Oil-gas isolation type stable buffer for undercarriage

Abstract

The oil-gas isolation type stable buffer comprises an earring bolt, a piston rod, an outer cylinder, a moving cylinder, a stop cover, a movable floating plug and an oil guide channel, the outer cylinder is provided with a front end cover and a rear end cover, the moving cylinder and the movable floating plug are both arranged in the outer cylinder, a first gas cavity is formed between the moving cylinder and the movable floating plug, and a second gas cavity is formed between the moving cylinder and the movable floating plug. A compression stroke hydraulic cavity is formed between the movable floating plug and the rear end cover, the stop cover is installed at the front end of the moving cylinder and located in the outer cylinder, the piston rod penetrates through the front end cover and the stop cover to be connected with the moving cylinder, and a stretching stroke hydraulic cavity is formed among the piston rod, the stop cover and the moving cylinder. The compression stroke hydraulic cavity is communicated with the stretching stroke hydraulic cavity through an oil guide channel; the earring bolt is arranged at the front end of the piston rod and forms a second air cavity with an inner cavity of the piston rod. According to the buffer, an oil-gas isolation type structure is adopted, damping is adjustable, and the two-way buffering function of stretching and compressing is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of aeronautical landing gear, in particular to an oil-gas isolation type stable buffer for landing gear. BACKGROUND

[0002] The hydraulic buffer mainly realizes two functions of buffering and resetting, when the high-speed running object suddenly impacts the buffer, through the throttling and energy storage effect, the object is controlled to decelerate and gradually stop running, and then reset. At present, most of the aircraft landing gears adopt oil-gas type buffers. The internal design of the oil-gas type buffer has been improving and developing. In order to improve the capacity absorption capacity of the landing gear buffer and reduce the dynamic load of the landing gear during landing, especially during ground sliding and operation, a single-stage double-cavity buffer (i.e. there are low-pressure and high-pressure two air cavities in one buffer) is generally used at present, and a spring control throttle valve is added in the buffer strut piston of the double-cavity buffer, so that the valve will be opened under a given load, thereby improving the buffering performance of the buffer strut.

[0003] The frame type landing gear stable buffer is arranged between the frame and the buffer strut, and is a necessary functional component of the modern landing gear. The stable buffer can make the frame attitude controllable and absorb the impact energy of the wheel group around the shaft during the take-off, landing and ground sliding of the aircraft. However, the existing frame type landing gear stable buffer is generally of spring structure type or oil-gas hybrid type. The spring structure type stable buffer can only buffer in one direction, and the damping effect will decay, resulting in short fatigue life. The oil-gas hybrid type stable buffer is prone to cavitation phenomenon, resulting in bubbles and unstable damping performance.

[0004] Through retrieval, the patent document with authorized announcement number CN206889552U discloses a new oil-gas hybrid type buffer, and the patent document with application publication number CN106352005A discloses an oil-gas separation type buffer and its exhaust method. From the contents disclosed in the two patent documents retrieved, a buffer meeting the use requirements is provided from different angles. In order to avoid the problem that the spring structure type one-way buffer will decay due to the damping effect, and the problem that the oil-gas hybrid type buffer is prone to cavitation phenomenon to cause bubbles, a buffer different from the buffer disclosed in the prior art is provided to meet the use requirements. CONTENT OF THE UTILITY MODEL

[0005] The utility model wants to solve the technical problem in the prior art, thereby provide a kind of simple structure, easy to operate and use buffer, utilize the buffer can effectively solve the problem of one-way buffering, unstable damping performance, and through the damping flap being equipped with outside buffer can realize the adjustable feature of damping, so as to meet more use requirements, specifically speaking, a kind of oil-gas isolation type stable buffer for landing gear.

[0006] To solve the above technical problems, the utility model adopts the technical scheme: a kind of oil-gas isolation type stable buffer for landing gear, including ear ring bolt, piston rod, outer tube, movable cylinder, stop cap, movable float and oil guide channel, the outer tube front end is equipped with front end cover, rear end is equipped with rear end cover, the movable cylinder and movable float are all arranged in outer tube, and the movable float is located between movable cylinder and rear end cover, first gas cavity is formed between the movable cylinder and movable float, compression stroke hydraulic cavity is formed between the movable float and rear end cover, the movable cylinder and movable float are all set as the cylinder structure of one end opening, and the piston rod is set as the cylinder structure of two ends opening, the stop cap is installed in movable cylinder front end and is located in outer tube, the rear end of the piston rod is sequentially passed through front end cover and stop cap and is connected with movable cylinder, and the piston rod and stop cap and movable cylinder form the hydraulic cavity of stretching stroke between them;The compression stroke hydraulic cavity and the hydraulic cavity of stretching stroke are connected by oil guide channel;The ear ring bolt is set in the front end of piston rod, and the second gas cavity that communicates with the outside world is formed between the ear ring bolt and the inner cavity of piston rod.

[0007] Further, the utility model discloses a kind of oil-gas isolation type stable buffer for landing gear, the inner wall surface of the outer tube is also equipped with ring, and the rear end outer wall surface of the movable cylinder is equipped with the limit slot corresponding with the ring, the ring is set in limit slot, the rear end of the movable cylinder is slidably connected with the inner wall surface of outer tube by ring, and its front end is slidably connected with the inner wall surface of outer tube;The movable float is slidably connected with the inner wall surface of outer tube.

[0008] Further, the utility model discloses a kind of oil-gas isolation type stable buffer for landing gear, is equipped with inflation hole, first oil injection hole and first oil discharge hole on the outer tube, the first oil injection hole and first oil discharge hole are annularly arranged on the outer tube, the inflation hole communicates with first gas cavity, and inflation valve is equipped at the inflation hole;First oil receiving groove corresponding with first oil injection hole and first oil discharge hole and first channel communicating with first oil receiving groove are equipped in the movable cylinder, second oil receiving groove corresponding with first channel is equipped in the rear end surface of the front end cover, and second channel communicating with the hydraulic cavity of stretching stroke is equipped in the stop cap, and first plug is equipped at the first oil injection hole;The oil guide channel communicates with the hydraulic cavity of stretching stroke by first oil discharge hole.

[0009] Further, the oil-gas isolation type stable buffer for landing gear has a second oil injection hole and a second oil discharge hole arranged on the rear end cover of the outer cylinder, a third channel communicated with the compression stroke hydraulic cavity, the second oil injection hole and the second oil discharge hole are arranged in a ring shape on the rear end cover, the second oil injection hole and the second oil discharge hole are communicated with the third channel respectively, and a second plug is arranged at the second oil injection hole; the oil guide channel is communicated with the compression stroke hydraulic cavity through the second oil discharge hole.

[0010] Further, the oil-gas isolation type stable buffer for landing gear has a second oil injection hole and a second oil discharge hole arranged on the rear end cover of the outer cylinder, a third channel communicated with the compression stroke hydraulic cavity, the second oil injection hole and the second oil discharge hole are arranged in a ring shape on the rear end cover, the second oil injection hole and the second oil discharge hole are communicated with the third channel respectively, and a second plug is arranged at the second oil injection hole; the oil guide channel is communicated with the compression stroke hydraulic cavity through the second oil discharge hole.

[0011] Further, the oil-gas isolation type stable buffer for landing gear has a second oil injection hole and a second oil discharge hole arranged on the rear end cover of the outer cylinder, a third channel communicated with the compression stroke hydraulic cavity, the second oil injection hole and the second oil discharge hole are arranged in a ring shape on the rear end cover, the second oil injection hole and the second oil discharge hole are communicated with the third channel respectively, and a second plug is arranged at the second oil injection hole; the oil guide channel is communicated with the compression stroke hydraulic cavity through the second oil discharge hole.

[0012] Further, the oil-gas isolation type stable buffer for landing gear has a second oil injection hole and a second oil discharge hole arranged on the rear end cover of the outer cylinder, a third channel communicated with the compression stroke hydraulic cavity, the second oil injection hole and the second oil discharge hole are arranged in a ring shape on the rear end cover, the second oil injection hole and the second oil discharge hole are communicated with the third channel respectively, and a second plug is arranged at the second oil injection hole; the oil guide channel is communicated with the compression stroke hydraulic cavity through the second oil discharge hole.

[0013] Further, the oil-gas isolation type stable buffer for landing gear has a second oil injection hole and a second oil discharge hole arranged on the rear end cover of the outer cylinder, a third channel communicated with the compression stroke hydraulic cavity, the second oil injection hole and the second oil discharge hole are arranged in a ring shape on the rear end cover, the second oil injection hole and the second oil discharge hole are communicated with the third channel respectively, and a second plug is arranged at the second oil injection hole; the oil guide channel is communicated with the compression stroke hydraulic cavity through the second oil discharge hole.

[0014] Further, the oil-gas isolation type stable buffer for landing gear has an adjusting washer arranged at the rear end of the outer cylinder, the rear end cover is connected with the outer cylinder through the adjusting washer, the tail of the rear end cover is a single ear part, a second connecting hole is arranged in the single ear part of the rear end cover, and a joint bearing is arranged at the second connecting hole; the front end of the ear ring bolt is a double ear part, a first connecting hole is arranged in the double ear part of the ear ring bolt, and a bushing is arranged at the first connecting hole; a limiting lug is further arranged on the outer side of the outer cylinder, the limiting lug is arranged on the outer cylinder close to the rear end cover, a fuse is arranged between the limiting lug and the rear end cover, and the rear end cover is limited and prevented from loosening through the fuse; and a limiting screw is further arranged in the front end cover, and the front end cover is limited and prevented from loosening through the limiting screw.

[0015] Further, the oil-gas isolation type stable buffer for landing gear has a piston rod, and the rod diameter cross-sectional area of the piston rod is equal to one half of the inner cavity cross-sectional area of the floating cylinder.

[0016] The oil-gas isolation type stable buffer for landing gear comprises an ear ring bolt, a piston rod, an outer cylinder, a floating cylinder, a stop cover, a movable float and an oil guide channel, and a front end cover and a rear end cover arranged at two ends of the outer cylinder, and four cavities are formed, an atmosphere cavity, an intermediate gas cavity and two side intercommunication hydraulic oil cavities are formed, so that the stable buffer can buffer and absorb energy when subjected to a pulling load or a pressing load, and is always in a neutral fixed position when not subjected to an external load, the neutral position can ensure that the attitude of the landing gear is controllable after the airplane takes off and before the airplane lands, the oil-gas isolation type structure is adopted, no cavitation phenomenon occurs, the damping performance is stable, and the intercommunication channels between the two side hydraulic oil cavities are arranged on the outside and connected with the damping valve through a guide pipe, so that the hydraulic oil flows through the damping valve during compression and stretching, and the damping of the buffer can be adjusted by adjusting the external damping valve.

[0017] Therefore, the stable buffer has the oil-gas isolation type structure, has the bidirectional damping function of stretching and compression through the double-acting mode, has the damping adjustment function, has the simple overall structure, the reasonable design, avoids the influence of the mixture of oil and gas on the damping performance, ensures the stable operation of the buffer, has the wide guiding significance for the structure design of the buffer, and is suitable for promotion and application. BRIEF DESCRIPTION OF DRAWINGS

[0018] The utility model will be further explained in detail in connection with the drawings.

[0019] Figure 1 It is the three-dimensional structure schematic diagram of the utility model.

[0020] Figure 2 This is a schematic diagram of the structure of the utility model;

[0021] Figure 3 This is a schematic cross-sectional view of the present invention. Figure 1 ;

[0022] Figure 4 This is a schematic cross-sectional view of the present invention. Figure 2 ;

[0023] Figure 5 This is a structural schematic diagram of the present invention in a neutral position.

[0024] Figure 6 This is a structural diagram of the present invention in the compression stroke state;

[0025] Figure 7 This is a structural schematic diagram of the present invention in the stretching stroke state.

[0026] The diagram shows: 1-Earring bolt, 101-Nut, 102-Intake passage, 103-Bushing, 2-Piston rod, 21-Limiting lock block, 3-Outer cylinder, 31-Limiting protrusion, 4-Rolling cylinder, 41-Limiting groove, 42-First oil receiving groove, 43-First channel, 5-Stop cover, 51-Second channel, 6-Modible float, 7-Oil guide channel, 71-Conduit, 72-Outer cylinder nozzle, 73-End cap nozzle, 74-Damping piston. Door, 75-pipe connector, 76-support connecting rod, 8-front end cover, 81-second oil inlet groove, 82-limit screw, 9-rear end cover, 91-third channel, 92-spherical bearing, 10-first air chamber, 11-compression stroke hydraulic chamber, 12-tension stroke hydraulic chamber, 13-second air chamber, 14-expansion ring, 15-inflation valve, 16-first plug, 17-second plug, 18-sealing groove, 19-adjusting washer. Detailed Implementation

[0027] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0028] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," and "right" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection" and "provided with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] It should be noted that the term "comprising" or any other variation is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Example 1

[0031] like Figures 1 to 4As shown, this embodiment provides an oil-gas isolated stabilizing buffer for landing gear, including an eyelet bolt 1, a piston rod 2, an outer cylinder 3, a floating cylinder 4, a stop cover 5, a movable float 6, and an oil guide channel 7. The outer cylinder 3 has a front cover 8 at its front end and a rear cover 9 at its rear end. The floating cylinder 4 and the movable float 6 are both disposed inside the outer cylinder 3, and the movable float 6 is located between the floating cylinder 4 and the rear cover 9. A first air chamber 10 is formed between the floating cylinder 4 and the movable float 6, and a compression stroke hydraulic chamber 11 is formed between the movable float 6 and the rear cover 9. The floating cylinder 4 and the movable float 6 are both configured as cylindrical structures with one open end, while the piston rod 2 is configured as a cylindrical structure with both ends open. The stop cover 5 is installed at the front end of the floating cylinder 4 and located inside the outer cylinder 3. The rear end of the piston rod 2 passes through the front end cover 8 and the stop cover 5 in sequence and is connected to the floating cylinder 4. A tension stroke hydraulic cavity 12 is formed between the piston rod 2, the stop cover 5, and the floating cylinder 4. The compression stroke hydraulic cavity 11 and the tension stroke hydraulic cavity 12 are connected by an oil guide channel 7. The ear bolt 1 is set at the front end of the piston rod 2. A second air cavity 13 communicating with the outside is formed between the ear bolt 1 and the inner cavity of the piston rod 2. The tail of the rear end cover 9 is a single ear part. A second connecting hole is also provided in the single ear part of the rear end cover 9, and a joint bearing 92 is provided at the second connecting hole. The front end of the ear bolt 1 is a double ear part. A first connecting hole is provided in the double ear part of the ear bolt 1, and a bushing 103 is provided at the first connecting hole.

[0032] Furthermore, in the oil-gas isolated stabilizing buffer for landing gear described in this embodiment, an air inlet, a first oil injection hole, and a first oil drain hole are provided on the outer cylinder 3. The first oil injection hole and the first oil drain hole are arranged in a ring on the outer cylinder 3. The air inlet communicates with the first air chamber 10, and an air inlet valve 15 is provided at the air inlet. A first oil receiving groove 42 corresponding to the first oil injection hole and the first oil drain hole, and a first channel 43 communicating with the first oil receiving groove 42 are provided in the moving cylinder 4. A second oil receiving groove 81 corresponding to the first channel 43 is provided in the rear end face of the front end cover 8, and a tensioning groove 81 is provided in the stop cover 5. The second channel 51 communicates with the hydraulic cavity 12 during the stroke, and a first plug 16 is provided at the first oil injection hole; the oil guide channel 7 communicates with the hydraulic cavity 12 during the stretching stroke through the first oil drain hole; at the same time, a second oil injection hole and a second oil drain hole are provided on the rear end cover 9 at the rear end of the outer cylinder 3, as well as a third channel 91 communicating with the hydraulic cavity 11 during the compression stroke. The second oil injection hole and the second oil drain hole are arranged in a ring on the rear end cover 9. The second oil injection hole and the second oil drain hole communicate with the third channel 91 respectively, and a second plug 17 is provided at the second oil injection hole; the oil guide channel 7 communicates with the hydraulic cavity 11 during the compression stroke through the second oil drain hole.

[0033] Furthermore, in the oil-gas isolated stabilizing buffer for landing gear described in this embodiment, the oil channel 7 includes a conduit 71, an outer cylinder nozzle 72, an end cap nozzle 73, and a damping valve 74. The outer cylinder nozzle 72 is installed at the first oil drain hole in the outer cylinder 3, while the end cap nozzle 73 is installed at the second oil drain hole in the rear end cap 9. The outer cylinder nozzle 72 and the end cap nozzle 73 are connected by the conduit 71, and a damping valve 74 is provided in the conduit 71.

[0034] Furthermore, in the oil-gas isolated stabilizing buffer for landing gear described in this embodiment, the oil channel 7 further includes a pipe joint 75 and a supporting connecting rod 76. The conduit 71 is connected to the outer cylinder nozzle 72 and the end cap nozzle 73 respectively through the pipe joint 75. The supporting connecting rod 76 is disposed on the outer side of the outer cylinder 3, and the damping valve 74 is installed in the supporting connecting rod 76. The damping valve 74 is connected to the conduit 71 through the pipe joint 75.

[0035] Furthermore, in the oil-gas isolation stabilizing buffer for landing gear described in this utility model, the lug bolt 1 includes a connecting part and a cylindrical part, which form an integral structure. The cylindrical part is a cylindrical structure with one open end. The lug bolt is screwed into the piston rod 2 through the cylindrical part, and a nut 101 that abuts against the piston rod 2 is screwed onto the outer wall of the cylindrical part. An air intake channel 102 communicating with the second air chamber 13 is also provided in the cylindrical part. At the same time, a limiting locking block 21 is provided at the front end of the piston rod 2, and a fuse is provided between the nut 101 and the limiting locking block 21. The fuse limits and prevents the nut 101 from loosening. In addition, a limiting protrusion 31 is provided on the outer side of the outer cylinder 3. The limiting protrusion 31 is located on the outer cylinder 3 near the rear end cover 9. A fuse is provided between the limiting protrusion 31 and the rear end cover 9. The fuse limits and prevents the rear end cover 9 from loosening. A limiting screw 82 is also provided in the front end cover 8. The limiting screw 82 limits and prevents the front end cover 8 from loosening between the front end cover 8 and the outer cylinder 3. Example 2

[0036] This embodiment is based on Embodiment 1. To facilitate the sliding of the movable cylinder 4 in the outer cylinder 3 on the inner wall surface of the outer cylinder 3, and the sliding of the piston rod 2 on the inner wall surface of the movable cylinder 4, and to achieve sealing so that the first air chamber 10, the compression stroke hydraulic chamber 11, and the extension stroke hydraulic chamber 12 form a sealed structure, an oil-gas isolation type stabilizing buffer for landing gear as described in this embodiment is adopted. An expansion ring 14 is also provided on the inner wall surface of the outer cylinder 3, and a limiting groove 41 corresponding to the expansion ring 14 is provided on the outer wall surface of the rear end of the movable cylinder 4. The expansion ring 14 is set in the limiting groove 41. The rear end of the movable cylinder 4 is slidably connected to the inner wall surface of the outer cylinder 3 through the expansion ring 14, while its front end is in contact with the inner wall surface of the outer cylinder 3; the movable float 6 is slidably connected to the inner wall surface of the outer cylinder 3.

[0037] Furthermore, in the oil-gas isolated stabilizing buffer for landing gear described in this embodiment, sealing grooves 18 are respectively provided on the outer wall surfaces of the front cover 8, the floating cylinder 4, the movable float 6, and the piston rod 2, as well as on the inner wall surfaces of the front cover 8 and the rear cover 9. A sealing element is disposed in the sealing groove 18. The floating cylinder 4 and the movable float 6 are slidably connected to the inner wall surface of the outer cylinder 3 through the sealing element; while the piston rod 2 is slidably connected to the inner wall surface of the front cover 8 and the floating cylinder 4 through the sealing element. Example 3

[0038] This embodiment is based on Embodiment 2. To ensure that the stabilizing buffer has the same tensile or compressive stroke under the same tensile / compressive load, a hydroponic isolation stabilizing buffer for landing gear as described in this embodiment is used. It only requires that the cross-sectional area of ​​the piston rod 2 be equal to half the cross-sectional area of ​​the outer circle of the piston end, i.e., the cross-sectional area of ​​the piston rod 2 is equal to half the cross-sectional area of ​​the inner cavity of the floating cylinder 4. In the specific design and manufacturing process, if there are no specific requirements for the tensile or compressive stroke, a structure that meets the usage requirements can be designed according to the different landing gear requirements. Example 4

[0039] like Figures 5 to 7 As shown, this embodiment discloses a method for using the above-mentioned oil-gas isolated stabilizing buffer for landing gear, the method comprising the following steps:

[0040] S1. Before use, inert gas is injected into the first gas chamber 10, and hydraulic oil is injected into the compression stroke hydraulic chamber 11 and the extension stroke hydraulic chamber 12. The inert gas is nitrogen, and the hydraulic oil is No. 15 aviation hydraulic oil. The amount of nitrogen and No. 15 aviation hydraulic oil injected is required to keep the buffer in a neutral position when there is no external load. The neutral position means that the landing gear ensures that the frame attitude is controllable after the aircraft leaves the ground and before landing.

[0041] S2. When the buffer is in the neutral position, its structure is as follows: Figure 5 As shown, when the buffer is not subjected to external load or the load is less than or equal to a set value, the buffer maintains a neutral position;

[0042] S3. When the buffer is in the compression stroke state, its structure is as follows: Figure 6 As shown, when the buffer is subjected to pressure Pa, it begins to compress using the lateral load. The piston rod 2 pushes the moving cylinder 4 to compress the first air chamber 10, reducing its volume and increasing its pressure. Simultaneously, during the movement of the moving cylinder 4, the volume of the stretching stroke hydraulic chamber 12 increases, causing the movable float 6 to push the oil in the compression stroke hydraulic chamber 11 through the damping valve 74 in the oil guide channel 7 and through the conduit 71 to flow into the stretching stroke hydraulic chamber 12, thus realizing the compression process, forming a buffer, and absorbing the energy generated by the lateral load. When the lateral load disappears, the inert gas compressed in the first air chamber 10 expands, and the moving cylinder 4 pushes the hydraulic oil in the stretching stroke hydraulic chamber 12 through the damping valve 74 in the oil guide channel 7 into the compression stroke hydraulic chamber 11, ultimately restoring the buffer to the neutral position.

[0043] S4. When the buffer is in the extended stroke state, its structure is as follows: Figure 7 As shown, when the buffer is subjected to a tensile force Pb, it begins to work by utilizing the tensile load. The piston rod 2 pushes the oil in the hydraulic cavity 12 of the tensile stroke through the damping valve 74 in the oil guide channel 7 and through the conduit 71 to flow into the hydraulic cavity 11 of the compression stroke. This increases the volume of the oil in the hydraulic cavity 11 of the compression stroke, pushing the movable float 6 to move and compressing the inert gas in the first air cavity 10, thus realizing the tensile motion process, forming a buffer, and absorbing the energy generated by the tensile load. When the tensile load disappears, the compressed inert gas in the first air cavity 10 will expand, causing the movable float 6 to push the hydraulic oil in the hydraulic cavity 11 of the compression stroke through the damping valve 74 in the oil guide channel 7 into the hydraulic cavity 12 of the tensile stroke, ultimately restoring the stable buffer to the neutral position.

[0044] The present invention discloses an oil-gas isolated stabilizing buffer for landing gear, which adopts an oil-gas isolated structure with adjustable damping and a dual-actuation mechanism, providing bidirectional buffering functions of tension and compression. The buffer comprises a four-chamber structure consisting of an eyelet bolt 1, a piston rod 2, an outer cylinder 3, a floating cylinder 4, a stop cover 5, a movable float 6, and an oil guide channel 7, as well as front end caps 8 and rear end caps 9 located at both ends of the outer cylinder 3. This structure forms a gas chamber, a central gas chamber, and two interconnected hydraulic oil chambers. This allows the stabilizing buffer to absorb energy under tensile or compressive loads, while remaining in a neutral and fixed position when no external load is applied. This neutral position ensures that the aircraft's frame attitude remains uniquely controllable after takeoff and before landing. The oil-gas isolation system eliminates cavitation and provides stable damping performance. Furthermore, the interconnecting oil guide channel 7 between the two hydraulic oil chambers is designed outside the outer cylinder 3 and connected to the damping valve 74 via the 71 conduit. During the compression / tension stroke, the hydraulic oil flows through the damping valve 74, thus the damping of the buffer can be adjusted by regulating the external damping valve 74.

[0045] In summary, the stable buffer described in this utility model adopts an oil-gas isolation structure and, through a dual-actuation method, not only has adjustable damping but also bidirectional buffering functions of tension and compression. Its overall structure is simple and reasonably designed, effectively avoiding the influence of oil-gas mixing on buffering performance, making the buffer work stably. It has broad guiding significance for buffer structure design and is suitable for widespread application.

[0046] Other aspects of this utility model that are not detailed herein are all conventional techniques known to those skilled in the art.

[0047] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Various modifications and variations can be made by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made using the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hydro-gas isolated stabilizing buffer for landing gear, characterized in that: The system includes an earring bolt (1), a piston rod (2), an outer cylinder (3), a floating cylinder (4), a stop cover (5), a movable float (6), and an oil guide channel (7). The outer cylinder (3) has a front cover (8) at its front end and a rear cover (9) at its rear end. The floating cylinder (4) and the movable float (6) are both located inside the outer cylinder (3), and the movable float (6) is located between the floating cylinder (4) and the rear cover (9). A first air chamber (10) is formed between the floating cylinder (4) and the movable float (6), and a compression stroke hydraulic chamber (11) is formed between the movable float (6) and the rear cover (9). The floating cylinder (4) and the movable float (6) are both cylindrical structures with one open end. The piston rod (2) is configured as a cylindrical structure with open ends. The stop cover (5) is installed at the front end of the moving cylinder (4) and located inside the outer cylinder (3). The rear end of the piston rod (2) passes through the front end cover (8) and the stop cover (5) in sequence and is connected to the moving cylinder (4). A tension stroke hydraulic cavity (12) is formed between the piston rod (2), the stop cover (5) and the moving cylinder (4). The compression stroke hydraulic cavity (11) and the tension stroke hydraulic cavity (12) are connected through an oil guide channel (7). The ear bolt (1) is set at the front end of the piston rod (2). A second air cavity (13) communicating with the outside is formed between the ear bolt (1) and the inner cavity of the piston rod (2).

2. The oil-gas isolated stabilizing buffer for landing gear according to claim 1, characterized in that: An expansion ring (14) is provided on the inner wall of the outer cylinder (3), and a limiting groove (41) corresponding to the expansion ring (14) is provided on the outer wall of the rear end of the moving cylinder (4). The expansion ring (14) is set in the limiting groove (41). The rear end of the moving cylinder (4) is slidably connected to the inner wall of the outer cylinder (3) through the expansion ring (14), and its front end is slidably connected to the inner wall of the outer cylinder (3). The movable float (6) is slidably connected to the inner wall of the outer cylinder (3).

3. The oil-gas isolated stabilizing buffer for landing gear according to claim 2, characterized in that: An air inlet, a first oil inlet, and a first oil outlet are provided on the outer cylinder (3). The first oil inlet and the first oil outlet are arranged in a ring on the outer cylinder (3). The air inlet communicates with the first air chamber (10), and an air inlet valve (15) is provided at the air inlet. A first oil receiving groove (42) corresponding to the first oil inlet and the first oil outlet is provided in the moving cylinder (4), and a first channel (43) communicating with the first oil receiving groove (42) is provided. A second oil receiving groove (81) corresponding to the first channel (43) is provided in the rear end face of the front end cover (8), and a second channel (51) communicating with the extension stroke hydraulic chamber (12) is provided in the stop cover (5), and a first plug (16) is provided at the first oil inlet. The oil guide channel (7) communicates with the extension stroke hydraulic chamber (12) through the first oil outlet.

4. The oil-gas isolated stabilizing buffer for landing gear according to claim 3, characterized in that: A second oil injection hole and a second oil drain hole are provided on the rear end cover (9) at the rear end of the outer cylinder (3), as well as a third channel (91) communicating with the compression stroke hydraulic cavity (11). The second oil injection hole and the second oil drain hole are arranged in a ring on the rear end cover (9). The second oil injection hole and the second oil drain hole are respectively connected to the third channel (91), and a second plug (17) is provided at the second oil injection hole. The oil guide channel (7) is connected to the compression stroke hydraulic cavity (11) through the second oil drain hole.

5. A hydro-gas isolated stabilizing buffer for landing gear according to claim 4, characterized in that: The oil guide channel (7) includes a guide tube (71), an outer cylinder nozzle (72), an end cap nozzle (73), and a damping valve (74). The outer cylinder nozzle (72) is installed at the first oil drain hole in the outer cylinder (3), while the end cap nozzle (73) is installed at the second oil drain hole in the rear end cap (9). The outer cylinder nozzle (72) and the end cap nozzle (73) are connected by a guide tube (71), and a damping valve (74) is provided in the guide tube (71).

6. A hydro-gas isolated stabilizing buffer for landing gear according to claim 5, characterized in that: The oil guide channel (7) also includes a pipe joint (75) and a support connecting rod (76). The guide tube (71) is connected to the outer cylinder nozzle (72) and the end cap nozzle (73) respectively through the pipe joint (75). The support connecting rod (76) is located on the outer side of the outer cylinder (3). The damping valve (74) is installed in the support connecting rod (76). The damping valve (74) is connected to the guide tube (71) through the pipe joint (75).

7. A hydro-gas isolated stabilizing buffer for landing gear according to claim 6, characterized in that: The earring bolt (1) includes a connecting part and a cylindrical part. The earring bolt forms an integral structure through the connecting part and the cylindrical part. The cylindrical part is a cylindrical structure with one end open. The earring bolt is screwed into the piston rod (2) through the cylindrical part. A nut (101) that abuts against the piston rod (2) is also screwed onto the outer wall of the cylindrical part. An air inlet channel (102) communicating with the second air chamber (13) is also provided in the cylindrical part. A limiting locking block (21) is also provided at the front end of the piston rod (2). A fuse is arranged between the nut (101) and the limiting locking block (21). The nut (101) is limited and prevented from loosening by the fuse.

8. A hydro-gas isolated stabilizing buffer for landing gear according to claim 7, characterized in that: The outer walls of the front cover (8), the moving cylinder (4), the movable float (6), and the piston rod (2), as well as the inner walls of the front cover (8) and the rear cover (9), are respectively provided with sealing grooves (18), and sealing elements are arranged in the sealing grooves (18). The moving cylinder (4) and the movable float (6) are slidably connected to the inner wall of the outer cylinder (3) through the sealing elements in the sealing grooves (18); while the piston rod (2) is slidably connected to the inner wall of the front cover (8) and the moving cylinder (4) through the sealing elements in the sealing grooves (18).

9. A hydro-gas isolated stabilizing buffer for landing gear according to claim 8, characterized in that: An adjusting washer (19) is provided at the rear end of the outer cylinder (3). The rear end cover (9) is connected to the outer cylinder (3) through the adjusting washer (19). The tail of the rear end cover (9) is a single-ear part. A second connecting hole is provided in the single-ear part of the rear end cover (9), and a joint bearing (92) is provided at the second connecting hole. The front end of the earring bolt (1) is a double-ear part. A first connecting hole is provided in the double-ear part of the earring bolt (1), and a bushing (103) is provided at the first connecting hole. 3) A limiting protrusion (31) is also provided on the outer surface. The limiting protrusion (31) is provided on the outer cylinder (3) near the rear end cover (9). A fuse is provided between the limiting protrusion (31) and the rear end cover (9). The fuse limits and prevents the rear end cover (9) from loosening. A limiting screw (82) is also provided in the front end cover (8). The limiting screw (82) limits and prevents the front end cover (8) from loosening between the front end cover (8) and the outer cylinder (3).

10. A hydro-gas isolated stabilizing buffer for landing gear according to claim 9, characterized in that: The cross-sectional area of ​​the piston rod (2) is equal to half the cross-sectional area of ​​the inner cavity of the moving cylinder (4).

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