Swing-up limiting mechanism of coaxial unmanned helicopter

Abstract

The utility model discloses an upward swing limiting mechanism of a coaxial unmanned helicopter, which belongs to the technical field of helicopters, and comprises an upper rotor hub, a lower rotor hub, an upper rotor blade, a lower rotor blade and a lower rotor upper swing limiting component, the upper rotor blade is fixedly installed on the outer side of the upper rotor hub, the lower rotor blade is fixedly installed on the outer side of the lower rotor hub, the lower rotor upper flapping limiting assembly is installed on the lower rotor hub, and the mechanism improves the safety and stability of the helicopter.

Description

Technical Field

[0001] This utility model relates to the field of helicopter technology, and more specifically, to a coaxial unmanned helicopter upper control limiting mechanism. Background Technology

[0002] Currently, in coaxial unmanned helicopters, the bearingless rotor configuration has advantages such as high control efficiency, good agility, high reliability, and simple maintenance. However, existing technologies do not include a lower rotor blade flapping limiter for the rotor system. When the rotor is stationary or at low speed, encountering gusts or other situations, the lower rotor blades are prone to flapping upwards, causing a flapping problem with the upper rotor blades, which affects the safety and stability of the helicopter. Utility Model Content

[0003] To overcome the above deficiencies, this utility model provides a coaxial unmanned helicopter upper control limit mechanism, which aims to improve the problem of low safety and stability of helicopters.

[0004] This utility model is implemented as follows: A coaxial unmanned helicopter flapping limiting mechanism includes an upper rotor hub, a lower rotor hub, upper rotor blades, lower rotor blades, and a lower rotor flapping limiting assembly. Both the upper and lower rotor hubs are mounted on the helicopter's rotation shaft. The upper rotor blades are fixedly mounted on the outer side of the upper rotor hub, and the lower rotor blades are fixedly mounted on the outer side of the lower rotor hub. The lower rotor flapping limiting assembly is mounted on the lower rotor hub and includes an upper flapping limiting pivot and a centrifugal spring. The system includes a spring, a spring fixing assembly, an upper limit moving support, a counterweight rod, a first counterweight, and a second counterweight. One end of the upper flapping limit pivot is fixedly mounted on the lower rotor hub, and the other end of the upper flapping limit pivot is rotatably connected to the upper limit moving support via an oil-free bushing. One end of the upper limit moving support is fixedly mounted on the centrifugal spring, and the other end of the centrifugal spring is connected to the spring fixing assembly. The counterweight rod is fixedly connected to the upper limit moving support via screws, and the first and second counterweights are mounted on the counterweight rod and fixed with nuts.

[0005] In the preferred embodiment of this utility model, one end of the upper flapping limiting pivot is fixedly connected to the center of the lower rotor hub. The design of the upper flapping limiting pivot ensures the stable installation of the lower rotor upper flapping limiting component on the lower rotor hub and can effectively transmit the upper flapping torque of the lower rotor blades when subjected to external force to the central component of the hub, thereby achieving the limiting effect.

[0006] In the preferred embodiment of this utility model, the size and specifications of the centrifugal spring are determined by the spring calculation formula and the centrifugal force calculation formula to ensure the correct operation of the spring at different speeds.

[0007] In the preferred embodiment of this utility model, one end of the upper limit moving support is rotatably connected to the upper flapping limit pivot via an oil-free bushing, and the other end of the upper limit moving support is connected to the lower rotor hub via a connecting structure. The structural design of the upper limit moving support takes into account the dynamic characteristics and space constraints of the rotor system, and optimizes its shape and size.

[0008] In the preferred embodiment of this utility model, the counterweight rod, counterweight block one, and counterweight block two can be adjusted in number and distribution as needed to adjust the center of gravity of the upper swing limiting mechanism, thereby changing its action characteristics at different speeds. The design of the counterweight rod and counterweight blocks takes into account the mass distribution and dynamic characteristics of the helicopter rotor system.

[0009] In the preferred embodiment of this utility model, the spring fixing assembly is designed to fix one end of the centrifugal spring and ensure that the spring is in a stretched state during assembly, thereby providing the necessary tension to support the initial position of the upper limit support. The structural design of the spring fixing assembly takes into account the mechanical characteristics and installation requirements of the spring. Through precise calculation and optimization, the stability and reliability of the spring during assembly and use are ensured.

[0010] In the preferred embodiment of this utility model, the core part of the lower rotor hub is the lower rotor hub central component and the upper flapping baffle. The surface of the lower rotor hub central component is machined with precise mounting surfaces and positioning holes. The lower rotor hub central component not only bears the important responsibility of connecting the upper and lower rotor hubs and blades, but also has a specially designed structure that cooperates with the lower rotor upper flapping limiting component to ensure that the lower rotor upper flapping limiting component can be stably and accurately installed on it. At the same time, its material and strength are strictly selected to meet the mechanical requirements of the helicopter during flight.

[0011] In the preferred embodiment of this utility model, the upper flapping baffle and the lower rotor hub center component are fastened together by high-strength bolts. When the rotor system is stationary or rotating at low speed, the upper flapping baffle and the lower rotor upper flapping limiting component maintain a certain gap. When the rotor encounters abnormal conditions such as gusts of wind, the upper flapping baffle can quickly contact the lower rotor upper flapping limiting component and effectively transfer the upper flapping torque of the lower rotor blade to the hub center component, thereby realizing the limiting function.

[0012] The beneficial effects of this invention are: it effectively solves the problem of upward flapping of the lower rotor blades in coaxial unmanned helicopters, improving the safety and stability of the helicopter. Simultaneously, the upward flapping limiting mechanism has a simple structure, low manufacturing cost, and is easy to install and maintain. Furthermore, by optimizing the structural design and component connection methods of the limiting mechanism, the reliability and durability of the mechanism are improved, while maintenance and operating costs are reduced. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of a coaxial unmanned helicopter upper control limiting mechanism provided by an embodiment of the present invention;

[0015] Figure 2 A schematic diagram of the structure of the flapping limiting component on the lower rotor is provided for the embodiment of this utility model;

[0016] Figure 3 This invention provides structural schematic diagrams of the lower rotor upper waving limiting component under different states for embodiments of the present invention.

[0017] Figure 4 A structural schematic diagram of the upper limit dynamic support member is provided for the embodiments of this utility model.

[0018] In the diagram: 101-Upper rotor hub; 102-Lower rotor hub; 1021-Lower rotor hub central component; 1022-Upper flap baffle; 103-Upper rotor blade; 104-Lower rotor blade; 105-Lower rotor upper flap limit assembly; 1051-Upper flap limit pivot; 1052-Centrifugal spring; 1053-Spring fixing assembly; 1054-Upper limit support; 1055-Counterweight rod; 1056-Weight 1; 1057-Weight 2; 1058-Oil-free bushing. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0020] Please see Figures 1-4This utility model provides a technical solution: a coaxial unmanned helicopter upper flapping limiting mechanism, including an upper rotor hub 101, a lower rotor hub 102, an upper rotor blade 103, a lower rotor blade 104, and a lower rotor upper flapping limiting assembly 105. Both the upper rotor hub 101 and the lower rotor hub 102 are mounted on the helicopter's rotating shaft. The upper rotor blade 103 is fixedly mounted on the outer side of the upper rotor hub 101, and the lower rotor blade 104 is fixedly mounted on the outer side of the lower rotor hub 102. The lower rotor upper flapping limiting assembly 105 is mounted on the lower rotor hub 102 and includes an upper flapping limiting pivot 1051, a centrifugal spring 1052, and a spring fixing assembly 105. 053, Upper limit moving support 1054, counterweight rod 1055, counterweight block one 1056 and counterweight block two 1057, one end of the upper flapping limit pivot 1051 is fixedly installed on the lower rotor hub 102, the other end of the upper flapping limit pivot 1051 is rotatably connected to the upper limit moving support 1054 through an oil-free bushing 1058, one end of the upper limit moving support 1054 is fixedly installed with a centrifugal spring 1052, the other end of the centrifugal spring 1052 is connected to the spring fixing assembly 1053, the counterweight rod 1055 is fixedly connected to the upper limit moving support 1054 by screws, and the counterweight block one 1056 and counterweight block two 1057 are installed on the counterweight rod 1055 and fixed by nuts.

[0021] In some specific implementations, one end of the upper flapping limit pivot 1051 is fixedly connected to the center of the lower rotor hub 102. The design of the upper flapping limit pivot 1051 ensures the stable installation of the lower rotor upper flapping limit assembly 105 on the lower rotor hub 102 and can effectively transmit the upper flapping torque of the lower rotor blade 104 when subjected to external force to the central component of the hub, thereby achieving the limiting effect. The material selection and size design of the upper flapping limit pivot 1051 have been precisely calculated to ensure its sufficient strength and rigidity to meet the safety requirements of the helicopter under various flight conditions.

[0022] In some specific implementation schemes, the size and specifications of the centrifugal spring 1052 are determined by the spring calculation formula and the centrifugal force calculation formula to ensure the correct operation of the spring at different speeds. The selection and calculation of the centrifugal spring 1052 are based on the dynamic characteristics of the helicopter rotor system. Through precise mathematical model simulation and optimization, the best limiting effect and stability are achieved.

[0023] In some specific implementations, one end of the upper limit moving support 1054 is rotatably connected to the upper flapping limit pivot 1051 via an oil-free bushing 1058, while the other end of the upper limit moving support 1054 is connected to the lower rotor hub 102 via a connecting structure. The structural design of the upper limit moving support 1054 takes into account the dynamic characteristics and space constraints of the rotor system. By optimizing its shape and size, the reliability and stability of the limiting mechanism are improved.

[0024] In some specific implementation schemes, the counterweight rod 1055, counterweight block one 1056, and counterweight block two 1057 can be adjusted in number and distribution as needed to adjust the center of gravity of the upward swing limiting mechanism, thereby changing its action characteristics at different speeds. The design of the counterweight rod 1055 and the counterweight blocks takes into account the mass distribution and dynamic characteristics of the helicopter rotor system. Through precise calculation and optimization, precise control of the action characteristics of the upward swing limiting mechanism is achieved.

[0025] In some specific implementations, the spring fixing assembly 1053 is designed to fix one end of the centrifugal spring 1052 and ensure that the spring is in the pulled-out state during assembly, thereby providing the necessary tension to support the initial position of the upper limit support 1054. The structural design of the spring fixing assembly 1053 takes into account the mechanical characteristics and installation requirements of the spring. Through precise calculation and optimization, the stability and reliability of the spring during assembly and use are ensured.

[0026] In some specific implementation schemes, the core components of the lower rotor hub 102 are the lower rotor hub central component 1021 and the upper flapping baffle 1022. The lower rotor hub central component 1021 has precisely machined mounting surfaces and positioning holes. The lower rotor hub central component 1021 not only bears the important responsibility of connecting the upper and lower rotor hubs 102 and the blades, but also has a specially designed structure that cooperates with the lower rotor upper flapping limiting component 105 to ensure that the lower rotor upper flapping limiting component 105 can be stably and accurately installed on it. At the same time, its material and strength have been strictly selected. To meet the mechanical requirements of the helicopter during flight, the upper flapping baffle 1022 and the lower rotor hub center component 1021 are fastened together by high-strength bolts. When the rotor system is stationary or rotating at low speed, the upper flapping baffle 1022 and the lower rotor upper flapping limit component 105 maintain a certain gap. When the rotor encounters abnormal conditions such as gusts, the upper flapping baffle 1022 can quickly contact the lower rotor upper flapping limit component 105 and effectively transfer the upper flapping torque of the lower rotor blade 104 to the hub center component, thereby realizing the limiting function.

[0027] Working Principle: This invention utilizes a lower rotor upper flapping limiting component mounted on the lower rotor hub. By employing the centrifugal force of a centrifugal spring and counterweight, the component remains horizontal and in close contact with the upper flapping baffle when the rotor system is at low speed or stationary. When the rotor encounters an abnormal situation such as a gust of wind causing the lower rotor blades to flap upwards, the upper flapping baffle contacts the lower rotor upper flapping limiting component and transmits the upward flapping torque to the central component of the rotor hub, thus achieving the limiting function. Simultaneously, when the rotor rotates at high speed, the lower rotor upper flapping limiting component tilts under the action of centrifugal force, preventing interference with the lower rotor blades.

[0028] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A coaxial unmanned helicopter upper control limiting mechanism, characterized in that, The system includes an upper rotor hub, a lower rotor hub, an upper rotor blade, a lower rotor blade, and a flapping limit assembly on the lower rotor. Both the upper rotor hub and the lower rotor hub are mounted on the helicopter's rotating shaft. The upper rotor blade is fixedly mounted on the outside of the upper rotor hub, and the lower rotor blade is fixedly mounted on the outside of the lower rotor hub. The flapping limit assembly on the lower rotor is mounted on the lower rotor hub. The upper flapping limit assembly of the lower rotor includes an upper flapping limit pivot, a centrifugal spring, a spring fixing assembly, an upper limit moving support, a counterweight rod, a first counterweight, and a second counterweight. One end of the upper flapping limit pivot is fixedly mounted on the lower rotor hub, and the other end of the upper flapping limit pivot is rotatably connected to the upper limit moving support via an oil-free bushing. One end of the upper limit moving support is fixedly mounted with the centrifugal spring, and the other end of the centrifugal spring is connected to the spring fixing assembly. The counterweight rod is fixedly connected to the upper limit moving support with screws, and the first and second counterweights are mounted on the counterweight rod and fixed with nuts.

2. The coaxial unmanned helicopter upper control limiting mechanism according to claim 1, characterized in that, One end of the upper waving limit pivot is fixedly connected to the center of the lower rotor hub.

3. The coaxial unmanned helicopter upper control limiting mechanism according to claim 1, characterized in that, The size and specifications of the centrifugal spring are determined by the spring calculation formula and the centrifugal force calculation formula.

4. The coaxial unmanned helicopter upper control limiting mechanism according to claim 1, characterized in that, One end of the upper limit moving support is rotatably connected to the upper flapping limit pivot via an oil-free bushing, while the other end of the upper limit moving support is connected to the lower rotor hub via a connecting structure.

5. The coaxial unmanned helicopter upper control limiting mechanism according to claim 1, characterized in that, The number and distribution of the counterweight rod, counterweight block one, and counterweight block two can be adjusted according to requirements.

6. The coaxial unmanned helicopter upper control limiting mechanism according to claim 1, characterized in that, The spring retaining assembly is designed to secure one end of the centrifugal spring and ensure that the spring is in the extended state during assembly.

7. The coaxial unmanned helicopter upper control limiting mechanism according to claim 1, characterized in that, The core part of the lower rotor hub includes a lower rotor hub central component and an upper flap plate. The surface of the lower rotor hub central component is machined with precise mounting surfaces and positioning holes.

8. The coaxial unmanned helicopter upper control limiting mechanism according to claim 7, characterized in that, The upper flapper plate and the central component of the lower rotor hub are fastened together by high-strength bolts.

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