Seesaw type propeller hub structure
By using a seesaw-type propeller hub structure, combined with limiting components and elastic elements, the problem of vibration and flapping caused by uneven lift during flight is solved, resulting in a lighter and more stable propeller system.
Patent Information
- Application Number
- CN202520545212.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2026-03-06
- Estimated Expiration
- 2035-03-26
AI Technical Summary
Existing propeller hubs suffer from vibration and blade flapping problems during flight due to uneven lift on both sides of the propeller clamp. Furthermore, seesaw-type propellers cannot effectively limit movement when the rotational speed decreases, resulting in rigid collisions and insufficient lift.
It adopts a seesaw-type propeller hub structure, and through the combination of components such as limiting components, rubber damping, elastic damping and shock absorbers, it realizes pitch-flailing coupling, reduces the number of parts, integrates flapping and pitch-changing functions, and uses elastic elements to absorb energy and provide reaction force to reduce vibration and impact.
It effectively reduces the flapping amplitude and vibration of the blades, improves the reliability and stability of the system, simplifies the structure, reduces the overall weight, and enhances the system's shock resistance and maintainability.
Smart Images
Figure CN223972725U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of propeller hub technology, specifically a seesaw-type propeller hub structure. Background Technology
[0002] A propeller is a crucial component of a rotorcraft, used to convert the rotation of the output shaft of a motor or engine into thrust or lift to enable takeoff, landing, steering, hovering, and other maneuvers. A propeller typically consists of a hub and blades. The hub is connected to the motor's output shaft via a transmission mechanism. When the motor drives the output shaft to rotate, the hub, connected to the output shaft, also rotates, causing the blades fixed to the hub to rotate and form a propeller disk. This, in turn, causes airflow near the blades, generating lift or thrust for the rotorcraft.
[0003] In the use of existing propeller hubs, uneven lift on both sides of the propeller clamp during flight restricts the free movement of the blades in the vertical and horizontal directions relative to the propeller plane. This results in the inability to release the bending moment momentum generated during blade flapping, causing vibration and damage to the internal motor. Furthermore, existing seesaw-type propellers have the problem of being either infinitely or infinitely limited in position, failing to mitigate the rigid collision between the blade flapping process and the limit. In addition, when using lift propellers in aircraft, during the transition flight phase or level cruise phase, the lift propeller speed decreases while the aircraft speed increases. The advancing and retreating blades are subjected to different incoming flow velocities, causing blade flapping. At the same time, the centrifugal force generated by the corresponding lift propeller speed is insufficient to overcome the blade flapping. The seesaw propeller itself needs to maintain a torsional stiffness, making the limiting mechanism for the blade flapping position particularly important. In view of this, we propose a seesaw-type propeller hub structure. Utility Model Content
[0004] The purpose of this invention is to provide a seesaw-type propeller hub structure to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, this utility model provides the following technical solution: a seesaw-type propeller hub structure, including a motor housing, a fixed base fixedly connected to the outer wall of the motor housing, a shaft provided on the top inner wall of the fixed base, a locking nut provided on the outer wall of the shaft, a sleeve provided on the inner ring of the shaft, a propeller clamp bushing movably connected to the outer surface of the sleeve, a pin provided on the outer wall of the sleeve, a propeller clamp provided on the outer wall of the fixed base, a propeller blade detachably mounted on the outer wall of the propeller clamp, a main propeller bolt provided at the root of the propeller blade, a limit assembly provided on the outer wall of the fixed base, the limit assembly including a limit block, the limit block being disposed on the outer wall of the fixed base, a limit shaft rotatably mounted on the inner wall of the limit block, and a spring fixedly connected to one end of the limit block.
[0006] Preferably, one end of the limiting block is mounted on the fixed base via a limiting pivot, allowing the limiting block to rotate around the limiting pivot and offset its center of gravity from the pivot. The other end of the limiting block is connected to the fixed base via a spring. When the spring is installed, there is an initial tension, which keeps the limiting block in the limited position.
[0007] Preferably, the outer wall of the fixed base is provided with rubber damping, the inner wall of the rubber damping is provided with a limiting bushing, and the outer wall of the propeller clamp is provided with a limiting bolt.
[0008] Preferably, the limiting bolt passes through the limiting bushing and is fixedly installed on the outer wall of the propeller clamp, the rubber damper is installed in the hole on the fixing seat, the limiting bushing is installed in the inner hole of the rubber damper, and the limiting bolt passes through the limiting bushing and is fixedly installed on the propeller clamp.
[0009] Preferably, the rubber damper can also be installed in the bottom hole of the propeller clamp, and the limiting pin is installed in the inner hole of the rubber damper through the hole of the fixing seat. The two ends of the limiting pin are positioned by shaft clips or bolts.
[0010] Preferably, the outer wall of the fixing seat is threaded with a fixing screw, and the outer wall of the fixing screw is provided with elastic damping.
[0011] Preferably, the elastic damper is fixedly installed on the outer wall of the mounting base by fixing screws. During installation, both ends of the elastic damper are compressed. The propeller clamp rotates around the swing pitch hinge during swing, with one end contacting and compressing the elastic damper while the other end is raised, and vice versa. The deformation process of the elastic damper can absorb energy, provide elasticity, and reduce the impact load generated during swing. A mechanical limit is designed inside the elastic damper to prevent excessive swinging of the propeller clamp.
[0012] Preferably, a buffer support is fixedly connected to the outer wall of the fixed base, and a buffer is provided on the outer wall of the buffer support. The buffer is fixedly installed on the fixed base through the buffer support. When the blade clamp swings, the blade clamp contacts the top rod of the buffer, maintaining the blade amplitude limit while absorbing energy and reducing vibration. The buffer stroke has an adjustable mechanical limit to prevent excessive blade swing.
[0013] Preferably, the shaft is an elastic bearing.
[0014] Preferably, the shaft is a self-lubricating bushing.
[0015] Compared with the prior art, this utility model provides a seesaw-type propeller hub structure, which has the following beneficial effects:
[0016] 1. The seesaw-type propeller hub structure reduces the flapping amplitude relative to the rotor shaft through pitch-flapping coupling, and reduces transient and steady-state flapping relative to the shaft. It integrates flapping and pitch-changing functions into a single hinge point, reducing the number of parts and simplifying the overall structure. Due to the reduction in parts, the overall weight is lighter and easier to manufacture. At the same time, fewer moving parts can improve the reliability and maintainability of the system.
[0017] 2. The seesaw-type propeller hub structure and the centrifugal block limiting mechanism can limit the blade flapping at low speeds. At high speeds, the position of the centrifugal block changes, reducing the degree of blade flapping limitation; preventing the blade angle of attack from increasing and avoiding blade stall.
[0018] 3. In this seesaw-type propeller hub structure, the rubber damper is compressed and deformed when the blades flap. The deformation process of the rubber damper provides a reaction force, absorbs energy, and reduces vibration.
[0019] 4. In this seesaw propeller hub structure, the elastic damper is fixedly installed on the fixed base by fixing screws. When the propeller clamp swings around the swing pitch hinge, one end contacts the elastic damper and is compressed, while the other end is tilted up, and vice versa. The deformation process of the elastic damper can absorb energy, provide elastic force, and reduce the impact load generated during the swinging process.
[0020] 5. In this seesaw-type propeller hub structure, the buffer is fixedly installed on the fixed base through the buffer support. When the propeller clamp swings, the propeller clamp contacts the top rod of the buffer, which keeps the propeller blade amplitude limited while absorbing energy and reducing vibration, ultimately further improving the overall stability and practicality. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0022] Figure 2 This is an enlarged schematic diagram of region A of this utility model;
[0023] Figure 3 This is a top view of the present invention;
[0024] Figure 4 This is a schematic diagram of the cross-sectional structure of the fixing base of this utility model;
[0025] Figure 5 This is a schematic diagram of the limiting block structure in the spring-tensioned state of this utility model;
[0026] Figure 6 This is a schematic diagram of the structure of Embodiment 2 of this utility model;
[0027] Figure 7 This is a schematic diagram of the structure of Embodiment 2 of this utility model;
[0028] Figure 8 This is a schematic diagram of the structure of Embodiment 3 of this utility model;
[0029] Figure 9 This is a schematic diagram of the structure of Embodiment 4 of this utility model;
[0030] Figure 10 This is a schematic diagram of the structure of Embodiment 1 of the present utility model.
[0031] In the diagram: 1. Motor housing; 2. Mounting base; 3. Limiting assembly; 311. Spring; 312. Limiting shaft; 313. Limiting block; 321. Amplitude limiting bolt; 322. Amplitude limiting bushing; 323. Rubber damper; 331. Elastic damper; 332. Fixing screw; 341. Buffer; 342. Buffer support; 7. Blade; 8. Blade clamp; 9. Shaft; 10. Pin; 11. Sleeve; 12. Locking nut; 13. Main blade bolt; 14. Blade clamp bushing. Detailed Implementation
[0032] Example 1
[0033] like Figures 1-5 , Figure 10 As shown, this utility model provides a technical solution: a seesaw-type propeller hub structure, including a motor housing 1, a fixed base 2 fixedly connected to the outer wall of the motor housing 1, a shaft 9 provided on the top inner wall of the fixed base 2, a locking nut 12 provided on the outer wall of the shaft 9, a sleeve 11 provided on the inner ring of the shaft 9, a propeller clamp bushing 14 movably connected to the outer surface of the sleeve 11, a pin 10 provided on the outer wall of the sleeve 11, a propeller clamp 8 provided on the outer wall of the fixed base 2, a propeller blade 7 detachably installed on the outer wall of the propeller clamp 8, a main propeller bolt 13 provided at the root of the propeller blade 7, a limit component 3 provided on the outer wall of the fixed base 2, the limit component 3 including a limit block 313, the limit block 313 being disposed on the outer wall of the fixed base 2, a limit shaft 312 being rotatably installed on the inner wall of the limit block 313, and a spring 311 fixedly connected to one end of the limit block 313.
[0034] One end of the limiting block 313 is mounted on the fixed base 2 via the limiting pivot 312, allowing the limiting block 313 to rotate around the limiting pivot 312 and its center of gravity to deviate from the limiting pivot 312. The other end of the limiting block 313 is connected to the fixed base 2 via the spring 311. When the spring 311 is installed, there is an initial tension, which keeps the limiting block 313 in the limiting position.
[0035] The shaft 9 can be a radial spherical bearing, an elastic bearing, or a self-lubricating bushing.
[0036] During aircraft flight, the rotor blades rotate, and the air convection velocity varies at different positions, resulting in varying lift at those positions. The relative airflow velocity of the advancing blade is greater than that of the retreating blade in the rotor plane, thus generating greater lift for the advancing blade. The force on the blade is equal in magnitude and opposite in direction to the lift. This force causes the advancing blade to rotate upwards around the flapping-pitch hinge point, while the corresponding retreating blade rotates downwards around the same point. Simultaneously, the rotation of the advancing blade decreases its angle of attack, reducing lift and the force on it. Similarly, the rotation of the retreating blade increases its angle of attack, increasing lift and the force on it. This increased force causes the advancing blade to rotate downwards around the flapping-pitch hinge point, while the corresponding retreating blade rotates upwards. Ultimately, the advancing and retreating blades achieve automatic lift balance.
[0037] Pitch-flailing coupling is the kinematic feedback of flapping displacement to the pitch motion of the propeller blades; it can be derived from... To describe this, the scheme is a positive pitch-flare coupling ( The upward flapping motion reduces the blade pitch, thus decreasing the blade angle of attack. This reduction in lift generates a change in flapping torque, opposing the original flapping motion. Specifically, the flapping hinge is positioned at an angle. This causes the flapping hinge to no longer be perpendicular to the radial axis of the blade. Therefore, the blade rotates about the hinge by a flapping angle. This will inevitably result in a change in propeller pitch. The feedback gain coefficient of this arrangement is Without periodic pitch control, Variable pitch flapping coupling reduces the flapping amplitude relative to the rotor shaft. This scheme employs... =45°( To reduce transient and steady-state flapping relative to the propeller shaft, the symbol is noted as follows: When the variable-pitch flapping coupling is coupled upward flapping, the pitch decreases to a positive value; The angle at which the paddle blades swing is upward; The angle of the swing hinge.
[0038] In this invention, the pitch-flapping coupling reduces the flapping amplitude relative to the rotor shaft, and reduces both transient and steady-state flapping relative to the rotor shaft. By integrating the flapping and pitch-variable functions into a single hinge point, the number of parts is reduced, the overall structure is simplified, and the overall weight is lighter and easier to manufacture due to the reduced number of parts. At the same time, fewer moving parts can improve the reliability and maintainability of the system.
[0039] Limiting principle: When the propeller rotates, the limiting block is subjected to centrifugal force and tends to rotate outward along the limiting axis. The higher the rotation speed, the greater the centrifugal force on the limiting block, and the spring will be stretched. At low speeds, the spring tension is greater than the centrifugal force of the limiting block, so the spring will not stretch, and the limiting block plays a limiting role on the propeller clamp. At high speeds, the spring tension is less than the centrifugal force of the limiting block, so the spring stretches, the limiting block rotates, and the propeller clamp can rotate around the flapping helix.
[0040] Example 2
[0041] like Figures 6-7 As shown, this utility model improves upon Embodiment 1 to obtain a new technical solution: the outer wall of the fixed base 2 is provided with a rubber damper 323, the inner wall of the rubber damper 323 is provided with a limiting bushing 322, and the outer wall of the propeller clamp 8 is provided with a limiting bolt 321, so that the limiting bolt 321 passes through the limiting bushing 322 and is fixedly installed on the outer wall of the propeller clamp 8, the rubber damper 323 is installed in the hole on the fixed base 2, the limiting bushing 322 is installed in the inner hole of the rubber damper 323, and the limiting bolt 321 passes through the limiting bushing 322 and is fixedly installed on the propeller clamp 8.
[0042] Limiting principle: When the propeller rotates, the propeller clamp swings up and down, and the limiting bolt squeezes the rubber damper. The limiting is achieved by the deformation of the rubber damper itself.
[0043] Meanwhile, the rubber damper 323 can also be installed in the bottom hole of the propeller clamp 8, and the limiting bolt 321 passes through the rubber damper 323 and is connected to the fixed base 2.
[0044] Example 3
[0045] like Figure 8 As shown, this utility model improves upon Embodiment 1 to obtain a new technical solution: a fixing screw 332 is threaded onto the outer wall of the fixing base 2, and an elastic damper 331 is provided on the outer wall of the fixing screw 332. The elastic damper 331 is fixedly installed on the outer wall of the fixing base 2 by the fixing screw 332. When the elastic damper 331 is installed, both ends are compressed. When the propeller clip 8 swings around the swing pitch hinge, one end contacts and is compressed with the elastic damper 331, while the other end is raised, and vice versa. The deformation process of the elastic damper 331 can absorb energy, provide elasticity, and reduce the impact load generated during the swinging process. The elastic damper is internally designed with mechanical limits to prevent excessive up-and-down swinging of the propeller blade.
[0046] Limiting principle: When the propeller rotates, the blade clamp swings up and down, which compresses the elastic damper. The design limits the amplitude by using the stroke of the elastic damper. At the same time, the support reaction force generated by the deformation of the elastic damper can ensure the constraint stiffness of the blade swing.
[0047] Example 4
[0048] like Figure 9 As shown, this utility model improves upon the first embodiment to obtain a new technical solution: a buffer 341 support is fixedly connected to the outer wall of the fixed base 2, and a buffer 341 is provided on the outer wall of the buffer 341 support. The buffer 341 is fixedly installed on the fixed base 2 through the buffer 341 support. When the paddle clip 8 swings, the paddle clip 8 contacts the top rod of the buffer 341, maintaining the amplitude limit of the paddle blade 7 while absorbing energy and reducing vibration.
[0049] Limiting principle: When the propeller rotates, the blade clamp swings up and down, squeezing the buffer below. The buffer's stroke changes to limit the amplitude. The buffer has an adjustable mechanical limit to prevent excessive blade swinging.
[0050] The shaft, mounted in the hole at the top of the fixed base, primarily bears the load and bending moment caused by the propeller rotation. A surface-contact radial spherical plain bearing or bushing is preferred, as it offers better axial load and bending moment bearing capacity compared to deep groove ball bearings. Alternatively, a flexible bearing can be selected; compared to sliding and rolling bearings, it requires no lubrication, reducing maintenance. Furthermore, the absence of metal-to-metal contact and friction results in a longer lifespan and enhanced corrosion resistance, improving system reliability in harsh environments. The elastic deformation of the flexible bearing can provide torsional stiffness for blade flapping, reducing the deformation of the limiting device and even eliminating it altogether, thus lightening the structure.
[0051] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the protection scope of the present invention.
Claims
1. A seesaw type propeller hub structure comprising a motor casing (1), characterized in that: The outer wall of the motor shell (1) is fixedly connected with a fixing seat (2), the top inner wall of the fixing seat (2) is provided with a shaft piece (9), the outer wall of the shaft piece (9) is provided with a locking nut (12), the inner ring of the shaft piece (9) is provided with a sleeve (11), the outer surface of the sleeve (11) is movably connected with a paddle clamp bushing (14), the outer wall of the sleeve (11) is provided with a pin shaft (10), the outer wall of the fixing seat (2) is provided with a paddle clamp (8), the outer wall of the paddle clamp (8) is detachably provided with a paddle (7), the root of the paddle (7) is provided with a main paddle bolt (13), the outer wall of the fixing seat (2) is provided with a limiting assembly (3), the limiting assembly (3) comprises: A limiting block (313) is arranged on the outer wall of the fixing seat (2), the inner wall of the limiting block (313) is rotatably provided with a limiting rotating shaft (312), one end of the limiting block (313) is fixedly connected with a spring (311).
2. A seesaw propeller hub structure according to claim 1, characterized in that: The limiting block (313) is installed on the fixing seat (2) through the limiting rotating shaft (312).
3. A seesaw propeller hub structure according to claim 1, characterized in that: The outer wall of the fixing seat (2) is provided with a rubber damping (323), the inner wall of the rubber damping (323) is provided with a limiting bushing (322), the outer wall of the paddle clamp (8) is provided with a limiting bolt (321).
4. A seesaw propeller hub structure according to claim 3, wherein: The limiting bolt (321) is fixedly installed on the outer wall of the paddle clamp (8) through the limiting bushing (322).
5. A seesaw propeller hub structure according to claim 3, wherein: The rubber damping (323) is installed in the bottom hole of the paddle clamp (8), and the limiting bolt (321) passes through the rubber damping (323) and is connected with the fixing seat (2).
6. A seesaw propeller hub structure according to claim 1, wherein: The outer wall of the fixing seat (2) is threadedly connected with a fixing screw (332), and the outer wall of the fixing screw (332) is provided with an elastic damping (331).
7. A seesaw propeller hub structure according to claim 6, wherein: The elastic damping (331) is fixedly installed on the outer wall of the fixing seat (2) through the fixing screw (332).
8. The seesaw propeller hub structure of claim 1, wherein: The outer wall of the fixing seat (2) is fixedly connected with a bumper support (342), and the outer wall of the bumper support (342) is provided with a bumper (341).
9. The seesaw propeller hub structure of claim 1, wherein: The shaft piece (9) is an elastic bearing.
10. The seesaw propeller hub structure of claim 1, wherein: The shaft piece (9) is a self-lubricating shaft sleeve.