitch of 62.2mm, a chord length of 8.4mm at position r4, a maximum thickness of 1.008mm, and a distance of 84mm from the rotation center to the airfoil. This reasonable distribution ensures the structural strength of the blade while reducing air resistance and its own weight. It can reduce the risk of air resistance and centrifugal deformation during large-pitch rotation while ensuring the overall structural strength of the blade. It can also ensure that the airfoil at each radius of the blade is always in the optimal angle of attack state for large pitch through gradual adjustment of the torsion angle, avoiding pitch efficiency loss caused by local airflow slippage. It provides structural adaptability for the core function of large pitch, which pushes more air per unit rotation cycle. At the same rotation speed, it can move more volume of air, directly increasing the air displacement per unit time, thereby enhancing the thrust output. Taking a static test data voltage of 11.1V as an example, the parameter design of each airfoil section effectively corresponds to the actual thrust output. When the throttle opening increases from 10% to 100%, the current increases from 0.17A to 22.39A, the thrust gradually increases from 5g to 414g, and the force efficiency remains between 1.00-2.80g / W. When the throttle opening is between 10% and 30%, the first and second sections closest to the hub 6 mainly play a role. The large twist angle and thick airfoil ensure stable power transmission, enabling the thrust to increase rapidly from 5g to 39g. As the throttle opening increases from 40% to 70%, the third section in the middle and rear becomes the core of thrust output. The optimized angle of attack and low-drag airfoil design push the thrust from 81g to 262g. Although the force efficiency decreases slightly, it still remains above 1.80g / W, demonstrating the efficient energy conversion capability of this section. When the throttle opening reaches 80% to 100%, the fourth section at the blade tip works in conjunction with other sections. With a significant increase in current, the thrust continues to increase to 414g, and the force efficiency remains stable at 1.40-1.50g / W. This indicates that the vortex control design of the blade tip section is effective, avoiding energy waste at high speeds and ensuring the continuous increase of overall thrust. The propeller is mounted on the oval-shaped connector 2 via a hub 6 located at the top. A color-coded label 4 on top of connector 2 helps align the hub 6 to the correct position, preventing incorrect installation. Existing drone propellers come in two types: A-blades and B-blades. Incorrect installation of either type can easily affect the drone's flight. The core of connector 2 is a vertically placed, smooth oval structure. Its shape is not a random cone, but rather a streamlined form resembling an egg or a bullet. Its outer surface is smooth and continuous, and coated with a polytetrafluoroethylene (PTFE) material. The smooth coating 8, when the drone flies forward, the horizontal airflow and the tangential airflow generated by the rotation of the propeller cap will superimpose to form a complex spiral airflow. The gentle front end of the oval structure can very smoothly separate this airflow, avoiding the formation of a huge high-pressure area in front. Then, the separated airflow will adhere to its smooth surface, forming a stable adhering flow, which flows smoothly backward along the spiral path, reducing energy loss. Finally, because the airflow can adhere for a long time, the low-pressure wake area behind the propeller cap becomes extremely narrow, thus fundamentally reducing the pressure drag, which is the main source of wind resistance. In this way, the oval structure reduces parasitic drag in the central region of the propeller, allowing more of the energy output from the motor to be used to generate lift, directly improving the drone's endurance. At the bottom physical edge of the connector 2, that is, on the circumference where the airflow is about to leave the object's surface, a retaining ring 3 is integrated, running backwards with the airflow. The outer surface of the retaining ring 3 is wavy, and its function is specifically to solve the noise problem. The core of its working principle is to actively disrupt the conditions for the formation of pitch noise. At any smooth trailing edge, a series of highly ordered, periodically falling vortices will be formed when the airflow leaves. The flow will generate strong resonance, forming a piercing buzzing sound. The wave-shaped structure will force the airflow to break away at different crests and troughs at different minute points and in different ways, completely destroying the synchronicity of the vortex shedding. In this process, it is forcibly broken and reorganized into countless small, low-energy, randomly appearing micro vortices. Acoustically, this transforms the originally piercing tone noise concentrated at a specific frequency into a wide range of frequencies. Through the specific shape of the propeller blade 1, the fixed ring 3, and the connector 2, the effect of large pitch, high tension, low wind resistance, and low noise is achieved.

Claims

1. A large-pitch, high-pulse propeller for unmanned aerial vehicles (UAVs), characterized in that, include: The hub (6) has a hole vertically penetrating its center; The propeller blade (1) is fixed on both sides of the hub (6) and is centrally symmetrically distributed. The outer surface of the propeller blade (1) has a gradually twisted structure, and the chord length and maximum thickness parameters of the propeller blade (1) change with the twist angle. The propeller blade (1) and the hub (6) are integrally formed, and an arc-shaped transition surface is provided at the connection.

2. A mounting assembly for a large-pitch, high-pulse propeller for a drone, as described in claim 1, characterized in that: The large-pitch, high-tension propeller mounting assembly for UAVs includes a connector (2), the top of which is fixed to the bottom of the propeller hub (6), and the outer surface of the connector (2) has an oval streamline structure that is larger at the top and smaller at the bottom.

3. The mounting assembly for a large-pitch, high-tension propeller for a drone according to claim 2, characterized in that: The bottom edge of the connector (2) is fixedly connected to a fixing ring (3), and the outer surface of the fixing ring (3) has a wave structure.

4. The mounting assembly for a large-pitch, high-tension propeller for a drone according to claim 2, characterized in that: The connector (2) has a groove (7) on its surface and is coated with a smooth coating (8).

5. A large-pitch, high-tension propeller mounting assembly for unmanned aerial vehicles according to claim 4, characterized in that: The outer surface of the connector (2) is provided with a label plate (4), which is attached to the inner wall of the groove (7) and has the same thickness as the inner wall of the groove (7).

6. The mounting assembly for a large-pitch, high-tension propeller for a drone according to claim 5, characterized in that: The surface of the label plate (4) is rectangular and matches the curvature of the surface of the connector (2).

7. A large-pitch, high-tension propeller mounting assembly for unmanned aerial vehicles according to claim 2, characterized in that: The connector (2) has an insertion hole (5) inside. An electric motor (9) is provided at the bottom of the connector (2). A fixing pin (10) is sleeved on the surface of the output rod of the electric motor (9). A locking ring (11) is provided at the bottom of the outer wall of the fixing pin (10). The locking ring (11) is in contact with the bottom of the fixing ring (3).

8. A large-pitch, high-tension propeller mounting assembly for unmanned aerial vehicles according to claim 7, characterized in that: The outer wall of the fixing pin (10) passes through the insertion hole (5) inside the connector (2) and extends to the top of the propeller hub (6). The top of the fixing pin (10) is threaded with a bullet head (12). The surface of the bullet head (12) is provided with a circular hole. The bullet head (12) fits against the top of the propeller hub (6).

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