Aircraft anti-twisting device

Abstract

The invention belongs to the technical field of aircraft landing gear structural design, and particularly relates to an aircraft anti-twisting device. The device comprises an anti-twisting device inner rod, an upper end cover, an anti-twisting device outer cylinder and a lower end cover, one end of the anti-twisting device inner rod is hinged to a buffering supporting column outer cylinder of the aircraft landing gear, and the other end of the anti-twisting device inner rod penetrates through the upper end cover and extends into the anti-twisting device outer cylinder. The outer barrel of the anti-twisting device is hinged to a piston rod of a buffer strut of an aircraft landing gear; the bottom of the anti-twisting device inner rod is plugged through a lower end cover, the anti-twisting device inner rod, the anti-twisting device outer cylinder and the lower end cover jointly form a closed cavity, and an inflation nozzle communicated with the closed cavity is arranged on the lower end cover. According to the anti-torsion arm, the folding and unfolding space required by the anti-torsion arm can be smaller, the space design of the undercarriage is more facilitated, the structure is simple, the folding and unfolding space is small, the design is flexible, and the adaptability is good.

Description

Technical Field

[0001] This application belongs to the field of aircraft landing gear structure design technology, and specifically relates to an aircraft anti-torsion device. Background Technology

[0002] In aircraft landing gear systems, the shock absorber strut is a core component, its function being to absorb the impact energy generated during aircraft landing and taxiing. To prevent the piston rod of the shock absorber strut from rotating around its central axis under stress, a specialized anti-torsion mechanism must be installed. Currently, the most commonly used technical solution in this field is the use of a linkage-type anti-torsion arm.

[0003] A linkage-type anti-torsion arm typically consists of two or more rigid links connected by hinge points, forming a telescopic linkage mechanism. Its upper and lower ends are hinged to the outer cylinder of the buffer support and the piston rod, respectively. When the buffer support compresses or extends, the anti-torsion arm adapts to the change in length by adjusting the angle between the links, while simultaneously using its own geometric constraints to prevent the piston rod from rotating.

[0004] However, this traditional linkage-type anti-torsion arm solution has several inherent drawbacks:

[0005] The system has high spatial requirements and is structurally bulky: To meet the functions of retraction and anti-torsion, multiple linkages are usually required in combination. These linkages require a large space to fold and extend during the landing gear retraction and extension process, which is not conducive to the design of compact and efficient landing gear retraction and extension systems in modern aircraft, and often limits the design space of the airframe structure.

[0006] Limited functionality and lack of cushioning capacity: The anti-torsion arm is essentially a rigid linkage mechanism whose main function is only to transmit torque to prevent rotation; it does not possess any cushioning or energy absorption capacity itself. When the landing gear is subjected to impact loads, all the cushioning function is borne by the main shock absorber strut. As a rigid connecting component, the anti-torsion arm may transfer additional stress to its connection point, posing a potential fatigue risk.

[0007] Multiple hinge points lead to wear and maintenance issues: The presence of multiple hinge points means a greater need for bearings, bushings, and pins. These moving parts will experience wear over long-term use, requiring regular inspection and maintenance, thus increasing the total life-cycle maintenance costs. Summary of the Invention

[0008] To address the aforementioned issues, this application provides an aircraft anti-torsion device, which mainly includes an inner rod, an upper end cap, an outer cylinder, and a lower end cap.

[0009] One end of the inner rod of the anti-torsion device is hinged to the outer cylinder of the buffer strut of the aircraft landing gear, and the other end extends through the upper end cover into the outer cylinder of the anti-torsion device.

[0010] The outer cylinder of the anti-torsion device is hinged to the piston rod of the buffer strut of the aircraft landing gear;

[0011] The bottom of the inner rod of the anti-torsion device is sealed by the lower end cover. The inner rod of the anti-torsion device, the outer cylinder of the anti-torsion device, and the lower end cover together form a sealed cavity. An air inlet is provided on the lower end cover that communicates with the sealed cavity.

[0012] Preferably, the inner rod of the anti-torsion device is provided with a single lug, and the outer cylinder of the aircraft landing gear buffer strut is provided with two lugs. The inner rod of the anti-torsion device and the outer cylinder of the buffer strut are connected by a first bolt assembly that passes through the single lug and the two lugs.

[0013] Preferably, the outer cylinder of the anti-torsion device is provided with a single lug, and the piston rod of the buffer strut of the aircraft landing gear is provided with two lugs. The outer cylinder of the anti-torsion device and the piston rod of the buffer strut are connected by a second bolt assembly that passes through the single lug and the two lugs.

[0014] Preferably, the sealed cavity is filled with nitrogen gas.

[0015] Preferably, the outer cylinder of the anti-torsion device has a first cavity and a second cavity, the lower end cap is located at the bottom of the first cavity, the upper end cap is installed at the top of the second cavity, a shoulder is provided between the first cavity and the second cavity to restrict the bottom plate of the inner rod of the anti-torsion device from sliding in the first cavity, a wavy protrusion is provided on the inner wall of the second cavity surrounding the inner rod of the anti-torsion device, a first sealing ring and a second sealing cavity are provided between the wavy protrusion and the inner rod of the anti-torsion device, an annular groove is provided on the bottom plate of the inner rod of the anti-torsion device to install a third sealing ring, and a fourth sealing cavity is provided between the lower end cap and the inner wall of the outer cylinder of the anti-torsion device.

[0016] Preferably, the anti-torsion device provides a buffering effect through the gas pressure within its sealed cavity.

[0017] Preferably, the device also includes a condition monitoring system integrated into the anti-torsion device. The condition monitoring system includes a pressure sensor, a temperature sensor, and a data processing unit. The pressure sensor is used to monitor the gas pressure inside the sealed cavity, the temperature sensor is used to monitor the gas temperature inside the sealed cavity, and the data processing unit is used to calculate the health status of the anti-torsion device based on the gas pressure and temperature data and to provide fault warnings.

[0018] Preferably, the sealed cavity is filled with intelligent magnetorheological fluid, and an excitation coil is provided on the outer cylinder or lower end cover of the anti-torsion device. By controlling the current of the excitation coil, the viscosity of the magnetorheological fluid is changed in real time, thereby actively adjusting the damping characteristics of the anti-torsion device.

[0019] This application allows for a smaller retraction and extension space required for the anti-torsion arm, which is more conducive to the space design of the landing gear. It has a simple structure, small retraction and extension space, flexible design, and good adaptability. Attached Figure Description

[0020] Figure 1 This is an external structural view of a preferred embodiment of the aircraft anti-torsion device of this application.

[0021] Figure 2 yes Figure 1 A cross-sectional view of the embodiment shown.

[0022] Among them, 1-buffer support outer cylinder, 2-first bolt assembly, 3-anti-torsion device inner rod, 4-upper end cover, 5-anti-torsion device outer cylinder, 6-second bolt assembly, 7-inflation nozzle, 8-buffer support piston rod, 9-lower end cover, 10-fourth sealing ring, 11-third sealing ring, 12-first sealing ring, 13-second sealing ring. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0024] This application provides an aircraft anti-torsion device, such as Figure 1 and Figure 2 As shown, it mainly includes the inner rod 3 of the anti-torsion device, the upper end cover 4, the outer cylinder 5 of the anti-torsion device, and the lower end cover 9.

[0025] One end of the inner rod 3 of the anti-torsion device is hinged to the outer cylinder 1 of the buffer strut of the aircraft landing gear, and the other end extends through the upper end cover 4 into the outer cylinder 5 of the anti-torsion device.

[0026] The outer cylinder 5 of the anti-torsion device is hinged to the piston rod 8 of the buffer strut of the aircraft landing gear.

[0027] The bottom of the inner rod 3 of the anti-torsion device is sealed by the lower end cover 9. The inner rod 3 of the anti-torsion device, the outer cylinder 5 of the anti-torsion device, and the lower end cover 9 together form a sealed cavity. An air inlet 7 communicating with the sealed cavity is provided on the lower end cover 9.

[0028] This application provides an integrated anti-torsion and cushioning solution for aircraft landing gear. This device cleverly replaces the traditional double anti-torsion arm structure by assembling the inner rod and outer cylinder of the anti-torsion device in a relatively telescopic manner to form a sealed cavity. When the aircraft lands or taxis, the cushioning strut extends or retracts. This device adapts to this length change through the compression and expansion of gas within its internal cavity, while its rigid connection effectively prevents the piston rod from twisting. Compared to existing technologies, this solution integrates anti-torsion and auxiliary cushioning functions into a compact unit, significantly reducing the space required for the anti-torsion mechanism's retraction and extension, providing greater design flexibility for the overall landing gear layout, and offering a simple, compact structure with better adaptability.

[0029] In some alternative embodiments, the inner rod 3 of the anti-torsion device is provided with a single lug, and the outer cylinder 1 of the buffer strut of the aircraft landing gear is provided with two lugs. The inner rod 3 of the anti-torsion device and the outer cylinder 1 of the buffer strut are connected by a first bolt assembly 2 that passes through the single lug and the two lugs.

[0030] This hinged connection method, which combines single and double lugs and is linked by bolt assemblies, is a reliable and mature solution. It ensures that torque can be transmitted between the upper end of the anti-torsion device and the outer cylinder of the buffer strut to prevent rotation, while allowing the device to swing at necessary angles within the landing gear's plane of motion, ensuring smooth movement. This connection method has a robust structure, a clear force transmission path, and is easy to install and maintain.

[0031] In some alternative embodiments, the outer cylinder 5 of the anti-torsion device is provided with a single lug, and the piston rod 8 of the aircraft landing gear buffer strut is provided with two lugs. The outer cylinder 5 of the anti-torsion device and the piston rod 8 of the buffer strut are connected by a second bolt assembly 6 that passes through the single lug and the two lugs.

[0032] Similar to the connection at the top, the outer cylinder of the anti-torsion device and the piston rod of the buffer support also adopt a hinged connection using a single-ear-double-ear-bolt assembly. This symmetrical or similar connection design makes the force distribution of the entire device more balanced. The second bolt assembly plays a crucial role in transmitting the torque of the piston rod to the anti-torsion device, and its reliable connection is the foundation for the anti-torsion function.

[0033] In some alternative embodiments, the sealed cavity is filled with nitrogen gas.

[0034] In this embodiment, nitrogen, as an inert gas, is chemically stable and does not readily react with the internal metal components and sealing materials of the device, ensuring the performance stability of the device during long-term operation and extending its service life. Furthermore, by injecting nitrogen at a specific pressure through the inflation nozzle 7, the buffer stiffness of the device can be precisely preset to meet the landing gear performance requirements of different aircraft models.

[0035] In some alternative embodiments, the outer cylinder 5 of the anti-torsion device has a first cavity and a second cavity. The lower end cover 9 is located at the bottom of the first cavity, and the upper end cover 4 is installed at the top of the second cavity. A shoulder is provided between the first cavity and the second cavity to restrict the bottom plate of the inner rod 3 of the anti-torsion device from sliding in the first cavity. A wavy protrusion surrounding the inner rod 3 of the anti-torsion device is provided on the inner wall of the second cavity. A first sealing ring 12 and a second sealing cavity 13 are provided between the wavy protrusion and the inner rod 3 of the anti-torsion device. An annular groove is provided on the bottom plate of the inner rod 3 of the anti-torsion device to install a third sealing ring 11. A fourth sealing cavity 10 is provided between the lower end cover 9 and the inner wall of the outer cylinder 5 of the anti-torsion device.

[0036] In this embodiment, the outer cylinder of the anti-torsion device adopts a stepped inner cavity design, and the sliding stroke of the inner rod is mechanically limited by the shoulder to prevent excessive extension and retraction. A key improvement lies in the multi-seal design: a wave-shaped protrusion is provided on the inner wall of the second cavity, forming a labyrinthine sealing area between it and the inner rod of the anti-torsion device, and is equipped with a first sealing ring 12 and a second sealing ring 13, greatly enhancing the dynamic sealing effect and effectively preventing gas leakage. Simultaneously, the third sealing ring 11 on the bottom plate of the inner rod and the fourth sealing ring 10 at the lower end cap together constitute the main sealing barrier. This multi-seal scheme ensures the long-term airtightness of the sealed cavity, thereby guaranteeing the sustained stability of the cushioning performance.

[0037] In some alternative embodiments, the anti-torsion device provides a buffering effect through the gas pressure within its sealed cavity.

[0038] This application utilizes the compressibility of gas. When the aircraft lands, the shock absorber strut is compressed and shortened, which pushes the inner rod of the anti-torsion device to compress relative to the outer cylinder, resulting in a reduction in the volume of the sealed cavity and an increase in the internal gas pressure, thereby absorbing the impact energy. When the load is released, the high-pressure gas expands, pushing the device back to its original length. This cushioning effect distributes part of the load of the main shock absorber strut, helping to improve the cushioning efficiency of the landing gear and making the stress distribution of the entire system smoother.

[0039] In some alternative embodiments, a condition monitoring system integrated into the anti-torsion device is also included. The condition monitoring system includes a pressure sensor, a temperature sensor, and a data processing unit. The pressure sensor is used to monitor the gas pressure in the sealed cavity, the temperature sensor is used to monitor the gas temperature in the sealed cavity, and the data processing unit is used to calculate the health status of the anti-torsion device based on the gas pressure and temperature data and to provide fault warnings.

[0040] This embodiment integrates a condition monitoring system, enabling real-time sensing of the device's operating status. Pressure sensors directly monitor cavity pressure, providing a direct indicator of gas leakage (such as seal failure). Temperature sensors monitor operating temperature, helping to assess the device's thermal load and performance changes. The data processing unit analyzes pressure and temperature data (e.g., whether pressure changes with temperature within a normal range) to calculate the device's health status and issue early warnings of faults when data is abnormal, thereby enabling predictive maintenance and significantly improving the safety and reliability of the aircraft landing gear system.

[0041] In some alternative embodiments, the sealed cavity is filled with intelligent magnetorheological fluid, and an excitation coil is provided on the outer cylinder 5 or the lower end cover 9 of the anti-torsion device. By controlling the current of the excitation coil, the viscosity of the magnetorheological fluid is changed in real time, thereby actively adjusting the damping characteristics of the anti-torsion device.

[0042] This embodiment replaces the working medium with a smart magnetorheological fluid and adds an excitation coil, allowing the damping characteristics of the device to be actively and in real time adjusted by an electrical signal. When the excitation coil is not energized, the magnetorheological fluid is in a Newtonian fluid state with low viscosity; once energized to generate a magnetic field, the particles in the magnetorheological fluid instantly form a chain-like structure, causing a sharp increase in its apparent viscosity and shear stress, thereby enhancing the damping force. This means that the aircraft can actively adjust the damping of the anti-torsion device according to different landing weights, runway conditions, or taxiing states, always achieving optimal cushioning performance—a leap forward that traditional passive devices cannot achieve.

[0043] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An aircraft anti-torsion device, characterized in that, It includes the inner rod (3) of the anti-torsion device, the upper end cover (4), the outer cylinder (5) of the anti-torsion device, and the lower end cover (9); One end of the inner rod (3) of the anti-torsion device is hinged to the outer cylinder (1) of the buffer strut of the aircraft landing gear, and the other end passes through the upper end cover (4) and extends into the outer cylinder (5) of the anti-torsion device. The outer cylinder (5) of the anti-torsion device is hinged to the piston rod (8) of the buffer strut of the aircraft landing gear; The bottom of the inner rod (3) of the anti-torsion device is sealed by the lower end cover (9). The inner rod (3), the outer cylinder (5) of the anti-torsion device and the lower end cover (9) together form a sealed cavity. An air inlet (7) is provided on the lower end cover (9) and communicates with the sealed cavity.

2. The aircraft anti-torsion device as described in claim 1, characterized in that, The anti-torsion device inner rod (3) is provided with a single ear, and the aircraft landing gear buffer strut outer cylinder (1) is provided with a double ear. The anti-torsion device inner rod (3) and the buffer strut outer cylinder (1) are connected by a first bolt assembly (2) that passes through the single ear and the double ear.

3. The aircraft anti-torsion device as described in claim 1, characterized in that, The outer cylinder (5) of the anti-torsion device is provided with a single ear, and the piston rod (8) of the buffer strut of the aircraft landing gear is provided with a double ear. The outer cylinder (5) of the anti-torsion device and the piston rod (8) of the buffer strut are connected by a second bolt assembly (6) that passes through the single ear and the double ear.

4. The aircraft anti-torsion device as described in claim 1, characterized in that, The sealed cavity is filled with nitrogen gas.

5. The aircraft anti-torsion device as described in claim 1, characterized in that, The outer cylinder (5) of the anti-torsion device has a first cavity and a second cavity. The lower end cover (9) is located at the bottom of the first cavity, and the upper end cover (4) is installed at the top of the second cavity. There is a shoulder between the first cavity and the second cavity to restrict the bottom plate of the inner rod (3) of the anti-torsion device from sliding in the first cavity. The inner wall of the second cavity is provided with a wave-shaped protrusion surrounding the inner rod (3) of the anti-torsion device. A first sealing ring (12) and a second sealing cavity (13) are provided between the wave-shaped protrusion and the inner rod (3) of the anti-torsion device. An annular groove is provided on the bottom plate of the inner rod (3) of the anti-torsion device to install a third sealing ring (11). A fourth sealing cavity (10) is provided between the lower end cover (9) and the inner wall of the outer cylinder (5) of the anti-torsion device.

6. The aircraft anti-torsion device as described in claim 1, characterized in that, The anti-torsion device provides a buffering effect through the gas pressure within its sealed cavity.

7. The aircraft anti-torsion device as described in claim 1, characterized in that, It also includes a condition monitoring system integrated into the anti-torsion device, the condition monitoring system including a pressure sensor, a temperature sensor and a data processing unit; the pressure sensor is used to monitor the gas pressure in the sealed cavity, the temperature sensor is used to monitor the gas temperature in the sealed cavity, and the data processing unit is used to calculate the health status of the anti-torsion device based on the gas pressure and temperature data and to provide fault warning.

8. The aircraft anti-torsion device as described in claim 1, characterized in that, The sealed cavity is filled with intelligent magnetorheological fluid. An excitation coil is provided on the outer cylinder (5) or lower end cover (9) of the anti-torsion device. By controlling the current of the excitation coil, the viscosity of the magnetorheological fluid is changed in real time, thereby actively adjusting the damping characteristics of the anti-torsion device.

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