Variable stiffness shock-absorbing aircraft landing gear and aircraft

Abstract

The present invention provides a variable-stiffness shock-absorbing aircraft landing gear and an aircraft. The aircraft landing gear includes a flat spring, a variable-stiffness elastic component, an aircraft wheel, and a controller. The aircraft wheel is arranged at one end of the flat spring, and the variable-stiffness elastic component is arranged on the upper surface of the flat spring and adjacent to the other end thereof. The variable-stiffness elastic component is electrically connected to the controller and is used to control the variable-stiffness elastic component so that it can present different stiffness values ​​according to load changes. The variable-stiffness elastic component is connected to the fuselage frame via a connecting seat. The aircraft landing gear has good versatility and can adjust its stiffness under different operating environments of aircraft takeoff and landing, thereby improving the stability and comfort of aircraft operation.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft landing devices, and in particular to a variable-rigidity shock-absorbing aircraft landing gear and an aircraft. Background Art

[0002] Flat spring landing gear is currently widely used in small and medium-sized general-purpose aircraft and drones. It features a simple configuration, low cost, easy maintenance, and no seal leakage issues. However, the energy absorption efficiency of flat spring landing gear is close to that of a linear spring, making it prone to bouncing off the ground during hard landings. It also has low shock absorption efficiency and slow landing vibration convergence. Therefore, some aircraft have added elastomer shock absorbers to their flat spring landing gear.

[0003] For some heavier general-purpose aircraft, the difference between landing loads and ground roll impact loads can be as much as 6-7 times. Elastomeric shock absorbers with fixed stiffness struggle to meet both requirements simultaneously, and matching them with suitable nonlinear stiffness is particularly challenging. During ground operation, the landing gear experiences small static loads or fluctuations near these loads, requiring a softer elastomer shock absorber. However, this type of shock absorber can crush and fail under high loads. During landing impact, the landing gear experiences significant impact forces, requiring a stiffer elastomer shock absorber. However, this type of shock absorber offers little to no damping effect under low loads.

[0004] A Chinese patent application with application number 2023112111432 discloses an elastomer-buffered aircraft main landing gear structure. This patent application utilizes a primary elastomer element between the landing gear and the fuselage to absorb vertical impact loads during aircraft takeoff and landing, and uses a secondary elastomer element to prevent the aircraft from bouncing during landing, thereby improving the stability of the aircraft during landing. However, both the primary and secondary elastomer elements have fixed stiffness, which cannot meet the variable stiffness requirements of the shock absorber during aircraft landing and taxiing, and cannot effectively improve passenger comfort.

[0005] Therefore, there is an urgent need for a variable stiffness shock-absorbing aircraft landing gear and an aircraft, which has good versatility and can adjust its stiffness under different working environments of aircraft take-off and landing to improve the stability and comfort of aircraft operation. Summary of the Invention

[0006] The purpose of the present invention is to provide a variable stiffness shock-absorbing aircraft landing gear and an aircraft, aiming to solve the technical problems that landing gear using traditional oil-gas shock absorption and flat spring shock absorption cannot meet the shock absorption requirements of larger unmanned aerial vehicles and general aircraft, and that lever-type elastomer shock absorption cannot simultaneously meet the different elastic stiffness requirements for takeoff and landing.

[0007] To achieve the above objectives, in a first aspect, the present invention provides a variable stiffness shock absorbing aircraft landing gear, comprising a flat spring, a variable stiffness elastic component, an aircraft wheel, and a controller;

[0008] The aircraft wheel is arranged at one end of the flat spring, and the variable stiffness elastic component is arranged on the upper surface of the flat spring and adjacent to the other end thereof;

[0009] The variable stiffness elastic component is electrically connected to the controller and is used to control the variable stiffness elastic component so that it can present different stiffness values ​​according to load changes;

[0010] The variable stiffness elastic component is connected to the fuselage frame via a connecting seat.

[0011] As a further improvement of the above solution, the variable stiffness elastic component includes a variable stiffness elastic body, an electromagnet and a core rod; the core rod passes through the connecting seat, the variable stiffness elastic body and the electromagnet in sequence and is connected to the flat spring;

[0012] The electromagnet is electrically connected to the controller and is used to control the magnitude of the electromagnet current to change the magnetic induction intensity of the magnetic field, so that the variable stiffness elastic body presents different stiffness values ​​according to changes in load conditions.

[0013] As a further improvement of the above solution, the variable stiffness elastic component includes two electromagnets, and the variable stiffness elastic body is arranged between the two electromagnets.

[0014] As a further improvement of the above solution, a fixed stiffness elastic element is further provided on the lower surface of the flat spring, and the core rod also passes through the fixed stiffness elastic element and is connected to the flat spring.

[0015] As a further improvement of the above solution, the fixed stiffness elastic element is a compression spring element or an elastic rubber block or a polymer elastic block.

[0016] As a further improvement of the above solution, the aircraft landing gear further includes a limit plate, which is laterally connected to the other end of the flat spring and is used to be connected to the fuselage frame.

[0017] As a further improvement of the above solution, hinged seats are further provided at both ends of the limiting plate, and the hinged seats are used to be connected to the fuselage frame.

[0018] As a further improvement to the above solution, the flat spring includes a leg section and a wheel mounting section connected to the leg section, and the leg section and the wheel mounting section are arranged at a preset angle;

[0019] The variable stiffness elastic component is arranged on the upper surface of the leg segment.

[0020] As a further improvement of the above scheme, the electromagnet includes a supporting iron core and a coil wound on the outer wall of the supporting iron core; the supporting iron core includes a cylindrical iron core body and an iron core edge arranged on the edge of one end of the iron core, the coil is wound on the outer wall of the cylindrical iron core body, and the iron core edge is used to connect with the flat spring or the connecting seat.

[0021] In a second aspect, the present invention further provides an aircraft, comprising the variable stiffness shock absorbing aircraft landing gear provided in the first aspect.

[0022] Since the present invention adopts the above technical solution, the beneficial effects of this application are:

[0023] The present invention provides a variable stiffness shock-absorbing aircraft landing gear, comprising a flat spring, a variable stiffness elastic component, an aircraft wheel, and a controller. The aircraft wheel is disposed at one end of the flat spring, and the variable stiffness elastic component is disposed on the upper surface of the flat spring and adjacent to the other end. The variable stiffness elastic component is electrically connected to the controller and is configured to control the variable stiffness elastic component to exhibit different stiffness values ​​in response to load changes. In the present invention, by disposing the variable stiffness elastic component on the flat spring, the controller can control the variable stiffness elastic component to exhibit different stiffness values ​​in response to load changes, thereby enabling the present invention to achieve variable stiffness shock absorption, thereby balancing cushioning performance and passenger comfort during aircraft landing and taxiing.

[0024] Compared with the traditional flat spring type aircraft landing gear, the present invention provides a variable stiffness elastic component on the flat spring, thereby making the supporting legs have a stronger load-bearing capacity, better flexibility, better comfort and lower cost.

[0025] In a preferred embodiment, the variable stiffness elastic component includes a variable stiffness elastomer, an electromagnet and a core rod; the core rod passes through the connecting seat, the variable stiffness elastomer and the electromagnet in sequence and is connected to the flat spring; the electromagnet is electrically connected to the controller, and is used to control the magnitude of the electromagnet current to change the magnetic induction intensity of the magnetic field, so that the variable stiffness elastomer presents different stiffness values ​​according to the load condition; in the present invention, the magnitude of the electromagnet current is controlled to change the magnetic induction intensity of the magnetic field, so that the variable stiffness elastomer presents different stiffness values ​​according to the load condition. Compared with the traditional use of magnetorheological fluid buffers, the present invention uses magnetorheological elastomers for shock absorption, which is pollution-free, environmentally friendly, highly environmentally adaptable, highly resistant to pollution, light in weight (no need for bulky structures such as piston cylinders), and low in cost; and can be more conveniently installed on the aircraft landing gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0027] Figure 1 This is a schematic front view of a variable stiffness shock absorbing aircraft landing gear disclosed in the present invention;

[0028] Figure 2 This is a side view schematic diagram of a variable stiffness shock absorbing aircraft landing gear disclosed in the present invention;

[0029] Figure 3 It is a schematic side partial cross-sectional view of a variable stiffness shock absorbing aircraft landing gear disclosed in the present invention;

[0030] Figure 4 A three-dimensional diagram of a variable stiffness shock-absorbing aircraft landing gear disclosed in the present invention Figure 1 ;

[0031] Figure 5 A three-dimensional diagram of a variable stiffness shock-absorbing aircraft landing gear disclosed in the present invention Figure 2 ;

[0032] Figure 6 The present invention is a partial front view schematic diagram of an aircraft disclosed in the present invention.

[0033] Reference numerals:

[0034] 0. Aircraft landing gear; 1. Flat spring; 2. Variable stiffness elastic component; 21. Variable stiffness elastomer; 22. Electromagnet; 23. Core rod; 24. Support iron core; 25. Coil; 3. Aircraft wheel; 4. Connecting seat; 5. Fixed stiffness elastic element; 6. Limit plate; 7. Articulated seat; 01. Fuselage frame.

[0035] The realization of the objectives, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0037] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one of these features.

[0039] Moreover, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. Example

[0040] See also Figure 1-Figure 5 The present invention provides a variable stiffness shock absorbing aircraft landing gear, comprising a flat spring 1, a variable stiffness elastic component 2, an aircraft wheel 3, and a controller;

[0041] The aircraft wheel 3 is arranged at one end of the flat spring 1, and the variable stiffness elastic component 2 is arranged on the upper surface of the flat spring 1 and adjacent to the other end thereof;

[0042] The variable stiffness elastic component 2 is electrically connected to the controller, and is used to control the variable stiffness elastic component 2 so that it can present different stiffness values ​​according to load changes; in this embodiment, the variable stiffness elastic component 2 includes a variable stiffness elastomer 21, an electromagnet 22 and a core rod 23; the core rod 23 passes through the connecting seat 4, the variable stiffness elastomer 21 and the electromagnet 22 in sequence and is connected to the flat spring 1; preferably, the variable stiffness elastomer 21 is a magnetorheological elastomer, which is a magnetorheological elastomer, or MRE; due to the magnetostrictive effect of the magnetorheological elastomer, that is, under the action of a magnetic field, the particles inside the magnetorheological elastomer are magnetized and generate an interaction force. When the magnetorheological elastomer is deformed, these magnetic forces form a reverse torque inside it, enhancing the material's ability to resist deformation, that is, increasing the stiffness, and this ability changes with the change of the magnetic field. As the external magnetic field increases, the elastic modulus of the magnetorheological elastomer increases, and the stiffness in the direction of force also increases accordingly;

[0043] The electromagnet 22 is electrically connected to the controller, and is used to control the magnitude of the current of the electromagnet 22 so that the variable stiffness elastic body 21 can present different stiffness values ​​according to load changes;

[0044] The variable stiffness elastic component 2 is connected to the fuselage frame 01 via a connecting seat 4;

[0045] In the present invention, by providing a variable stiffness elastic component 2 on the flat spring 1, a controller can control the variable stiffness elastic component 2 so that it can present different stiffness values ​​according to load changes, thereby enabling the present invention to achieve variable stiffness shock absorption, and can take into account both the cushioning performance and the passenger comfort during landing and taxiing of the aircraft;

[0046] Compared with the conventional flat spring 1 type aircraft landing gear 0, the present invention provides a variable stiffness elastic component 2 with variable stiffness on the flat spring 1, thereby making the supporting legs have a stronger load-bearing capacity, better flexibility, better comfort and lower cost.

[0047] In the present invention, the magnitude of the current of the electromagnet 22 is controlled to change the magnetic induction intensity of the magnetic field, so that the variable stiffness elastomer 21 presents different stiffness values ​​according to the load conditions. Compared with the traditional magnetorheological fluid buffer, the present invention uses magnetorheological elastomer for shock absorption, which is pollution-free, environmentally friendly, highly adaptable to the environment, highly resistant to pollution, and lightweight, i.e., no bulky structures such as piston cylinders are required, and the cost is low; and it can be more conveniently installed on the aircraft landing gear 0.

[0048] As a preferred embodiment, the variable stiffness elastic component 2 includes two electromagnets 22, and the variable stiffness elastic body 21 is arranged between the two electromagnets 22;

[0049] The electromagnet 22 includes a supporting iron core 24 and a coil 25 wound around the outer wall of the supporting iron core 24; the supporting iron core 24 includes a cylindrical iron core body and an iron core edge provided at one end edge of the iron core, the coil 25 is wound around the outer wall of the cylindrical iron core body, and the iron core edge is used to connect to the flat spring 1 or the connecting seat 4;

[0050] In this embodiment, the iron cores of the two electromagnets 22 are arranged opposite to each other. For the convenience of description, they are divided into a first electromagnet 22 and a second electromagnet 22. The middle part of the first electromagnet 22 is provided with a first through hole for the core rod 23 to pass through along its thickness direction, and the middle part of the second electromagnet 22 is provided with a second through hole for the core rod 23 to pass through along its thickness direction; the two ends of the magnetorheological elastomer are respectively in contact with the ends of the two electromagnets 22 away from the iron core, and the middle part of the magnetorheological elastomer is provided with a third through hole for the core rod 23 to pass through along its thickness direction. The core rod 23 passes through the connecting seat 4, the first through hole of the first electromagnet 22, the third through hole of the magnetorheological elastomer and the second through hole of the second electromagnet 22 in sequence and is connected to the flat spring 1;

[0051] The arrangement of the two electromagnets 22 arranged relative to each other makes the current control range of the magnetorheological elastomer between the two larger, thereby making the stiffness variable range of the variable stiffness elastomer 21 larger, and can be used in more different models and take-off and landing conditions.

[0052] As a preferred embodiment, the lower surface of the flat spring 1 is further provided with a fixed stiffness elastic element 5, and the core rod 23 also passes through the fixed stiffness elastic element 5 and is connected to the flat spring 1;

[0053] Specifically, the fixed stiffness elastic element 5 is a compression spring element or an elastic rubber block or a polymer elastic block;

[0054] Rigidity elastic members are provided on the upper and lower surfaces of the flat spring 1, respectively. A variable-rigidity elastic component 2 is provided on the upper surface of the flat spring 1, and a fixed-rigidity elastic element 5 is provided on the lower surface of the flat spring 1, further improving the shock absorption performance of the aircraft landing gear 0.

[0055] When the aircraft lands, when the landing gear first touches the ground and sinks, the flat spring 1 is subjected to the reaction force of the ground. The flat spring 1 begins to compress and absorb energy, and the kinetic energy is converted into elastic potential energy. Part of this elastic potential energy is fed back to the fixed-stiffness elastic element 5 and absorbed and dissipated by it; the other part of this elastic potential energy is fed back to the variable-stiffness elastic component 2. The controller controls the variable-stiffness elastic body 21 to increase its stiffness to prevent the impact force during landing from being transmitted to the fuselage frame 01, completing a smooth landing.

[0056] During taxiing, the landing gear is subjected to random loads from the uneven road surface. The controller then controls the variable-stiffness elastic body 21 to reduce its stiffness, thereby increasing its compression stroke. This allows it to absorb more elastic potential energy under low loads, reducing the bumpy ride caused by road surface irregularities and improving passenger comfort. Furthermore, the controller can adjust the variable-stiffness elastic body 21 to an appropriate stiffness based on different road surface conditions, roughness, and hardness, such as concrete, asphalt, simple earth and stone, or icy surfaces, thereby increasing its adaptability.

[0057] As a preferred embodiment, the aircraft landing gear 0 also includes a limit plate 6, which is laterally connected to the other end of the flat spring 1; specifically, hinge seats 7 are also provided at both ends of the limit plate 6, and the hinge seats 7 are used to connect to the fuselage frame 01; the arrangement of the two hinge seats 7 and the connecting seat 4 enables the aircraft landing gear 0 to form a triangular connection relationship with the fuselage frame 01, which is more stable. At the same time, the two connections are hinged connections, which enables the structure to better adapt to deformation when subjected to external force, reducing the risk of stress concentration and damage.

[0058] As a preferred embodiment, the flat spring 1 includes a leg section and a wheel mounting section connected to the leg section, and the leg section and the wheel mounting section are arranged at a preset angle;

[0059] The variable stiffness elastic component 2 is arranged on the upper surface of the leg segment, and the fixed stiffness elastic element 5 is correspondingly arranged on the lower surface of the leg segment. Example

[0060] See also Figure 6 The present invention also provides an aircraft, comprising a variable stiffness shock-absorbing aircraft landing gear 0 as described in Example 1; further comprising a fuselage frame 01, and the aircraft landing gear 0 symmetrically arranged at the bottom of the fuselage frame 01; the aircraft landing gear 0 is provided with a variable stiffness elastic component 2. When the aircraft is operating on the ground, the landing gear is subjected to a small static load or fluctuates near the static load. The variable stiffness elastic body 21 is controlled to reduce its stiffness to improve the stability of the aircraft operation; when the aircraft is impacted during landing, the landing gear is subjected to a huge impact force. The variable stiffness elastic body 21 is controlled to increase its stiffness, and the flat spring 1 can be used to change the impact force consumption to improve the comfort of the aircraft landing.

[0061] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present description and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A variable stiffness shock absorbing aircraft landing gear, characterized in that: including a flat spring, a variable stiffness elastic component, an aircraft wheel, and a controller; The aircraft wheel is arranged at one end of the flat spring, and the variable stiffness elastic component is arranged on the upper surface of the flat spring and adjacent to the other end thereof; The variable stiffness elastic component is electrically connected to the controller and is used to control the variable stiffness elastic component so that it can present different stiffness values ​​according to load changes; The variable stiffness elastic component is connected to the fuselage frame via a connecting seat; The variable stiffness elastic component includes a variable stiffness elastic body, an electromagnet and a core rod; the core rod passes through the connecting seat, the variable stiffness elastic body and the electromagnet in sequence and is connected to the flat spring; The electromagnet is electrically connected to the controller and is used to control the magnitude of the electromagnet current to change the magnetic induction intensity of the magnetic field, so that the variable stiffness elastic body presents different stiffness values ​​according to the load working condition; the electromagnet includes a support core and a coil wound around the outer wall of the support core; the support core includes a cylindrical core body and an iron core edge arranged at the edge of one end of the iron core, the coil is wound around the outer wall of the cylindrical core body, and the iron core edge is used to connect to the flat spring or the connecting seat; A fixed stiffness elastic element is further provided on the lower surface of the flat spring, and the core rod passes through the fixed stiffness elastic element and is connected to the flat spring.

2. The variable stiffness shock absorbing aircraft landing gear according to claim 1, characterized in that: The variable stiffness elastic component includes two electromagnets, and the variable stiffness elastic body is arranged between the two electromagnets.

3. A variable stiffness shock absorbing aircraft landing gear according to claim 1 or 2, characterized in that: The fixed stiffness elastic element is a compression spring element, an elastic rubber block, or a polymer elastic block.

4. A variable stiffness shock absorbing aircraft landing gear according to claim 1 or 2, characterized in that: The aircraft landing gear further comprises a limiting plate, which is transversely connected to the other end of the flat spring and is used for being connected to the fuselage frame.

5. The variable stiffness shock absorbing aircraft landing gear according to claim 4, characterized in that: Hinge seats are also provided at both ends of the limiting plate, and the hinge seats are used to be connected to the fuselage frame.

6. The variable stiffness shock absorbing aircraft landing gear according to claim 1 or 2, characterized in that: The flat spring includes a leg section and a wheel mounting section connected to the leg section, and the leg section and the wheel mounting section are arranged at a preset angle; The variable stiffness elastic component is arranged on the upper surface of the leg segment.

7. An aircraft, characterized in that: The invention comprises a variable stiffness shock absorbing aircraft landing gear as described in any one of claims 1 to 6.

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