Surface self-adaptive anti-deformation actuator

Abstract

The invention relates to the technical field of hydraulic actuators, in particular to a surface self-adaption anti-deformation actuator which comprises an outer cylinder body, an inner cylinder body, an energy storage assembly and a piston assembly. The outer cylinder body is connected with the oil guide piece; the inner cylinder body is arranged in the outer cylinder body; the energy storage assembly is arranged between the outer cylinder body and the inner cylinder body; the piston assembly is connected with the energy storage assembly; vacuum isolation is carried out on the outer cylinder body and the inner cylinder body, cold energy is recycled in the air, hydraulic oil and a piston inner rod are pre-cooled through the recycled cold energy when an undercarriage is opened, the buffering damping force in the landing braking process is enhanced, connection between an energy storage assembly and the outer cylinder body is disconnected in the braking process, heat of an external braking system is isolated, and the braking effect is improved. The temperature change range of the inner cylinder body is greatly reduced, and thermal deformation is prevented; the problems that when an actuator is used on an aircraft landing gear, the temperature changes sharply in the process from high-altitude low temperature to landing braking, and the inner surface of a cylinder body deforms due to the fact that the actuator bears too large instant impact load are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic actuators, and in particular to a surface self-adaptive anti-deformation actuator. Background Art

[0002] A hydraulic actuator is a device that uses hydraulic energy to generate mechanical motion. It mainly includes two categories: hydraulic cylinders and hydraulic motors. It is an indispensable power device in modern industry and engineering fields and is currently widely used in heavy machinery, aerospace, and shipbuilding.

[0003] When the hydraulic actuator is used on the landing gear of an aircraft, the ambient temperature of the hydraulic actuator will drop to below -50°C when the aircraft is cruising at high altitude. During the landing and braking process, a large amount of heat will be generated under the action of huge friction and impact load, causing the temperature of the hydraulic actuator to rise sharply. This drastic temperature difference will cause uneven thermal expansion and contraction, generating thermal stress, which will cause the inner surface of the actuator cylinder to deform, and the seal will soften, and the viscosity of the hydraulic oil will decrease. At this time, the piston rod is subjected to a huge impact load, and the slight deformation between the piston rod and the inner surface of the cylinder will be magnified, resulting in permanent deformation and creating a safety hazard. A method for heat dissipation of the hydraulic cylinder has been proposed in the prior art, such as patent publication number CN22295 0161U is a servo hydraulic cylinder pressure-bearing device, which is equipped with a telescopic body at the left end of the piston connecting rod. During the sliding process of the piston connecting rod, the telescopic body will be driven to be repeatedly compressed and reset, so that the air inside the cylinder body can be exchanged at a high frequency, thereby improving the heat exchange efficiency of the connected cylinder, reducing the load risk caused by excessive internal heat, and improving the practicality of the servo hydraulic cylinder pressure-bearing device; for the rapid temperature rise caused by the huge instantaneous impact load, the heat generation rate is much greater than the heat exchange rate of the air, and it is impossible to help the cylinder body to dissipate heat by pumping air, and effective support needs to be ensured after the landing gear is supported, so after the landing gear is supported, it is also necessary to ensure that the heat dissipation will not affect the support effect of the actuator itself.

[0004] In view of the above situation, in order to overcome the above technical problems, the present invention designs a surface adaptive anti-deformation actuator. Summary of the Invention

[0005] The present invention provides a surface adaptive anti-deformation actuator, which solves the problem that when the actuator is used on the aircraft landing gear, the inner surface of the cylinder will be deformed due to the rapid temperature change from high altitude and low temperature to landing and braking, and the excessive instantaneous impact load. Through the double-layer cylinder structure of the outer cylinder and the inner cylinder, a vacuum layer 1, an energy storage component and a vacuum layer 2 are arranged between the two. At high altitude, the energy storage component contacts the outer cylinder to accumulate and store cold energy. During the landing and braking process, the temperature around the outer cylinder rises, and the energy storage component automatically disconnects from the outer cylinder, greatly reducing the external heat transferred to the inner cylinder. In the process of opening the landing gear, the pumping piston will slide with the piston outer rod to suck the energy storage medium into the piston inner rod, pre-cooling the hydraulic oil, improving the damping force of the landing support and greatly reducing the temperature rise peak of the inner cylinder when subjected to impact load, thereby preventing the surface deformation of the inner cylinder.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A surface adaptive anti-deformation actuator; comprising an oil guide member, an outer cylinder, an inner cylinder, an energy storage assembly and a piston assembly; the outer cylinder is connected to the oil guide member; the inner cylinder is arranged in the outer cylinder; the energy storage assembly is arranged between the outer cylinder and the inner cylinder; when the temperature is higher than a limit value, the energy storage assembly and the outer cylinder are changed from a connected state to a disconnected state; after the temperature drops below the limit value, the energy storage assembly is connected to the outer cylinder again; the piston assembly is connected to the energy storage assembly; when the piston assembly slides, the energy storage medium in the energy storage assembly is sucked into the piston assembly.

[0008] Preferably, a first vacuum layer is provided between the outer cylinder and the energy storage assembly; and a second vacuum layer is provided between the energy storage assembly and the inner cylinder.

[0009] In the above scheme, in a high-altitude and low-temperature environment, the heat transfer between the outer cylinder and the inner cylinder can be greatly reduced through the energy storage component and the vacuum gap, ensuring that the inner cylinder can maintain a normal temperature in a high-altitude and low-temperature environment, and in the process of braking, the heat generated by external friction can be prevented from being transferred to the inner cylinder, so that the heat for heating the inner cylinder only comes from the heat generated during the compression process, and in a low-temperature environment, the cold energy will be absorbed by the energy storage component. The vacuum layer 2 can prevent the temperature of the inner cylinder from dropping, thereby reducing the temperature change range of the inner cylinder, preventing large and drastic temperature changes, and then reducing the generated thermal stress and preventing the inner surface of the inner cylinder from deformation.

[0010] Preferably, the energy storage assembly includes an energy storage chamber, an SMA spring, an energy guiding bridge, a bias spring and a fixing member; the energy storage chamber is arranged between vacuum layer one and vacuum layer two; the SMA spring is connected to the energy storage chamber; the energy guiding bridge is connected to the SMA spring; the bias spring is connected between the energy guiding bridge and the SMA spring; the fixing member is connected to the energy storage chamber, and the outer ring of the fixing member is connected to the inner wall of the outer cylinder body, and the inner ring of the fixing member is connected to the outer wall of the inner cylinder body.

[0011] In the above scheme, the outer cylinder will be cooled by the low-temperature air outside at high altitude, and the cold energy will be transferred to the energy storage chamber for accumulation. During the subsequent landing and braking process of the aircraft, the accumulated cold energy can be released for adaptive cooling; the use of SMA springs can control the contact between the energy-conducting bridge and the energy storage chamber according to temperature changes.

[0012] Preferably, the cold energy storage medium in the energy storage chamber is fluorinated liquid; the fixing part is made of PEEK; the energy conducting bridge piece is made of a material with a high thermal conductivity coefficient, and the energy conducting bridge piece is an arc piece structure with an inner wall radius equal to the outer wall radius of the energy storage chamber.

[0013] In the above scheme, the fluorinated liquid has a very low freezing point of below -100°C, and has good heat transfer performance, and can still maintain good fluidity at extremely low temperatures; the fixing parts can ensure good thermal insulation capabilities while being fixed, and the energy-conducting bridge piece conducts cold energy by fitting with the energy storage cavity. The energy-conducting bridge piece is an arc-shaped structure with an inner wall radius equal to the outer wall radius of the energy storage cavity, which can increase the contact area and stability, thereby ensuring the conduction efficiency.

[0014] Preferably, the piston assembly includes a piston head, a piston inner rod, a piston outer rod and a cooling component; the piston head is slidably mounted in the inner cylinder body; the piston inner rod is mounted on the central axis of the inner cylinder body; the piston outer rod is connected to the piston head and slidably mounted on the piston inner rod; the cooling component is connected between the energy storage chamber and the piston inner rod.

[0015] In the above scheme, the radial force generated by the piston head during the impact process will be divided into the piston inner rod and the inner cylinder body, thereby significantly reducing the radial pressure exerted by the piston head on the inner cylinder body and the reaction force exerted on the outer ring of the piston head itself, thereby preventing the deformation of the inner cylinder body surface and the outer ring of the piston head, and ensuring the sealing performance; the process of the piston outer rod sliding out can drive the cooling component to suck the energy storage medium into the piston inner rod. At this time, the piston inner rod will transfer the cold energy of the energy storage medium to the hydraulic oil, thereby reducing the temperature of the hydraulic oil for pre-cooling and increasing the viscosity, so that it can generate greater damping force during the impact process and provide better buffering support effect.

[0016] Preferably, the cooling component includes a cooling chamber, a connecting pipe and a pumping piston; the cooling chamber is opened in the inner rod of the piston; the connecting pipe is connected between the inner rod of the piston and the energy storage chamber; the pumping piston is slidably installed in the cooling chamber and connected to the outer rod of the piston.

[0017] In the above scheme, the radial force generated by the piston head can be further dispersed by the pumping piston, so that the radial force generated by the piston head on the inner wall of the inner cylinder and the outer surface of the piston inner rod is reduced, thereby preventing its deformation and resulting in a decrease in sealing performance. In the process of the piston head and the piston outer rod sliding to extension, the pumping piston can be driven to slide together. At this time, the pumping piston will suck the low-temperature energy storage medium that has accumulated cold energy into the cooling chamber, and exchange heat with the heat generated by the hydraulic oil during the impact process through the cooling chamber. Moreover, this pumping process is completed during the opening of the aircraft landing gear, so the hydraulic oil and the piston inner rod can be pre-cooled in advance to avoid deformation caused by low temperature on one side of the piston inner rod and high temperature on the other side.

[0018] Preferably, a liquid inlet channel is provided at the tail of the inner rod of the piston, and the liquid inlet channel is connected to the cooling chamber; the connecting tube and the head of the liquid pumping piston are both made of PEEK material, and the tail of the connecting tube is installed in the liquid inlet channel.

[0019] In the above scheme, the connecting pipe and the head of the pumping piston are set to thermal insulation materials, which can ensure that the cold energy in part of the energy storage medium in the connecting pipe will not dissipate at high altitudes, thereby ensuring the storage effect of cold energy. At the same time, it can prevent the cold energy from being transferred to the piston inner rod and hydraulic oil at high altitudes, resulting in the subsequent increase in the viscosity of the hydraulic oil and the slower response speed during the opening process of the landing gear.

[0020] Preferably, the inner diameter of the piston head and the piston outer rod is equal to the outer wall diameter of the piston inner rod, and the outer edge of the piston head is provided with a pressure-proof fillet; the liquid pumping piston is a rod-shaped structure, and the outer diameter of the liquid pumping piston is equal to the inner wall diameter of the cooling chamber.

[0021] In the above scheme, since the inner ring diameter of the piston head and the piston outer rod is equal to the outer wall diameter of the piston inner rod, the contact area between the piston inner rod and the piston outer rod can be increased during the impact load, so that the radial pressure is significantly reduced, and the risk of radial compression deformation is reduced. In addition, the anti-pressure fillet can prevent the contact surface between the piston head and the inner cylinder body from being compressed and deformed when a slight radial deflection occurs.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Compared with the existing hydraulic actuators, the present invention designs the cylinder body into a double-layer structure of an outer cylinder body and an inner cylinder body, and sequentially arranges a vacuum layer 1, an energy storage component and a vacuum layer 2 between the outer cylinder body and the inner cylinder body, so that the external heat cannot cause the temperature of the inner cylinder body to change drastically in a high-altitude low-temperature environment and during the braking process, thereby narrowing the temperature change range of the inner cylinder body, reducing thermal stress, and preventing deformation of the inner surface of the inner cylinder body. In a high-altitude low-temperature environment, the energy storage component will accumulate and recover cold energy. In the subsequent landing and braking process, the recovered cold energy is used to pre-cool the hydraulic oil and the inner rod of the piston, thereby reducing the temperature rise peak when subjected to a huge instantaneous impact, limiting the diffusion of heat to the inner wall of the inner cylinder body, and thus preventing sealing leakage caused by deformation of the inner cylinder body and the inner rod of the piston.

[0024] 2. The present invention provides a pumping piston. During the opening process of the aircraft landing gear, the outer rod of the piston slides out and drives the pumping piston to slide to draw the energy storage medium from the energy storage chamber into the inner rod of the piston. At this time, the inner rod of the piston will transfer the cold energy of the energy storage medium to the hydraulic oil, thereby reducing the temperature of the hydraulic oil for pre-cooling and increasing the viscosity, so that it can generate a greater damping force during the impact process and provide a better buffering support effect. Moreover, since it is used on the aircraft landing gear, the hydraulic oil does not need to circulate, and it only needs to protect the body in a one-time extreme impact. Therefore, pre-cooling will not affect the working response efficiency, and can also effectively reduce the peak value of the hydraulic oil temperature rise. Moreover, the pre-cooling process is completed during the opening process of the aircraft landing gear, so the hydraulic oil and the inner rod of the piston can be pre-cooled in advance to avoid deformation caused by low temperature on one side and high temperature on the other side of the inner rod of the piston, thereby ensuring the sealing performance.

[0025] 3. The present invention disperses the radial force generated during the impact process to the inner cylinder body and the piston inner rod through the inner cylinder body, the piston head, the piston outer rod, the piston inner rod and the pumping piston, thereby significantly reducing the radial pressure exerted by the piston head on the inner cylinder body and the reaction force exerted on the outer ring of the piston head itself, thereby preventing deformation of the inner cylinder body surface and the outer ring of the piston head, ensuring sealing performance, the piston outer rod and the piston inner rod have a longer part of the socket, and the contact area is larger, which can significantly reduce the radial pressure and reduce the risk of radial compression deformation. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0027] Figure 1It is the overall structural diagram of the present invention;

[0028] Figure 2 Schematic diagram of the internal structure of the present invention;

[0029] Figure 3 is a cross-sectional view of the present invention;

[0030] Figure 4 for Figure 3 A magnified view of the structure at center A;

[0031] Figure 5 for Figure 3 A magnified view of the structure at point B in the middle;

[0032] Figure 6 This is a diagram of the cold energy recovery state of the present invention at high altitude and low temperature;

[0033] Figure 7 This is a state diagram of the piston assembly and the energy storage assembly when the landing gear of the aircraft is opened during landing brake operation of the present invention;

[0034] Figure 8 for Figure 7 Enlarged view of the structure at point C in the middle.

[0035] In the figure: 1. Oil guide part; 2. Outer cylinder body; 3. Inner cylinder body; 4. Energy storage assembly; 41. Energy storage chamber; 42. SMA spring; 43. Energy guide bridge; 44. Bias spring; 45. Fixing part; 5. Piston assembly; 51. Piston head; 511. Anti-pressure fillet; 52. Piston inner rod; 521. Liquid inlet channel; 53. Piston outer rod; 54. Cooling part; 541. Cooling chamber; 542. Connecting pipe; 543. Liquid pumping piston; 6. Vacuum layer one; 7. Vacuum layer two. DETAILED DESCRIPTION

[0036] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0037] See also Figures 1 to 8 The present invention provides a surface adaptive anti-deformation actuator, the technical solution is as follows:

[0038] As a specific embodiment of the present invention, refer to Figure 1 and Figure 2, a surface adaptive anti-deformation actuator; it includes an oil guide part 1, the pipes of the oil guide part 1 are all made of thermal insulation material, and it also includes an outer cylinder body 2, an inner cylinder body 3, an energy storage component 4 and a piston assembly 5; the outer cylinder body 2 is connected to the oil guide part 1; the inner cylinder body 3 is arranged in the outer cylinder body 2; the energy storage component 4 is arranged between the outer cylinder body 2 and the inner cylinder body 3. When the temperature is higher than the limit value (the limit value here is 25°C), the energy storage component 4 and the outer cylinder body 2 are changed from a connected state to a disconnected state. After the temperature drops to below the limit value (the limit value here is 25°C), the energy storage component 4 is connected to the outer cylinder body 2 again; the piston assembly 5 is connected to the energy storage component 4; when the piston assembly 5 slides, the energy storage medium in the energy storage component 4 is sucked into the piston assembly 5.

[0039] As a specific embodiment of the present invention, refer to Figure 2 and Figure 3 A vacuum layer 1 6 is provided between the outer cylinder 2 and the energy storage assembly 4; a vacuum layer 2 7 is provided between the energy storage assembly 4 and the inner cylinder 3. In a high-altitude, low-temperature environment, the energy storage assembly 4 and the vacuum gap between the outer cylinder 2 and the inner cylinder 3 can greatly reduce heat transfer, ensuring that the inner cylinder 3 can maintain a normal temperature in a high-altitude, low-temperature environment. In addition, during the braking process, the heat generated by external friction can be prevented from being transferred to the inner cylinder 3, so that the heat generated by the heating of the inner cylinder 3 only comes from the heat generated during the compression process. In a low-temperature environment, the cold energy will be absorbed by the energy storage assembly 4. The vacuum layer 2 7 can prevent the temperature of the inner cylinder 3 from dropping, thereby reducing the temperature variation range of the inner cylinder 3 and preventing large and drastic temperature changes, thereby reducing the generated thermal stress and preventing deformation of the inner surface of the inner cylinder 3. During the manufacturing process, the vacuum layer 1 6 and the vacuum layer 2 7 are permanently sealed using electron beam deep-penetration welding. After vacuuming, the exhaust port is sealed, and a non-evaporable getter film is coated on the wall to maintain long-term high vacuum conditions.

[0040] As a specific embodiment of the present invention, refer to Figure 3 、 Figure 4 and Figure 8The energy storage assembly 4 includes an energy storage chamber 41, an SMA spring 42, an energy guiding bridge piece 43, a bias spring 44 and a fixing part 45; the energy storage chamber 41 is arranged between the vacuum layer 1 6 and the vacuum layer 2 7, and the energy storage chamber 41 uses a material that is convenient for cold energy conduction; the SMA spring 42 is connected to the energy storage chamber 41; the energy guiding bridge piece 43 is connected to the SMA spring 42; the bias spring 44 is connected between the energy guiding bridge piece 43 and the SMA spring 42; the fixing part 45 is connected to the energy storage chamber 41, and the outer ring of the fixing part 45 is connected to the inner wall of the outer cylinder body 2, and the inner ring of the fixing part 45 is connected to the outer wall of the inner cylinder body 3. At high altitudes, the outer cylinder 2 will be cooled by the external low-temperature air, and the cold energy will be transferred to the energy storage medium in the energy storage chamber 41 for accumulation. In the subsequent landing and braking process of the aircraft, the accumulated cold energy can be released for adaptive cooling. The SMA spring 42 can be used to control the contact between the energy-conducting bridge 43 and the energy storage chamber 41 according to temperature changes. The phase change temperature of the SMA spring 42 can be set to about 25°C. When the temperature rises to above 25°C, the SMA spring 42 returns to the memory shape under the one-way memory effect. At this time, the SMA spring 42 will overcome the elastic force of the bias spring 44 (that is, the total elastic force generated by the SMA spring 42 when it returns to the memory shape is greater than the total elastic force of the bias spring 44), and pull the energy-conducting bridge 43 in the radial direction of the outer cylinder 2, and pull it out of the energy storage chamber 41, thereby disconnecting the heat. The amount of heat is transferred, so that the heat of the outer cylinder body 2 cannot be transferred to the energy storage chamber 41, ensuring that the energy storage medium in the energy storage chamber 41 remains in a low temperature state (cold energy accumulated from high altitude). When the temperature drops below 25°C, the SMA spring 42 becomes soft again (returns to the martensite state). At this time, under the biasing force of the bias spring 44, the SMA spring 42 returns to its original elongated state, and the energy guiding bridge 43 contacts the energy storage chamber 41 again. The material of the SMA spring 42 is nickel-titanium alloy, and the phase change temperature is controlled at about 25°C, which can quickly disconnect the heat transfer when the temperature rises. Since the SMA spring 42 is directly connected to the outer cylinder body 2, it can ensure that the contact is disconnected before the heat is transferred to the energy storage chamber 41 when the temperature rises rapidly, thereby ensuring the low temperature state in the energy storage chamber 41.

[0041] As a specific embodiment of the present invention, refer to Figure 4 and Figure 8The cold energy storage medium in the energy storage chamber 41 is a fluorinated liquid; the fixing member 45 is made of PEEK; the energy conducting bridge piece 43 is made of a material with a high thermal conductivity coefficient, and has an arc-shaped structure with an inner wall radius equal to the outer wall radius of the energy storage chamber 41. Fluorinated liquid has a very low freezing point, reaching below -100°C, and has excellent heat transfer properties, maintaining good fluidity even at extremely low temperatures; the fixing member 45 ensures excellent thermal insulation while maintaining fixation. The energy conducting bridge piece 43 conducts cold energy by fitting with the energy storage chamber 41. The arc-shaped structure with an inner wall radius equal to the outer wall radius of the energy storage chamber 41 can increase the contact area and stability, thereby ensuring conduction efficiency.

[0042] As a specific embodiment of the present invention, refer to Figure 5 、 Figure 6 and Figure 7 The piston assembly 5 includes a piston head 51, a piston inner rod 52, a piston outer rod 53 and a cooling component 54; the piston head 51 is slidably installed in the inner cylinder body 3; the piston inner rod 52 is installed on the central axis of the inner cylinder body 3; the piston outer rod 53 is connected to the piston head 51 and is slidably installed on the piston inner rod 52; the cooling component 54 is connected between the energy storage chamber 41 and the piston inner rod 52. The radial force generated by the piston head 51 during the impact process will be divided into the piston inner rod 52 and the inner cylinder body 3, thereby significantly reducing the radial pressure exerted by the piston head 51 on the inner cylinder body 3 and the reaction force on the outer ring of the piston head 51 itself, thereby preventing the surface of the inner cylinder body 3 and the outer ring of the piston head 51 from being deformed, thereby ensuring the sealing performance; the cooling element 54 can be driven to suck the energy storage medium into the piston inner rod 52 through the process of sliding out the piston outer rod 53. At this time, the piston inner rod 52 will transfer the cold energy of the energy storage medium to the hydraulic oil, thereby reducing the temperature of the hydraulic oil for pre-cooling and increasing the viscosity (and due to the landing gear opening time It is relatively short, so the pre-cooling process will not reduce the temperature of the hydraulic oil and the piston inner rod 52 too much, thereby ensuring that there will be no large temperature difference in the subsequent heat absorption process), so that it can generate a greater damping force during the impact process, providing a better buffering support effect, and because it is used on the aircraft landing gear, it is not a scenario where the hydraulic oil needs to circulate, and it only needs to protect the body in a one-time extreme impact, so pre-cooling will not affect the work response efficiency, and can also reduce the peak temperature rise caused by the heat generated by the hydraulic oil when it is impacted, and at the same time limit the diffusion of heat to the inner wall of the inner cylinder 3.

[0043] As a specific embodiment of the present invention, refer to Figure 5 、 Figure 6 and Figure 7The cooling component 54 includes a cooling chamber 541, a connecting pipe 542 and a pumping piston 543; the cooling chamber 541 is provided in the piston inner rod 52; the connecting pipe 542 is connected between the piston inner rod 52 and the energy storage chamber 41; the pumping piston 543 is slidably installed in the cooling chamber 541 and is connected to the piston outer rod 53. The pumping piston 543 can further disperse the radial force generated by the piston head 51, so that the radial force generated by the piston head 51 on the inner wall of the inner cylinder body 3 and the outer surface of the piston inner rod 52 is reduced, thereby preventing its deformation and causing a decrease in sealing performance. In the process of the piston head 51 and the piston outer rod 53 sliding to extend, the pumping piston 543 can be driven to slide together. At this time, the pumping piston 543 will draw the low-temperature energy storage medium that has accumulated cold energy into the cooling chamber 541, and exchange heat with the heat generated by the hydraulic oil during the impact process through the cooling chamber 541, and this The suction process is completed during the opening of the aircraft landing gear, so the hydraulic oil and the piston inner rod 52 can be pre-cooled in advance to avoid deformation caused by low temperature on one side and high temperature on the other side of the piston inner rod 52. When the aircraft landing gear is opened, the entire actuator will become a vertical state. At this time, the energy storage medium sucked into the cooling chamber 541 can stay in the cooling chamber 541 under the action of gravity. When the aircraft landing gear is retracted, the piston outer rod 53 returns to the retracted state and presses the pumping piston 543 again to press the energy storage medium back into the energy storage chamber 41.

[0044] As a specific embodiment of the present invention, refer to Figure 5 、 Figure 6 and Figure 7 The rear end of the piston inner rod 52 is provided with a liquid inlet channel 521, which communicates with the cooling chamber 541. The connecting tube 542 and the head of the pumping piston 543 are both made of PEEK, with the rear end of the connecting tube 542 mounted within the liquid inlet channel 521. The connecting tube 542 and the head of the pumping piston 543 are made of a thermally insulating material. This prevents the cold energy in the energy storage medium within the connecting tube 542 from dissipating at high altitudes, ensuring the effective storage of cold energy. This also prevents the cold energy from being transferred to the piston inner rod 52 and the hydraulic oil at high altitudes, which could cause the hydraulic oil viscosity to increase and the response speed to slow down during the subsequent landing gear deployment process.

[0045] As a specific embodiment of the present invention, refer to Figure 6 and Figure 7The inner diameters of the piston head 51 and the piston outer rod 53 are equal to the outer diameter of the piston inner rod 52, and the outer edge of the piston head 51 is provided with a pressure-proof fillet 511. The liquid extraction piston 543 is a rod-shaped structure, and the outer diameter of the liquid extraction piston 543 is equal to the inner diameter of the cooling chamber 541. Since the inner diameters of the piston head 51 and the piston outer rod 53 are equal to the outer diameter of the piston inner rod 52, the contact area between the piston inner rod 52 and the piston outer rod 53 is increased during the impact load process, which significantly reduces the radial pressure and the risk of radial compression deformation. In addition, the pressure-proof fillet 511 prevents compression deformation of the contact surface between the piston head 51 and the inner cylinder body 3 when a slight radial deflection occurs.

[0046] Working process: When the aircraft landing gear is retracted, the piston outer rod 53 is retracted into the inner cylinder 3. At this time, the pumping piston 543 blocks the liquid inlet channel 521, preventing the energy storage medium from entering the cooling chamber 541. During the aircraft's high-altitude flight, the ambient temperature will drop below -50°C. At this time, the ambient cold energy will be transferred to the outer cylinder 2 and then transferred to the energy guide bridge 43 through the outer cylinder 2. The energy guide bridge 43 then transfers the cold energy to the energy storage medium in the energy storage chamber 41 for storage.

[0047] Before the aircraft lands, the landing gear will be opened first. At this time, the piston outer rod 53 will slide out and drive the pumping piston 543 to slide together. The pumping piston 543 slides to suck the low-temperature energy storage medium in the energy storage chamber 41 into the cooling chamber 541, pre-cooling the hydraulic oil and the piston inner rod 52 in advance.

[0048] When the aircraft lands on the ground and stops, the brake system generates huge heat due to friction, causing the ambient temperature of the entire actuator to rise rapidly. The outer cylinder 2 will heat up rapidly when the temperature rises due to the heat. When the temperature rises to above 25°C, the SMA spring 42 returns to its memory shape under the one-way memory effect. At this time, the SMA spring 42 will overcome the elastic force of the bias spring 44 and pull the energy-conducting bridge 43 to separate from the energy storage chamber 41, thereby disconnecting the heat transfer and preventing the heat of the outer cylinder 2 from being transferred to the energy storage chamber 41, ensuring that the energy storage medium in the energy storage chamber 41 remains at a low temperature. At the same time, when the aircraft lands, the piston outer rod 53 will be In the event of a huge instantaneous impact, since the hydraulic oil is pre-cooled in advance, it can generate a greater damping force during the impact process and provide a better cushioning support effect. Moreover, since it is used on the aircraft landing gear, the hydraulic oil does not need to circulate, and it only needs to protect the aircraft body in a one-time extreme impact. Therefore, pre-cooling will not affect the working response efficiency. It can also reduce the peak temperature rise caused by the heat generated by the hydraulic oil when it is impacted, and at the same time limit the diffusion of heat to the inner wall of the inner cylinder body 3, thereby preventing the inner wall of the inner cylinder body 3 and the piston inner rod 52 from being deformed due to the temperature increase and the huge instantaneous impact load.

[0049] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A surface adaptive anti-deformation actuator, comprising an oil guide member (1), characterized in that: The invention also comprises an outer cylinder (2), an inner cylinder (3), an energy storage assembly (4) and a piston assembly (5); the outer cylinder (2) is connected to the oil guide member (1); the inner cylinder (3) is arranged in the outer cylinder (2); the energy storage assembly (4) is arranged between the outer cylinder (2) and the inner cylinder (3); when the temperature is higher than a limit value, the energy storage assembly (4) and the outer cylinder (2) are changed from a contact state to a disconnected state; when the temperature drops below the limit value, the energy storage assembly (4) is connected to the outer cylinder (2) again; the piston assembly (5) is connected to the energy storage assembly (4); when the piston assembly (5) slides, the energy storage medium in the energy storage assembly (4) is sucked into the piston assembly (5).

2. The surface adaptive anti-deformation actuator according to claim 1, characterized in that: A first vacuum layer (6) is provided between the outer cylinder (2) and the energy storage component (4); and a second vacuum layer (7) is provided between the energy storage component (4) and the inner cylinder (3).

3. The surface adaptive anti-deformation actuator according to claim 2, characterized in that: The energy storage assembly (4) comprises an energy storage chamber (41), an SMA spring (42), an energy guiding bridge piece (43), a bias spring (44) and a fixing member (45); the energy storage chamber (41) is arranged between the vacuum layer 1 (6) and the vacuum layer 2 (7); the SMA spring (42) is connected to the energy storage chamber (41); the energy guiding bridge piece (43) is connected to the SMA spring (42); the bias spring (44) is connected between the energy guiding bridge piece (43) and the SMA spring (42); the fixing member (45) is connected to the energy storage chamber (41), and the outer ring of the fixing member (45) is connected to the inner wall of the outer cylinder body (2), and the inner ring of the fixing member (45) is connected to the outer wall of the inner cylinder body (3).

4. The surface adaptive anti-deformation actuator according to claim 3, characterized in that: The cold energy storage medium in the energy storage chamber (41) is a fluorinated liquid; the fixing member (45) is made of PEEK; the energy conducting bridge piece (43) is made of a material with a high thermal conductivity coefficient, and the energy conducting bridge piece (43) is an arc piece structure with an inner wall radius equal to an outer wall radius of the energy storage chamber (41).

5. The surface adaptive anti-deformation actuator according to claim 3, characterized in that: The piston assembly (5) comprises a piston head (51), a piston inner rod (52), a piston outer rod (53) and a cooling element (54); the piston head (51) is slidably mounted in the inner cylinder body (3); the piston inner rod (52) is mounted on the central axis of the inner cylinder body (3); the piston outer rod (53) is connected to the piston head (51) and slidably mounted on the piston inner rod (52); the cooling element (54) is connected between the energy storage chamber (41) and the piston inner rod (52).

6. The surface adaptive anti-deformation actuator according to claim 5, characterized in that: The cooling element (54) comprises a cooling chamber (541), a connecting pipe (542) and a liquid pumping piston (543); the cooling chamber (541) is provided in the piston inner rod (52); the connecting pipe (542) is connected between the piston inner rod (52) and the energy storage chamber (41); the liquid pumping piston (543) is slidably mounted in the cooling chamber (541) and connected to the piston outer rod (53).

7. The surface adaptive anti-deformation actuator according to claim 6, characterized in that: The tail of the piston inner rod (52) is provided with a liquid inlet channel (521), which is communicated with the cooling chamber (541); the connecting tube (542) and the head of the liquid pumping piston (543) are made of PEEK material, and the tail of the connecting tube (542) is installed in the liquid inlet channel (521).

8. The surface adaptive anti-deformation actuator according to claim 6, characterized in that: The inner diameters of the piston head (51) and the piston outer rod (53) are equal to the outer wall diameter of the piston inner rod (52), and the outer edge of the piston head (51) is provided with a pressure-proof fillet (511); the liquid pumping piston (543) is a rod-shaped structure, and the outer diameter of the liquid pumping piston (543) is equal to the inner wall diameter of the cooling chamber (541).

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