An experimental device suitable for observing internal deformation of a sealing ring under multi-field coupling

Abstract

The application discloses a kind of experimental devices suitable for the internal deformation observation of sealing ring under multi-field coupling, including mechanics loading module, external field applying module and observation module.The application is novel and reasonable in structure, by constructing mechanics loading module, simulating the continuous application of radial compression load of sealing ring from original state to sealing working state, constructing oil pressure / heating / refrigeration integrated module for the application of oil pressure and high / low temperature load near the sealing interface of sealing ring, together with force-thermal-flow field coupling loading platform, quantitative application of multiple external fields can be carried out flexibly on sealing ring, and the construction of observation module can be carried out. Under the coupling of multiple external fields, the real evolution process of internal deformation of sealing ring can be observed, and it is suitable for simulating and establishing accurate leakage mechanism model for piston sealing ring in aircraft landing gear, flap and other hydraulic buffer / actuator devices. The application also has the advantages of compact structure, wide application range for various piston sealing rings, large variation range of oil pressure and high / low temperature load, etc.

Description

Technical Field

[0001] This invention belongs to the field of testing and measurement, and relates to deformation measurement technology, particularly to an experimental device suitable for observing the internal deformation of a sealing ring under multi-field coupling. Background Technology

[0002] Seals are a common type of sealing structure. For example, piston seals in hydraulic damping / actuating devices such as aircraft landing gear and flaps are critical sealing structures. During actual flight, they frequently face harsh conditions involving radial compression loads, wide temperature ranges (high or low temperatures), and high hydraulic pressure coupling, inevitably leading to leakage problems that affect flight safety. Therefore, simulating and establishing an accurate model of piston seal leakage mechanisms has become a primary task in guiding sealing structure design and ensuring flight safety.

[0003] In some known solutions, researchers propose leakage mechanism models based on hybrid lubrication theory, primarily using quasi-static finite element analysis to calculate the stress distribution at the sealing interface to obtain the sealing state of the piston seal ring during operation. However, the internal deformation and stress state of the piston seal ring under the coupling of multiple fields such as force, heat, and flow are extremely complex. It is difficult to obtain an accurate stress distribution at the sealing interface using quasi-static finite element methods, thus making it impossible for the leakage mechanism model to accurately predict leakage behavior. Therefore, this invention innovatively proposes an experimental testing technique for the actual evolution of the internal deformation of the piston seal ring under multi-field coupling, to calculate an accurate stress distribution at the sealing interface and improve the leakage mechanism model. Summary of the Invention

[0004] The purpose of this invention is to provide an experimental device suitable for observing the internal deformation of a sealing ring under multi-field coupling. It can observe the real evolution process of the internal deformation of the sealing ring under multiple external field couplings, which is beneficial to further calculate the accurate stress distribution of the sealing interface based on the real interface displacement field, thereby improving the leakage mechanism model and solving the problem that the existing quasi-static finite element method is difficult to obtain the accurate stress distribution of the sealing interface, thus making the leakage mechanism model unable to accurately predict leakage behavior.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides an experimental apparatus suitable for observing the internal deformation of a sealing ring under multi-field coupling, comprising:

[0007] A mechanical loading module includes a support platform, a radial loading drive, a piston, and a sleeve movably mounted outside the piston. The piston has a sealing groove for fitting a test sealing ring. When the test sealing ring is located in the sealing groove, it can seal the gap between the sleeve and the piston. The inner wall of the sleeve has a push-stop structure for moving the test sealing ring. One of the sleeve and the piston is fixedly connected to the support platform, and the other is connected to the radial loading drive. The radial loading drive can move the sleeve and the piston relative to each other and use the push-stop structure to push the test sealing ring to the sealing groove, thereby achieving radial loading on the test sealing ring.

[0008] An external field application module is disposed on the sleeve or the piston. The external field application module is capable of applying at least one of the following external fields to the test sealing ring when the test sealing ring is radially loaded: a hydraulic flow field, a heating field, and a cooling field.

[0009] The observation module is capable of observing the internal deformation process of the test sealing ring when it is subjected to radial loading.

[0010] In some embodiments, a mounting baffle is provided inside the piston, and the mounting baffle is located at one end of the sealing groove;

[0011] The external field application module includes a heating component, a cooling component, and a hydraulic component, wherein:

[0012] The heating component is disposed on the piston or the sleeve;

[0013] The refrigeration component is disposed on the piston or the sleeve;

[0014] The hydraulic assembly includes a sealing ring and a fluid guide pipe formed within the mounting partition. The sealing ring is fitted around the piston and located at the end of the mounting partition away from the sealing groove. One end of the fluid guide pipe passes through the side wall of the piston and communicates with the gap between the piston and the sleeve. The other end of the fluid guide pipe is located on the end face of the mounting partition and is used to connect to an external pressure liquid source to apply a hydraulic flow field to the sealing surface of the test sealing ring at the sealing groove.

[0015] In some embodiments, the fluid guiding pipe includes a main fluid guiding pipe and branch fluid guiding pipes. The main fluid guiding pipe is located at the center of the mounting partition. Multiple branch fluid guiding pipes are radially arranged inside the mounting partition. One end of any branch fluid guiding pipe is connected to the main fluid guiding pipe, and the other end of any branch fluid guiding pipe passes through the side wall of the piston. The main fluid guiding pipe is used to connect to the external pressure fluid source.

[0016] In some embodiments, both the piston and the mounting plate are metal structures;

[0017] The heating assembly includes a heating resistor pipe disposed on the mounting partition, wherein a heating resistor capable of heating and raising the temperature is installed inside the heating resistor pipe, and the heating resistor can transfer the temperature to the test sealing ring through the mounting partition and the piston;

[0018] The refrigeration assembly includes a liquid nitrogen pipe disposed on the mounting partition. The liquid nitrogen pipe is used to connect to an external cryogenic nitrogen source, which can transfer temperature to the test sealing ring using the mounting partition and the piston.

[0019] In some embodiments, the experimental apparatus for observing the internal deformation of a sealing ring under multi-field coupling further includes a peripheral module, which comprises:

[0020] A liquid pump and a hydraulic sensor are provided, and the liquid guiding pipe is connected to the external pressure liquid source through the liquid pump and the hydraulic sensor;

[0021] The liquid nitrogen pipeline is connected to the cryogenic nitrogen source via the solenoid valve.

[0022] A temperature sensor is disposed on the piston or the sleeve, and is located at the sealing interface between the test sealing ring and the sleeve;

[0023] The controller is communicatively connected to at least one of the liquid pump, the hydraulic sensor, the solenoid valve, the temperature sensor, and the radial load drive.

[0024] In some embodiments, the piston outer wall is provided with a stepped groove, the stepped groove including a large end and a small end opposite to the large end, the outer diameter of the large end being larger than the outer diameter of the small end, and the large end and the small end being smoothly connected; the small end is used for initial fitting of the test sealing ring, the large end serving as the sealing groove, and the push-stop structure located at the end of the small end away from the large end, the push-stop structure being able to move the test sealing ring from the small end to the large end when the sleeve and the piston move relative to each other, thereby achieving radial loading on the test sealing ring.

[0025] In some embodiments, the push-stop structure is an annular retaining ring disposed on the inner wall of the sleeve.

[0026] In some embodiments, the radial loading drive is disposed on the support platform and connected to the bottom end of the piston; the bottom end of the sleeve is fixedly connected to the support platform.

[0027] In some embodiments, the radial loading drive is a vertical displacement loading stage, which includes:

[0028] A screw jack is mounted on the support platform and connected to the bottom end of the piston via a force sensor;

[0029] An electric motor is mounted on the support platform and connected to the screw jack. The electric motor is used to drive the screw jack to lift and lower, so as to move the piston relative to the sleeve.

[0030] In some embodiments, the observation module is a DR image acquisition module, which includes:

[0031] An X-ray source, located outside the sleeve, is used to emit X-rays into the sealing groove.

[0032] A detector is disposed outside the sleeve and located on both sides of the sleeve, respectively, along with the X-ray source. The detector is used to receive X-rays that pass through the sleeve and convert them into DR images for computer processing.

[0033] A sample rotation stage is located below the support platform, and the sample rotation stage is used to drive the mechanical loading module to rotate in situ.

[0034] The present invention achieves the following technical effects compared to the prior art:

[0035] The experimental device proposed in this invention, suitable for observing the internal deformation of sealing rings under multi-field coupling, has a novel and reasonable structure. It simulates the continuous application of radial compressive loads to the sealing ring from its original state to its sealed working state by constructing a mechanical loading module, and constructs an integrated oil pressure / heating / cooling module for applying oil pressure and high / low temperature loads near the sealing interface of the sealing ring. Together, they form a force-heat-flow field coupled loading platform, which can flexibly apply multiple external fields quantitatively to the sealing ring. With the construction of the observation module, it is possible to observe the real evolution process of internal deformation of the sealing ring under multiple external field coupling. It is suitable for simulating and establishing accurate leakage mechanism models of piston sealing rings in hydraulic buffer / actuator devices such as aircraft landing gear and flaps.

[0036] In some of the technical solutions disclosed in this invention, not only can the quantitative application of force-heat-flow field coupling be achieved, but the observation module is also built based on a digital X-ray radiography (DR) image acquisition module, enabling in-situ observation of the internal deformation of the piston seal ring under force-heat-flow field coupling. This invention also has advantages such as a compact experimental platform structure, wide applicability to various piston seal rings, and a large range of oil pressure and high / low temperature load variations. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the overall structure of the experimental device for observing the internal deformation of a sealing ring under multi-field coupling, as disclosed in an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of the main structure of the experimental apparatus for observing the internal deformation of a sealing ring under multi-field coupling, as disclosed in an embodiment of the present invention.

[0040] Figure 3 This is a partial structural cross-sectional view of the experimental apparatus for observing the internal deformation of a sealing ring under multi-field coupling, as disclosed in an embodiment of the present invention.

[0041] Figure 4 for Figure 3 Enlarged structural diagram at point A;

[0042] Figure 5 This is a schematic diagram of the assembly of the stepped groove and the push-block structure disclosed in an embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram of the sealing principle of the test sealing ring at the stepped groove disclosed in an embodiment of the present invention;

[0044] Figure 7 This is a schematic diagram illustrating the assembly and sealing principle of the test sealing ring and the plugging sealing ring disclosed in an embodiment of the present invention;

[0045] Figure 8 This is a schematic diagram illustrating the principle of DR image observation for the test sealing ring disclosed in an embodiment of the present invention.

[0046] In the figure, the attached reference numeral is: 100, experimental setup suitable for observing the internal deformation of a sealing ring under multi-field coupling;

[0047] 1. Mechanical loading module; 11. Support platform; 12. Radial loading drive; 1201. Screw jack; 1202. Motor; 1203. Power supply and controller interface; 13. Piston; 14. Sleeve; 15. Stepped groove; 1501. Small end; 1502. Sealing groove; 1503. Transition ramp; 16. Push-stop structure; 17. Mounting partition; 18. Spacing; 19. Force sensor; 110. Connecting device; 111. Heat insulation device; 112. Rectangular groove;

[0048] 2. External application module; 21. Main liquid guide pipe; 22. Branch liquid guide pipe; 23. Heating resistance pipe; 24. Liquid nitrogen pipe; 25. Sealing ring;

[0049] 3. Radiation source;

[0050] 4. Detector;

[0051] 5. Sample rotating stage;

[0052] 6. Test the sealing ring. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] The purpose of this invention is to provide an experimental device suitable for observing the internal deformation of a sealing ring under multi-field coupling. It can observe the real evolution process of the internal deformation of the sealing ring under multiple external field couplings, which is beneficial to further calculate the accurate stress distribution of the sealing interface based on the real interface displacement field, thereby improving the leakage mechanism model and solving the problem that the existing quasi-static finite element method is difficult to obtain the accurate stress distribution of the sealing interface, thus making the leakage mechanism model unable to accurately predict leakage behavior.

[0055] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] like Figures 1-4As shown, this embodiment provides an experimental device 100 suitable for observing the internal deformation of a sealing ring under multi-field coupling. It mainly includes a mechanical loading module 1, an external field application module 2, and an observation module. The mechanical loading module 1 includes a support platform 11, a radial loading drive 12, a piston 13, and a sleeve 14 movably assembled outside the piston 13. Both the sleeve 14 and the piston 13 are standard parts with compatible specifications. After assembly, the sleeve 14 and piston 13 are clearance-fitted, leaving an appropriate gap 18 (i.e., an annular gap). The piston 13 is provided with a sealing groove 1502 for mounting the test sealing ring 6 to be observed. When the test sealing ring 6 is located in the sealing groove 1502, it can seal the gap 18 between the sleeve 14 and the piston 13. At this time, the test sealing ring 6 is in a sealed working state and is subjected to radial extrusion force from the sleeve 14 and the piston 13. The inner wall of the sleeve 14 is provided with a push-stop structure 16 for moving the test sealing ring 6. One of the sleeve 14 and the piston 13 is connected to the support platform 11. One is fixedly connected (preferably a detachable fixed connection, such as a fixed assembly with the support platform 11 via screws or other connectors), and the other is connected to the radial loading drive 12. During use, the support platform 11 remains stationary in the driving direction of the radial loading drive 12. The radial loading drive 12 can drive the sleeve 14 and the piston 13 to move relative to each other. In the original state, that is, before the test observation, the test sealing ring 6 is fitted on the piston 13, but is not located at the sealing groove 1502. At this time, the test sealing ring 6 can be regarded as not being subjected to radial loading, and it does not form a sealing interface with the inner wall of the sleeve 14. By driving the sleeve 14 and the piston 13 to move relative to each other, the test sealing ring 6 can be pushed along the axial direction of the piston 13 to the sealing groove 1502 by the push structure 16 during the movement, thereby realizing the sliding seal between the test sealing ring 6 and the sleeve 14, and completing the radial pressure loading on the test sealing ring 6. It can be seen that the mechanical loading module 1 is essentially used to apply a radial pressure external field to the test sealing ring 6. The external field application module 2 is mounted on the sleeve 14 or the piston 13. When the test sealing ring 6 is radially loaded, the external field application module 2 can apply at least one of the hydraulic flow field, heating field and cooling field to the test sealing ring 6, thereby realizing the coupling of at least one of the hydraulic flow field, heating field and cooling field with the radial pressure external field, simulating the deformation condition of the sealing ring under multi-field coupling. The observation module is placed outside the sleeve 14 and is used to observe the deformation process of the test sealing ring 6 under multi-field coupling.

[0057] In some implementations, such as Figure 3 and Figure 4As shown, a mounting baffle 17 is provided inside the piston 13, and the mounting baffle 17 is located at one end of the sealing groove 1502. Based on this, the external field application module 2 includes a heating component, a cooling component, and a hydraulic component, wherein: the heating component is provided on the piston 13 or the sleeve 14 and can apply a heating field to the test sealing ring 6; the cooling component is provided on the piston 13 or the sleeve 14 and can apply a cooling field to the test sealing ring 6; the hydraulic component includes a sealing ring 25 and a liquid guiding pipe opened in the mounting baffle 17, such as... Figure 4 and Figure 7 As shown, the sealing ring 25 is sleeved on the outside of the piston 13 and located at the end of the mounting partition 17 away from the sealing groove 1502. Generally, it is preferred that the mounting partition 17 is close to the sealing groove 1502 and arranged axially below the sealing groove 1502 of the piston 13. At the same time, a rectangular groove 112 is provided on the outer wall of the piston 13 below the mounting partition 17. The sealing ring 25 is embedded and clamped in the rectangular groove 112. The piston 13 is sealed to the inner wall of the sleeve 14 through the sealing ring 25. During the test, the sealing ring 25 and the test sealing ring 6 are located at the two ends of the mounting partition 17 respectively, which are used to block the liquid with a certain pressure discharged through the liquid guide pipe and ensure that the liquid flows accurately to the test sealing ring 6. One end of the fluid guide pipe passes through the side wall of the piston 13 and communicates with the gap 18 between the piston 13 and the sleeve 14. The other end of the fluid guide pipe is located on the end face of the mounting partition 17 and is used to connect an external pressure fluid source to apply a hydraulic flow field to the sealing surface of the test sealing ring 6 at the sealing groove 1502 (i.e., the sealing interface between the test sealing ring 6 and the sleeve 14). The aforementioned pressure fluid source includes, but is not limited to, an oil supply device, which can supply oil with a certain pressure to the fluid guide pipe, thereby realizing the application of an external hydraulic field.

[0058] In some embodiments, to ensure sufficient liquid application, the liquid delivery conduit preferably includes a main liquid delivery pipe 21 and branch liquid delivery pipes 22, such as... Figure 4 As shown, the main fluid guide pipe 21 is located at the center of the mounting partition 17. Multiple fluid guide branches 22 are radially arranged inside the mounting partition 17. One end of any one fluid guide branch 22 is connected to the main fluid guide pipe 21, and the other end of any one fluid guide branch 22 passes through the side wall of the piston 13 and is connected to the partition 18. The main fluid guide pipe 21 is used to connect to the aforementioned pressure liquid source.

[0059] In some embodiments, to improve the overall structural compactness of the experimental platform and avoid interference between the heating and cooling components and other parts, it is preferable that both the heating and cooling components are located inside the piston 13 and integrated with the aforementioned hydraulic components. Specifically, both the piston 13 and the mounting partition 17 are made of thermally conductive metal. The heating component includes a heating resistor pipe 23 disposed on the mounting partition 17. A heating resistor capable of heating and raising the temperature is installed inside the heating resistor. When the heating resistor is energized, it generates heat and can transfer the temperature to the test sealing ring 6 through the mounting partition 17 and the piston 13 to achieve high-temperature heating loading. Similarly, the cooling component includes a liquid nitrogen pipe 24 disposed on the mounting partition 17. The liquid nitrogen pipe 24 is used to connect to an external low-temperature nitrogen source. The low-temperature liquid nitrogen supplied to the liquid nitrogen pipe 24 can transfer the temperature to the test sealing ring 6 through the mounting partition 17 and the piston 13 to achieve low-temperature cooling loading.

[0060] In some embodiments, the mounting plate 17 is preferably integrally formed with the piston 13.

[0061] In some embodiments, the heating resistor pipe 23 is preferably opened on the mounting partition 17 and avoids the liquid guiding branch pipe 22. The heating resistor pipe 23 passes through both ends of the mounting partition 17 in the axial direction, and the heating resistor is installed inside it.

[0062] In some embodiments, the liquid nitrogen pipe 24 can be a blind pipe structure opened within the mounting partition 17, avoiding the liquid guide branch pipe 22 and the heating resistance pipe 23. After the liquid nitrogen pipe 24 is connected to an external nitrogen source, the liquid nitrogen flows within the liquid nitrogen pipe 24 without leakage, serving only to cool the mounting partition 17. Alternatively, the liquid nitrogen pipe 24 can also be located outside the mounting partition 17, that is, one end of the liquid nitrogen pipe 24 is sealed to one end face of the mounting partition 17, and the other end of the liquid nitrogen pipe 24 is connected to an external nitrogen source. The liquid nitrogen reaches the mounting partition 17 through the liquid nitrogen pipe 24 and cools the mounting partition 17.

[0063] In some embodiments, the aforementioned experimental apparatus 100 for observing the internal deformation of a sealing ring under multi-field coupling also includes peripheral modules, which mainly include a liquid pump, a hydraulic sensor, a solenoid valve, a temperature sensor, and a controller. The aforementioned main liquid guide pipe 21 can be connected to an external pressure liquid source through the pipeline. The pipeline is equipped with a liquid pump to provide power for liquid flow and a hydraulic sensor for liquid pressure detection. The liquid nitrogen pipeline 24 can be connected to a cryogenic nitrogen source through a solenoid valve. The temperature sensor is set on the piston 13 or the sleeve 14 and is located at the sealing interface between the test sealing ring 6 and the sleeve 14. At least one of the aforementioned liquid pump, hydraulic sensor, solenoid valve, temperature sensor, and radial loading drive 12 is communicatively connected to the controller, wherein: the oil pressure pump is connected to the oil guide pipe through the controller, and the controller and the hydraulic sensor can jointly control the oil pressure at the sealing interface; the controller can control the liquid nitrogen supply by controlling the solenoid valve; and the temperature sensor installed near the sealing interface can jointly control the application of high / low temperature loads with the controller.

[0064] In some embodiments, the outer wall of the piston 13 is preferably provided with a stepped groove 15 for assembling the aforementioned test sealing ring 6. Specifically, the stepped groove 15 is a two-stage stepped groove, which includes a large end and a small end 1501 opposite to the large end, such as... Figure 5 and Figure 6 As shown, the outer diameter of the large end is larger than that of the small end 1501, and the large end and the small end 1501 can be smoothly connected by a transition ramp 1503. The small end 1501 is used for the initial fitting of the test sealing ring 6. At this time, the test sealing ring 6 is in its original state and is not subject to radial pressure. The large end serves as the sealing groove 1502. The push-stop structure 16 is located at the end of the small end 1501 that is far from the large end. When the sleeve 14 and the piston 13 move relative to each other, the push-stop structure 16 can move the test sealing ring 6 from the small end 1501 to the large end, thereby switching the test sealing ring 6 from its original state to the sealing working state and completing the radial loading of the test sealing ring 6.

[0065] In some implementations, such as Figure 5 As shown, the push-stop structure 16 is preferably an annular retaining ring disposed on the inner wall of the sleeve 14.

[0066] In some embodiments, the aforementioned radial loading drive 12 is preferably fixedly mounted on the support platform 11 by bolts or other connecting components and connected to the bottom end of the piston 13; simultaneously, the bottom end of the sleeve 14 is fixedly connected to the support platform 11 by bolts or other connecting components to provide a piston chamber for the piston 13. Based on this, the aforementioned stepped groove 15, mounting partition 17, and rectangular groove 112 are preferably arranged sequentially from the top to the bottom of the piston 13, with the small end 1501 facing the top of the piston 13 and the sealing groove 1502 facing the bottom of the piston 13; the push-stop structure 16 is always located above or flush with the sealing groove 1502. Figure 6 The test sealing ring 6 in its original state is fitted onto the small end 1501. The piston 13 is lifted upward by the aforementioned radial loading drive 12, which causes the piston 13 to move upward relative to the sleeve 14. During the upward movement, the push-stop structure 16 first contacts the top of the test sealing ring 6 in its original state. Then the test sealing ring 6 is pushed under the push-stop structure 16, but the piston 13 continues to move upward, thereby causing the piston 13 and the test sealing ring 6 to move relative to each other until the test sealing ring 6 reaches the sealing groove 1502 of the piston 13.

[0067] In some embodiments, the radial loading drive 12 is preferably a vertical displacement loading platform, such as a jack, a vertically arranged electric slide, an electric telescopic cylinder, a pneumatic cylinder, a hydraulic cylinder, etc. In this embodiment, the vertical displacement loading platform preferably adopts a jack structure, specifically including a screw jack 1201 and a motor 1202. The screw jack 1201 is fixedly installed on the support platform 11 and connected to the bottom end of the piston 13 through a force sensor 19. The motor 1202 is set on the support platform 11 and connected to the screw jack 1201. The motor 1202 is used to drive the screw jack 1201 to rise and fall, so as to realize the movement of the piston 13 relative to the sleeve 14. The above-mentioned screw jack is an existing finished part, and its specific structure and working principle will not be described in detail here. The motor 1202 is preferably a servo motor, which is equipped with a power supply and controller interface 1203. It can be connected to the controller in the peripheral module through the power supply and controller interface 1203, so as to accurately control the position and movement speed of the test sealing ring 6 on the piston 13. Force sensor 19 can monitor the frictional force at the sealing interface of the test sealing ring 6 in real time during the continuous application of radial compressive load. In practical applications, the aforementioned controller can also have data receiving and processing functions, and force sensor 19, hydraulic sensor and temperature sensor can all be connected to the controller for communication.

[0068] In some embodiments, considering that a heating component and a cooling component are integrated within the piston 13, to prevent heat loss, the force sensor 19 is preferably connected to the bottom end of the piston 13 sequentially via a connecting device 110 and a heat insulation device 111. Both the connecting device 110 and the heat insulation device 111 are preferably cylindrical structures, and they can be connected and assembled using bolts or other connecting components. The heat insulation device 111 can be a ceramic heat insulation ring or the like.

[0069] In some embodiments, the observation module is preferably a DR image acquisition module (DR stands for "digital radiography"), specifically a micron-CT device. This device includes a radiation source 3, a detector 4, and a sample rotation stage 5. The radiation source 3 is located outside the sleeve 14 and can be supported and installed by a corresponding mounting bracket or other structure. The radiation source 3 is generally arranged at the same height as the sealing groove 1502 and is used to emit X-rays into the sealing groove 1502. The detector 4 is located outside the sleeve 14 and can be supported and installed by a corresponding mounting bracket or other structure. The detector 4 and the radiation source 3 are located on opposite sides of the sleeve 14. The detector 4 is used to receive the X-rays that penetrate the sleeve 14 and convert them into DR images (i.e., real-time DR images of the test sealing ring 6) for computer processing. The sample rotation stage 5 is located below the support platform 11 and is used to support and install the entire mechanical loading module 1. The sample rotation stage 5 is an existing finished product and is mainly used to drive the mechanical loading module 1 to rotate in situ, so that the radiation source 3 can emit X-rays from the sleeve 14 at multiple angles, realizing 360-degree all-round observation of the test sealing ring 6. The aforementioned micron-CT equipment can specifically be the Zeiss Xradia 520 Versa X-ray microscopy system.

[0070] As described above, the observation module selected is the DR image acquisition module. Its X-ray source 3 emits X-rays into the sleeve 14, enabling transmission observation of the cross-section of the sealing ring and achieving the purpose of observing the internal deformation of the sealing ring. This solves the current problem of the "invisibility" of the internal deformation of the sealing ring. This observation module is coupled with the aforementioned multi-field coupling loading device, thus realizing rapid in-situ observation of the internal deformation of the sealing ring under force-heat-flow field coupling.

[0071] In some embodiments, the experimental apparatus 100 suitable for observing the internal deformation of the sealing ring under multi-field coupling can be specially equipped with heating resistors, liquid nitrogen supply sources, and oil supply devices. Among them, the heating resistors can be finished resistance wires or other heating resistors; the liquid nitrogen supply source can be a liquid nitrogen tank.

[0072] In summary, in this scheme, the mechanical loading module 1 is used to apply radial compressive load to the test sealing ring 6 from its original state to its sealed working state. The test sealing ring 6 is installed inside the stepped groove 15 on the outer wall of the piston 13, and in its original state, it is located at the smaller end 1501 with a smaller diameter, so that the test sealing ring 6 is in its original undeformed state. When the piston 13 moves upward, the test sealing ring 6 is pushed from the smaller end 150 to the larger diameter sealing groove 1502, thereby realizing the continuous application of radial compressive load to the test sealing ring 6. The design principle of the stepped groove 15 to realize the continuous application of radial compressive load is as follows: Figure 5 and Figure 6 As shown.

[0073] The external application module 2 is equipped with heating, cooling, and hydraulic components, and innovatively integrates hydraulic and temperature loading functions onto the piston 13, achieving integrated hydraulic / heating / cooling. This allows for the application of hydraulic loads and high / low temperature loads near the sealing interface of the sealing ring, thus enabling the quantitative application of force-heat-flow field coupling. Specifically, by installing a partition 17 between the rectangular groove 112 and the stepped groove 15, and by creating an oil guide pipe within the partition 17 for oil delivery, hydraulic loading at the sealing interface is achieved. This design also effectively avoids the high pressure effect of liquid oil on the piston and force loading device in traditional testing devices. Furthermore, by machining a liquid nitrogen pipe 24 and a heating resistance pipe 23 inside the piston 13, the high thermal conductivity of the metal material is utilized to apply high / low temperature loads.

[0074] The DR image acquisition module is used to continuously acquire DR images of the internal deformation evolution of the test sealing ring 6 during the application of a coupled force-thermal-fluid field. Continuous DR image acquisition mainly targets the following two processes: the radial compressive load application process of the test sealing ring 6 from its initial state to its sealed working state, and the application process of hydraulic load and high / low temperature load under the sealed working state. The entire mechanical loading module 1, containing the test sealing ring 6, is fixed on the sample rotation stage 5. X-rays emitted by the X-ray source 3 pass through the test sealing ring 6, are received by the detector 4, and converted into DR images for computer processing. This micron-CT device can acquire DR images at a rate of at least 2 frames per second. The principle of the DR image continuous acquisition module for in-situ observation of the internal deformation of the sealing ring is as follows: Figure 8 As shown.

[0075] The following section uses the piston seal ring in hydraulic buffer / actuator devices such as aircraft landing gear and flaps as the test seal ring 6 to specifically explain the usage and experimental principle of the aforementioned experimental apparatus 100 suitable for observing the internal deformation of seal rings under multi-field coupling. The usage process is as follows:

[0076] Step 1: Prepare the test sealing ring 6 to be tested and check whether there is any damage on the surface of the sealing structure that may affect the sealing performance; check whether all components such as the mechanical loading module 1, the external field application module 2, and the observation module are complete, and verify whether they can normally achieve extreme working conditions such as high oil pressure and high / low temperature, so as to avoid dangerous situations such as personnel injury and equipment damage during the experiment.

[0077] Step 2: Install the test sealing ring 6 in the stepped groove 15 on the piston 13. At this time, a sealing ring 25 is provided in the rectangular groove 112. Then push the piston 13 into the sleeve 14. Further check whether the test sealing ring 6 in the stepped groove 15 is located at the step with the smaller diameter, whether the upper end of the test sealing ring 6 is located below the push-stop structure 16 of the sleeve 14, and whether the sealing ring 25 is in a normal interference fit state.

[0078] Step 3: Fix the support platform 11 of the mechanical loading module 1 to the sample rotation stage 5 of the micron-CT equipment with bolts. Simultaneously adjust the xyz coordinates and rotation angle of the sample rotation stage 5, as well as the z coordinates of the X-ray source 3 and detector 4, to ensure that the circumferential section of the test sealing ring 6 is included within the field of view, and the pixel resolution is less than 5μm. The sample rotation stage 5, X-ray source 3, and detector 4 are all existing finished parts, and their specific structures and working principles will not be described in detail here.

[0079] Step 4: Radial loading drive 12 lifts piston 13, causing piston 13 to move upward at a constant speed of 0.5 mm / s until the push structure 16 completely pushes the test sealing ring 6 in the stepped groove 15 to the larger diameter step (i.e., sealing groove 1502), achieving the sealing working state of the test sealing ring 6, and simultaneously recording the value of force sensor 19.

[0080] Step 5: At this time, the test sealing ring 6 and the plugging sealing ring 25 are in the same working state. Keep the current room temperature unchanged and gradually apply oil pressure at a rate of 0.5MPa / s. The oil pressure application range is 0MPa~38MPa.

[0081] Step Six: When piston 13 begins to move in Step Four, the micron-CT device is synchronously controlled to continuously acquire DR images of the internal deformation evolution of the test sealing ring 6 at a rate of 2 frames per second.

[0082] Step 7: To further study the effect of different temperatures on the internal deformation evolution of the test sealing ring 6, repeat steps 2 to 6, and adjust the temperature load in step 5. The temperature load is applied in the range of -50℃ to 160℃.

[0083] Step 8: After completing all tests, reduce the oil pressure to zero and remove the mechanical loading module 1; after the device temperature returns to room temperature, remove the test sealing ring 6.

[0084] As described above, the experimental setup 100 for observing the internal deformation of the piston seal under multi-field coupling in this scheme simulates the continuous application of radial compressive loads to the piston seal from its original state to its sealed working state by constructing a mechanical loading module. An integrated oil pressure / heating / cooling module is constructed to apply oil pressure and high / low temperature loads near the sealing interface of the piston seal. Together, they form a force-heat-flow field coupled loading platform, thus enabling the quantitative application of force-heat-flow field coupling. Combined with the construction of a digital X-ray imaging (DR) module based on a micron-scale CT device, in-situ observation of the internal deformation of the piston seal under force-heat-flow field coupling is achieved. This scheme has significant advantages in achieving quantitative application of force-heat-flow field coupling and in-situ observation of the internal deformation of the piston seal. It also has advantages such as a compact experimental platform structure, wide applicability to various piston seals, and a large range of oil pressure and high / low temperature load variations.

[0085] 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 the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and objectives of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0086] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An experimental apparatus suitable for observing the internal deformation of a sealing ring under multi-field coupling, characterized in that, include: The mechanical loading module (1) includes a support platform (11), a radial loading drive (12), a piston (13), and a sleeve (14) movably mounted outside the piston (13). The piston (13) is provided with a sealing groove (1502) for mounting a test sealing ring (6). When the test sealing ring (6) is located in the sealing groove (1502), it can seal the gap (18) between the sleeve (14) and the piston (13). The inner wall is provided with a push-stop structure (16) for moving the test sealing ring (6). One of the sleeve (14) and the piston (13) is fixedly connected to the support platform (11), and the other is connected to the radial loading drive (12). The radial loading drive (12) enables the sleeve (14) and the piston (13) to move relative to each other, and uses the push-stop structure (16) to push the test sealing ring (6) to the sealing groove (1502). The piston (13) is provided with an installation partition (17) inside, and the installation partition (17) is located at one end of the sealing groove (1502); the piston (13) is provided with a stepped groove (15) on its outer wall, the stepped groove (15) including a large end and a small end (1501) opposite to the large end, the outer diameter of the large end is larger than the outer diameter of the small end (1501), and the large end and the small end (1501) are smoothly connected; the small end ( 1501) is used for the initial fitting of the test sealing ring (6), the large end is used as the sealing groove (1502), the push structure (16) is located at the end of the small end (1501) away from the large end, the push structure (16) can move the test sealing ring (6) from the small end (1501) to the large end when the sleeve (14) and the piston (13) move relative to each other, so as to realize radial loading on the test sealing ring (6); An external field application module (2) is disposed on the sleeve (14) or the piston (13). The external field application module (2) is capable of applying at least one of a hydraulic flow field, a heating field, and a cooling field to the test sealing ring (6) when the test sealing ring (6) is radially loaded. The external field application module (2) includes a heating component, a cooling component, and a hydraulic component, wherein: the heating component is disposed on the piston (13) or the sleeve (14); the cooling component is disposed on the piston (13) or the sleeve (14); and the hydraulic component includes a sealing ring (25) and an opening component. A liquid guiding pipe is provided in the mounting partition (17), and the sealing ring (25) is sleeved on the outside of the piston (13) and located at the end of the mounting partition (17) away from the sealing groove (1502); one end of the liquid guiding pipe passes through the side wall of the piston (13) and communicates with the gap (18) between the piston (13) and the sleeve (14); the other end of the liquid guiding pipe is located on the end face of the mounting partition (17) for connecting an external pressure liquid source to apply a hydraulic flow field to the sealing surface of the test sealing ring (6) at the sealing groove (1502); The observation module is capable of observing the internal deformation process of the test sealing ring (6) when it is subjected to radial loading. The observation module is a DR image acquisition module, which includes a radiation source (3), a detector (4) and a sample rotation stage (5). The radiation source (3) is located outside the sleeve (14) and is used to emit X-rays to the sealing groove (1502). The detector (4) is located outside the sleeve (14) and is located on both sides of the sleeve (14) respectively with the radiation source (3). The detector (4) is used to receive the X-rays that pass through the sleeve (14) and convert them into DR images for computer processing. The sample rotation stage (5) is located below the support platform (11) and is used to drive the mechanical loading module (1) to rotate in place.

2. The experimental apparatus for observing the internal deformation of a sealing ring under multi-field coupling as described in claim 1, characterized in that, The fluid guiding pipe includes a main fluid guiding pipe (21) and branch fluid guiding pipes (22). The main fluid guiding pipe (21) is located at the center of the mounting partition (17). Multiple branch fluid guiding pipes (22) are radially arranged inside the mounting partition (17). One end of any branch fluid guiding pipe (22) is connected to the main fluid guiding pipe (21), and the other end of any branch fluid guiding pipe (22) penetrates the side wall of the piston (13). The main fluid guiding pipe (21) is used to connect to the external pressure liquid source.

3. The experimental apparatus for observing the internal deformation of a sealing ring under multi-field coupling as described in claim 1, characterized in that, Both the piston (13) and the mounting partition (17) are metal structures; The heating assembly includes a heating resistor pipe (23) disposed on the mounting partition (17), wherein a heating resistor capable of heating and raising the temperature is installed in the heating resistor pipe (23), and the heating resistor can transfer the temperature to the test sealing ring (6) by means of the mounting partition (17) and the piston (13); The refrigeration assembly includes a liquid nitrogen pipe (24) disposed on the mounting partition (17), the liquid nitrogen pipe (24) being used to connect to an external low-temperature nitrogen source, the low-temperature nitrogen source being able to transfer temperature to the test sealing ring (6) using the mounting partition (17) and the piston (13).

4. The experimental apparatus for observing the internal deformation of a sealing ring under multi-field coupling as described in claim 3, characterized in that, It also includes peripheral modules, which include: A liquid pump and a hydraulic sensor are provided, and the liquid guiding pipe is connected to the external pressure liquid source through the liquid pump and the hydraulic sensor; The liquid nitrogen pipeline (24) is connected to the cryogenic nitrogen source via the solenoid valve. A temperature sensor is disposed on the piston (13) or the sleeve (14) and located at the sealing interface between the test sealing ring (6) and the sleeve (14); The controller is communicatively connected to at least one of the liquid pump, the hydraulic sensor, the solenoid valve, the temperature sensor, and the radial load drive (12).

5. The experimental apparatus for observing the internal deformation of a sealing ring under multi-field coupling according to any one of claims 1 to 4, characterized in that, The push-stop structure (16) is an annular retaining ring disposed on the inner wall of the sleeve (14).

6. The experimental apparatus for observing the internal deformation of a sealing ring under multi-field coupling according to any one of claims 1 to 4, characterized in that, The radial loading drive (12) is disposed on the support platform (11) and connected to the bottom end of the piston (13); the bottom end of the sleeve (14) is fixedly connected to the support platform (11).

7. The experimental apparatus for observing the internal deformation of a sealing ring under multi-field coupling as described in claim 6, characterized in that, The radial loading drive (12) is a vertical displacement loading stage, which includes: A spiral jack (1201) is mounted on the support platform (11) and connected to the bottom end of the piston (13) via a force sensor (19); A motor (1202) is mounted on the support platform (11) and connected to the screw jack (1201). The motor (1202) is used to drive the screw jack (1201) to lift and lower, so as to realize the movement of the piston (13) relative to the sleeve (14).

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