A blade flutter limiting mechanism

Abstract

This application discloses a blade flapping restriction mechanism, including a blade clamp, a variable-pitch rotor hub, and a limiting mechanism. The blade clamp is rotatably connected to the variable-pitch rotor hub. One end of the limiting mechanism abuts against the side of the variable-pitch rotor hub and can slide relative to it, while the other end is slidably connected to the blade clamp. When the blade is in a folded state, the limiting mechanism abuts against the side of the variable-pitch rotor hub, and at this time, the limiting mechanism is in a first position. When the blade is in an operating state, the limiting mechanism engages with the variable-pitch rotor hub, and at this time, the limiting mechanism is in a second position. This application solves the problem of collision between the upper and lower blades caused by excessive flapping motion of the blades in existing coaxial twin-rotor helicopters with folded blades during extreme weather or violent movements. When the blade is in an operating state, the limiting mechanism can lock and restrict the blade flapping motion, thereby preventing the upper and lower blades from colliding and slapping under abnormal weather and attitude conditions. The locking state of the limiting mechanism can also be manually released for blade folding and storage.

Description

Technical Field

[0001] This application relates to the field of coaxial twin-rotor helicopter technology, and more particularly to a rotor blade flapping limiting mechanism. Background Technology

[0002] Folding-blade coaxial twin-rotor helicopters achieve a compact fuselage and good flight performance through coaxial twin rotors, and achieve efficient space saving when parked through the blade folding function.

[0003] Currently used coaxial rotor helicopters with folding blades rely on the inertia of the rotating blades to maintain parallel movement of the blades. However, in extreme weather or during violent movements, the inertia of the blades alone is not enough to suppress the amplitude of the blade flapping motion, often causing the upper and lower blades to collide, thus leading to the helicopter crash.

[0004] To effectively overcome the above situation, this application provides a blade waving limiting mechanism. Utility Model Content

[0005] This application provides a blade flapping limiting mechanism, which solves the problem of upper and lower blade collisions caused by excessive blade flapping motion in existing coaxial twin-rotor helicopters with folding blades during extreme weather or violent movements.

[0006] This utility model embodiment provides a blade flapping restriction mechanism, including a blade clamp, a variable-pitch blade hub, and a limiting mechanism; the blade clamp is rotatably connected to the variable-pitch blade hub; one end of the limiting mechanism abuts against the side of the variable-pitch blade hub and can slide relative to it, and the other end is slidably connected to the blade clamp; when the blade is in a folded state, the limiting mechanism abuts against the side of the variable-pitch blade hub, at which time the limiting mechanism is in a first position; when the blade is in a working state, the limiting mechanism engages with the variable-pitch blade hub, at which time the limiting mechanism is in a second position.

[0007] In one possible implementation, the limiting mechanism includes an elastic element and a limiting pin; the propeller clamp has a mounting groove; the variable-pitch propeller hub has a limiting groove at one end near the propeller clamp; the limiting pin is disposed in the mounting groove and slidably connected to the propeller clamp, and the limiting pin is configured to engage with the variable-pitch propeller hub through the limiting groove; one end of the elastic element abuts against the propeller clamp, and the other end of the elastic element abuts against the limiting pin; when the propeller blade is in a folded state, the limiting pin abuts against the side of the variable-pitch propeller hub, at which time the limiting pin is in a first position, the elastic element is in a compressed state, and the variable-pitch propeller hub can rotate relative to the propeller clamp; when the propeller blade is in a working state, the limiting pin is in the limiting groove, and the limiting pin engages with the variable-pitch propeller hub, at which time the limiting pin is in a second position, the elastic element is in a free state, and the variable-pitch propeller hub is in a locked state.

[0008] In one possible implementation, the blade flapping limiting mechanism further includes a mounting plate; the mounting plate is disposed at the mounting groove and connected to the blade clamp; one end of the elastic member abuts against the mounting plate, and the other end of the elastic member abuts against the limiting pin; the mounting plate is in contact with the side of the limiting pin.

[0009] In one possible implementation, the limiting mechanism includes a protrusion; the protrusion is connected to the side of the limiting pin near the mounting plate; the mounting plate has a sliding groove, and the protrusion is slidably connected to the mounting plate through the sliding groove.

[0010] In one possible implementation, the limiting pin has a mounting hole; the elastic element is disposed in the mounting hole and abuts against the limiting pin.

[0011] In one possible implementation, the blade flapping limiting mechanism further includes a pressure plate fastener and a hub fastener; the mounting pressure plate is connected to the blade clamp via the pressure plate fastener; the blade clamp is rotatably connected to the variable pitch blade hub via the hub fastener.

[0012] One or more technical solutions provided in this application have at least the following technical effects:

[0013] This utility model embodiment employs a blade flapping limiting mechanism, including a blade clamp, a variable-pitch hub, and a limiting mechanism. The blade clamp is rotatably connected to the variable-pitch hub. One end of the limiting mechanism is slidably connected to the variable-pitch hub, and the other end is slidably connected to the blade clamp. When the blade is in a folded state, the limiting mechanism abuts against the side of the variable-pitch hub, at which point the limiting mechanism is in a first position. When the blade is in an operating state, the limiting mechanism engages with the variable-pitch hub, at which point the limiting mechanism is in a second position. This effectively suppresses blade flapping amplitude: the limiting mechanism includes an elastic element and a limiting pin. When the blade is in an operating state, the limiting pin, under the action of the elastic element, engages with the limiting groove of the variable-pitch hub, forming a rigid lock, directly limiting the relative displacement between the blade clamp and the variable-pitch hub. This application solves the problem of excessive flapping amplitude caused by insufficient blade inertia during extreme weather or violent movements, completely avoiding collisions between the upper and lower rotors and the resulting crash risk. In the folded state, the limiting pin retracts under pressure, disengaging from the limiting groove and allowing the rotor clamp to rotate freely, ensuring the rotor blades fit snugly against the fuselage. This saves helicopter parking space and adapts to demanding scenarios such as tube storage and transportation. Furthermore, the protrusion has a manual unlocking function; specifically, pressing the protrusion manually during folding releases the limiting mechanism, making operation simple and efficient. This application solves the problem of upper and lower rotor blade collisions caused by excessive rotor flapping motion during extreme weather or violent movements in existing coaxial twin-rotor helicopters with folding blades. When the rotor blades are in operation, the limiting mechanism locks and restricts their flapping motion, preventing collisions and blade slapping under abnormal weather and attitude conditions. The locking mechanism can also be manually released for rotor blade folding and storage. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 An isometric drawing of a blade flapping limiting mechanism provided in an embodiment of this application;

[0016] Figure 2 A front view of a blade flapping limiting mechanism provided in an embodiment of this application;

[0017] Figure 3 for Figure 2 AA section view;

[0018] Figure 4 An exploded view of a blade flapping limiting mechanism provided in an embodiment of this application;

[0019] Figure 5 A schematic diagram of a blade flapping limiting mechanism with the blade in a folded state, provided for an embodiment of this application;

[0020] Figure 6 This is a schematic diagram of a blade flapping limiting mechanism in the working state, provided as an embodiment of this application.

[0021] Icons: 1-propeller clip; 11-mounting slot; 2-variable pitch hub; 21-limiting slot; 3-limiting mechanism; 31-elastic element; 32-limiting pin; 33-protrusion; 4-mounting pressure plate; 5-pressure plate fastener; 6-hub fastener. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0023] In the description of the embodiments of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the embodiments of this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In addition, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this utility model can be understood according to the specific circumstances.

[0024] This utility model embodiment provides a blade flapping restriction mechanism, including a blade clamp 1, a variable-pitch blade hub 2, and a limiting mechanism 3; the blade clamp 1 is rotatably connected to the variable-pitch blade hub 2; one end of the limiting mechanism 3 abuts against the side of the variable-pitch blade hub 2 and can slide relative to it, and the other end is slidably connected to the blade clamp 1; when the blade is in a folded state, the limiting mechanism 3 abuts against the side of the variable-pitch blade hub 2, at which time the limiting mechanism 3 is in a first position; when the blade is in a working state, the limiting mechanism 3 engages with the variable-pitch blade hub 2, at which time the limiting mechanism 3 is in a second position.

[0025] For example, such as Figure 5 As shown, when the propeller blades are in a folded state, the propeller clamp 1 can rotate. This method, when combined with a suitable airframe, can effectively reduce the size of the folded aircraft airframe, making it suitable for applications such as tube storage and transportation. In this state, the limiting mechanism 3 is in the first position, and it is in an unlocked state in the propeller clamp 1 mounting position. Figure 6 As shown, when the propeller clamp 1 rotates around the propeller hub fastener 6 to the unfolded position, that is, when the propeller blade is in the working state, the limiting mechanism 3 can lock and restrict the flapping movement of the propeller blade, thereby preventing the upper and lower propeller blades from colliding and splashing under abnormal weather and attitude conditions. Furthermore, the locking state of the limiting mechanism 3 can also be manually released to allow the propeller blade to be folded and stored.

[0026] In the embodiments of this application, such as Figure 1-6 As shown, the limiting mechanism 3 includes an elastic element 31 and a limiting pin 32; the propeller clamp 1 has an installation groove 11; the variable pitch hub 2 has a limiting groove 21 at one end near the propeller clamp 1; the limiting pin 32 is disposed in the installation groove 11 and is slidably connected to the propeller clamp 1, and the limiting pin 32 is configured to engage with the variable pitch hub 2 through the limiting groove 21; one end of the elastic element 31 abuts against the propeller clamp 1, and the other end of the elastic element 31 abuts against the limiting pin 32; when the propeller blade is in a folded state, the limiting pin 32 abuts against the side of the variable pitch hub 2, at which time the limiting pin 32 is in the first position, the elastic element 31 is in a compressed state, and the variable pitch hub 2 can rotate relative to the propeller clamp 1; when the propeller blade is in a working state, the limiting pin 32 is in the limiting groove 21, and the limiting pin 32 engages with the variable pitch hub 2, at which time the limiting pin 32 is in the second position, the elastic element 31 is in a free state, and the variable pitch hub 2 is in a locked state.

[0027] For example, such as Figure 5 As shown, when the propeller blades are in a folded state, the propeller clamp 1 can rotate. This method, when combined with a suitable airframe, can effectively reduce the size of the folded aircraft, making it suitable for applications such as tube storage and transportation. In this state, the limiting mechanism 3 is in the first position, and the limiting pin 32 is unlocked in the propeller clamp 1 mounting position. At this time, the elastic element 31 is in a compressed state; as... Figure 6 As shown, when the propeller clamp 1 rotates around the propeller hub fastener 6 to the unfolded position, that is, when the propeller blade is in the working state, the elastic element 31 releases its elastic force, causing the limiting pin 32 to slide into the limiting groove 21 of the variable pitch propeller hub 2. This locks and restricts the flapping movement of the propeller blade, thereby preventing the upper and lower propeller blades from colliding and splashing under abnormal weather and attitude conditions. Furthermore, the locking state of the limiting mechanism 3 can also be manually released for folding and storing the propeller blade.

[0028] In the embodiments of this application, such as Figure 1-6As shown, it also includes a mounting plate 4; the mounting plate 4 is disposed at the mounting groove 11 and connected to the paddle clamp 1; one end of the elastic member 31 abuts against the mounting plate 4, and the other end of the elastic member 31 abuts against the limiting pin 32; the mounting plate 4 and the side of the limiting pin 32 are in contact.

[0029] For example, the mounting plate 4 is configured to prevent the limit pin 32 from falling out of the mounting slot 11.

[0030] In the embodiments of this application, such as Figure 1-6 As shown, the limiting mechanism 3 includes a protrusion 33; the protrusion 33 is connected to the side of the limiting pin 32 near the mounting plate 4; the mounting plate 4 has a sliding groove, and the protrusion 33 is slidably connected to the mounting plate 4 through the sliding groove.

[0031] For example, the protrusion 33 is connected to the side of the limiting pin 32 near the mounting plate 4 and passes through the groove on the mounting plate 4. Its top protrudes from the upper surface of the mounting plate 4, which can easily release the locking state of the limiting mechanism 3 manually so as to fold and store the blade.

[0032] In the embodiments of this application, such as Figure 1-6 As shown, the limiting pin 32 has an installation hole; the elastic element 31 is disposed in the installation hole and abuts against the limiting pin 32.

[0033] For example, the elastic element 31 includes an elastic component such as a spring.

[0034] In the embodiments of this application, such as Figure 1-6 As shown, it also includes a pressure plate fastener 5 and a propeller hub fastener 6; the mounting pressure plate 4 is connected to the propeller clamp 1 through the pressure plate fastener 5; the propeller clamp 1 is rotatably connected to the variable pitch propeller hub 2 through the propeller hub fastener 6.

[0035] For example, the hub fastener 6 includes a through bolt, and the clamping fastener 5 includes a screw.

[0036] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0037] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A blade flutter limiting mechanism, characterized by, It includes a propeller clamp (1), a variable pitch propeller hub (2), and a limiting mechanism (3); The propeller clip (1) is rotatably connected to the variable pitch propeller hub (2); One end of the limiting mechanism (3) abuts against the side of the variable pitch hub (2) and can slide relative to it, while the other end is slidably connected to the blade clamp (1). When the blade is in a folded state, the limiting mechanism (3) abuts against the side of the variable pitch hub (2), and at this time, the limiting mechanism (3) is in the first position; when the blade is in a working state, the limiting mechanism (3) engages with the variable pitch hub (2), and at this time, the limiting mechanism (3) is in the second position.

2. The blade flutter limiting mechanism of claim 1, wherein, The limiting mechanism (3) includes an elastic element (31) and a limiting pin (32); The propeller clip (1) is provided with an installation groove (11); The variable pitch hub (2) has a limiting groove (21) at one end near the propeller clip (1); The limiting pin (32) is disposed in the mounting groove (11) and is slidably connected to the propeller clamp (1). The limiting pin (32) is configured to engage with the variable pitch hub (2) through the limiting groove (21). One end of the elastic element (31) abuts against the paddle clamp (1), and the other end of the elastic element (31) abuts against the limiting pin (32); When the blade is in a folded state, the limiting pin (32) abuts against the side of the variable pitch hub (2). At this time, the limiting pin (32) is in the first position, the elastic element (31) is in a compressed state, and the variable pitch hub (2) can rotate relative to the blade clamp (1). When the blade is in a working state, the limiting pin (32) is in the limiting groove (21), and the limiting pin (32) is engaged with the variable pitch hub (2). At this time, the limiting pin (32) is in the second position, the elastic element (31) is in a free state, and the variable pitch hub (2) is in a locked state.

3. The blade flapping limiting mechanism according to claim 2, characterized in that, It also includes installing the tablet press (4); The mounting plate (4) is disposed in the mounting groove (11) and connected to the paddle clamp (1); One end of the elastic element (31) abuts against the mounting plate (4), and the other end of the elastic element (31) abuts against the limiting pin (32); The mounting plate (4) is in contact with the side of the limiting pin (32).

4. The blade flutter limiting mechanism of claim 3, wherein The limiting mechanism (3) includes a protrusion (33); The protrusion (33) is connected to the side of the limiting pin (32) near the mounting plate (4); The mounting plate (4) is provided with a sliding groove, and the protrusion (33) is slidably connected to the mounting plate (4) through the sliding groove.

5. The blade flutter limiting mechanism of claim 2, wherein, The limiting pin (32) has a mounting hole; The elastic element (31) is disposed in the mounting hole and abuts against the limiting pin (32).

6. The blade flutter limiting mechanism of claim 3, wherein It also includes a pressing fastener (5) and a propeller hub fastener (6); The mounting plate (4) is connected to the paddle clamp (1) via the plate fastener (5); The propeller clamp (1) is rotatably connected to the variable pitch propeller hub (2) via the propeller hub fastener (6).

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