A sealed interface contact pressure measurement device

Abstract

The application relates to the technical field of sealing, in particular to a sealing interface contact pressure measuring device. The device comprises a measuring shell, a measuring sealing ring, a measuring rod, a strain sensor, a displacement sensor and an actuator. The measuring rod is arranged in a sliding channel. The measuring sealing ring is in interference fit with the outer peripheral wall of the measuring rod to seal the oil storage gap along the axial extension path of the sliding channel. The measuring rod is internally provided with a cavity extending to both axial ends. The measuring rod comprises a fitting rod section and a deformation rod section coaxially connected. The radial wall thickness of the deformation rod section is smaller than that of the fitting rod section. The measuring sealing ring has contact pressure on the deformation rod section when the deformation rod section slides through the position of the measuring sealing ring. The strain sensor is connected to the inner peripheral wall of the deformation rod section. The strain sensor is used for detecting the radial and axial strain of the deformation rod section. The actuator is used for driving the measuring rod to slide along the sliding channel. Thus, the problem that it is difficult to accurately measure the contact pressure of the sealing ring is solved.

Description

Technical Field

[0001] This application relates to the field of sealing technology, and more specifically, to a sealing interface contact pressure measuring device. Background Technology

[0002] The contact pressure at the sealing interface between the sealing ring and the piston rod is a core parameter determining the sealing performance of a hydraulic cylinder. The design optimization and performance evaluation of the sealing structure both use interface contact pressure as the core evaluation indicator. Under normal operating conditions, the sealing interface needs to maintain a contact pressure within a reasonable range to prevent leakage of internal high-pressure oil, ensuring the working pressure and execution accuracy of the hydraulic cylinder. When the interface contact pressure is too low, the sealing interface cannot form an effective sealing barrier, and oil easily leaks through the interface gap, preventing the hydraulic cylinder from reaching the expected working pressure, thus affecting the power output and operational reliability of the entire hydraulic system. When the interface contact pressure is too high, the assembly and fitting difficulty between the sealing ring and the piston rod increases significantly, the motion resistance during the reciprocating motion of the piston rod increases substantially, and the wear rate of the sealing ring accelerates under continuous high-pressure contact, easily leading to early seal failure and a significant reduction in the service life of the seal.

[0003] Currently, accurate measurement of contact pressure at sealing interfaces faces multiple technical challenges. The sealing interface is a closed, millimeter-narrow slit structure immersed in a high-pressure oil environment, making it difficult to achieve non-destructive embedding of pressure sensors. The embedding process easily alters the original contact morphology of the sealing interface, disrupting its original stress state. Flexible pressure sensors are prone to damage under extreme temperature environments and the dynamic reciprocating friction of the piston rod, making in-situ, high-spatial-resolution measurement impossible without disrupting the original stress state of the sealing interface. Furthermore, the dynamic reciprocating motion of the piston rod, coupled with high-pressure conditions and temperature changes, results in a non-uniform, non-linear distribution of contact stress at the sealing interface, further increasing the difficulty of accurate contact pressure measurement. Summary of the Invention

[0004] To address the problem of difficulty in accurately measuring the contact pressure of a sealing ring, this application provides a device for measuring the contact pressure of a sealing interface, comprising:

[0005] The measuring housing has a sliding channel and an oil inlet; the oil inlet is connected to the sliding channel.

[0006] A measuring sealing ring is installed on the inner circumferential wall of the sliding channel;

[0007] A measuring rod passes through the sliding channel; an oil storage gap is formed between the outer peripheral wall of the measuring rod and the inner peripheral wall of the measuring housing; the oil storage gap communicates with the oil injection port; the measuring sealing ring is interference-fitted with the outer peripheral wall of the measuring rod to cut off and seal the oil storage gap along the axial extension path of the sliding channel; the measuring rod has an internal cavity extending to both axial ends; the measuring rod includes a coaxially connected assembly rod section and a deformation rod section; the radial wall thickness of the deformation rod section is smaller than the radial wall thickness of the assembly rod section; when the deformation rod section slides past the position of the measuring sealing ring, the measuring sealing ring exerts contact pressure on the deformation rod section;

[0008] A strain sensor is connected to the inner peripheral wall of the deformed rod segment; the strain sensor is used to detect the radial and axial strain of the deformed rod segment.

[0009] A displacement sensor is connected to the measuring rod;

[0010] An actuator is connected to the measuring rod, and the actuator is used to drive the measuring rod to slide along the sliding channel.

[0011] Optionally, the assembly rod segment includes a first assembly rod and a second assembly rod arranged coaxially; the first assembly rod and the second assembly rod are detachably connected; an assembly ring groove is formed between the opposing end faces of the first assembly rod and the second assembly rod; the deformable rod segment is connected to the second assembly rod.

[0012] The measuring rod further includes a pressure ring and a sealing unit; the pressure ring is installed in the assembly ring groove; the opposing end faces of the first and second assembly rods have assembly gaps with the pressure ring respectively; the inner peripheral wall of the pressure ring is interference-fitted with the outer peripheral wall of the deformed rod segment; when the pressure ring slides past the measuring sealing ring, the measuring sealing ring exerts contact pressure on the outer peripheral wall of the pressure ring; the sealing unit is connected between the deformed rod segment and the first assembly rod; the sealing unit isolates the cavity between the assembly ring groove and the inner peripheral side of the deformed rod segment.

[0013] Optionally, the axial length of the deformed rod segment is greater than the axial length of the pressure ring.

[0014] Optionally, the pressure ring includes a first pressure-bearing ring and a second pressure-bearing ring connected together; the first pressure-bearing ring is located on the outer periphery of the second pressure-bearing ring; the axial thickness of the first pressure-bearing ring is less than the axial thickness of the second pressure-bearing ring.

[0015] Optionally, an oil passage groove is provided on the inner circumferential side of the pressure ring; the oil passage groove extends to both axial ends of the pressure ring so that the oil passage groove communicates with the assembly gap.

[0016] Optionally, the first assembly rod includes a first rod body and a connecting screw connected coaxially; the outer diameter of the connecting screw is smaller than the outer diameter of the first rod body; the second assembly rod includes a second rod body and a connecting nut connected coaxially; the connecting nut is located on the inner circumference of the second rod body; the connecting screw is threadedly connected to the connecting nut.

[0017] Optionally, the end face of the first assembly rod facing the second assembly rod is provided with a receiving annular groove; the sealing unit is located in the receiving annular groove; the outer diameter of the receiving annular groove is equal to the outer diameter of the deformable rod segment; and the radial thickness of the pressure ring is greater than the radial thickness of the deformable rod segment.

[0018] Optionally, the sealing unit includes a sealing ring body and a first sealing ring; the sealing ring body is coaxially connected to the end of the deformable rod segment away from the second assembly rod; the first sealing ring is located between the outer peripheral wall of the sealing ring body and the inner peripheral wall of the receiving ring groove;

[0019] The axial distance between the first sealing ring and the pressure ring is greater than half the axial length of the deformed rod segment.

[0020] Optionally, the sealing unit further includes a second sealing ring; the second sealing ring is located between the sealing ring body and the opposing end faces of the first mounting rod;

[0021] The outer diameter of the second sealing ring is larger than the inner diameter of the deformed rod segment.

[0022] Optionally, the measuring housing includes an outer shell, a collar, and an end cap; the end cap is detachably connected to the outer shell; the collar is located between the end cap and the outer shell; and the measuring sealing ring is fitted onto the inner circumferential wall of the collar.

[0023] To address the problem of difficulty in accurately measuring the contact pressure of the sealing ring, this application has the following advantages:

[0024] By connecting a strain sensor to the inner circumferential wall of the deformed section of the measuring rod, the radial and axial strain of the deformed section is used to obtain the contact pressure at the sealing interface. This allows for in-situ measurement without disrupting the original assembly state of the measuring seal ring or the contact morphology of the sealing interface, thus minimizing the risk of oil leakage. It closely reflects the actual service stress conditions of the seal, improving the reliability of the test data. Furthermore, the built-in design of the strain sensor minimizes its impact on the sealing interface, and the high-pressure oil environment and dynamic reciprocating friction do not easily interfere with the strain sensor's detection. Attached Figure Description

[0025] Figure 1 A schematic diagram of a sealing interface contact pressure measuring device according to one embodiment is shown;

[0026] Figure 2 It shows Figure 1 A schematic diagram of the measuring housing of the sealing interface contact pressure measuring device;

[0027] Figure 3 It shows Figure 1 A schematic diagram of the measuring rod of the sealing interface contact pressure measuring device;

[0028] Figure 4 It shows Figure 3 Enlarged view of point A on the middle sealing interface contact pressure measuring device;

[0029] Figure 5 A schematic diagram showing a measurement seal ring and pressure ring not in contact in one embodiment is shown;

[0030] Figure 6 A schematic diagram showing the contact between the measuring sealing ring and the pressure ring portion in one embodiment is shown;

[0031] Figure 7 A schematic diagram showing the measuring seal ring in full contact with the pressure ring in one embodiment is shown;

[0032] Figure 8 A schematic diagram showing the contact between the measuring sealing ring and the pressure ring portion of another embodiment is shown;

[0033] Figure 9 A schematic diagram of another embodiment is shown where the measuring seal ring and pressure ring are not in contact;

[0034] Figure 10 A cross-sectional view of the pressure ring is shown.

[0035] Reference numerals: Measuring housing 10; Sliding channel 11; Oil inlet 12; Outer shell 13; Collar 14; End cap 15; Observation hole 16; Oil reservoir 17; Oil reservoir gap 18; Measuring sealing ring 20; Measuring rod 30; Assembly rod segment 31; First assembly rod 311; First rod body 3111; Connecting screw 3112; Second assembly rod 312; Second rod body 3121; Connecting nut 3122; Receiving ring groove 313; Assembly ring groove 314; Oil reservoir ring groove 315; Deformation rod segment 32; Pressure ring 33; First pressure bearing ring 331; Second pressure bearing ring 332; Oil passage groove 333; Sealing unit 34; Sealing ring body 341; First sealing ring 342; Second sealing ring 343; Assembly gap 35; Displacement sensor 40; Displacement sensing element 41; Displacement sensing wire 42; Connecting plate 43; Sensing nut 44; Adapter nut 45. Detailed Implementation

[0036] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, and are not intended to imply any limitation on the scope of the disclosure.

[0037] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientations or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. In addition, the terms "installed", "set up", "equipped with", "connected", and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0038] In the scenario of pressure measurement at a sealed interface, the sealing contact interface between the measuring sealing ring 20 and the measuring rod 30 is a closed, millimeter-narrow slit structure. This interface is immersed in the high-pressure oil environment within the oil reservoir 18. Conventional pressure sensors are difficult to embed without damage. The sensor embedding process easily disrupts the original contact shape of the measuring sealing ring 20 and the original stress state of the sealing interface, making it impossible to achieve in-situ measurement without changing the original stress state of the sealing interface. At the same time, flexible pressure sensors are prone to damage under the combined effects of extreme temperature environments and the dynamic reciprocating frictional motion of the measuring rod 30, making it difficult to meet the measurement requirements for high spatial resolution.

[0039] In this embodiment, a sealing interface contact pressure measuring device is provided, such as... Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the sealing interface contact pressure measuring device includes a measuring housing 10, a measuring sealing ring 20, a measuring rod 30, a strain sensor, a displacement sensor 40, and an actuator.

[0040] The measuring housing 10 has a sliding channel 11 and an oil inlet 12. The oil inlet 12 is connected to the sliding channel 11 and is used to inject oil into the sliding channel 11.

[0041] The measuring sealing ring 20 is installed on the inner peripheral wall of the sliding channel 11, thereby simulating the position and movement relationship of the measuring sealing ring 20 in real working conditions.

[0042] The measuring rod 30 passes through the sliding channel 11. An oil-retaining gap 18 is formed between the outer peripheral wall of the measuring rod 30 and the inner peripheral wall of the measuring housing 10. The oil-retaining gap 18 is part of the assembly gap 35 between the measuring housing 10 and the measuring rod 30. Figure 4 As shown, the oil storage gap 18 is the gap between the two measuring sealing rings 20. The oil storage gap 18 is connected to the oil inlet 12. The measuring sealing ring 20 is interference-fitted with the outer peripheral wall of the measuring rod 30, cutting off and sealing the oil storage gap 18 along the axial extension path of the sliding channel 11 to reduce the possibility of oil leakage.

[0043] The measuring rod 30 has an internal cavity extending to both axial ends. The measuring rod 30 includes a coaxially connected assembly rod segment 31 and a deformation rod segment 32. The radial wall thickness of the deformation rod segment 32 is less than that of the assembly rod segment 31. When the deformation rod segment 32 slides past the position of the measuring sealing ring 20, the measuring sealing ring 20 exerts contact pressure on the deformation rod segment 32, causing radial elastic deformation. The internal cavity of the measuring rod 30 allows the internal space of the measuring rod 30 to communicate with the external atmosphere, preventing the gas pressure inside the closed cavity from generating a reaction force due to changes in cavity volume during radial elastic deformation of the deformation rod segment 32. This eliminates the interference of internal air pressure changes on the deformation process of the deformation rod segment 32, ensuring the accuracy of the strain detection results.

[0044] The strain sensor is connected to the inner peripheral wall of the deformed rod segment 32. The strain sensor is used to detect the radial and axial strain of the deformed rod segment 32. The strain sensor can achieve in-situ detection of contact pressure without damaging the sealing interface of the measuring seal ring 20, thus preventing media leakage. It closely matches the actual stress conditions of the test seal ring, improving the reliability of the test data. Simultaneously, it does not affect the sealing interface, does not interfere with the reciprocating motion of the measuring rod 30, and avoids damage to the strain sensor in dynamic reciprocating friction and high-pressure oil environments.

[0045] The displacement sensor 40 is connected to the measuring rod 30, and the actuator is also connected to the measuring rod 30. The actuator drives the measuring rod 30 to slide along the sliding channel 11. By driving the measuring rod 30 to slide back and forth along the sliding channel 11, and with the displacement sensor 40 detecting the displacement of the measuring rod 30, the axial movement distance of the measuring rod 30 during the process from the initial contact of the measuring sealing ring 20 with the deformed rod segment 32 to the complete separation from the deformed rod segment 32 can be measured. Subtracting the axial length of the deformed rod segment 32 from this movement distance yields the contact interface length between the measuring sealing ring 20 and the measuring rod 30, achieving high spatial resolution contact parameter measurement. The reciprocating acquisition method enables repeatable testing and is suitable for long-term continuous testing.

[0046] This embodiment connects a strain sensor to the inner peripheral wall of the deformable segment 32 of the measuring rod 30. By utilizing the radial and axial strain of the deformable segment 32, the contact pressure at the sealing interface can be obtained. This allows for in-situ measurement without disrupting the original assembly state of the sealing ring 20 or the contact morphology of the sealing interface, thus minimizing the risk of oil leakage. It closely reflects the actual service stress conditions of the seal, improving the reliability of the test data. Furthermore, the built-in placement of the strain sensor minimizes its impact on the sealing interface, and the high-pressure oil environment and dynamic reciprocating friction motion do not easily interfere with the strain sensor's detection.

[0047] Furthermore, the assembly rod segment 31 includes a first assembly rod 311 and a second assembly rod 312 coaxially arranged. The first assembly rod 311 and the second assembly rod 312 are detachably connected, i.e., threadedly connected, which allows for convenient assembly and disassembly of the pressure ring 33, enabling the pressure ring 33 to be replaced with different specifications to adapt to different measurement conditions. An assembly ring groove 314 is formed between the facing end faces of the first assembly rod 311 and the second assembly rod 312, and the deformable rod segment 32 is connected to the second assembly rod 312.

[0048] The measuring rod 30 also includes a pressure ring 33 and a sealing unit 34. The pressure ring 33 is installed in the assembly ring groove 314, and the opposing end faces of the first assembly rod 311 and the second assembly rod 312 have assembly gaps 35 with the pressure ring 33. The inner peripheral wall of the pressure ring 33 is interference-fitted with the outer peripheral wall of the deformable rod segment 32. When the pressure ring 33 slides past the measuring sealing ring 20, the measuring sealing ring 20 exerts contact pressure on the outer peripheral wall of the pressure ring 33. It should be understood that by leaving an assembly gap 35 between the opposing end faces of the first assembly rod 311 and the second assembly rod 312 and the pressure ring 33, the radial force of the measuring sealing ring 20 can be transmitted radially along the pressure ring 33, and is less susceptible to interference from the first assembly rod 311 and the second assembly rod 312, thus ensuring the accuracy of the contact pressure transmission.

[0049] The pressure ring 33 of different thicknesses can be replaced according to measurement needs, thereby achieving measurement requirements for different contact interface widths. Moreover, the sensitivity of the contact interface width can be improved by using the pressure ring 33 without changing the length of the deformable rod segment 32, that is, without changing the thickness of the sensitive area.

[0050] The sealing unit 34 is connected between the deformable rod segment 32 and the first assembly rod 311, and the sealing unit 34 isolates the assembly ring groove 314 from the cavity on the inner circumference of the deformable rod segment 32. This provides a clean installation environment for the strain sensor, reduces the negative impact of oil on the strain sensor detection, and improves the reliability of the detection results.

[0051] The first assembly rod 311 has a connecting hole in the radial direction. This hole is used to connect to the cavity inside the measuring rod 30, so as to avoid the reaction force generated by the gas pressure in the closed cavity changing with the cavity volume when the deformed rod segment 32 undergoes radial elastic deformation, thus ensuring the accuracy of the strain detection results.

[0052] Furthermore, the axial length of the deformable rod segment 32 is greater than the axial length of the pressure ring 33. The width of the contact interface between the deformable rod segment 32 and the pressure ring 33 is the same as the width of the pressure ring 33. The area of ​​the contact interface between the deformable rod segment 32 and the pressure ring 33 is relatively small, enabling measurement of a narrower contact interface and thus improving the spatial resolution of the contact interface.

[0053] Furthermore, such as Figure 4As shown, the pressure ring 33 includes a first pressure-bearing ring 331 and a second pressure-bearing ring 332 connected together. The first pressure-bearing ring 331 is located on the outer periphery of the second pressure-bearing ring 332, and the axial thickness of the first pressure-bearing ring 331 is smaller than the axial thickness of the second pressure-bearing ring 332. First, the axial thickness of the first pressure-bearing ring 331 is equal to the width of the contact interface, thereby further improving the spatial resolution of the contact pressure measurement. Furthermore, different contact interface width measurement requirements can be achieved by changing the axial thickness of the first pressure-bearing ring 331. Then, the connection area between the pressure ring 33 and the deformable rod segment 32 can be increased, reducing the frictional force exerted by the measuring sealing ring 20 on the pressure ring 33 when it slides over it, thus avoiding large axial deformation, making the structure more stable, and further improving measurement accuracy. Finally, the larger axial thickness of the second pressure-bearing ring 332 facilitates the machining of chamfers at the contact point between the pressure ring 33 and the deformable rod segment 32, thereby facilitating the assembly operation of the pressure ring 33.

[0054] Furthermore, such as Figure 10 As shown, an oil passage groove 333 is provided on the inner circumference of the pressure ring 33. The oil passage groove 333 extends to both axial ends of the pressure ring 33, so that the oil passage groove 333 communicates with the assembly gap 35. By providing an oil passage groove 333 extending to both axial ends on the inner circumference of the pressure ring 33, and connecting the oil passage groove 333 with the assembly gap 35, the oil passages on both axial sides of the pressure ring 33 can be connected during the axial movement of the measuring rod 30 and the partial passage of the pressure ring 33 through the measuring sealing ring 20. This keeps the oil pressure on the left and right sides of the pressure ring 33 balanced, minimizes errors in contact pressure measurement due to inconsistent oil pressure on both sides, and ensures the accuracy of the measurement results.

[0055] Meanwhile, the pressure ring 33 is provided with an oil passage groove 333, which makes it easier to assemble the inner peripheral wall of the pressure ring 33 with the outer peripheral wall of the deformation rod section 32 through an interference fit.

[0056] Furthermore, the first assembly rod 311 includes a first rod body 3111 coaxially connected to a connecting screw 3112. The outer diameter of the connecting screw 3112 is smaller than the outer diameter of the first rod body 3111. The second assembly rod 312 includes a second rod body 3121 coaxially connected to a connecting nut 3122. The connecting nut 3122 is located on the inner circumference of the second rod body 3121, and the connecting screw 3112 and the connecting nut 3122 are threadedly connected. This threaded connection structure, where the connecting screw 3112 and the connecting nut 3122 mate, allows for convenient assembly and disassembly of the first assembly rod 311 and the second assembly rod 312, facilitating the replacement of the pressure ring 33.

[0057] Furthermore, the end face of the first assembly rod 311 facing the second assembly rod 312 is provided with a receiving annular groove 313. The sealing unit 34 is located within the receiving annular groove 313, the outer diameter of which is equal to the outer diameter of the deformable rod segment 32, and the radial thickness of the pressure ring 33 is greater than that of the deformable rod segment 32. Due to the greater radial thickness of the pressure ring 33, when the pressure ring 33 is assembled to the outer circumferential surface of the deformable rod segment 32, the outer diameter of the pressure ring 33 needs to be equal to the outer diameter of the first assembly rod 311 and the second assembly rod 312 to ensure the stability of the measuring sealing ring 20 during measurement. This indirectly indicates that the structural strength of the first rod body 3111 and the second rod body 3121 is high, thereby ensuring the structural stability of the first rod body 3111 and the second rod body 3121 on both sides of the assembly gap 35, avoiding interference from additional deformation on the measurement results of the strain sensor, and ensuring measurement accuracy.

[0058] Furthermore, the sealing unit 34 includes a sealing ring 341 and a first sealing ring 342. The sealing ring 341 is coaxially connected to the end of the deformable rod segment 32 away from the second mounting rod 312, and the first sealing ring 342 is located between the outer peripheral wall of the sealing ring 341 and the inner peripheral wall of the receiving annular groove 313. The axial distance between the first sealing ring 342 and the pressure ring 33 is greater than half the axial length of the deformable rod segment 32.

[0059] It should be understood that the structural arrangement of the sealing ring 341 in conjunction with the first sealing ring 342 reliably isolates the assembly ring groove 314 from the inner circumferential cavity of the deformed rod segment 32, preventing oil from entering the cavity. By setting the axial distance between the first sealing ring 342 and the pressure ring 33 to be greater than half the axial length of the deformed rod segment 32, a lower limit for this axial distance is defined, ensuring sufficient axial distance between the first sealing ring 342 and the pressure ring 33. This avoids the contact pressure of the first sealing ring 342 affecting the deformation detection area of ​​the deformed rod segment 32, reduces interference from additional stress on strain detection, and ensures the accuracy of the contact pressure measurement results.

[0060] Furthermore, the inner circumferential wall of the sealing ring 341 is conical, and the inner diameter of the sealing ring 341 gradually increases along the direction approaching the deformable rod segment 32, thereby facilitating the attachment of strain sensors to the inner circumferential side of the deformable rod segment 32. The maximum value of the inner diameter of the sealing ring 341 is smaller than the inner diameter of the second assembly rod 312, ensuring the thickness and rigidity of the sealing ring 341, thereby reducing the impact of the deformation of the sealing ring 341 on the deformation detection of the deformable rod segment 32.

[0061] The end face of the second rod 3121 facing the first rod 3111 is provided with an oil storage ring groove 315. The oil storage ring groove 315 communicates with the assembly ring groove 314, and the inner diameter of the oil storage ring groove 315 is equal to the outer diameter of the deformed rod segment 32. The gap between the sealing ring 341 and the inner peripheral wall of the receiving ring groove 313 can reduce the oil flow resistance on one side of the pressure ring 33 in the axial direction, and the oil storage ring groove 315 can balance the oil flow resistance on the other side of the pressure ring 33 in the axial direction, thereby improving the balance of oil pressure on both sides of the pressure ring 33 in the axial direction.

[0062] Furthermore, the sealing unit 34 also includes a second sealing ring 343. The second sealing ring 343 is located between the opposing end faces of the sealing ring body 341 and the first mounting rod 311. The outer diameter of the second sealing ring 343 is larger than the inner diameter of the deformable rod segment 32.

[0063] By providing a second sealing ring 343 between the opposing end faces of the sealing ring 341 and the first assembly rod 311, the sealing performance of the sealing unit 34 can be further improved in conjunction with the first sealing ring 342. This enhances the isolation effect between the assembly ring groove 314 and the inner circumferential cavity of the deformable rod segment 32, and more reliably prevents oil from entering the cavity. By setting the outer diameter of the second sealing ring 343 to be larger than the inner diameter of the deformable rod segment 32, the contact pressure area of ​​the second sealing ring 343 can avoid the deformation detection area of ​​the deformable rod segment 32. This prevents the axial contact pressure of the second sealing ring 343 from causing additional deformation in the deformable rod segment 32, reduces the interference of the contact pressure of the sealing structure itself on the strain detection results, and ensures the accuracy of the contact pressure measurement.

[0064] Furthermore, the measuring housing 10 includes an outer shell 13, a collar 14, and an end cap 15. The end cap 15 is detachably connected to the outer shell 13, the collar 14 is located between the end cap 15 and the outer shell 13, and the measuring sealing ring 20 is fitted onto the inner circumferential wall of the collar 14. This detachable connection between the end cap 15 and the outer shell 13 allows for easy disassembly and replacement of the collar 14, facilitating the replacement of collars 14 and measuring sealing rings 20 of different specifications to meet the testing requirements of sealing interface contact pressure with different parameters, thus expanding the applicability of the device.

[0065] An observation hole 16 is provided on the outer casing 13, and an oil storage cavity 17 is provided at the end of the end cap 15 near the collar 14. The observation hole 16 communicates with the oil storage cavity 17 and is used to observe whether there is any oil leakage.

[0066] The displacement sensor 40 includes a displacement sensing element 41, a displacement sensing cable 42, a connecting plate 43, a sensing nut 44, and an adapter nut 45. The displacement sensing element 41 and the displacement sensing cable 42 are connected, the displacement sensor 40 is connected to the displacement sensing cable 42, and the displacement sensing cable 42 is connected to the connecting plate 43. The sensing nut 44 is used to lock the displacement sensing cable 42 and the connecting plate 43. The connecting plate 43 and the adapter nut 45 are detachably connected. One end of the adapter nut 45 has an external thread, and the other end has an internal thread. The external thread end is used to connect the connecting plate 43 and the displacement sensing cable 42, and the internal thread end is used to connect to the actuator.

[0067] Figure 5 This indicates that the measuring sealing ring 20 has not yet moved to the pressure ring 33. Figure 6 This indicates the situation where the sealing ring 20 presses against both the deformable rod segment 32 and the pressure ring 33 simultaneously. At this time, liquid pressure enters through the gap on the left side of the pressure ring 33, while the gap on the right side is covered by the sealing ring. The elastic deformation zone simultaneously experiences hydraulic pressure and the pressure exerted by the sealing ring on the pressure ring 33. Figure 7 This indicates that the measuring seal 20 completely covers the pressure ring 33. Figure 8 This indicates that the measuring sealing ring 20 is about to move out of the pressure ring 33. At this time, the sealing ring acts on the first assembly rod 311 and the pressure ring 33. The gap on the right side of the pressure ring 33 is connected to the air in the right cavity. The pressure of the oil in the gap is released to the same as the external atmospheric pressure. The sensitive area only feels the pressure of the measuring sealing ring 20 acting on the pressure ring 33. Figure 9 This indicates that the elastic deformation area has completely separated from the contact area of ​​the sealing ring, and the force measured by the sealing ring 20 is no longer acting on the elastic deformation area, meaning the force on the elastic deformation area has disappeared.

[0068] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes can be made in form and detail without departing from the scope of this disclosure.

Claims

1. A sealing interface contact pressure measuring device, characterized in that, The sealing interface contact pressure measuring device includes: The measuring housing has a sliding channel and an oil inlet; the oil inlet is connected to the sliding channel. A measuring sealing ring is installed on the inner circumferential wall of the sliding channel; A measuring rod passes through the sliding channel; an oil storage gap is formed between the outer peripheral wall of the measuring rod and the inner peripheral wall of the measuring housing; the oil storage gap communicates with the oil injection port; the measuring sealing ring is interference-fitted with the outer peripheral wall of the measuring rod to cut off and seal the oil storage gap along the axial extension path of the sliding channel; the measuring rod has an internal cavity extending to both axial ends; the measuring rod includes a coaxially connected assembly rod section and a deformation rod section; the radial wall thickness of the deformation rod section is smaller than the radial wall thickness of the assembly rod section; when the deformation rod section slides past the position of the measuring sealing ring, the measuring sealing ring exerts contact pressure on the deformation rod section; A strain sensor is connected to the inner peripheral wall of the deformed rod segment; the strain sensor is used to detect the radial and axial strain of the deformed rod segment. A displacement sensor is connected to the measuring rod; An actuator, connected to the measuring rod, is used to drive the measuring rod to slide along the sliding channel; The assembly rod segment includes a first assembly rod and a second assembly rod arranged coaxially; the first assembly rod and the second assembly rod are detachably connected; an assembly ring groove is formed between the opposing end faces of the first assembly rod and the second assembly rod; the deformable rod segment is connected to the second assembly rod; The measuring rod further includes a pressure ring and a sealing unit; the pressure ring is installed in the assembly ring groove; the opposing end faces of the first and second assembly rods have assembly gaps with the pressure ring respectively; the inner peripheral wall of the pressure ring is interference-fitted with the outer peripheral wall of the deformed rod segment; when the pressure ring slides past the measuring sealing ring, the measuring sealing ring exerts contact pressure on the outer peripheral wall of the pressure ring; the sealing unit is connected between the deformed rod segment and the first assembly rod; the sealing unit isolates the cavity between the assembly ring groove and the inner peripheral side of the deformed rod segment; The axial length of the deformable rod segment is greater than the axial length of the pressure ring.

2. The sealing interface contact pressure measuring device according to claim 1, characterized in that, The pressure ring includes a first pressure-bearing ring and a second pressure-bearing ring connected together; the first pressure-bearing ring is located on the outer periphery of the second pressure-bearing ring; the axial thickness of the first pressure-bearing ring is less than the axial thickness of the second pressure-bearing ring.

3. The sealing interface contact pressure measuring device according to claim 1, characterized in that, An oil passage groove is provided on the inner circumferential side of the pressure ring; the oil passage groove extends to both axial ends of the pressure ring so that the oil passage groove communicates with the assembly gap.

4. The sealing interface contact pressure measuring device according to claim 1, characterized in that, The first assembly rod includes a first rod body and a connecting screw connected coaxially; the outer diameter of the connecting screw is smaller than the outer diameter of the first rod body; the second assembly rod includes a second rod body and a connecting nut connected coaxially; the connecting nut is located on the inner circumference of the second rod body; the connecting screw is threadedly connected to the connecting nut.

5. The sealing interface contact pressure measuring device according to claim 1, characterized in that, The end face of the first assembly rod facing the second assembly rod is provided with a receiving annular groove; the sealing unit is located in the receiving annular groove; the outer diameter of the receiving annular groove is equal to the outer diameter of the deformable rod segment; the radial thickness of the pressure ring is greater than the radial thickness of the deformable rod segment.

6. The sealing interface contact pressure measuring device according to claim 5, characterized in that, The sealing unit includes a sealing ring body and a first sealing ring; the sealing ring body is coaxially connected to the end of the deformable rod segment away from the second assembly rod; the first sealing ring is located between the outer peripheral wall of the sealing ring body and the inner peripheral wall of the receiving ring groove; The axial distance between the first sealing ring and the pressure ring is greater than half the axial length of the deformed rod segment.

7. The sealing interface contact pressure measuring device according to claim 6, characterized in that, The sealing unit further includes a second sealing ring; the second sealing ring is located between the sealing ring body and the opposing end faces of the first assembly rod; The outer diameter of the second sealing ring is larger than the inner diameter of the deformed rod segment.

8. The sealing interface contact pressure measuring device according to claim 1, characterized in that, The measuring housing includes an outer shell, a collar, and an end cap; the end cap is detachably connected to the outer shell; the collar is located between the end cap and the outer shell; and the measuring sealing ring is assembled on the inner circumferential wall of the collar.

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