CN118144985A

CN118144985A - Landing gear assembly method

Info

Publication number: CN118144985A
Application number: CN202211312864.8A
Authority: CN
Inventors: 田瑜; 代春旭
Original assignee: Autoflight Kunshan Co Ltd
Current assignee: Autoflight Kunshan Co Ltd
Priority date: 2022-10-25
Filing date: 2022-10-25
Publication date: 2024-06-07

Abstract

The application relates to the technical field of aircrafts and discloses an undercarriage assembling method, which comprises the following steps of S1, providing a movable oil cylinder and a static oil cylinder, and oppositely arranging and sleeving openings of the movable oil cylinder and the static oil cylinder together so as to form a movable inner cavity capable of axially stretching and changing; s2, providing a piston and a piston rod connected with the piston, connecting the end part of the piston, which is far away from the piston, to the inner wall of the static cylinder, and enabling the piston to axially slide in the movable cylinder along with the expansion and contraction change of the movable inner cavity; s3, providing a limiting connecting piece for connecting the movable oil cylinder and the static oil cylinder; s4, providing a steering component, a wheel fork and a landing gear wheel; the steering component is arranged at the end part of the movable oil cylinder and is connected with the fork, and the fork is connected with the landing gear wheel. The landing gear assembly mode is simplified in design and low in cost.

Description

Landing gear assembly method

Technical Field

The application relates to the technical field of aircrafts, in particular to an undercarriage assembling method.

Background

Various types of aircraft landing gear shock absorbers exist at present, wherein the oil-gas shock absorbers have the best performance and the best comfort, but have the advantages of high manufacturing cost, difficult maintenance, high design difficulty and complex assembly, and are mostly used for large or heavy aircraft such as civil aviation, military aircraft and the like. Aiming at the models of small-sized airplanes, unmanned aerial vehicles and the like, the inventor seeks to design a simple landing gear assembly method.

Disclosure of Invention

The application aims to provide a landing gear assembly method, which is simplified in design and low in cost.

In order to solve the technical problems, the application provides an undercarriage assembling method, which comprises the following steps: step S1, providing a movable oil cylinder and a static oil cylinder, and oppositely arranging and sleeving an opening of the movable oil cylinder and an opening of the static oil cylinder together so as to form a movable inner cavity capable of axially stretching and changing; step S2, providing a piston and a piston rod connected with the piston, connecting the end part of the piston rod far away from the piston to the inner wall of the static cylinder, and enabling the piston to axially slide in the movable cylinder along with the expansion and contraction change of the movable inner cavity; step S3, providing a limiting connecting piece for connecting the movable oil cylinder and the static oil cylinder; step S4, providing a steering component, a wheel fork and a landing gear wheel; the steering component is arranged at the end part of the movable oil cylinder and is connected with the wheel fork, and the wheel fork is connected with the landing gear wheel so that the steering component drives the landing gear wheel to steer.

Preferably, the limit connecting piece comprises a first connecting rod and a second connecting rod which are connected in a rotating way; the step S4 specifically includes: and the end part of the second connecting rod, which is far away from the first connecting rod, is connected with the static oil cylinder.

Preferably, a limiting block is further arranged on the second connecting rod in the direction towards the static oil cylinder, and the movable oil cylinder and the static oil cylinder move away from each other in the axial direction to enable the first connecting rod and the second connecting rod to rotate mutually until the limiting block abuts against the static oil cylinder to limit the first connecting rod and the second connecting rod to continue to rotate.

Preferably, the steering member comprises a first portion and a second portion, the second portion being rotatably connected to the first portion; in the step S5, the setting the steering member at the end of the movable cylinder and connecting with the fork, and connecting the fork with the landing gear wheel specifically includes: the first part of the steering component is fixedly connected to the end part of the movable oil cylinder and is rotationally connected with the end part of the limiting connecting piece, and the second part of the steering component is connected to the landing gear wheel through the wheel fork.

Preferably, the connecting end of the steering piece and the movable oil cylinder protrudes out of the surface of the movable oil cylinder to form a protruding part, and the protruding part is used for forming a stroke limit when the movable oil cylinder and the static oil cylinder are axially compressed.

Preferably, the steering component comprises a bearing connector and a restoring member, wherein the second part is rotatably connected to the first part through the bearing connector and can return to a preset initial position under the action of the restoring member after rotation.

Preferably, the bearing connector comprises an inner bearing ring, an outer bearing ring, and balls between the inner bearing ring and the outer bearing ring, the inner bearing ring being connected to the first member, and the outer bearing ring being connected to the second member.

Preferably, before the step S3, the method further includes a step S20 of filling a fixed amount of hydraulic oil into the movable inner cavity through an oil inlet hole on the static cylinder and filling the hydraulic oil into the movable cylinder through a piston oil passing hole of the piston.

Preferably, after the step S20, the method further includes: and S21, compressing the movable oil cylinder and the static oil cylinder to discharge air in the movable oil cylinder, and filling quantitative nitrogen into the static oil cylinder through an inflation inlet on the static oil cylinder.

Preferably, a piston groove is formed in the side wall, connected with the movable oil cylinder, of the piston, and a sealing ring is arranged in the piston groove.

According to the landing gear assembly method, the buffer systems of the movable oil cylinder and the static oil cylinder are limited through the limiting connecting piece, the damping effect is provided by utilizing hydraulic oil and gas, and the landing gear assembly mode is simplified in design and low in cost.

Drawings

FIG. 1 is a schematic flow chart of a landing gear assembly method according to an embodiment of the present application;

FIG. 2 shows a schematic view of the construction of a landing gear according to an embodiment of the present application;

FIG. 3 shows a side view of an embodiment landing gear of the present application;

FIG. 4 shows a cross-sectional view of a landing gear according to an embodiment of the present application;

FIG. 5 shows a cross-sectional view of a landing gear steering system according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, those of ordinary skill in the art will understand that in various embodiments of the present application, numerous technical details have been set forth in order to provide a better understanding of the present application. The technical solutions claimed in the claims of the present application can be realized without these technical details and various changes and modifications based on the following embodiments.

Throughout the specification and claims, unless the context requires otherwise, the word "comprise" and variations such as "comprises" and "comprising" will be understood to be open-ended, meaning of inclusion, i.e. to be interpreted to mean "including, but not limited to.

The following detailed description of various embodiments of the present invention will be provided in connection with the accompanying drawings to provide a clearer understanding of the objects, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the invention, but rather are merely illustrative of the true spirit of the invention.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and/or" unless the context clearly dictates otherwise.

In the following description, for the purposes of clarity of presentation of the structure and manner of operation of the present invention, the description will be made with the aid of directional terms, but such terms as "forward," "rearward," "left," "right," "outward," "inner," "outward," "inward," "upper," "lower," etc. are to be construed as convenience, and are not to be limiting.

Embodiments of the present application are described below with reference to the accompanying drawings, as shown in fig. 1, and provide a landing gear assembly method comprising the steps of:

Step S1: providing a movable oil cylinder and a static oil cylinder, and oppositely arranging and sleeving the opening of the movable oil cylinder and the opening of the static oil cylinder together so as to form a movable inner cavity capable of axially stretching and changing.

Specifically, the landing gear assembly method of the application is characterized in that the opening of one movable oil cylinder 11 and the opening of one static oil cylinder 12 are oppositely arranged and sleeved together to serve as a landing gear shock-absorbing column, and a movable inner cavity 10 capable of telescopically changing is formed in the landing gear shock-absorbing column. Wherein, as shown in fig. 4, the movable cylinder 11 and the static cylinder 12 are cylinders with openings. The outer diameter of the movable oil cylinder 11 is smaller than that of the static oil cylinder 12, and the movable oil cylinder and the static oil cylinder are sleeved together and are connected in an interference fit manner. The movable chamber 10 stores a fluid (gas or liquid), preferably nitrogen, for providing a cushioning damping effect, and the liquid is preferably hydraulic oil. Further, a plurality of circumferential ring grooves 15 are arranged on the inner wall of the end part, which is sleeved and connected with the static oil cylinder 12 and the movable oil cylinder 11, and sealing rings are arranged in the circumferential ring grooves 15 and used for preventing internal fluid from flowing out from the connecting gap of the static oil cylinder 12 and the movable oil cylinder 11.

And S2, providing a piston and a piston rod connected with the piston, connecting the end part of the piston, which is far away from the piston, with the inner wall of the static cylinder, and enabling the piston to axially slide in the movable cylinder along with the expansion and contraction change of the movable inner cavity.

Specifically, a piston 14 and a piston rod 13 connected with the piston 14 are arranged in the movable inner cavity 10, the end part of the piston rod 13 far away from the piston 14 is connected to the top inner wall of the static cylinder 12, and when the movable cylinder 11 and the static cylinder 12 do reciprocating motion along the axial direction, the piston 14 is driven to slide axially and reciprocally in the movable cylinder 11, so that hydraulic oil and nitrogen in the movable inner cavity 10 are compressed or loosened, and a buffering effect is formed. The piston 14 divides the movable chamber 10 into an upper and a lower space, i.e. a first space 101 between the lower part and the movable cylinder 11, and a second space 102 between the upper part and the stationary cylinder 12. Further, a piston groove 16 is arranged on the side wall of the piston 14 connected with the movable oil cylinder 11, and a sealing ring is arranged in the piston groove 16 to prevent hydraulic oil and nitrogen from flowing in a gap between the static oil cylinder 12 and the movable oil cylinder 11.

And step S20, filling quantitative hydraulic oil into the movable inner cavity through an oil inlet hole on the static oil cylinder and filling the hydraulic oil into the movable oil cylinder through a piston oil passing hole of the piston.

Specifically, an oil inlet 120 is provided on the side wall of the static cylinder 12, and hydraulic oil is filled into the movable cavity 10 through the oil inlet 120. A piston oil passing hole 140 is provided in the piston 14 for communicating the first space 101 and the second space 102, and hydraulic oil flows between the first space 101 and the second space 102 through the piston oil passing hole 140 as the piston 14 axially reciprocates. After hydraulic oil is filled into the movable inner chamber 10, the hydraulic oil is filled into the movable cylinder 11 through the piston oil passing hole 140 of the piston 14. Further, the top of the static cylinder 12 is also provided with an inflation inlet 121. After step S20, step S21 is also performed: the movable oil cylinder (11) and the static oil cylinder (12) are compressed, air in the movable oil cylinder (11) is discharged, and quantitative nitrogen is filled into the static oil cylinder 12 through the charging port 121. The nitrogen gas is filled to provide a cushioning damping effect. The nitrogen charge can be calculated from the load and the amount of expansion required of the shock absorber (three examples shown in the table below):

Gas-receiving body height H2 (mm)	Expansion amount (mm)	Load pressure (mpa)	Load F (N)
				63.97	56.02	0.94	5000
21.32	98.67	2.84	15000
				7.11	112.89	8.52	45000

When an impact load exists, gas in the oil cylinder is compressed, and a part of buffering damping effect is provided. The temperature difference before and after compression and the corresponding compression amount can be calculated according to the following formula: Wherein T ₀ is the initial temperature, T ₁ is the post-compression temperature, P ₀ is the initial pressure, P ₁ is the post-compression pressure, V ₀ is the initial volume, P ₁ is the post-compression volume, and K is the specific heat ratio. In this example, the initial pressure was 0.505mpa, the initial temperature was 298k, and the initial volume was 85mm.

It should be noted that the air tap needs to be opened before nitrogen is injected, and the length of the landing gear body 1 is adjusted to be the shortest so as to remove the internal air, prevent oxygen in the air from remaining in the cylinder, and burn and explode with hydraulic oil under the action of high pressure, and the ignition point of nitrogen is far higher than that of hydraulic oil, so that the nitrogen and hydraulic oil can be ensured not to have explosion reaction under the high pressure.

And step S3, providing a limiting connecting piece for connecting the movable oil cylinder and the static oil cylinder.

The movable oil cylinder 11 and the static oil cylinder 12 are connected by a limiting connecting piece 7 so as to limit the axial reciprocating movement and the circumferential movement of the movable oil cylinder 11 and the static oil cylinder 12. Specifically, the limiting connection piece 7 includes a first connecting rod 71 and a second connecting rod 72 that are rotatably connected with each other, an end portion of the second connecting rod 72, which is far away from the first connecting rod 71, is rotatably connected with an outer side wall of the static cylinder 12, an end portion of the first connecting rod 71, which is far away from the second connecting rod 72, is rotatably connected with the outer side wall of the static cylinder 12, and when the first connecting rod 71 and the second connecting rod 72 rotate to an axially longest length in the axial reciprocating process of the movable cylinder 11 and the static cylinder 12, the movable cylinder 11 and the static cylinder 12 also reach a maximum buffering stroke, so that an axially maximum stroke of the damping system is limited.

Further, the second connecting rod 72 is further provided with a limiting part 70, the limiting part 70 extends towards the direction of the static cylinder 12, the movable cylinder 11 and the static cylinder 12 move away from each other axially so that the first connecting rod 71 and the second connecting rod 72 rotate mutually until the limiting part 70 abuts against the static cylinder 11, thereby preventing the first connecting rod 71 and the second connecting rod 72 from rotating further in advance, controlling the axial maximum stroke of the movable cylinder 11 and the static cylinder 12, further, the limiting part 70 and the second connecting rod 72 can be designed to be connected in a detachable way, and different axial maximum strokes of the movable cylinder 11 and the static cylinder 12 can be realized by replacing different limiting parts 70, but it is understood that the limiting part 70 can also be arranged on the first connecting rod 71. According to the embodiment of the application, the limiting block is added on the connecting rod, and after the limiting block reaches the preset maximum stroke, the limiting block is contacted with the shock absorption column static oil cylinder, so that the connecting rod is limited to continue to rotate, and then the shock absorption column movable oil cylinder is pulled, thus the maximum stroke setting of the shock absorption column is completed, and if the stroke of the shock absorption column needs to be changed, the limiting part on the connecting rod can be changed, and thus the requirement of multiple strokes can be adapted.

Further, the first connecting rod and the second connecting rod can be designed to be long-strip-shaped connecting rods, and a plurality of grooves are formed in the first connecting rod and the second connecting rod, so that light-weight design is achieved on the premise of ensuring strength.

And S4, providing a steering component, a fork and a landing gear wheel, wherein the steering component is arranged at the end part of the movable oil cylinder and is connected with the fork, and the fork is connected with the landing gear wheel.

Providing a steering component 2, a fork 3 and a landing gear wheel 4, wherein the steering component 2 is arranged at the end of a movable oil cylinder 11 and is connected with the fork 3, and the fork 3 is connected with the landing gear wheel 4; the steering member 2 steers the landing gear wheels 4. Specifically, the steering member 2 includes a first portion 21 and a second portion 22, where the first portion 21 is fixedly connected to the end of the movable cylinder 11 and is rotatably connected to the end of the limit link 7, that is, in this embodiment, the limit link 7 is connected to the end of the movable cylinder 11 through the first portion 21, and the second portion 22 is fixedly connected to the fork 3. The steering component 2 comprises a bearing connection 5 and a return member 6, the second part 22 being rotatably connected to the first part 21 by the bearing connection 5 and being rotatable and then returned to a preset initial position by the return member 6. Specifically, the bearing connector 5 includes an inner bearing ring 51 and an outer bearing ring 52, the inner bearing ring 51 is connected to the first portion 21, the outer bearing ring 52 is connected to the second portion 22, the first portion 21 is a bearing fixing shaft, the second portion 22 is a steering bearing box, that is, the inner bearing ring 51 is sleeved on the bearing fixing shaft, and the outer bearing ring 52 is embedded in the steering bearing box. One end of the restoring member 6 is connected to the first fixing portion 210 of the first portion 21, the first fixing portion 210 protrudes from the outer peripheral wall of the first portion 21, the other end of the restoring member 6 is connected to the second fixing portion 220 of the second portion 22, and the second fixing portion 220 protrudes from the outer peripheral wall of the second portion 22. The preset initial position of the return member 6 is the forward running position of the landing gear wheel 4. Wherein the return member 6 is preferably a spring.

The steering part 2 is partially sleeved on the surface of the movable oil cylinder 11 to form a protruding part 110, and part of the steering part can rotate relative to the limiting mechanism so as to drive the landing gear wheel 4 to steer. Wherein the protruding part 110 is used for forming travel limit for the movable oil cylinder 11 and the static oil cylinder 12 during axial compression, so as to limit the minimum axial compression distance of the damping system. In this embodiment, the protrusion 110 of the steering member 2 is used to limit the axial compression distance, so that the function of the parts is utilized to the maximum, and the design is lighter. Meanwhile, the first link 71 and the second link 72 connect the static cylinder 12 and the steering part 2 at the same time, and can also restrict the relative rotation of the movable cylinder 11 and the static cylinder 12. Therefore, the movable oil cylinder 11, the static oil cylinder 12 and the circumferential rotation are limited through the limiting connecting piece 7, the utilization rate of parts is highest, and the lightweight design is utilized.

According to the landing gear assembly method, the buffer systems of the movable oil cylinder and the static oil cylinder are limited through the connecting rods, the damping effect is provided by utilizing hydraulic oil, the design is simplified, the cost is low, and meanwhile, the steering and automatic homing of the landing gear wheels are realized by utilizing the steering component.

The above embodiments are merely illustrative of the principles of the present application and its effectiveness, and are not intended to limit the application. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the application. Accordingly, it is intended that all equivalent modifications and variations of the application be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims

1. A landing gear assembly method, comprising:

Step S1, providing a movable oil cylinder (11) and a static oil cylinder (12), and oppositely arranging and sleeving an opening of the movable oil cylinder (11) and an opening of the static oil cylinder (12) together so as to form a movable inner cavity (10) capable of axially stretching and changing inside;

Step S2, providing a piston (14) and a piston rod (13) connected with the piston (14), connecting the end part of the piston rod (13) far away from the piston (14) to the inner wall of the static cylinder (12), and enabling the piston (14) to axially slide in the movable cylinder (11) along with the expansion and contraction change of the movable inner cavity (10);

Step S3, providing a limiting connecting piece (7) for connecting the movable oil cylinder (11) with the static oil cylinder (12);

step S4, providing a steering component (2), a fork (3) and a landing gear wheel (4); the steering component (2) is arranged at the end part of the movable oil cylinder (11) and is connected with the wheel fork (3), and the wheel fork (3) is connected with the landing gear wheel (4) so that the steering component 2 drives the landing gear wheel (4) to steer.

2. Landing gear assembly method according to claim 1, wherein the limit connection (7) comprises a first link (71) and a second link (72) connected in rotation; the step S4 specifically includes: a limiting connecting piece (7) is provided for connecting the end part of the first connecting rod (71) far away from the second connecting rod (72) with the movable oil cylinder, and the end part of the second connecting rod (72) far away from the first connecting rod (71) is connected with the static oil cylinder (12).

3. Landing gear assembly method according to claim 2, wherein the second link (72) is further provided with a stopper (70) in a direction towards the static cylinder (12), and the movable cylinder (11) and the static cylinder (12) move axially away from each other such that the first link (71) and the second link (72) rotate relative to each other until the stopper (70) abuts against the static cylinder, limiting the continued rotation of the first link (71) and the second link (72).

4. A landing gear assembly method according to claim 1, wherein the steering member (2) comprises a first portion (21) and a second portion (22), the second portion (22) being in rotational connection with the first portion (21); in the step S4, the setting of the steering member (2) at the end of the movable cylinder (11) and connecting with the fork (3) connects the fork (3) with the landing gear wheel (4), specifically includes: the first part (21) of the steering component (2) is fixedly connected to the end of the movable oil cylinder (11) and is rotationally connected with the end of the limit connecting piece (7), and the second part (22) is connected to the landing gear wheel (4) through the wheel fork (3).

5. Landing gear assembly method according to claim 1, characterized in that the connecting end of the steering member (2) and the movable cylinder (11) protrudes from the surface of the movable cylinder (11) to form a protruding part (110), the protruding part (110) being used for forming a travel limit for the movable cylinder (11) and the stationary cylinder (12) during axial compression.

6. Landing gear assembly method according to claim 4, wherein the steering component (2) comprises a bearing connection and a return member, the second portion (22) being rotatably connected to the first portion (21) by means of the bearing connection (5) and being rotatable back to a preset initial position under the influence of the return member (6).

7. Landing gear assembly method according to claim 6, wherein the bearing connection (5) comprises an inner bearing ring (51), an outer bearing ring (52) and balls (50) between the inner bearing ring and the outer bearing ring, the inner bearing ring (51) being connected to the first part (21) and the outer bearing ring (52) being connected to the second part (22).

8. The landing gear assembly method according to claim 1, further comprising, before the step S3, a step S20 of filling a fixed amount of hydraulic oil into the movable inner chamber (10) through an oil inlet hole (120) in the stationary cylinder (12) and filling hydraulic oil into the movable cylinder (11) through a piston oil passing hole (140) of the piston (14).

9. The landing gear assembly method of claim 8, further comprising, after step S20: and S21, compressing the movable oil cylinder (11) and the static oil cylinder (12) to discharge air in the movable oil cylinder (11), and filling quantitative nitrogen into the static oil cylinder (12) through an inflation inlet (121) on the static oil cylinder (12).

10. Landing gear assembly method according to claim 1, characterized in that the inner wall of the end of the stationary cylinder (12) connected to the movable cylinder (11) is provided with a plurality of circumferential ring grooves (15), and in the circumferential ring grooves (15) a sealing ring is provided.