Blade hub, propeller and aircraft based on an integrated blade

Abstract

The embodiment of the present disclosure discloses a hub based on an integrated blade, which comprises a fork for connecting the blade with the main body of an aircraft, a flap shaft assembly comprising a symmetrical fixing structure for tightly fixing the blade, and an elastic bearing assembly for combining the flap shaft assembly with the fork. The fork comprises symmetrically arranged shaft sleeves, the elastic bearing assembly is arranged in the shaft sleeves, the symmetrical structure of the flap shaft assembly is arranged in the elastic bearing assembly, the flap shaft assembly can swing around the elastic bearing assembly as the axis, and the bottom of the flap shaft assembly is provided with a limiting structure. The hub is provided with two elastic bearings with elastic deformation capacity, which can provide the freedom of swinging through the elastic deformation of the hub, and the blades on both sides can swing up and down when encountering unbalanced airflow or maneuvering. This process greatly absorbs the impact from the airflow and the maneuvering, so that the aircraft moves more smoothly, responds more quickly, and greatly reduces the vibration of the main body.

Description

Technical Field

[0001] This disclosure relates to the field of rotorcraft technology, specifically to a rotor hub, propeller, and aircraft based on an integrated blade. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of this disclosure and is not necessarily an admission or implication in any way that such information constitutes related technology that is already known to those skilled in the art.

[0003] The flight performance and stability of multi-rotor aircraft (such as drones) largely depend on the performance of their propellers. Currently, the mainstream multi-rotor propellers on the market are mainly divided into split quick-release blades and integrated blades.

[0004] One-piece blades have significant advantages because the blade is a single unit: Excellent aerodynamic performance: One-piece molding, no connecting gaps, complete aerodynamic shape, and high efficiency.

[0005] High rigidity and low vibration: The overall rigidity is high and the deformation is small at high speeds, which can effectively reduce flight vibration and provide better conditions for flight.

[0006] High reliability: There is no risk of wear and failure due to quick-release structure.

[0007] However, traditional one-piece rotor blades also have inherent technical defects that have not yet been overcome, especially when the aircraft is in forward flight, the problem is particularly prominent: Asymmetric lift in forward flight: This is a fundamental aerodynamic flaw of traditional rigid one-piece rotor blades. When an aircraft flies forward, there is an angle between its rotor plane of rotation and the flight direction. This results in: the relative airflow velocity of the forward rotor blade equals its rotational linear velocity plus the airspeed, while the relative airflow velocity of the backward rotor blade equals its rotational linear velocity minus the airspeed. Therefore, the forward rotor blade has a larger effective angle of attack and a higher relative airspeed, thus generating much more lift than the backward rotor blade. For a rigidly connected one-piece rotor blade, this huge lift difference creates a strong rolling moment that attempts to push the aircraft toward the backward side.

[0008] To overcome this unbalanced torque, the flight control system must perform forced compensation electronically. This compensation method is inefficient, increases energy consumption, shortens flight time, and causes continuous, high-frequency fuselage vibration, severely deteriorating flight quality.

[0009] Rigid connections lead to maneuverability limitations and impact loads: In traditional integrated rotor blades, the hub is rigidly connected to the motor shaft, and all blades rotate rigidly as a single unit. During rapid maneuvers or when encountering gusts, the angle of attack, velocity, and load on each blade change instantaneously and unevenly. However, the rigid hub forces all blades to move synchronously. This, combined with the aforementioned lift asymmetry, exacerbates the situation, resulting in less agile maneuverability and a certain delay. Furthermore, significant torsional loads and bending stresses concentrate at the hub root, which can easily lead to material fatigue damage and even fracture over time.

[0010] The requirements for the motor mounting surface are stringent: rigid, one-piece propellers cannot compensate for unevenness in the mounting surface of the tiny motor or errors in the main shaft tilt angle, which will directly translate into flight vibration.

[0011] Therefore, while pursuing high rigidity and low vibration, existing integrated rotor blades cannot solve the inherent lift asymmetry problem during forward flight, thus sacrificing flight efficiency, range, and maneuverability, while also facing problems such as high impact loads and limited durability. The purpose of this invention is to propose a method that, while retaining the high-performance advantages of integrated rotor blades, fundamentally overcomes their aerodynamic defects and other related problems in forward flight. Summary of the Invention

[0012] Therefore, this disclosure provides a rotor hub, propeller, and aircraft based on an integrated blade to solve the problems of low flight efficiency, increased energy consumption, and easy breakage of the rotor hub due to asymmetrical blade lift in the forward flight state of the aircraft in the related art.

[0013] To achieve the above objectives, the embodiments of this disclosure provide the following technical solutions: In embodiments of this disclosure, a rotor hub based on an integral blade is provided, including... Fork-shaped components are used to connect the propeller blades to the aircraft body; The waving shaft assembly includes a symmetrical fixing structure for holding and fixing the blades; Flexible bearing assembly for combining the swing shaft assembly with the fork-type component; The fork-shaped component includes symmetrically arranged bushings, with the elastic bearing assembly disposed inside the bushings. The symmetrical structure of the swing shaft assembly passes through the elastic bearing assembly, and the swing shaft assembly can swing about the elastic bearing assembly as an axis. The bottom of the swing shaft assembly is provided with a limiting structure.

[0014] Furthermore, the fork-shaped component includes a centrally symmetrical left structure and a right structure. Both the left structure and the right structure include a connecting section. One end of the connecting section is longitudinally provided with the bushing, and the other end is provided with an engaging member. The engaging members of the left structure and the right structure are fixed by bolts.

[0015] Furthermore, the left and right structures are fastened by two sets of bolts, the connecting section is provided with two screw holes, the interlocking member is provided with one screw hole, the left and right structures are interlocked, and a fuse is provided between the two bolts in the lateral direction.

[0016] Furthermore, a reinforcing boss is provided near the bushing at the connection section between the left and right structures, and a waving limiting member is provided at the bottom of the waving shaft assembly. The reinforcing boss and the waving limiting member together form the limiting structure.

[0017] Furthermore, the waving shaft assembly includes two symmetrically arranged mounting portions, each mounting portion including a C-shaped clamp that can fit against the outer wall of the blade. The sides of the clamps extend outward to form a waving shaft for fixing the elastic bearing assembly, and the ends of the waving shaft are fixed by slotted nuts and cotter pins.

[0018] Furthermore, the elastic bearing assembly includes an elastic body fitted inside the bushing, with an inner elastic bearing ring on the inner side of the elastic body and an outer elastic bearing ring on the outer side that contacts the inner wall of the bushing. The swing shaft passes through the elastic body and is fixed by a slotted nut and a cotter pin.

[0019] Furthermore, the inner ring of the elastic bearing is a trapezoidal column, and the elastic body is composed of a left structure and a right structure. Both the left and right structures are trapezoidal columns, and their bottom surfaces are integrally joined together, forming a cavity inside that can accommodate the inner ring of the elastic bearing. The length of the inner ring of the elastic bearing is the same as the length of the elastic body. The outer ring of the elastic bearing is a cylinder, and its length is the same as the length of the right structure of the elastic body. The interior of the outer ring of the elastic bearing forms a cavity that can accommodate the right structure of the elastic body.

[0020] Furthermore, the cross-sectional line of the inner wall of the elastomer is parallel to the cross-sectional line of the outer wall of the right structure.

[0021] A propeller includes an integral blade and a hub. The blade is fixed to the hub by blade bolts. The hub clamps the blade at its geometric center. The axis of the hub forms a 45° angle with the axis of the blade in the vertical extension direction.

[0022] An aircraft, including Body and power unit And at least one of the aforementioned propellers, the propellers being mounted on the drive end of a power unit, the power unit being mounted on the fuselage.

[0023] According to the embodiments of this disclosure, the following advantages are available: The rotor hub includes a fork-shaped component for connecting the rotor blades to the aircraft body; a flapping shaft assembly including a symmetrical fixing structure for clamping and fixing the rotor blades; and an elastic bearing assembly for combining the flapping shaft assembly with the fork-shaped component and providing flapping constraint stiffness. The fork-shaped component includes symmetrically arranged bushings, within which the elastic bearing assembly is disposed. The symmetrical structure of the flapping shaft assembly passes through the elastic bearing assembly, allowing the flapping shaft assembly to swing about the elastic bearing assembly as its axis. A limiting structure is provided at the bottom of the flapping shaft assembly. The rotor hub is provided with two elastic bearings with elastic deformation capabilities, which can provide flapping freedom through their own elastic deformation, allowing the rotor blades on both sides to flap up and down when encountering unbalanced airflow or maneuvers. When the lift of one rotor blade increases due to an increased angle of attack, that rotor blade can flap upwards, effectively reducing the actual angle of attack, thereby automatically balancing the lift on both sides. This process greatly absorbs the impact from airflow and maneuvers, making the aircraft maneuver smoother, responding more quickly, and significantly reducing airframe vibration. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments or related technologies of this disclosure, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0025] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which this disclosure can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this disclosure can produce, should still fall within the scope of the technical content disclosed herein.

[0026] Figure 1 This is a three-dimensional structural diagram of a hub-mounted blade based on an integral blade, according to an exemplary embodiment. Figure 2 An exploded view of a hub-mounted blade based on an integral blade according to an exemplary embodiment; Figure 3 This is a three-dimensional structural diagram of a fork-shaped member in a rotor hub based on an integral blade, according to an exemplary embodiment. Figure 4 This is a three-dimensional structural schematic diagram of the left structure of the fork-shaped member in a propeller hub based on an integral blade, according to an exemplary embodiment. Figure 5This is a three-dimensional structural schematic diagram of a fixing structure in a flapping shaft assembly in a propeller hub based on an integral blade, according to an exemplary embodiment. Figure 6 This is a three-dimensional structural schematic diagram of an elastic bearing assembly in a rotor hub based on an integral blade, according to an exemplary embodiment. Figure 7 This is a cross-sectional view of a resilient bearing assembly according to an exemplary embodiment; Figure 8 This is a top view of the propeller's structure.

[0027] In the diagram: 11. Connecting section; 12. Bushing; 13. Slotted nut; 14. Cotter pin; 15. Bolt; 16. Engaging part; 17. Fuse; 21. Clamping plate; 22. Swinging shaft; 23. Reinforcing boss; 24. Swinging limiter; 31. Outer ring of the flexible bearing; 32. Inner ring of the flexible bearing; 33. Elastomer; 4. Blade; 41 Blade bolt. Detailed Implementation

[0028] The following specific embodiments illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0029] The terms “upper,” “lower,” “left,” “right,” and “middle” used in this specification are merely for clarity of description and are not intended to limit the scope of this disclosure. Any changes or adjustments to their relative relationships, without substantially altering the technical content, shall also be considered within the scope of this disclosure.

[0030] like Figure 1 , Figure 2 As shown, a disclosed embodiment provides a rotor hub based on an integral blade 4, including... Fork-shaped component, used to connect propeller blade 4 to the aircraft body; The waving shaft assembly includes a symmetrical fixing structure for holding and fixing the blade 4; Flexible bearing assembly for combining the swing shaft assembly with the fork member and providing swing constraint stiffness; The fork-shaped component includes symmetrically arranged bushings 12, with an elastic bearing assembly inside the bushings 12. The symmetrical structure of the swing shaft assembly passes through the elastic bearing assembly, allowing the swing shaft assembly to swing about the elastic bearing assembly as its axis. The bottom of the swing shaft assembly is provided with a limiting structure.

[0031] The rotor hub is equipped with two elastic bearings capable of elastic deformation, which provide freedom of movement through their own elastic deformation. The flapping shaft assembly, through the combination of the elastic bearing assembly and the fork-shaped component, forms a seesaw-like rotor hub, allowing the blades 4 on both sides to flap up and down when encountering unbalanced airflow or maneuvers. When the lift of one blade 4 increases due to an increased angle of attack, that blade 4 can flap upwards, effectively reducing the actual angle of attack and thus automatically balancing the lift on both sides. This process greatly absorbs the impact from airflow and maneuvers, making the aircraft maneuver smoother, more responsive, and significantly reducing airframe vibration.

[0032] like Figure 3 , Figure 4 As shown, the fork-shaped component includes a centrally symmetrical left structure and a right structure. Both the left and right structures include a connecting section 11. One end of the connecting section 11 is provided with a bushing 12 in the longitudinal direction, and the other end is provided with a meshing member 16. The meshing members 16 of the left and right structures are fixed by bolts 15.

[0033] The left and right structures are fastened by two sets of bolts 15. Two screw holes are provided on the connecting section 11 and one screw hole is provided on the interlocking part 16. The left and right structures are interlocked. A fuse 17 is provided between the two horizontal bolts 15. Washers can be set when the bolts 15 are tightened. The fuse 17 can further ensure the tightening effect of the bolts 15 and prevent the bolts from loosening.

[0034] In another embodiment, a reinforcing boss 23 is provided on the connecting section 11 between the left and right structures near the bushing 12, and a waving limiting member 24 is provided at the bottom of the waving shaft assembly. The reinforcing boss 23 and the waving limiting member 24 form a limiting structure.

[0035] The waving limiter 24 is a rubber component, and its mechanical connection with the clamping plate 21 is achieved by adding adhesive. The waving limiter structure prevents the blade 4 from waving when its maximum designed waving angle is reached. This structure consists of the waving limiter 24 mounted on the legs of the waving shaft assembly and the reinforcing boss 23. Within the designed waving range, this structure does not constrain the movement. When the maximum designed angle is reached, the waving limiter 24 impacts the reinforcing boss 23 on the fork-shaped component, stopping the waving movement and automatically balancing the lift on both sides by adjusting the waving posture.

[0036] The waving axis assembly includes two symmetrically arranged mounting parts, such as Figure 5As shown, the mounting part includes a C-shaped clamp 21, which can be assembled to fit against the outer wall of the blade 4. The side (web) of the clamp 21 extends outward to form a swing shaft 22 for fixing the elastic bearing assembly. The end of the swing shaft 22 is fixed by a slotted nut 13 and a cotter pin 14. The swing limiting member 24 is provided on the bottom side wing plate of the clamp 21.

[0037] like Figure 6 , Figure 7 The elastic bearing assembly includes an elastic body 33 fitted inside the bushing 12. The inner side of the elastic body 33 is provided with an inner ring 32 of the elastic bearing, and the outer side is provided with an outer ring 31 of the elastic bearing that contacts the inner wall of the bushing 12. The swing shaft 22 passes through the elastic body 33 and is fixed by a slotted nut 13 and a cotter pin 14.

[0038] The flapping shaft 22 can be connected to the inner ring 32 of the elastic bearing via a keyway, allowing it to rotate around the axis of the inner ring 32 of the elastic bearing to achieve the flapping motion of the blade 4. The flapping shaft 22 is aligned with the diameter direction of the hub of the integrated blade 4.

[0039] To provide stable support during swinging adjustments and to prevent the elastic body 33 from dislodging, the inner ring 32 of the elastic bearing is a trapezoidal column. The elastic body 33 consists of a left structure and a right structure, both of which are trapezoidal columns with their bottom surfaces facing each other and integrally joined together, forming a cavity inside that can accommodate the inner ring 32 of the elastic bearing. The length of the inner ring 32 of the elastic bearing is the same as the length of the elastic body 33. The outer ring 31 of the elastic bearing is a cylinder, and its length is the same as the length of the right structure of the elastic body 33. The interior of the outer ring 31 of the elastic bearing forms a cavity that can accommodate the right structure of the elastic body 33.

[0040] The cross-sectional line of the inner wall of the elastic body 33 is parallel to the cross-sectional line of the outer wall of the right structure. The parallel cross-section ensures that the elastic body 33 experiences the same force after contacting the inner ring 32 and the outer ring 31 of the elastic bearing, thus ensuring bidirectional force balance and further improving its stability.

[0041] like Figure 8 As shown, this disclosure also provides a propeller, including an integral blade 4 and the aforementioned hub. The blade 4 is fixed to the hub by blade bolts 41, and the hub clamp 21 is clamped at the geometric center of the blade 4. The axis of the hub forms a 45° angle with the axis of the blade 4 in the vertical extension direction.

[0042] The integrated blade 4 is combined with the seesaw-type hub, and the installation method is quite special. The flapping shaft 22 needs to be installed on the hub fork, then the blade 4 is installed, the motor bolt 15 is installed at the same time, and finally the elastic bearing is installed.

[0043] Meanwhile, the flapping shaft 22 forms a 45° angle with the axis perpendicular to the extension direction, which not only provides excellent structural strength but also allows the two flapping shafts 22 to be connected into a single structure, replacing the traditional metal flapping shaft 22. This enables the blade 4 to rotate together with the flapping shaft 22 around the flapping shaft line. Compared to the metal flapping shaft 22 used in typical seesaw propeller hubs, this structure has the advantage of being lightweight.

[0044] The four roots of the blades have a certain bending angle, which is used to shorten the length of the hub fork structure and reduce the weight of the hub while maintaining the strength of the four roots of the composite blades.

[0045] This propeller has the following characteristics: Significantly improved maneuverability and flight stability: By introducing a seesaw flapping hinge, the blades 4 on both sides can flap up and down when encountering unbalanced airflow or maneuvers. When the lift of one blade 4 increases due to an increased angle of attack, that blade 4 can flap upwards, effectively reducing the actual angle of attack and thus automatically balancing the lift on both sides. This process greatly absorbs the impact from airflow and maneuvers, making the aircraft maneuver smoother, responding more quickly, and significantly reducing airframe vibration.

[0046] Effectively reduces load and extends service life: The flapping motion releases the stress concentration at the blade root, transforming the huge static and dynamic bending moments into controllable motion at the hinge, significantly reducing the structural load on the blade roots, motor and frame, and improving the reliability and service life of the entire power system.

[0047] Increased fault tolerance and environmental adaptability: Even if blade 4 has minor manufacturing errors, installation errors or slight damage, the seesaw structure automatically adjusts to compensate for the resulting unbalanced forces, improving the fault tolerance of blade 4 and making it more robust in complex turbulent environments.

[0048] Balancing high performance and high reliability: This invention perfectly combines the dual advantages of an integrated blade (high aerodynamic efficiency and low vibration) and a flapping hinge (good maneuverability and low load), providing a high-performance, high-reliability, and long-life propeller solution.

[0049] This disclosure also provides an aircraft, including Body and power unit And at least one of the aforementioned propellers, the propellers being mounted on the drive end of the power unit, the power unit being mounted on the fuselage.

[0050] Although the present disclosure has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of the present disclosure are all within the scope of protection claimed by the present disclosure.

Claims

1. A propeller hub based on an integrated blade, characterized in that, The hub includes Fork-shaped components are used to connect the propeller blades to the aircraft body; The waving shaft assembly includes a symmetrical fixing structure for holding and fixing the blades; Flexible bearing assembly for combining the swing shaft assembly with the fork-type component; The fork-shaped component includes symmetrically arranged bushings, with the elastic bearing assembly disposed inside the bushings. The symmetrical structure of the swing shaft assembly passes through the elastic bearing assembly, and the swing shaft assembly can swing about the elastic bearing assembly as an axis. The bottom of the swing shaft assembly is provided with a limiting structure.

2. The propeller hub based on an integrated blade according to claim 1, characterized in that, The fork-shaped component includes a centrally symmetrical left structure and a right structure. Both the left and right structures include a connecting section. One end of the connecting section is provided with the bushing longitudinally, and the other end is provided with an engagement member. The engagement members of the left and right structures are fixed by bolts.

3. The propeller hub based on an integrated blade according to claim 2, characterized in that, The left and right structures are fastened by two sets of bolts. The connecting section is provided with two screw holes, and the interlocking part is provided with one screw hole. The left and right structures are interlocked in an alternating manner, and a fuse is provided between the two bolts in the transverse direction.

4. The propeller hub based on an integrated blade according to claim 3, characterized in that, The connecting section between the left and right structures is provided with a reinforcing boss near the bushing, and the bottom of the waving shaft assembly is provided with a waving limiting component. The reinforcing boss and the waving limiting component together form the limiting structure.

5. The propeller hub based on an integrated blade according to claim 1, characterized in that, The waving shaft assembly includes two symmetrically arranged mounting parts, each mounting part including a C-shaped clamp that can fit against the outer wall of the blade. The sides of the clamps extend outward to form a waving shaft for fixing the elastic bearing assembly. The ends of the waving shaft are fixed by slotted nuts and cotter pins.

6. The propeller hub based on an integrated blade according to claim 5, characterized in that, The elastic bearing assembly includes an elastic body fitted inside the bushing. The inner side of the elastic body is provided with an inner elastic bearing ring, and the outer side is provided with an outer elastic bearing ring that contacts the inner wall of the bushing. The swing shaft passes through the elastic body and is fixed by a slotted nut and a cotter pin.

7. The propeller hub based on an integrated blade according to claim 6, characterized in that, The inner ring of the elastic bearing is a trapezoidal column. The elastic body is composed of a left structure and a right structure, both of which are trapezoidal columns with their bottom surfaces facing each other and integrally joined together. The interior forms a cavity that can accommodate the inner ring of the elastic bearing. The length of the inner ring of the elastic bearing is the same as the length of the elastic body. The outer ring of the elastic bearing is a cylinder, and its length is the same as the length of the right structure of the elastic body. The interior of the outer ring of the elastic bearing forms a cavity that can accommodate the right structure of the elastic body.

8. The propeller hub based on an integrated blade according to claim 7, characterized in that, The cross-sectional line of the inner wall of the elastomer is parallel to the cross-sectional line of the outer wall of the right structure.

9. A propeller, characterized in that, The invention includes an integral blade and a hub based on the integral blade as described in any one of claims 1-8, wherein the blade is fixed to the hub by blade bolts, the hub clamps the blade at the geometric center, and the axis of the hub forms a 45° angle with the axis of the blade in the vertical extension direction.

10. An aircraft, characterized in that, include Body and power unit And at least one propeller as described in claim 9, the propeller being mounted on the drive end of a power unit, the power unit being mounted on the fuselage.

Images