Undercarriage

Abstract

The invention relates to the technical field of aircrafts, in particular to an undercarriage which comprises a retractable actuator (1), a support (2), an upper cylinder (3), a damper (4), a main elastic element (5), a middle cylinder (6), an auxiliary elastic element (7), a lower cylinder (8), a supporting plate (9) and airplane wheels (10). The undercarriage can be matched with a vertical take-off and landing (or low-speed take-off and landing or similar to vertical take-off and landing) aircraft, can bear large loads and stress generated by the gravity and gravitational acceleration (or deceleration) of the aircraft, is good in flexibility and reduces impact on the aircraft; the performance requirement on the airplane wheel and the like is reduced, and the manufacturing difficulty is reduced.

Description

Technical Field

[0001] This invention relates to the field of aircraft technology, and more specifically to a landing gear. Background Technology

[0002] Currently, the mainstream landing gear is mainly adapted to traditional aircraft. Vertical takeoff and landing (or low-speed takeoff and landing) aircraft have special requirements for landing gear during takeoff and landing, and the landing gear needs to be re-optimized.

[0003] The landing gear disclosed in this application has at least the following beneficial technical effects: it can be adapted to vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft; it can withstand the large loads and stresses generated by the aircraft's gravity and gravitational acceleration (or deceleration); at the same time, it has good flexibility, reducing the impact on the aircraft and improving comfort; it reduces the performance requirements of wheels, etc., reducing manufacturing difficulty, and facilitates the aircraft's movement on the ground; it is retractable, reducing air resistance during flight; and its structure is relatively simple and its manufacturing cost is low. Summary of the Invention

[0004] The purpose of this application is to provide a landing gear that is compatible with vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft, capable of withstanding large loads and stresses generated by the aircraft's gravity and gravitational acceleration (or deceleration), while also being flexible to reduce the impact on the aircraft and improve comfort; reducing the performance requirements of wheels and other components, thus reducing manufacturing difficulty, and facilitating aircraft movement on the ground; being retractable to reduce air resistance during flight; and having a relatively simple structure and low manufacturing cost.

[0005] The technical solution of this application is: a landing gear, the landing gear including a retraction actuator (1), a support (2), an upper cylinder (3), a damper (4), a main elastic element (5), an intermediate cylinder (6), a secondary elastic element (7), a lower cylinder (8), a support plate (9), and a wheel (10).

[0006] The retraction actuator (1) is used to control the retraction and extension of the landing gear and is installed on the support (or aircraft); when the retraction actuator (1) controls the landing gear to be lowered, the landing gear rotates downward (or deflects); after the aircraft takes off, when the retraction actuator (1) controls the landing gear to be retracted, the landing gear rotates upward (or deflects), reducing the frontal area of ​​the landing gear and reducing air resistance during flight;

[0007] The support (2) supports other components (or elements) of the landing gear. The support (2) is connected to the aircraft. The support part of the support (2) is connected to the upper cylinder (3). The retraction actuator (1) can control the connecting part of the upper cylinder (3) to rotate (or deflect) upward (or downward) around the support part of the support (2). For ease of explanation, the support (2) is described separately in this application. The support (2) can be integrated into the beam (or column, or other part) of the aircraft. The aircraft beam (or column, or other part) into which the support (2) is integrated is the support (2).

[0008] The upper cylinder (3) includes a connecting part, a prism cylinder (or a similar prism cylinder, or a cylindrical cylinder, or a similar cylindrical cylinder), etc.; the prism cylinder is a hollow prism with an empty interior. The line passing through the center point of the two bases of the prism is called the axis of the prism. The axis of the prism is also the axis of the prism cylinder. The cross section perpendicular to the axis of the prism cylinder is a polygon with a certain thickness (or a shape composed of a similar polygon and a polygon offset by a certain distance, or a polygon, or a similar polygon). The outer surface of the side of the prism cylinder is also called the outer surface of the side of the prism cylinder. The inner surface of the side of the prism cylinder is also called the inner surface of the side of the prism cylinder. The cylindrical cylinder is a hollow cylinder with an empty interior. The axis of the cylinder is also the axis of the cylindrical cylinder. The cross section perpendicular to the axis of the cylindrical cylinder is an annular shape (or a similar annular shape, or a circle with a certain thickness, or a shape composed of a similar circle and a circle offset by a certain distance). The outer surface of the side of the cylindrical cylinder is also called the outer surface of the side of the cylindrical cylinder. The inner surface of the side of the cylindrical cylinder is also called the inner surface of the side of the cylindrical cylinder.

[0009] The function of the damper (4) is to reduce vibration (or shock) and impact, and improve stability and comfort;

[0010] The main elastic element (5) and the secondary elastic element (7) are designed to bear and transmit loads (or forces) and to mitigate and suppress vibrations (or shocks) and impacts through their own deformation.

[0011] The intermediate cylinder (6) includes a support part, a prism cylinder (or a similar prism cylinder, or a cylindrical cylinder, or a similar cylindrical cylinder), etc.

[0012] The lower cylinder (8) includes a connecting part, a supporting part, a prism cylinder (or a similar prism cylinder, or a cylindrical cylinder, or a similar cylindrical cylinder), etc.

[0013] The upper cylinder (3), the middle cylinder (6), and the lower cylinder (8) all have a prism cylinder (or a similar prism cylinder, or a cylindrical cylinder, or a similar cylindrical cylinder) structure;

[0014] The inner surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the upper cylinder (3) is connected to the outer surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the upper part (facing the upper cylinder) of the intermediate cylinder (6), or the outer surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the upper cylinder (3) is connected to the outer surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the upper part (facing the upper cylinder) of the intermediate cylinder (6). The upper cylinder (3) is connected to the inner surface of the side of the cylinder (6) (or similar prism cylinder, or cylindrical cylinder, or similar cylindrical cylinder); the axis of the upper cylinder (3) is coincident with (or similarly coincident, or parallel, or similarly parallel) the axis of the middle cylinder (6) (or similar prism cylinder, or cylindrical cylinder, or similar cylindrical cylinder); the upper cylinder (3) and the middle cylinder (6) can move relative to each other along the axial direction (or similarly along the axial direction, or parallel to the axial direction);

[0015] The inner surface of the prism (or similar prism, or cylindrical, or similar cylindrical) side of the lower part (facing away from the upper cylinder) of the intermediate cylinder (6) is connected to the outer surface of the prism (or similar prism, or cylindrical, or similar cylindrical) side of the lower cylinder (8), or the outer surface of the prism (or similar prism, or cylindrical, or similar cylindrical) side of the lower part (facing away from the upper cylinder) of the intermediate cylinder (6) is connected to the outer surface of the prism (or similar prism, or cylindrical, or similar cylindrical) side of the lower cylinder (8). The inner surface of the side of the intermediate cylinder (6) is connected to the inner surface of the cylindrical tube (or similar cylindrical tube, or cylindrical tube, or similar cylindrical tube); the axis of the intermediate cylinder (6) is coincident with (or similarly coincident, or parallel, or similarly parallel to) the axis of the lower cylinder (8) (or similar cylindrical tube, or cylindrical tube, or similar cylindrical tube); the intermediate cylinder (6) and the lower cylinder (8) can move relative to each other along the axial direction (or similarly along the axial direction, or parallel to the axial direction);

[0016] The stiffness of the main elastic element (5) is greater than (or similarly greater than) the stiffness of the secondary elastic element (7); the upper part of the main elastic element (5) (facing the upper cylinder) is connected to the upper cylinder (3), and the lower part of the main elastic element (5) (facing away from the upper cylinder) is connected to the support part of the intermediate cylinder (6); the upper part of the secondary elastic element (7) (facing the upper cylinder) is connected to the support part of the intermediate cylinder (6), and the lower part of the secondary elastic element (7) (facing away from the upper cylinder) is connected to the support part of the lower cylinder (8);

[0017] The support plate (9) includes a connecting part, a support plate, etc.; the connecting part is connected to the lower part (opposite to the upper cylinder) of the intermediate cylinder (6); when the aircraft is landing, the load generated by gravity and gravitational acceleration (or deceleration) is large, the support plate contacts the ground (or similar ground, or related ground object, or crust) and bears the load together with the wheels; for ease of explanation, the support plate (9) is described separately in this application. The support plate (9) can be integrated into the intermediate cylinder (6). The part of the intermediate cylinder (6) that integrates the support plate (9) and contacts the ground (or similar ground, or related ground object, or crust) is the support plate (9).

[0018] The wheel (10) is connected to the lower cylinder (8) to support (or partially support) the landing gear, facilitating the movement of the aircraft on the ground (or similar ground, or related ground objects, or the earth's crust).

[0019] When a vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft is to land, the retraction actuator (1) controls the lowering of the landing gear. When the vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft is to land on the ground (or similar ground, or related ground object, or the earth's crust), the wheels (10) contact the ground (or similar ground, or related ground object, or the earth's crust). The load generated by the aircraft's gravity and gravitational acceleration (or deceleration) acts on the ground (or similar ground, or related ground object, or the earth's crust). At the same time, the ground (or similar ground, or related ground object, The reaction force generated by the earth's crust is applied to the wheel (10), which transmits the force to the lower cylinder (8). The lower cylinder (8) then transmits the force to the secondary elastic element (7), which transmits the force to the intermediate cylinder (6). When the secondary elastic element (7) is subjected to a certain force (or value), it deforms and transmits the force to the intermediate cylinder (6). The lower cylinder (8), along with the wheel (10), moves upward (towards the upper cylinder) following the secondary elastic element (7). The intermediate cylinder (6) transmits the force to the main elastic element. The main elastic element (5) transmits force to the upper cylinder (3). When the main elastic element (5) is subjected to a certain force (or value), it deforms and transmits the force to the upper cylinder (3). The intermediate cylinder (6), along with the support plate (9), the secondary elastic element (7), the lower cylinder (8), the wheel (10), etc., move upward (towards the upper cylinder) following the main elastic element (5). When the load (or ground reaction force) generated by the aircraft's gravity and gravitational acceleration (or deceleration) is small (or similarly small, or does not reach the set value), the load (or ground reaction force) generated by the aircraft's gravity and gravitational acceleration (or deceleration) is small (or similarly small, or does not reach the set value). When the value is (), the wheel (10) contacts the ground (or similar ground, or related ground object, or crust), the ground (or similar ground, or related ground object, or crust) generates a reaction force to the wheel (10), the wheel (10) supports the load (or ground reaction force) generated by the aircraft's gravity and gravitational acceleration (or deceleration), the force on the secondary elastic element (7) is equal to (or similarly equal to) the force on the primary elastic element (5), the secondary elastic element (7) has low rigidity and good flexibility, reduces the impact on the aircraft, and improves comfort;

[0020] During the landing of a vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft, when the aircraft lands on the ground (or a similar ground, or a related ground object, or the earth's crust), if the load (or ground reaction force) generated by the aircraft's gravity and gravitational acceleration (or deceleration) is large (or similarly large, or reaches a set value, or exceeds a set value), the secondary elastic element (7) will deform significantly under the force, and the lower cylinder (8) along with the wheel (10) will follow the secondary elastic element (7). When the elastic element (7) moves upward (towards the upper cylinder) significantly, the contact surface (or point) between the wheel (10) and the ground (or a similar ground, or a relevant ground object, or the earth's crust) and the lower part of the support plate (9) will be on the same plane (or similarly on the same surface) as the contact surface (or point) between the wheel (10) and the ground (or a similar ground, or a relevant ground object, or the earth's crust). At this time, the wheel (10) and the support plate (9) are simultaneously (or similarly simultaneously, or both) in contact with the ground (or a similar ground, or a relevant ground). When an object (or the earth's crust) comes into contact with the ground (or a similar ground, or a related ground object, or the earth's crust), the ground (or a similar ground, or a related ground object, or the earth's crust) generates a reaction force on the support plate (9) and the wheel (10). The support plate (9) transmits the force it receives to the intermediate cylinder (6), and at the same time, the wheel (10) transmits the force it receives to the lower cylinder (8), the secondary elastic element (7), and then to the intermediate cylinder (6). The intermediate cylinder (6) then transmits the force to the main elastic element (5). After being subjected to force, the main elastic element (5) deforms itself and transmits the force to the upper cylinder (3). The intermediate cylinder (6), together with the support plate (9), the secondary elastic element (7), the lower cylinder (8), the wheel (10), etc., move upward (towards the upper cylinder) with the main elastic element (5). At this time, the force received by the main elastic element (5) is greater than (or similarly greater than) the force received by the secondary elastic element (7). The main elastic element (5) has a large stiffness and can withstand a large load and stress.

[0021] During the landing of a vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft, when the aircraft lands on the ground (or similar ground, or related ground object, or crust), when the large (or similarly large, or reaching a set value, or exceeding a set value) load (or ground reaction force) generated by the aircraft's gravity and gravitational acceleration (or deceleration) is reduced to a certain size (or value), the reaction force generated by the ground (or similar ground, or related ground object, or crust) on the wheels (10) is reduced, and the secondary elastic element (7) rebounds (or rebounds similarly). The lower cylinder (8) and the wheel (10) move downward (away from the upper cylinder) following the secondary elastic element (7). The support plate (9) no longer contacts the ground (or similar ground, or related ground object, or crust). The wheel (10) remains in contact with the ground (or similar ground, or related ground object, or crust). The ground (or similar ground, or related ground object, or crust) generates a reaction force to the wheel (10). The wheel (10) supports the load (or ground reaction force) generated by the aircraft's gravity and gravitational acceleration (or deceleration).

[0022] When the lower cylinder (8) moves relative to the upper cylinder (3), the damper (4) is activated to reduce vibration (or shock) and impact;

[0023] During the landing phase of a vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft, the magnitude (or value) of the reaction force from the ground (or similar ground, or related ground objects, or the earth's crust) on the wheel (10) increases to a certain magnitude (or value) and then no longer increases (or increases slightly). The performance requirements for the wheel (10), the connection part (supporting wheel) of the lower cylinder (8), etc. are reduced, and the design and manufacturing difficulty is reduced.

[0024] When a vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft moves on the ground (or similar ground, or related ground object, or crust), the wheels (10) contact the ground (or similar ground, or related ground object, or crust) to facilitate the movement of the aircraft on the ground (or similar ground, or related ground object, or crust).

[0025] Unless otherwise defined, the technical or scientific terms used in this application description should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. In this application description, terms such as “outer,” “inner,” “segment,” “first level,” “inlet,” “outlet,” “axial,” “tangential,” “inner diameter,” “outer diameter,” “interlaced,” “corresponding,” “circumference,” “a,” “last,” “main,” and “subsidiary,” etc., indicating orientation or positional relationships, are used only for the convenience of describing the invention and simplifying the description, and 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 the invention. Furthermore, terms such as “first level,” “next level,” “step by step,” “a module unit,” “last level,” “main,” “subsidiary,” and similar terms are used for descriptive purposes only to distinguish different components and should not be construed as indicating or implying relative importance. The words “a,” “first level,” and similar terms used in this application description should not be construed as an absolute limitation on quantity, but should be understood as indicating the existence of at least one. The terms "downward deflection 90 degrees" and "horizontal backward" used in this application description should not be construed as absolute limitations on the degree, but rather as including "downward deflection 90 degrees" and "horizontal backward". The terms "including", "or", and "or" used in this application description indicate that the element or object preceding the term encompasses the elements or objects listed following the term and their equivalents, without excluding other elements or objects;

[0026] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, the terms such as “connection,” “assembly,” “installation,” “combination,” and “link” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal connection of two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the landing gear provided in the embodiments of this application;

[0028] Figure 2 This is a schematic diagram of the landing gear retraction actuator and support provided in the embodiments of this application;

[0029] Figure 3 This is a schematic diagram of the landing gear upper cylinder provided in the embodiments of this application;

[0030] Figure 4 This is a schematic diagram of the lower part of the upper landing gear cylinder provided in the embodiments of this application;

[0031] Figure 5This is a schematic diagram of the landing gear intermediate cylinder provided in the embodiments of this application;

[0032] Figure 6 This is a schematic diagram of the upper part of the landing gear intermediate tube provided in the embodiment of this application;

[0033] Figure 7 This is a schematic diagram of the lower part of the landing gear intermediate tube provided in the embodiment of this application;

[0034] Figure 8 This is a schematic diagram of the lower landing gear cylinder provided in an embodiment of this application;

[0035] Figure 9 This is a schematic diagram of the landing gear retracted as provided in the embodiments of this application;

[0036] Figure 10 This is a schematic diagram of the landing gear being lowered as provided in the embodiments of this application;

[0037] Among them: 1-retracting actuator, 2-support, 3-upper cylinder, 4-damper, 5-main elastic element, 6-intermediate cylinder, 7-secondary elastic element, 8-lower cylinder, 9-support plate, 10-wheel, a-damper mounting part of the upper cylinder, b-guide groove of the intermediate cylinder, c-support part of the intermediate cylinder;

[0038] To better illustrate this embodiment, some components in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. Furthermore, the drawings are for illustrative purposes only, and the terms used to describe positional relationships are limited to illustrative purposes and should not be construed as limiting this patent. Detailed Implementation

[0039] like Figure 1 The diagram shown is an exploded view of the landing gear, which has a relatively simple structure; the main elastic element (5) and the secondary elastic element (7) are compression springs.

[0040] like Figure 2 , 3 As shown, the retraction actuator (1) includes a drive gear, and the support (2) includes a support shaft;

[0041] like Figure 3 , 4 As shown, the upper cylinder (3) includes a driven sector tooth, a through hole connecting part that can rotate around the support shaft of the support (2) of the connecting part, a prism cylinder, and a damper mounting part of the upper cylinder;

[0042] The drive gear of the retraction actuator (1) drives the driven sector gear of the upper cylinder (3) to rotate the upper cylinder (3) around the support shaft of the support (2); the damper mounting part (a) of the upper cylinder is used to connect the damper (4).

[0043] like Figure 5 , 6 As shown in Figure 7, the intermediate cylinder has a support part in the middle; the upper part of the intermediate cylinder support part (c) is connected to the lower part of the main elastic element (5), and the lower part of the intermediate cylinder support part (c) is connected to the upper part of the secondary elastic element (7); the connecting part of the lower cylinder (8) passes through the guide groove (b) of the intermediate cylinder and is connected to the wheel (10).

[0044] The prism of the intermediate cylinder (6) is (or partially) inside the prism of the upper cylinder (3). The prism of the intermediate cylinder (6) and the prism of the upper cylinder (3) can move relative to each other along the axial direction. The corresponding relative moving surfaces are coated with plastic (similar to the plastic coating process of guide rails). The friction coefficient is small and the wear resistance is good.

[0045] like Figure 8 As shown, the lower cylinder (8) includes a middle connecting part, a supporting part, and a prism cylinder. The supporting part of the lower cylinder (8) is connected to the lower part of the secondary elastic element (7) and the damper (4).

[0046] The prism tube of the lower cylinder (8) is (or partially) inside the prism tube of the middle cylinder (6), and the prism tube of the lower cylinder (8) and the prism tube of the middle cylinder (6) can move relative to each other along the axial direction; the corresponding relative moving surfaces are coated with plastic (similar to the plastic coating process of guide rails), resulting in a small coefficient of friction and good wear resistance.

[0047] like Figure 9 , 10 As shown, the landing gear structure is regular and compact;

[0048] The stiffness of the secondary elastic element (7) and other components (or elements) of the landing gear are designed so that when the elastic element (7) is subjected to a force slightly greater than (or greater than a certain value) than the weight of the aircraft on the landing gear, the secondary elastic element (7) deforms significantly and drives the lower cylinder (8) and the wheel (10) to move significantly upward (towards the upper cylinder). The wheel (10) and the support plate (9) simultaneously (or similarly simultaneously, or both) come into contact with the ground (or similar ground, or related ground objects, or the earth's crust); the lower part of the support plate (9) is in contact with... The contact surface of the ground (or similar ground, or related ground objects, or the earth's crust) is large, and the bearing capacity is large, which can withstand the dynamic impact load (or force) generated by the aircraft's gravity and gravitational acceleration (or deceleration); since the support plate (9) intervenes to share the force, the magnitude of the reaction force of the ground (or similar ground, or related ground objects, or the earth's crust) on the wheel (10) will not increase (or increase slightly) after reaching a certain level, and the performance requirements of the wheel (10), the connection part of the lower cylinder (8) (supporting the wheel), etc. are reduced, and the design and manufacturing difficulty is reduced;

[0049] The damper (4) is designed to have a lower damping when contracted than when extended, thereby optimizing the vibration suppression of the landing gear and reducing impact.

[0050] When the aircraft moves on the ground (or similar ground, or related ground object, or crust), the landing gear is in the down position. The landing gear is subjected to a force (or similar to) the aircraft's vertical axis. The landing gear is subjected to the aircraft's weight. Since the set value is not reached, the support plate (9) does not contact the ground (or similar ground, or related ground object, or crust). Only the landing gear wheels (10) are in contact with the ground (or similar ground, or related ground object, or crust), which facilitates the aircraft's movement on the ground (or similar ground, or related ground object, or crust).

[0051] The landing gear employs a primary and secondary elastic element design, capable of withstanding significant loads and stresses generated by the aircraft's gravity and gravitational acceleration (or deceleration). Simultaneously, its high flexibility reduces the impact on the aircraft, improving comfort. The use of struts and wheels lowers the performance requirements of the wheels and other components, reducing design and manufacturing complexity, while also facilitating aircraft movement on the ground. Its retractable design reduces air resistance during flight. The structure is relatively simple, resulting in lower manufacturing costs.

Claims

1. A landing gear, characterized in that, The landing gear includes a retraction actuator (1), a support (2), an upper cylinder (3), a damper (4), a main elastic element (5), an intermediate cylinder (6), a secondary elastic element (7), a lower cylinder (8), a support plate (9), and a wheel (10).

2. The landing gear according to claim 1, characterized in that, The upper cylinder (3), the middle cylinder (6), and the lower cylinder (8) all have a prism cylinder (or a similar prism cylinder, or a cylindrical cylinder, or a similar cylindrical cylinder) structure.

3. The landing gear according to any one of the preceding claims, characterized in that, The inner surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the upper cylinder (3) is connected (or partially connected) to the outer surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the middle cylinder (6), or the outer surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the upper cylinder (3) is connected (or partially connected) to the inner surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the middle cylinder (6); the upper cylinder (3) and the middle cylinder (6) can move relative to each other along the axial direction (or similarly along the axial direction, or parallel to the axial direction).

4. The landing gear according to any one of the preceding claims, characterized in that, The inner surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the intermediate tube (6) is connected (or partially connected) to the outer surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the lower tube (8), or the outer surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the intermediate tube (6) is connected (or partially connected) to the inner surface of the prism tube (or similar prism tube, or cylindrical tube, or similar cylindrical tube) of the lower tube (8); the intermediate tube (6) and the lower tube (8) can move relative to each other along the axial direction (or similarly along the axial direction, or parallel to the axial direction).

5. The landing gear according to any one of the preceding claims, characterized in that, The stiffness of the main elastic element (5) is greater than (or similarly greater than) the stiffness of the secondary elastic element (7); the upper part of the main elastic element (5) (facing the upper cylinder) is connected to the upper cylinder (3), and the lower part of the main elastic element (5) (facing away from the upper cylinder) is connected to the intermediate cylinder (6); the upper part of the secondary elastic element (7) (facing the upper cylinder) is connected to the intermediate cylinder (6), and the lower part of the secondary elastic element (7) (facing away from the upper cylinder) is connected to the lower cylinder (8).

6. The landing gear according to any one of the preceding claims, characterized in that, When a vertical takeoff and landing (vertical takeoff and landing, or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft is about to land, the retraction actuator (1) controls the lowering of the landing gear. When the vertical takeoff and landing (vertical takeoff and landing, or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft is about to land on the ground (or similar ground, or related ground object, or crust), the wheels (10) come into contact with the ground (or similar ground, or related ground object, or crust). The load generated by the aircraft's gravity and gravitational acceleration (or deceleration) acts on the ground (or similar ground, or related ground object, or crust). At the same time, the ground (or similar ground, or related ground object, or crust) generates a reaction force on the wheels (10). The wheels (10) transmit this force to the lower cylinder (8), and the lower cylinder (8) then transmits the force to the secondary elastic element (7). The secondary elastic element (7) The force is transmitted to the intermediate cylinder (6). When the secondary elastic element (7) is subjected to a certain force (or value), it deforms and transmits the force to the intermediate cylinder (6). The lower cylinder (8) and the wheel (10) move upward (towards the upper cylinder) along with the secondary elastic element (7). The intermediate cylinder (6) transmits the force to the main elastic element (5). The main elastic element (5) transmits the force to the upper cylinder (3). When the main elastic element (5) is subjected to a certain force (or value), it deforms and transmits the force to the upper cylinder (3). The intermediate cylinder (6) and the support plate (9), the secondary elastic element (7), the lower cylinder (8), the wheel (10), etc., move upward (towards the upper cylinder) along with the main elastic element (5).

7. The landing gear according to any one of the preceding claims, characterized in that, During the landing of a vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft, when the aircraft lands on the ground (or similar ground, or related ground object, or the earth's crust), and the load (or ground reaction force) generated by the aircraft's gravity and gravitational acceleration (or deceleration) is small (or similarly small, or not reaching a set value), the wheels (10) come into contact with the ground (or similar ground, or related ground object, or the earth's crust), and the reaction force generated by the ground (or similar ground, or related ground object, or the earth's crust) is applied to the wheels (10).

8. The landing gear according to any one of the preceding claims, characterized in that, During the landing of a vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft, when the aircraft lands on the ground (or similar ground, or related ground objects, or the earth's crust), if the load (or ground reaction force) generated by the aircraft's gravity and gravitational acceleration (or deceleration) is large (or similarly large, or reaches a set value, or exceeds a set value), the secondary elastic element (7) will deform significantly after being subjected to force. When the lower cylinder (8) and the wheel (10) move significantly upward (towards the upper cylinder) following the secondary elastic element (7), the wheel (10) and the support plate (9) will simultaneously (or similarly simultaneously, or both) contact the ground (or similar ground, or related ground objects, or the earth's crust), and the ground (or similar ground, or related ground objects, or the earth's crust) will generate a reaction force on the support plate (9) and the wheel (10).

9. The landing gear according to any one of the preceding claims, characterized in that, During the landing of a vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft, when the aircraft lands on the ground (or a similar ground, or a relevant ground object, or the earth's crust), when the large (or similarly large, or reaching a set value, or exceeding a set value) load (or ground reaction force) generated by the aircraft's gravity and gravitational acceleration (or deceleration) weakens to a certain magnitude (or value), the reaction force generated by the ground (or a similar ground, or a relevant ground object, or the earth's crust) on the wheels (10) is reduced. When the secondary elastic element (7) rebounds (or similarly rebounds), the lower cylinder (8) and the wheel (10) move downwards (away from the upper cylinder) following the secondary elastic element (7). The support plate (9) no longer contacts the ground (or similar ground, or related ground object, or crust). The wheel (10) remains in contact with the ground (or similar ground, or related ground object, or crust). The ground (or similar ground, or related ground object, or crust) generates a reaction force on the wheel (10).

10. The landing gear according to any one of the preceding claims, characterized in that, When a vertical takeoff and landing (or low-speed takeoff and landing, or similar vertical takeoff and landing) aircraft with its landing gear in the down position moves on the ground (or similar ground, or related ground object, or crust), the wheels (10) contact the ground (or similar ground, or related ground object, or crust).

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