Helicopter rotor wing waving limiting device

Abstract

The invention relates to the technical field of helicopter rotor systems, in particular to a helicopter rotor flapping limiting device which comprises a propeller hub, and a flapping limiting mechanism, a range adjusting mechanism and a double-limiting latch hook mechanism are arranged on the surface of the propeller hub in an annular array with the propeller hub as the circle center. The double-limiting lock hook mechanism comprises a first lower waving limiting lock hook, a limiting support, a second lower waving limiting lock hook, a limiting block, an extension spring and a centrifugal balancing weight which are arranged on the surface of the waving limiting mechanism. When the rotor rotates at a high speed, centrifugal force drives the centrifugal balancing weight to move, the pulling force of the extension spring is overcome, the limiting support rotates, and the first downward-waving limiting lock hook and the second downward-waving limiting lock hook are separated from the initial positions, so that the paddles can freely wave to achieve pneumatic efficiency and operation flexibility, and therefore the double lock hooks are unlocked and closed at different speeds and stages; the overcoming process of centrifugal force is divided into two stages, the action of the lock hook is in a small-angle and slow-stroke gradual change mode, the impact load is reduced, and the action stability is improved.

Description

Technical Field

[0001] This invention relates to the field of helicopter rotor system technology, and in particular to a helicopter rotor flapping limiting device. Background Technology

[0002] The rotor flapping limiter is a key safety component of the helicopter rotor system. Its core function is to limit excessive blade flapping when the rotor is at low speed or stationary, preventing excessive blade flapping caused by excessive aerodynamic loads or structural resonance, which could lead to blade collisions with the fuselage, tail boom, or other structures, or between the upper and lower blades. The rotor flapping limiter automatically releases the restriction at high speeds, ensuring that the blades flap freely and normally to achieve flight control.

[0003] Most existing rotor flapping limiters typically consist of a hard stop block, rubber buffer block, or hydraulic damping device installed near the rotor hub or root. When the rotor blade flaps upward or downward to a preset angle due to lift differences, the limiter will physically contact and prevent further movement. This allows for necessary flapping to compensate for aerodynamic imbalances while strictly constraining the movement boundaries, ensuring the structural integrity and handling stability of the helicopter under various flight conditions.

[0004] However, in most existing rotor flapping limiters, a single flapping limiter hook is generally used to limit the rotor flapping. When the rotor speed reaches the critical value, the centrifugal force of the centrifugal counterweight will instantly overcome the spring tension, causing the single hook to quickly disengage from the limit position. This process is unbuffered and generates instantaneous impact loads, which not only cause collision wear between the hook and the limit surface, but may also cause the hook to deform slightly due to the impact. Under long-term operating conditions, the cumulative deformation will cause the hook to jam, making it impossible for the hook to completely limit the rotor movement. This makes it impossible to guarantee that the blades will not collide with the fuselage, tail boom, or other structures, or collide between the upper and lower blades.

[0005] Therefore, the present invention provides a helicopter rotor flapping limiting device to solve the above-mentioned problems. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a helicopter rotor flapping limiting device.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A helicopter rotor flapping limiting device includes: a rotor hub, wherein the surface of the rotor hub is provided with a flapping limiting mechanism, a range adjustment mechanism and a double limiting hook mechanism arranged in a circular array with the rotor hub as the center;

[0009] The double-limiting locking hook mechanism includes a lower swing limiting hook one, a limiting bracket, a lower swing limiting hook two, a limiting block, a tension spring, and a centrifugal counterweight block disposed on the surface of the swing limiting mechanism. The lower swing limiting hook one is fixedly connected to the limiting bracket. The lower swing limiting hook two is fixedly disposed on the surface of the limiting block by bolts, and the limiting block is fixedly connected to the limiting bracket by bolts, which is used to connect the lower swing limiting hook one and the lower swing limiting hook two. The centrifugal counterweight blocks are fixedly disposed symmetrically on the surface of the limiting bracket. A connecting rod is fixedly connected to the surface of the two centrifugal counterweight blocks. The two ends of the tension spring are fixedly connected to the swing limiting mechanism and the midpoint of the connecting rod, respectively.

[0010] Preferably, the waving limiting mechanism includes a plurality of waving hinge joints arranged in a ring and hinged to the surface of the propeller hub via a rotating shaft, and an upper waving limiting protrusion slidably disposed on one side of the waving hinge joint. A lower limiting rotating shaft is fixedly disposed below the waving hinge joint, and the limiting bracket is rotatably connected to the lower limiting rotating shaft.

[0011] Preferably, in the initial state of the device, the limiting bracket is in contact with the swinging hinge joint, and both the lower swing limiting hook one and the lower swing limiting hook two are in contact with the swinging hinge joint. One end of the tension spring is fixedly connected to the swinging hinge joint, and the tension spring can deform inside the limiting bracket.

[0012] Preferably, a damping pad is fixedly connected to one side of the upper surface of the limiting bracket. The damping pad fits into the flapping hinge and provides damping force between the limiting bracket and the flapping hinge. The damping force is adaptively adjusted according to the size of the rotor flapping.

[0013] Preferably, the range adjustment mechanism includes a locking rod fixedly disposed inside the movement limiting bracket. One end of the locking rod is fixedly connected to one side of the upper waving movement limiting protrusion, and can adjust the waving range of the rotor according to the unlocking state of the lower waving movement limiting hook one and the lower waving movement limiting hook two.

[0014] Preferably, the range adjustment mechanism further includes steel wire ropes fixedly disposed on both sides of the upper surface of the upper swing limiting protrusion, the surfaces of the two steel wire ropes are jointly attached to a support frame, and the support frame is fixedly connected to the swing hinge joint, and the interior of the support frame is provided with an arc-shaped rod fixedly connected to the swing hinge joint.

[0015] Preferably, the range adjustment mechanism further includes a support rod fixedly connected to the upper surface of the propeller hub, a drive block hinged to the arc-shaped rod is fixedly sleeved on the surface of the support rod, an adjustment block is slidably connected to the upper surface of the support rod, and a limit plate is fixedly connected to one end of the adjustment block.

[0016] Preferably, both the surface of the limiting bracket and the lower surface of the swinging hinge are provided with movable grooves to provide space for the movement of the tension spring and the locking rod. The lower surface of the swinging hinge is provided with a lower swinging limiting boss corresponding to the position of the damping pad.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. This device, through the coordinated operation of multiple components in the double-limiting locking hook mechanism, restricts the centrifugal counterweight when the rotor is stationary or at low speed. This causes the lower flapping limiting locking hook one and the lower flapping limiting locking hook two to limit the flapping hinge joint. When the rotor rotates at high speed, the centrifugal force drives the centrifugal counterweight to move and overcome the tension of the tension spring. The limiting bracket rotates around the lower limiting axis, causing the lower flapping limiting locking hook one and the lower flapping limiting locking hook two to disengage from their initial positions and eventually fully open. This allows the blades to flap freely to achieve aerodynamic efficiency and maneuverability. This enables the double locking hooks to unlock and close at different speeds and stages. The process of overcoming centrifugal force is divided into two stages, and the locking hook action is a gradual change with a small angle and slow stroke, reducing impact load and improving action stability.

[0019] 2. Through the coordination of multiple components in the flapping limiting mechanism, this device can simultaneously limit the range of the rotor's up-and-down flapping during the rotor's up-and-down flapping process, based on the setting of the upper flapping limiting protrusion and the lower flapping limiting protrusion. This avoids the rotor flapping range being too large, which would compromise the structural integrity and control stability of the helicopter under various flight conditions. Furthermore, by integrating the upper and lower flapping limiting protrusions with the flapping hinge, the error transmission links are reduced, effectively improving the installation and debugging accuracy.

[0020] 3. Through the coordinated operation of multiple components in the range adjustment mechanism, this device achieves the following: at low rotor speeds, when the double locking hooks are closed or in the first-level unlocked state, the limited-motion bracket has a small rotation angle, the damping pad has a small damping force, the upper flapping limited-motion protrusion extends to a large height, and the blades flap up and down in a small range, thus avoiding blade collisions with the fuselage at low altitudes and improving low-altitude flight safety; at high rotor speeds, when the double locking hooks are fully unlocked, the limited-motion bracket rotates to a large angle, the damping pad has a large damping force, and the upper flapping limited-motion protrusion is inserted into the flapping hinge joint, causing the upper flapping limited-motion protrusion to be finely adjusted, reducing its extension height and increasing the blades flap up and down in a large range, thus ensuring aerodynamic control flexibility at high altitudes.

[0021] 4. This device is based on the cooperation of support rods, arc rods, adjusting blocks, and limiting plates. When the upper swing limiting protrusion is adjusted, the wire rope drives the position of the adjusting block and the limiting plate, so that the limiting plate no longer limits the driving block and the arc rod. This further adjusts the swing range of the swinging joint and the blade, and precisely controls the maximum vertical swing angle of the swinging joint, thus achieving dual limiting protection for the helicopter rotor swing. Attached Figure Description

[0022] Figure 1 This is a front structural diagram of a helicopter rotor flapping limiting device proposed in this invention;

[0023] Figure 2 This is a side view of a helicopter rotor flapping limiting device proposed in this invention;

[0024] Figure 3 This is a schematic diagram of the rotor hub, flapping hinge, limiting bracket, and centrifugal counterweight structure of a helicopter rotor flapping limiting device proposed in this invention.

[0025] Figure 4 This is a schematic diagram of the double-limiting locking hook mechanism and the flapping hinge joint structure of a helicopter rotor flapping limiting device proposed in this invention;

[0026] Figure 5 This is a schematic diagram of the range adjustment mechanism, the limiting bracket, and the lower flapping limiting hook of a helicopter rotor flapping limiting device proposed in this invention.

[0027] Figure 6 This is a schematic diagram of the limiting bracket, lower limiting hook, tension spring, and centrifugal counterweight structure of a helicopter rotor flapping limiting device proposed in this invention.

[0028] Figure 7 This is a schematic diagram of the rotor hub and range adjustment mechanism of a helicopter rotor flapping limiting device proposed in this invention;

[0029] Figure 8 This is a schematic diagram of the clamping rod, steel wire rope, support rod, and upper flapping limiting protrusion structure of a helicopter rotor flapping limiting device proposed in this invention.

[0030] In the diagram: 1. Propeller hub; 2. Lower swing limiting hook one; 3. Limiting bracket; 4. Lower swing limiting hook two; 5. Limiting block; 6. Tension spring; 7. Centrifugal counterweight; 8. Connecting rod; 9. Swing hinge joint; 10. Lower limiting shaft; 11. Upper swing limiting protrusion; 12. Damping pad; 13. Connecting rod; 14. Wire rope; 15. Support frame; 16. Arc rod; 17. Support rod; 18. Drive block; 19. Adjusting block; 20. Limiting plate; 21. Movable groove; 22. Lower swing limiting protrusion. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0032] The terms used in this invention, such as "upper," "lower," "left," "right," "middle," and "one," are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0033] Reference Figures 1-8 A helicopter rotor flapping limiting device includes: a rotor hub 1, on the surface of the rotor hub 1, a flapping limiting mechanism, a range adjustment mechanism and a double limiting hook mechanism are arranged in a ring array with the rotor hub 1 as the center;

[0034] The waving limiting mechanism includes multiple waving hinge joints 9 arranged in a ring and hinged to the surface of the propeller hub 1 via a rotating shaft, and an upper waving limiting protrusion 11 slidably disposed on one side of the waving hinge joint 9. A lower limiting rotating shaft 10 is fixedly disposed below the waving hinge joint 9, and the limiting bracket 3 is rotatably connected to the lower limiting rotating shaft 10.

[0035] Among them, the flapping joint 9 is used to connect the rotor hub 1 and the rotor blade, and can follow the rotation of the rotor hub 1, so that the rotor blade and the flapping joint 9 can flap during the operation of the helicopter rotor.

[0036] Among them, the upper waving limit protrusion 11 is used to limit the waving range of the helicopter rotor;

[0037] The lower limit pivot 10 is used to connect the swing hinge joint 9 and the limit bracket 3, and allows the limit bracket 3 to rotate on the lower surface of the swing hinge joint 9.

[0038] The initial state of the device is that the limiting bracket 3 is in contact with the swinging hinge joint 9, and the lower swinging limiting lock hook 1 2 and the lower swinging limiting lock hook 2 4 are both in contact with the swinging hinge joint 9. One end of the tension spring 6 is fixedly connected to the swinging hinge joint 9, and the tension spring 6 can deform inside the limiting bracket 3.

[0039] The double-limiting locking hook mechanism includes a lower swing limiting locking hook 1 2, a limiting bracket 3, a lower swing limiting locking hook 2 4, a limiting block 5, a tension spring 6, and a centrifugal counterweight 7, all disposed on the surface of the swing limiting mechanism. The lower swing limiting locking hook 1 2 is fixedly connected to the limiting bracket 3. The lower swing limiting locking hook 2 4 is fixedly disposed on the surface of the limiting block 5 by bolts, and the limiting block 5 is fixedly connected to the limiting bracket 3 by bolts, which is used to connect the lower swing limiting locking hook 1 2 and the lower swing limiting locking hook 2 4. The centrifugal counterweight 7 is fixedly disposed symmetrically on the surface of the limiting bracket 3. The surfaces of the two centrifugal counterweights 7 are jointly fixedly connected to a connecting rod 8. The two ends of the tension spring 6 are fixedly connected to the swing limiting mechanism and the midpoint of the connecting rod 8, respectively.

[0040] Among them, the lower swing limiting lock hook 1 2 and the lower swing limiting lock hook 2 4 are used to follow the rotation of the limiting bracket 3 and to perform double closing or unlocking of the lower swing of the swing hinge joint 9.

[0041] Among them, the movement limiting bracket 3 is used to install the lower waving movement limiting lock hook 1 2 and the lower waving movement limiting lock hook 2 4, and connect the lower waving movement limiting lock hook 1 2 and the lower waving movement limiting lock hook 2 4 to the waving hinge joint 9;

[0042] Among them, the limiting block 5 is used to connect the lower swing limiting hook 2 4 and the limiting bracket 3, so that the lower swing limiting hook 2 4 can rotate synchronously with the lower swing limiting hook 1 2.

[0043] Among them, the tension spring 6 is used to control the position of the centrifugal counterweight 7;

[0044] Among them, the centrifugal counterweight 7 cooperates with the tension spring 6 to control the position of the lower swing limiting lock hook 1 2 and the lower swing limiting lock hook 2 4;

[0045] The connecting rod 8 is used to connect the two centrifugal counterweights 7 and connect the tension spring 6 to the midpoint of the connecting rod 8, thereby controlling the two centrifugal counterweights 7. The structure is simpler and less prone to lateral force, and the operation is stable and reliable.

[0046] In the embodiments of the above technical solution, when the rotor is stationary or at low speed, the tension spring 6 restricts the centrifugal counterweight 7, so that the lower flapping limit lock hook 1 2 and the lower flapping limit lock hook 2 4 limit the flapping hinge joint 9, so that the flapping hinge joint 9 restricts the flapping of the blades, and avoids excessive flapping that could cause the blades to collide with the fuselage, tail boom and other structures or between the upper and lower blades.

[0047] When the rotor rotates at high speed, the centrifugal force drives the centrifugal counterweight 7 to move and overcomes the tension of the tension spring 6, causing the limiting bracket 3 to rotate around the lower limiting shaft 10. This causes the lower flapping limiting hook 1 2 and the lower flapping limiting hook 2 4 to disengage from their initial positions and eventually open completely, allowing the blades to flap freely to achieve aerodynamic efficiency and maneuverability. This enables the double hooks to limit the movement of the flapping hinge joint 9.

[0048] When the rotor speed decreases, the centrifugal force decreases. When the centrifugal force is less than the elastic tension of the tension spring 6, the tension spring 6 drives the centrifugal counterweight 7 to slowly reset. As the centrifugal counterweight 7 gradually resets, the limiting hook 4 is driven to reset first. Based on the reset of the centrifugal counterweight 7, the limiting hook 2 is driven to reset, thereby realizing the speed-level unlocking and closing of the double hooks. The process of overcoming the centrifugal force is divided into two stages. The hook action is a gradual change with a small angle and slow stroke, which reduces the impact load and improves the stability of the action.

[0049] Reference Figure 5A damping pad 12 is fixedly connected to one side of the upper surface of the limiting bracket 3. The damping pad 12 fits with the flapping hinge joint 9 and provides damping force between the limiting bracket 3 and the flapping hinge joint 9. The damping force is adaptively adjusted according to the size of the rotor flapping.

[0050] The damping pad is made of composite damping material, consisting of a three-layer composite structure: an inner layer of wear-resistant base material, a middle layer of damping functional material, and an outer layer of protective material.

[0051] The damping pad 12 is set in the hinge gap of the lower limit rotating shaft 10. The damping force is positively correlated with the rotation angle of the limit bracket 3, which effectively reduces the rotational vibration of the limit bracket 3, reduces the collision and wear of the double locking hook with other components, and improves the overall operational stability of the device.

[0052] Reference Figures 4-8 The range adjustment mechanism includes a locking rod 13 fixedly installed inside the limiting bracket 3. One end of the locking rod 13 is fixedly connected to one side of the upper waving limiting protrusion 11, and can adjust the waving range of the rotor according to the unlocking state of the lower waving limiting lock hook 1 2 and the lower waving limiting lock hook 2 4.

[0053] Among them, the snap-fit ​​rod 13 is used to connect the upper swing limiting protrusion 11 and the limiting bracket 3;

[0054] When the helicopter rotor speed is low, the double locking hooks are in the closed or first-level unlocked state, the rotation angle of the limiting bracket 3 is small, the damping force of the damping pad 12 is small, and the limiting bracket 3 will not drive the locking rod 13 to move, thus not driving the upper waving limiting protrusion 11 to move. This results in the upper waving limiting protrusion 11 extending to a large height, and the blade waving range is small, avoiding low-altitude blade collision with the fuselage and improving low-altitude flight safety.

[0055] When the helicopter rotor speed is high, the double locking hooks are fully unlocked, the limited movement bracket 3 rotates at a large angle, the damping pad 12 has a large damping force, and based on the large rotation angle of the limited movement bracket 3, the driving locking rod 13 moves, thereby causing the locking rod 13 to drive the upper waving limited movement protrusion 11 to slide inside the waving hinge joint 9, so that the upper waving limited movement protrusion 11 is inserted into the waving hinge joint 9, and the upper waving limited movement protrusion 11 is finely adjusted to reduce its extension height, so that the blades have a large range of up and down waving, ensuring the aerodynamic control flexibility of high-altitude flight;

[0056] Regardless of high or low speed, if the blades swing out of range, the contact limit of the upper swing limiting protrusion 11 and the lower swing limiting protrusion 22 and the unlocking or closing stroke of the double locking hooks mutually constrain each other, always keeping the blade swing range within a safe range.

[0057] The range adjustment mechanism also includes steel wire ropes 14 fixedly installed on both sides of the upper surface of the upper swing limiting protrusion 11. The surfaces of the two steel wire ropes 14 are together attached to the support frame 15, and the support frame 15 is fixedly connected to the swing hinge joint 9. The inside of the support frame 15 is provided with an arc-shaped rod 16 fixedly connected to the swing hinge joint 9.

[0058] Among them, the steel wire rope 14 is used to connect the upper swing limiting protrusion 11 and the support rod 17;

[0059] Among them, the support frame 15 is used to support and guide the wire rope 14;

[0060] Among them, the arc-shaped rod 16 is used to connect the swing hinge joint 9 and the support rod 17;

[0061] The range adjustment mechanism also includes a support rod 17 fixedly connected to the upper surface of the propeller hub 1. A drive block 18 hinged to the arc rod 16 is fixedly sleeved on the surface of the support rod 17. An adjustment block 19 is slidably connected to the upper surface of the support rod 17, and a limit plate 20 is fixedly connected to one end of the adjustment block 19.

[0062] Among them, the support rod 17 is used to install the drive block 18;

[0063] The drive block 18 is used to install the arc rod 16, and the arc rod 16 is hinged to the drive block 18 and the support rod 17 by a universal ball.

[0064] The adjusting block 19 is used to slide inside the support rod 17;

[0065] The limiting plate 20 is used to limit the swing angle of the arc-shaped bar 16;

[0066] The lower surface of the swing hinge joint 9 is provided with a lower swing limiting boss 22 corresponding to the position of the damping pad 12;

[0067] Among them, the lower flapping limiting boss 22 is used to limit the range of the blade's lower flapping;

[0068] When the double locking hooks are in the closed state, the downward swing of the propeller blades is restricted. At this time, the positions of the adjusting block 19 and the limiting plate 20 remain unchanged, providing basic support for the swinging hinge joint 9, while limiting the maximum limit angle of the propeller blades swinging up and down. The dual structures work together to achieve multiple protections for low-speed parking, avoiding excessive swinging of the propeller blades by external forces that could cause them to collide with the fuselage.

[0069] When the centrifugal counterweight 7 overcomes the spring tension, the double locking hooks unlock in stages, and the blades can swing freely. The arc rod 16 swings synchronously with the swinging action of the swinging hinge joint 9, serving only as a safety guardrail and not interfering with the normal aerodynamic swinging of the blades. Only when the blades are about to overtravel due to aerodynamic abnormalities will the arc rod 16 contact the limit plate 20 and trigger the hard limit.

[0070] Secondary movement restriction is achieved when the movement restriction block 5 contacts the lower flapping movement restriction boss 22, and upper movement restriction is achieved when the upper flapping movement restriction boss 11 contacts the end face of the rotor hub 1. If the original device fails due to a malfunction, the arc rod 16 immediately becomes a backup limiting structure, which limits the over-range flapping of the rotor blades through rigid load-bearing to avoid rotor system instability and form movement restriction redundancy protection.

[0071] When the tension spring 6 pulls the double locking hook to reset, the arc rod 16, the adjusting block 19 and the limiting plate 20 swing back to their initial positions synchronously with the reset action of the swinging hinge 9, without additional resistance. Moreover, the supporting force of the arc rod 16 can reduce the reset sway of the swinging hinge 9 and improve the accuracy of the original device's locking hook reset.

[0072] Specifically, when the helicopter rotor rotates at low speed, the centrifugal counterweight 7 cannot overcome the tension of the tension spring 6. Therefore, the limiting bracket 3 will not drive the lower swing limiting hook 2 4 to move or the lower swing limiting hook 2 4 to unlock while the lower swing limiting hook 1 2 does not unlock. This results in a smaller rotation angle of the limiting bracket 3, so the limiting bracket 3 still limits the range of the blade's up and down swing. This prevents the swinging hinge joint 9 from pulling the wire rope 14 to move. Therefore, the wire rope 14 will not pull the adjusting block 19 and the limiting plate 20 to move, thus limiting the swinging range of the arc rod 16 and further supporting the swinging hinge joint 9 so that it will not swing.

[0073] When the helicopter rotor rotates at high speed, the centrifugal counterweight 7 overcomes the tension of the tension spring 6, and the limiting bracket 3 rotates on the lower limiting shaft 10, driving the lower waving limiting hook 1 2 and the lower waving limiting hook 2 4 to move, no longer restricting the waving hinge joint 9. At the same time, when the limiting bracket 3 rotates, the locking rod 13 pulls the upper waving limiting protrusion 11 to move, so that the upper waving limiting protrusion 11 is inserted into the waving hinge joint 9, so that the upper waving limiting protrusion 11 pulls the steel wire rope 14 to move. Through the setting of the support frame 15, the steel wire rope 14 is guided, so that the steel wire rope 14 drives the adjusting block 19 and the limiting plate 20 to move on the support rod 17, adjusting the position of the limiting plate 20, so that the limiting plate 20 no longer restricts the waving range of the waving hinge joint 9.

[0074] The three arc-shaped rods 16 and the three flapping hinge joints 9 are evenly arranged in a ring, so that the load-bearing and limiting forces of the rotor hub 1 are evenly distributed in the circumference, reducing the off-center load vibration when the rotor rotates at high speed and reducing the vibration wear of components such as locking hooks and springs.

[0075] Both the surface of the limiting bracket 3 and the lower surface of the swing hinge joint 9 are provided with movable grooves 21 to provide space for the movement of the tension spring 6 and the locking rod 13.

[0076] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A helicopter rotor flapping limiting device, comprising: The propeller hub (1) is characterized in that the surface of the propeller hub (1) is provided with a waving limiting mechanism, a range adjustment mechanism and a double limiting hook mechanism arranged in a circular array with the propeller hub (1) as the center. The double-limiting locking hook mechanism includes a lower swinging limiting locking hook one (2), a limiting bracket (3), a lower swinging limiting locking hook two (4), a limiting block (5), a tension spring (6), and a centrifugal counterweight (7) disposed on the surface of the swinging limiting mechanism. The lower swinging limiting locking hook one (2) is fixedly connected to the limiting bracket (3). The lower swinging limiting locking hook two (4) is fixedly disposed on the surface of the limiting block (5) by bolts. The limiting block (5) is fixedly connected to the limiting bracket (3) by bolts. It is used to connect the lower swinging limiting locking hook one (2) and the lower swinging limiting locking hook two (4). The centrifugal counterweight (7) is fixedly disposed on the surface of the limiting bracket (3) in a symmetrical manner. The surfaces of the two centrifugal counterweights (7) are fixedly connected to a connecting rod (8). The two ends of the tension spring (6) are fixedly connected to the swinging limiting mechanism and the midpoint of the connecting rod (8), respectively.

2. The helicopter rotor flapping limiting device according to claim 1, characterized in that, The waving limiting mechanism includes multiple waving hinge joints (9) arranged in a ring and hinged to the surface of the propeller hub (1) via a rotating shaft, and an upper waving limiting protrusion (11) slidably disposed on one side of the waving hinge joint (9). A lower limiting rotating shaft (10) is fixedly disposed below the waving hinge joint (9), and the limiting bracket (3) is rotatably connected to the lower limiting rotating shaft (10).

3. A helicopter rotor flapping limiting device according to claim 2, characterized in that, The initial state of the device is that the limiting bracket (3) is in contact with the swinging hinge (9), and the lower swing limiting hook one (2) and the lower swing limiting hook two (4) are both in contact with the swinging hinge (9). One end of the tension spring (6) is fixedly connected to the swinging hinge (9), and the tension spring (6) can deform inside the limiting bracket (3).

4. A helicopter rotor flapping limiting device according to claim 2, characterized in that, A damping pad (12) is fixedly connected to one side of the upper surface of the limiting bracket (3). The damping pad (12) fits into the flapping hinge (9) and provides damping force between the limiting bracket (3) and the flapping hinge (9). The damping force is adaptively adjusted according to the size of the rotor flapping.

5. A helicopter rotor flapping limiting device according to claim 4, characterized in that, The range adjustment mechanism includes a locking rod (13) fixedly installed inside the limiting bracket (3). One end of the locking rod (13) is fixedly connected to one side of the upper swing limiting protrusion (11), and can adjust the swing range of the rotor according to the unlocking state of the lower swing limiting lock hook one (2) and the lower swing limiting lock hook two (4).

6. A helicopter rotor flapping limiting device according to claim 5, characterized in that, The range adjustment mechanism also includes steel wire ropes (14) fixedly installed on both sides of the upper surface of the upper swing limiting protrusion (11). The surfaces of the two steel wire ropes (14) are together attached to a support frame (15), and the support frame (15) is fixedly connected to the swing hinge joint (9). The support frame (15) is provided with an arc-shaped rod (16) fixedly connected to the swing hinge joint (9) inside.

7. A helicopter rotor flapping limiting device according to claim 6, characterized in that, The range adjustment mechanism also includes a support rod (17) fixedly connected to the upper surface of the propeller hub (1). The surface of the support rod (17) is fixedly sleeved with a drive block (18) hinged to the arc rod (16). The upper surface of the support rod (17) is slidably connected with an adjustment block (19), and one end of the adjustment block (19) is fixedly connected to a limit plate (20).

8. A helicopter rotor flapping limiting device according to claim 5, characterized in that, The surface of the limiting bracket (3) and the lower surface of the swinging hinge (9) are both provided with movable grooves (21) to provide space for the movement of the tension spring (6) and the locking rod (13). The lower surface of the swinging hinge (9) is provided with a lower swinging limiting boss (22) corresponding to the position of the damping pad (12).

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