High-load propeller blade for cross-shaped unmanned aerial vehicle

Abstract

The utility model discloses a kind of high-load propeller blades of cross unmanned aerial vehicle, it is related to unmanned aerial vehicle technical field, including hub and blade, blade is formed by the leading edge curve, trailing edge curve, airfoil section and blade tip of hub extension, blade is provided with four, further including locking assembly installed in hub, locking assembly includes fixed column, extrusion ring, three arc extrusion blocks and motor shaft, three openings are equidistantly opened in the outer wall of fixed column, the outer wall of fixed column is provided with external thread, hub is threadedly connected in the external thread of the outer wall of fixed column one end, extrusion ring is threadedly sleeved in the outer wall of fixed column and is lifted, three arc extrusion blocks are set in the inside of fixed column.The utility model solves the problem that existing propeller is complicated and easily loosened by vibration, has the advantages of quick disassembly, no tool, double locking, reliable anti-loose, improve flight safety.

Description

Technical Field

[0001] This utility model relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a high-load propeller blade for a cross-shaped UAV. Background Technology

[0002] As a modern aircraft, the propeller in the power system of a drone is the core component that generates lift. The propeller needs to be reliably fixed to the drone's power output shaft to transmit torque.

[0003] Traditional propellers, especially those used in high-payload drones, need to be fixed to the motor's output shaft using bolts, nuts, or pressure plates. This method of fixing requires operators to use specialized tools such as wrenches and screwdrivers to tighten or loosen the fasteners one by one when installing or replacing propellers. This is especially problematic in situations where frequent maintenance or replacement of different types of blades is required. This method of disassembly and assembly is cumbersome, time-consuming, labor-intensive, and inefficient.

[0004] To address the issue of assembly and disassembly efficiency, some quick-assembly structures have emerged, such as those using snap-fit ​​or simple screw-on mechanisms. However, during drone flight, especially under high load, the high-speed rotation of the motors and the aerodynamic disturbances of the propeller blades generate severe vibrations. These simple quick-assembly structures, relying solely on a single thread or snap-fit ​​for locking, can loosen under high-frequency vibrations, resulting in an unreliable propeller fixation. Once the propeller loosens or falls off in the air, it will directly cause the drone to lose attitude control or even crash, creating serious safety hazards. In the field of small power equipment, the propeller, as a core propulsion component, directly affects the equipment's operating efficiency, energy consumption, and service life. Existing two- or three-bladed propellers suffer from low propulsion efficiency, high noise, and limited load capacity. Utility Model Content

[0005] In view of the problems of cumbersome and time-consuming installation and disassembly, and insufficient locking reliability under high vibration conditions, the present invention aims to provide a cross-shaped high-load propeller blade for drones with an improved structure that can effectively solve the above problems.

[0006] This utility model provides a high-load propeller blade for a cross-shaped UAV, including a hub, blades and a locking assembly installed on the hub. The blades are composed of a leading edge curve, a trailing edge curve, an airfoil profile and a blade tip formed by extending from the hub, and four blades are provided. The locking assembly includes a fixed post, a compression ring, three arc-shaped compression blocks, and a motor shaft. The outer wall of the fixed post has three openings at equal intervals around its perimeter. The outer wall of the fixed post is provided with external threads. The paddle hub is threadedly connected to one end of the external threads on the outer wall of the fixed post. The compression ring is threadedly fitted onto the outer wall of the fixed post for lifting and lowering. The three arc-shaped compression blocks are located inside the fixed post. Each of the three arc-shaped compression blocks has a locking block fixedly connected to its bottom. One end of each of the three locking blocks passes through a corresponding opening. The motor shaft passes through the fixed post.

[0007] Preferably, the compression ring is adapted to compress the block during descent.

[0008] Preferably, when the clamping block is squeezed, it is adapted to push the arc-shaped squeezing block to contract, and the contraction of the arc-shaped squeezing block is adapted to achieve clamping and fixing of the motor shaft.

[0009] Preferably, a sealing cap is threaded to the other end of the external thread on the outer wall of the fixed column, and a base is fixedly connected to the bottom of the fixed column. The motor shaft passes through the sealing cap and the base in sequence. The sealing cap is adapted to contact the extrusion ring by rotation to lock the position of the extrusion ring.

[0010] Preferably, the outer wall of the sealing cap is provided with anti-slip grooves.

[0011] Preferably, the leading edge curve, trailing edge curve, airfoil profile, and blade tip surface shape are suitable for reducing blade rotational drag.

[0012] Preferably, the rotor hub serves as the connection center for the four rotor blades and is used to connect with the fixed column.

[0013] This utility model has the following beneficial effects: 1. This utility model, by setting up a locking assembly with a squeezing ring, a fixed column, an external thread, an opening, and a locking block and an arc-shaped squeezing block that cooperate with each other, allows the operator to simply rotate the squeezing ring to push the arc-shaped squeezing block to contract or loosen through the locking block. This solves the problems of propeller assembly and disassembly relying on tools, cumbersome operation, and low efficiency in the prior art, achieving the effect of quick assembly and disassembly, tool-free operation, and improved maintenance convenience. At the same time, through the cross-shaped structure and the overall thickness distribution of the propeller, it has the characteristics of simple structure, high propulsion efficiency, low noise, and large load.

[0014] 2. This utility model solves the problems of propellers being prone to loosening under flight vibration and insufficient connection reliability in the prior art by locking the compression ring and then using a rotatable sealing cover to contact the compression ring to lock its position, and by setting an anti-slip groove on the outer wall of the sealing cover to facilitate tightening. It achieves the effect of double locking, reliable anti-loosening, and improved flight safety of UAVs. Attached Figure Description

[0015] Figure 1This is a partial top view of the structure of a cross-shaped high-load propeller blade for a UAV proposed in this utility model; Figure 2 This is a partial structural side view of a cross-shaped high-load propeller blade for a UAV proposed in this utility model. Figure 3 This is a partial three-dimensional view of a cross-shaped high-load propeller blade for a UAV proposed in this utility model; Figure 4 A partial structural cross-sectional view of the hub of a cross-shaped high-load propeller blade for a UAV proposed in this utility model. Figure 5 A partial structural cross-sectional view of a fixing column for a cross-shaped high-load propeller blade for an unmanned aerial vehicle (UAV) proposed in this utility model. Figure 6 This is a partial structural cross-sectional view of the base of a cross-shaped high-load propeller blade for a UAV proposed in this utility model. Figure 7 This invention presents a schematic diagram of a single helical blade and test data for a cross-shaped high-load propeller blade for a UAV.

[0016] Legend: 1. Leading edge curve; 2. Trailing edge curve; 3. Airfoil profile; 4. Blade tip; 5. Blade hub; 6. Extrusion ring; 7. Fixed post; 8. External thread; 9. Opening; 10. Base; 11. Clamping block; 12. Arc-shaped extrusion block; 13. Motor shaft; 14. Sealing cap. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the protection scope of this utility model. Example

[0018] Please refer to Figures 1 to 6 A high-load propeller blade for a cross-shaped unmanned aerial vehicle includes a hub 5, blades, and a locking assembly mounted on the hub 5. The blades are composed of a leading edge curve 1, a trailing edge curve 2, an airfoil section 3, and a blade tip 4 formed by extending from the hub 5. There are four blades. The locking assembly includes a fixed post 7, a compression ring 6, three arc-shaped compression blocks 12, and a motor shaft 13. The outer wall of the fixed post 7 has three openings 9 at equal intervals around its perimeter. The outer wall of the fixed post 7 is provided with an external thread 8. The paddle hub 5 is threaded to one end of the external thread 8 on the outer wall of the fixed post 7. The compression ring 6 is threaded onto the outer wall of the fixed post 7 for lifting and lowering. The three arc-shaped compression blocks 12 are located inside the fixed post 7. The bottom of each of the three arc-shaped compression blocks 12 is fixedly connected to a locking block 11. One end of each of the three locking blocks 11 passes through the corresponding opening 9. The motor shaft 13 passes through the fixed post 7. The bottom of the fixed post 7 is fixedly connected to a base 10. Specifically, three arc-shaped extrusion blocks 12 are placed inside the fixed post 7, and the locking block 11 extends out from the opening 9. The motor shaft 13 passes sequentially through the sealing cover 14, the center hole of the fixed post 7, and the base 10. The diameter of the motor shaft 13 is the same as the diameter of the holes in the sealing cover 14 and the base 10. The three fit together to ensure that the installation structure will not shake. The propeller hub 5, together with the four propeller blades, is screwed and fixed to one end of the external thread 8 on the fixed post 7. The extrusion ring 6 is screwed down, causing the extrusion ring 6 to descend along the external thread 8. As the extrusion ring 6 moves... The inner wall of the compression ring 6 begins to contact and compress the protruding ends of the three clamping blocks 11. After being subjected to the radial pressure of the compression ring 6, the clamping blocks 11 are forced to move inward. Since the clamping blocks 11 and the arc-shaped compression blocks 12 are fixedly connected, the inward movement of the clamping blocks 11 will push the three arc-shaped compression blocks 12 to contract towards the center at the same time. The contraction of the three arc-shaped compression blocks 12 causes the inner arc surfaces to work together to generate a strong clamping force on the motor shaft 13 from three directions, thereby achieving a firm fixation of the propeller hub 5 and the motor shaft 13 and torque transmission.

[0019] Please refer to Figures 3 to 7 The other end of the external thread 8 on the outer wall of the fixed column 7 is threaded with a sealing cap 14. The sealing cap 14 is adapted to contact the extrusion ring 6 by rotation to lock the position of the extrusion ring 6. The outer wall of the sealing cap 14 is provided with an anti-slip groove. The curved surface shapes of the leading edge curve 1, trailing edge curve 2, airfoil section 3 and blade tip 4 are adapted to reduce blade rotation resistance. The blade hub 5 serves as the connection center of the four blades and is used to connect with the fixed column 7. Specifically, after clamping, the sealing cover 14 can be screwed down to lower it and contact the compression ring 6, which is the top of the sealing fixing column 7 and also acts as a locking nut. By contacting the compression ring 6, the position of the compression ring 6 is locked to prevent the compression ring 6 from loosening during flight vibration. To facilitate screwing, the outer wall of the sealing cover 14 is provided with anti-slip grooves.

[0020] The propeller blades employ a gradient design to enhance their load-bearing capacity: the distance *r* from the center of rotation to the airfoil gradually increases along the propeller blade, while the chord length *b* and the maximum thickness *c* of the airfoil decrease inversely with *r*. When the distance *r* from the center of rotation to the airfoil is 15 mm, the chord length *b* is 12.1 mm and the maximum thickness *c* is 1.925 mm; when *r* is 32.3 mm, *b* is 11.7 mm and *c* is 1.521 mm; when *r* is 46.8 mm, *b* is 9.5 mm and *c* is 1.045 mm; when *r* is 54.9 mm, *b* is 6.7 mm and *c* is 0.737 mm; and when *r* is 62.5 mm, *b* is 4.3 mm and *c* is 0.473 mm. This gradient design optimizes the airflow path across the blade surface while maintaining the thickness at the center of the propeller blade. The gradually decreasing thickness towards the tip provides sufficient lift, thereby enhancing its load-bearing capacity. In actual flight use, by controlling the throttle, it is possible to ensure that the thrust, current, and speed increase in the same direction, while the system efficiency gradually decreases. When the throttle is controlled at 10%, the thrust is 26.5G, the current is 0.26A, the speed is 4560.6RPM, and the system efficiency is 4.65G / W. When the throttle is controlled at 20%, the thrust is 111.3G, the current is 1.03A, the speed is 8836.6RPM, and the system efficiency is 4.81G / W. At 30% throttle, the pulling force is 228.6G, the current is 2.39A, the speed is 12221.7RPM, and the system efficiency is 4.29G / W. When the throttle is controlled at 40%, the pulling force is 408.1G, the current is 4.96A, the speed is 15840.9RPM, and the system efficiency is 3.69G / W. When the throttle is controlled at 50%, the pulling force is 608.2G, the current is 8.68A, the speed is 19131.3RPM, and the system efficiency is 3. With a throttle of 0.16 G / W, at 60% throttle, the pulling force is 832.8 G, the current is 13.6 A, the speed is 22187.9 RPM, and the system efficiency is 2.77 G / W. At 70% throttle, the pulling force is 1074.2 G, the current is 20.18 A, the speed is 24961.1 RPM, and the system efficiency is 2.42 G / W. At 80% throttle, the pulling force is 11305.2 G, the current is 27.83 A, and the speed is 2735 RPM. With a throttle of 5.5 RPM and a system efficiency of 2.15 G / W, when the throttle is at 90%, the pulling force is 14830.6 G, the current is 36 A, the speed is 29535.3 RPM, and the system efficiency is 1.9 G / W. Finally, when the throttle is controlled at 100%, the pulling force is 1673.3 G, the current is 45.45 A, the speed is 31261.5 RPM, and the system efficiency is 1.72 G / W. Controlling the throttle can stably increase its pulling force, thereby ensuring its load performance.

[0021] Working principle: The leading edge curve 1, trailing edge curve 2, and airfoil section 3 are all curved surfaces of the blades. Through the curved shapes of these surfaces, the blade tip 4 cuts through the air more effectively, further reducing drag and improving the stability of the UAV during flight. Simultaneously, the blade hub 5, serving as the connection center for the four blades, is bolted to the external thread 8 on the outer wall of the fixing post 7 in the locking assembly. The locking assembly mainly includes the fixing post 7, external thread 8, opening 9, locking blocks 11, and arc-shaped compression blocks 12. A base 10 is fixedly connected to the bottom of the fixing post 7. When the blades need to be fixed, the blade hub 5 is rotated to lower it onto the external thread 8 on the outer wall of the fixing post 7 and press against the upper surface of the base 10. Since the three locking blocks 11 are respectively fixedly connected to the bottom of the three corresponding arc-shaped compression blocks 12, the three blades are secured... The arc-shaped extrusion block 12 is placed inside the fixed column 7, and the three clamping blocks 11 are respectively inserted through the openings 9 on the fixed column 7. Then, the motor shaft 13 is inserted through the fixed column 7 and the base 10 in sequence. At this time, the extrusion ring 6 is threaded onto the external thread 8 on the outer wall of the fixed column 7, and the extrusion ring 6 is screwed down to extrude the three clamping blocks 11 on the fixed column 7. After being extruded, the three clamping blocks 11 drive the three arc-shaped extrusion blocks 12 to move towards the center of the fixed column 7 and extrude and fix the motor shaft 13. At the same time, since the thickness of the propeller hub 5 is relatively thick, after the extrusion ring 6 extrudes the arc-shaped extrusion blocks 12, it descends on the fixed column 7 to the top of the propeller hub 5, so that the bottom of the extrusion ring 6 contacts and presses against the top of the propeller hub 5 to fix it. Finally, the sealing cap 14 is threaded onto the external thread 8 on the outer wall of the fixed column 7 to seal the end. Thus, the propeller hub 5 and the propeller blade are quickly disassembled and assembled. Since the installation of the drone requires four sets of propellers, each set of propellers has four blades, and the dimensions of the entire set of identical structures are consistent, during the installation of the motor shaft 13 of a single set of propellers, the top of the motor shaft 13 is horizontally parallel to the top of the fixing column 7, so that the length of the part of the bottom end of each set of motor shaft 13 that passes through the base 10 is the same, so that the height of each set of propellers can be kept consistent after the motor is installed on the motor shaft 13.

Claims

1. A high-load propeller blade for a cross-shaped unmanned aerial vehicle, comprising: propeller hub (5); The blade is composed of a leading edge curve (1), a trailing edge curve (2), an airfoil profile (3), and a blade tip (4) formed by extending the hub (5), and the blade is provided with four blades; Locking assembly installed on the propeller hub (5); Its features are, The locking assembly includes: The fixed column (7) has three openings (9) equidistantly spaced around its outer wall. The outer wall of the fixed column (7) is provided with an external thread (8). The propeller hub (5) is threadedly connected to one end of the external thread (8) on the outer wall of the fixed column (7). The extrusion ring (6) is threaded onto the outer wall of the fixed column (7) for lifting and lowering. Three arc-shaped extrusion blocks (12) are disposed inside the fixed column (7). Each of the three arc-shaped extrusion blocks (12) has a locking block (11) fixedly connected to its bottom. One end of each of the three locking blocks (11) passes through the corresponding opening (9). The motor shaft (13) passes through the fixed column (7).

2. The high-load propeller blade for a cross-shaped UAV according to claim 1, characterized in that, The compression ring (6) is adapted to compress the card block (11) when it descends.

3. The high-load propeller blade for a cross-shaped unmanned aerial vehicle according to claim 1, characterized in that, When squeezed, the clamping block (11) is adapted to push the arc-shaped squeezing block (12) to retract, and the retraction of the arc-shaped squeezing block (12) is adapted to achieve clamping and fixing of the motor shaft (13).

4. The high-load propeller blade for a cross-shaped UAV according to claim 1, characterized in that, The other end of the external thread (8) on the outer wall of the fixed column (7) is threaded with a sealing cap (14). The bottom of the fixed column (7) is fixedly connected with a base (10). The motor shaft (13) passes through the sealing cap (14) and the base (10) in sequence. The sealing cap (14) is adapted to contact the extrusion ring (6) by rotation to lock the position of the extrusion ring (6).

5. A high-load propeller blade for a cross-shaped unmanned aerial vehicle according to claim 4, characterized in that, The outer wall of the sealing cap (14) is provided with anti-slip grooves.

6. The high-load propeller blade for a cross-shaped unmanned aerial vehicle according to claim 1, characterized in that, The curved surface shapes of the leading edge curve (1), the trailing edge curve (2), the airfoil profile (3), and the blade tip (4) are suitable for reducing blade rotational drag.

7. A high-load propeller blade for a cross-shaped unmanned aerial vehicle according to claim 1, characterized in that, The rotor hub (5) serves as the connection center for the four rotor blades and is used to connect with the fixed column (7).

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