A variable stiffness high-cushion landing gear retraction actuator

Abstract

The present invention discloses a variable-stiffness, high-cushion landing gear retraction and extension actuator, comprising: an air inlet nozzle, an air inlet on-off valve, an actuator cylinder, a floating piston, a piston, a damping device, a piston rod, a seal A, and a seal B. The floating piston, piston, and piston rod are installed in the actuator cylinder; the floating piston, piston, and piston rod divide the actuator cylinder into three chambers; the air outlet of the air inlet on-off valve communicates with the air inlet of the actuator cylinder, and the air inlet of the air inlet on-off valve is connected to an air source via the air inlet nozzle; the damping device is installed inside the piston via a threaded connection; and the floating piston, piston, and actuator cylinder are sealed by seals B and A, respectively. The present invention can cut off air intake and reduce initial kinetic energy, resulting in low cushioning stiffness and faster speed in the early stages of actuator movement, and high cushioning stiffness and slower speed in the later stages, thereby improving cushioning performance and meeting the requirements for high-inertia cushioning.

Description

Technical Field

[0001] The present invention belongs to the technical field of pneumatic technology, and in particular relates to a variable-rigidity high-buffer landing gear retraction and extension actuator. Background Art

[0002] The landing gear retraction and extension actuator is an important unit of the landing gear retraction and extension subsystem. Its main function is to overcome the static friction load of the landing gear under the action of a constant-pressure cold air source, provide initial power for the landing gear lowering, and provide oil and gas damping during the landing gear lowering process, playing a buffering role and ensuring smooth landing gear lowering.

[0003] Existing landing gear retraction and extension systems are mostly hydraulic or electromechanical, with actuators also being hydraulic or electromechanical. However, hydraulic actuators are prone to oil leakage, which can easily contaminate flight equipment, while electromechanical actuators have more electrical components, are more complex to control, and are heavy. Pneumatic retraction and extension systems have fewer control components, and the downstream actuator timing is mechanically triggered, resulting in lower mass and higher reliability.

[0004] Existing pneumatic landing gear actuator technology primarily focuses on pneumatic cushioning. Pneumatic actuators are fast and uncontrollable, so they require a cushioning function during operation. Current landing gear actuator cushioning technology primarily relies on damping components and floating pistons. Some door actuators use a small amount of oil for air-liquid cushioning, but this has limited effectiveness and cannot meet cushioning requirements under heavy loads. Furthermore, the actuator's own thrust increases the initial velocity of the landing gear lowering motion. Summary of the Invention

[0005] The technology of the present invention solves the problem of overcoming the shortcomings of the existing technology and providing a variable-rigidity high-cushion landing gear retraction and extension actuator, which can realize air intake cut-off and reduce initial kinetic energy, so that the buffering stiffness of the actuator is low and the speed is fast in the early stage of movement, and the buffering stiffness is high and the speed is slowed in the later stage, thereby improving the buffering performance and meeting the large inertia buffering requirements.

[0006] In order to solve the above technical problems, the present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, comprising: an air intake nozzle, an air intake on-off valve, an actuator cylinder, a floating piston, a piston, a damping device, a piston rod, a seal A and a seal B;

[0007] The floating piston, piston and piston rod are installed in the actuator cylinder; the floating piston, piston and piston rod divide the actuator cylinder into three chambers: the rodless chamber A formed between the actuator cylinder and the floating piston, the rodless chamber B formed between the floating piston and the piston, and the rod chamber C where the piston rod is located;

[0008] The air intake on-off valve is installed at the air intake of the actuator cylinder;

[0009] The air outlet D of the air intake on-off valve is connected to the air intake of the actuator cylinder, and the air intake P of the air intake on-off valve is connected to the air source through the air intake nozzle;

[0010] The damping device is installed inside the piston through a threaded connection;

[0011] The floating piston and the actuator cylinder are sealed by seal B, and the piston and the actuator cylinder are sealed by seal A.

[0012] In the above-mentioned variable stiffness high-cushion landing gear retraction and extension actuator, the damping device includes: an elastic retaining ring, a damping plug and a sealing member C;

[0013] The damping plug is provided with a damping hole;

[0014] An elastic retaining ring is provided in front of the damping plug to prevent the thread from loosening;

[0015] The damping device and the piston are sealed by a seal C.

[0016] In the above-mentioned variable stiffness high-cushion landing gear retraction and extension actuator, the rod chamber C is filled with hydraulic oil to form an oil-gas mixing chamber, and is communicated with the rodless chamber B through the damping hole.

[0017] In the above-mentioned variable stiffness high-cushion landing gear retraction and extension actuator, the aperture of the damping hole is set according to different cushioning requirements to control the flow capacity of the hydraulic oil in the rod cavity C to the rodless cavity B under back pressure to achieve the cushioning purpose.

[0018] In the above-mentioned variable stiffness high-cushion landing gear retraction and extension actuator, the air intake on-off valve includes: a housing, a spring, a valve core, a sealing member D, a push rod and a striker;

[0019] The spring and valve core are located in the housing;

[0020] One end of the spring is connected to the housing, and the other end is connected to one end of the valve core; the other end of the valve core is connected to one end of the push rod; the other end of the push rod is connected to the striker;

[0021] The end face of the valve core adopts a special-shaped sealing groove structure, and the seal D is placed in the special-shaped sealing groove structure to achieve dynamic sealing of the valve core.

[0022] In the above-mentioned variable-rigidity high-cushion landing gear retraction and extension actuator, the push rod and the striker pass through the actuator cylinder and are installed at the initial position of the floating piston.

[0023] In the above-mentioned variable stiffness high-cushion landing gear retraction and extension actuator, the air intake on-off valve adopts a mechanical trigger structure, and the opening / closing of the air intake on-off valve is controlled by the movement position of the floating piston; wherein, when the floating piston is in the initial position, the floating piston pushes up the striker, and the air intake on-off valve is in the open state; when the floating piston moves away from the initial position and separates from the striker, the striker falls, and the air intake on-off valve is in the closed state.

[0024] In the above-mentioned variable stiffness high-cushion landing gear retraction and extension actuator, the striker is installed in the stepped hole of the actuator cylinder, and the striker and the push rod adopt a separate structure to avoid friction and jamming with the inner wall of the actuator cylinder during up and down movement.

[0025] In the above-mentioned variable stiffness high-cushion landing gear retraction and extension actuator, evenly distributed vent holes are opened around the valve core to ensure the gas flow capacity when the air intake on-off valve is opened.

[0026] In the above-mentioned variable stiffness high-cushion landing gear retraction and extension actuator, the air intake on-off valve also includes: an air consumption component; wherein the air consumption component is arranged at the bottom of the shell, and is used to release the pressure between the air intake and the floating piston after the actuator completes one action, thereby realizing the self-air consumption function.

[0027] The present invention has the following advantages:

[0028] (1) The present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, which adopts an air intake cut-off structure to realize air intake cut-off after the actuator has a fixed stroke, thereby reducing the impact of landing gear lowering and improving the cushioning effect.

[0029] (2) The present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, which controls the initial thrust of the actuator within a fixed stroke. By controlling the triggering distance of the air intake on-off valve striker, the air source intake can be controlled within a fixed stroke.

[0030] (3) The present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, which can realize the retraction and extension actuator to quickly output initial thrust, and then slowly lower with the landing gear. Through the change of the actuator's buffer stiffness, the stiffness changes from small to large and the speed changes from fast to slow.

[0031] (4) The present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, which can realize the self-gas consumption function. After the actuator completes an action, the pressure between the air inlet and the floating piston needs to be released. An air consumption component is set on the air inlet shut-off valve to realize the self-gas consumption function.

[0032] (5) The present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, which adopts a push rod and a floating piston mechanical trigger mechanism to improve the reliability of opening and closing the air intake on-off valve.

[0033] (6) The present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, in which the air intake on-off valve striker and the push rod adopt a separate structure to avoid jamming.

[0034] (7) The present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, which realizes that the landing gear retraction and extension actuator is driven by gas, cushioned by a gas-liquid mixed medium, and the cushioning stiffness is adjusted by the gas-liquid ratio.

[0035] (8) The present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, which uses a floating piston structure to achieve isolation between the driving gas and the buffer gas and liquid.

[0036] (9) The present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, which connects the rod chamber and the rodless chamber B through a replaceable damping device, so that the actuator gradually transitions from the differential connection of the piston and the rodless chamber, achieving high output and fast speed in the early stage, and no output and pure cushioning in the later stage.

[0037] (10) The present invention discloses a variable stiffness high-cushion landing gear retraction and extension actuator, which is suitable for aircraft landing gear retraction and extension mechanisms, aircraft landing systems, and various industrial uses. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 1 is a schematic structural diagram of a variable stiffness high-cushion landing gear retraction and extension actuator according to an embodiment of the present invention;

[0039] Figure 2 1 is a schematic structural diagram of an air intake on-off valve according to an embodiment of the present invention;

[0040] Figure 3 This is a schematic structural diagram of a push rod and a striker in an embodiment of the present invention;

[0041] Figure 4 This is a schematic structural diagram of a valve core in an embodiment of the present invention;

[0042] Figure 5 It is a structural schematic diagram of a damping device in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0044] like Figure 1In this embodiment, the variable-rigidity, high-cushion landing gear retraction and extension actuator comprises: an air inlet nozzle 1, an air inlet on-off valve 2, an actuator cylinder 3, a floating piston 4, a piston 5, a damping device 6, a piston rod 7, a seal A8, and a seal B9. The floating piston 4, piston 5, and piston rod 7 are installed within the actuator cylinder 3. The floating piston 4, piston 5, and piston rod 7 divide the actuator cylinder 3 into three chambers: a rodless chamber A formed between the actuator cylinder 3 and the floating piston 4, a rodless chamber B formed between the floating piston 4 and piston 5, and a rod chamber C where the piston rod 7 resides. The air intake on-off valve 2 is installed at the air intake of the actuator cylinder 3; the air outlet D of the air intake on-off valve 2 is connected to the air intake of the actuator cylinder 3, and the air intake P of the air intake on-off valve 2 is connected to the air source through the air intake nozzle 1; the damping device 6 is installed inside the piston 5 through a threaded connection; the floating piston 4 and the actuator cylinder 3 are sealed by the seal B9, and the piston 5 and the actuator cylinder 3 are sealed by the seal A8.

[0045] In this embodiment, if Figure 5 As shown, the damping device 6 may specifically include: an elastic circlip 61, a damping plug 62, and a seal C63. The damping plug 62 is provided with a damping hole; an elastic circlip 61 is provided in front of the damping plug 62 to prevent the threads from loosening; and the damping device 6 and the piston 5 are sealed by the seal C63.

[0046] In this embodiment, if Figure 2 As shown, the intake on-off valve 2 specifically includes: a housing 21, a spring 22, a valve core 23, a seal D24, a push rod 25, a striker 26, and an air-consuming component 27. The spring 22 and valve core 23 are located within the housing 21; one end of the spring 22 is connected to the housing 21, and the other end is connected to one end of the valve core 23; the other end of the valve core 23 is connected to one end of the push rod 25; and the other end of the push rod 25 is connected to the striker 26. The end surface of the valve core 23 adopts a special-shaped sealing groove structure, and the seal D24 is placed in the special-shaped sealing groove structure to achieve dynamic sealing of the valve core.

[0047] Preferably, Figure 3 As shown, the ejector rod 25 and the striker 26 pass through the actuator cylinder 3 and are installed in the initial position of the floating piston 4. The striker 26 is installed in the stepped hole of the actuator cylinder 3. The striker 26 and the ejector rod 25 adopt a separate structure to avoid friction and jamming with the inner wall of the actuator cylinder 3 during up and down movement.

[0048] Preferably, the air intake on-off valve 2 adopts a mechanical trigger structure, and the opening / closing of the air intake on-off valve 2 is controlled by the movement position of the floating piston 4: when the floating piston 4 is in the initial position, the floating piston 4 pushes up the striker 26, and the air intake on-off valve 2 is in the open state; when the floating piston 4 moves away from the initial position and separates from the striker 26, the striker 26 falls, and the air intake on-off valve 2 is in the closed state.

[0049] Preferably, Figure 4 As shown, evenly distributed vent holes are opened around the valve core 23 to ensure the gas flow capacity when the intake on-off valve 2 is opened.

[0050] Preferably, the gas consumption component 27 is arranged at the bottom of the housing 21, and is used to release the pressure between the air inlet and the floating piston 4 after the actuator completes one action, thereby realizing the self-gas consumption function.

[0051] In this embodiment, rodless chamber A is equipped with an air inlet D, which communicates with the outlet of inlet on-off valve 2. Rod chamber C is filled with hydraulic oil, forming an oil-air mixing chamber, which communicates with rodless chamber B through a damping orifice. The diameter of the damping orifice is adjusted according to different cushioning requirements to control the flow of hydraulic oil from rod chamber C to rodless chamber B under back pressure, thereby achieving the desired cushioning effect.

[0052] In this embodiment, the piston rod 7 compresses the normal-pressure gas in the rod chamber C in the early stage of movement, and the buffering stiffness is relatively small. When the gas pressure is balanced with the intake air, it begins to squeeze the hydraulic oil in the rod chamber C. The hydraulic oil in the rod chamber C enters the rodless chamber B through the damping hole on the damping device, forming a hydraulic buffer state, and the buffering stiffness increases.

[0053] In this embodiment, as previously described, the outlet D of the inlet on-off valve 2 communicates with the inlet port of the actuator cylinder 3. The inlet port P of the inlet on-off valve 2 is connected to the air source via the inlet nozzle 1. The push rod 25, striker 26, and floating piston 4 of the inlet on-off valve 2 form a mechanical trigger mechanism. Before air is supplied, the striker 26 is lifted by the floating piston 4. When air is supplied, the floating piston 4 begins to move toward the rod chamber C. After a certain travel, the floating piston 4 disengages from the striker 26. The spring 22 and the air pressure push the valve core 23 downward, tightening the seal D 24 and shutting off the air supply.

[0054] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

[0055] The contents not described in detail in the specification of the present invention belong to the common knowledge of professionals in this field.

Claims

1. A variable stiffness high cushion landing gear retraction actuator, characterized in that: include: Inlet nozzle (1), inlet on-off valve (2), actuator cylinder (3), floating piston (4), piston (5), damping device (6), piston rod (7), seal A (8) and seal B (9); The floating piston (4), piston (5) and piston rod (7) are installed in the actuator cylinder (3); the floating piston (4), piston (5) and piston rod (7) divide the actuator cylinder (3) into three chambers: the rodless chamber A formed between the actuator cylinder (3) and the floating piston (4), the rodless chamber B formed between the floating piston (4) and the piston (5) and the rod chamber C where the piston rod (7) is located; the air intake on-off valve (2) is installed in the actuator cylinder ( 3); the air outlet D of the air inlet on-off valve (2) is connected to the air inlet of the actuator cylinder (3); the air inlet P of the air inlet on-off valve (2) is connected to the air source through the air inlet nozzle (1); the damping device (6) is installed inside the piston (5) through a threaded connection; the floating piston (4) and the actuator cylinder (3) are sealed by the sealing member B (9), and the piston (5) and the actuator cylinder (3) are sealed by the sealing member A (8); An air intake on-off valve (2) comprises: a housing (21), a spring (22), a valve core (23), a sealing member D (24), a push rod (25) and a striker (26); wherein the spring (22) and the valve core (23) are located in the housing (21); one end of the spring (22) is connected to the housing (21), and the other end is connected to one end of the valve core (23); the other end of the valve core (23) is connected to one end of the push rod (25); the other end of the push rod (25) is connected to the striker (26); the end surface of the valve core (23) adopts a special-shaped sealing groove structure, and the sealing member D (24) is placed in the special-shaped sealing groove structure to realize dynamic sealing of the valve core.

2. The variable stiffness high cushion landing gear retraction actuator according to claim 1, characterized in that: A damping device (6) comprising: an elastic retaining ring (61), a damping plug (62) and a sealing member C (63); The damping plug (62) is provided with a damping hole; An elastic retaining ring (61) is provided in front of the damping plug (62) to prevent the thread from loosening; The damping device (6) and the piston (5) are sealed via a seal C (63).

3. The variable stiffness high cushion landing gear retraction actuator according to claim 2, characterized in that: The rod chamber C is filled with hydraulic oil to form an oil-gas mixing chamber, and is connected to the rodless chamber B through the damping hole.

4. The variable stiffness high cushion landing gear retraction actuator according to claim 3, characterized in that: The diameter of the damping hole is set according to different buffering requirements to control the flow capacity of the hydraulic oil in the rod chamber C to the rodless chamber B under back pressure to achieve the buffering purpose.

5. The variable stiffness high cushion landing gear retraction actuator according to claim 1, characterized in that: The ejector rod (25) and the striker (26) pass through the actuator cylinder (3) and are installed at the initial position of the floating piston (4).

6. The variable stiffness high cushion landing gear retraction actuator according to claim 5, characterized in that: The air intake on-off valve (2) adopts a mechanical triggering structure, and the opening / closing of the air intake on-off valve (2) is controlled by the movement position of the floating piston (4); wherein, when the floating piston (4) is at an initial position, the floating piston (4) pushes up the striker (26), and the air intake on-off valve (2) is in an open state; when the floating piston (4) moves away from the initial position and separates from the striker (26), the striker (26) falls, and the air intake on-off valve (2) is in a closed state.

7. The variable stiffness high cushion landing gear retraction actuator according to claim 5, characterized in that: The striker (26) is installed in the stepped hole of the actuator cylinder (3). The striker (26) and the push rod (25) adopt a separate structure to avoid friction and jamming with the inner wall of the actuator cylinder (3) when moving up and down.

8. The variable stiffness high cushion landing gear retraction actuator according to claim 1, characterized in that: The valve core (23) is provided with evenly distributed vent holes around its periphery to ensure the gas flow capacity when the air inlet on-off valve (2) is opened.

9. The variable stiffness high cushion landing gear retraction actuator according to claim 1, characterized in that: The air intake on-off valve (2) further comprises: an air consumption component (27); wherein the air consumption component (27) is arranged at the bottom of the housing (21) and is used to release the pressure between the air intake and the floating piston (4) after the actuator completes one action, thereby realizing a self-gas consumption function.

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