A hydraulic support liquid pipe joint sealing device

Abstract

The utility model relates to hydraulic support sealing technical field especially relates to a kind of hydraulic support liquid pipe joint sealing device to solve the problem that the material used in the prior art due to hydraulic support liquid pipe joint sealing is easy to break and affect the sealing performance of hydraulic support liquid pipe joint sealing. Hydraulic support liquid pipe joint sealing device includes sealing main body, sealing main body is made of hydrolytic polyurethane material, and the section of sealing main body is D-shaped structure, the curvature radius of arc-shaped sealing surface is adapted to the inner wall of liquid pipe joint, for converting the axial impact force of high-pressure emulsion into radial expansion force to realize hydraulic self-tight sealing. The corresponding plane of flat support back and installation groove forms surface contact, for providing anti-extrusion support. The hydraulic support liquid pipe joint sealing device provided by the utility model is used in the sealing of hydraulic support liquid pipe joint.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic support sealing technology, and in particular to a hydraulic support pipe joint sealing device. Background Technology

[0002] Hydraulic supports, as the core equipment for roof support, rely on the powerful hydraulic pressure provided by columns and jacks to achieve their support function. The hydraulic system consists of a main fluid supply system and a support hydraulic system. Powered by high-pressure emulsion supplied by a hydraulic pump station, it controls multiple hydraulic cylinders through various hydraulic valve groups, driving the supports to perform lifting, pushing, and other actions. In the hydraulic system, the fluid pipe joints are the weakest point in the seal. Vibration at the support's fluid pipe joints during fluid inflow and outflow causes uneven stress on the seals. During support movement, the fluid pipes are pulled back and forth, causing compression and deformation of the seals at the joints. Prolonged exposure to these adverse conditions makes the seals extremely prone to damage, leading to frequent leaks. Furthermore, workers must carry different sizes of fluid pipe joint seals for frequent replacement, resulting in high labor intensity and tedious work.

[0003] Currently, the hydraulic support pipe joint seal adopts a split-type structure, mainly composed of a nitrile rubber O-ring and a polyoxymethylene (POM) retaining ring. However, the existing seals frequently fail, primarily due to their poor wear and compression resistance. Furthermore, the split structure makes the seal prone to flipping under frequent tension, leading to seal damage after long-term operation. When the hydraulic support moves, the emulsion enters the support, causing severe vibration and significant tensile force at the pipe joint, resulting in O-ring wear and loss of resilience, thus affecting sealing performance.

[0004] Therefore, how to solve the problem that the sealing performance of hydraulic support pipe joints is affected by the easy damage of the materials used for sealing in the existing technology is one of the important problems that urgently need to be solved in this field. Utility Model Content

[0005] In view of this, the present invention provides a hydraulic support pipe joint sealing device to solve the problem in the prior art where the sealing performance of the hydraulic support pipe joint is affected by the easy damage of the materials used for sealing the hydraulic support pipe joint.

[0006] According to one aspect of the present invention, a hydraulic support pipe joint sealing device is provided. The hydraulic support pipe joint sealing device includes a sealing body made of hydrolyzed polyurethane material, and the cross-section of the sealing body is D-shaped. The D-shaped structure includes:

[0007] The arc-shaped sealing surface has a radius of curvature that is adapted to the inner wall of the liquid pipe joint to convert the axial impact force of the high-pressure emulsion into a radial expansion force to achieve a hydraulic self-tightening seal.

[0008] The planar support back forms a surface contact with the corresponding plane of the mounting groove to provide anti-extrusion support;

[0009] The sealing body and the mounting groove are interference fit with an interference amount of 15%. This is used to form an initial static seal through pre-compression under zero pressure and to enhance the sealing performance through hydraulic self-tightening effect under high pressure.

[0010] According to one aspect of the present invention, the hydraulic support pipe joint sealing device has a curvature center of curvature of the arc-shaped sealing surface biased towards the inner side of the sealing body. The arc-shaped sealing surface is also used to disperse the impact force of high-pressure liquid and convert the axial component of the liquid pressure into radial sealing force, thereby reducing the tangential deformation of the sealing lip under vibration conditions.

[0011] According to one aspect of the hydraulic support pipe joint sealing device of the present invention, when the outer diameter φD of the sealing body is ≤50mm, the outer diameter tolerance of the sealing body is -0.4mm to -0.1mm;

[0012] When the cross-sectional dimension CS of the sealing body is ≤30mm, the tolerance of the sealing body is +0.1mm~+0.3mm;

[0013] When the height H of the sealing body is ≤30mm, the tolerance is ±0.2mm.

[0014] According to one aspect of the present invention, the hydraulic support pipe joint sealing device has an axial dimension of 30%-40% of the axial dimension of the D-shaped structure; the surface roughness Ra of the flat support back is ≤0.8μm to ensure a tight fit with the mounting groove plane.

[0015] According to one aspect of the present invention, the sealing device for the hydraulic support pipe joint has a sealing body whose dimensions are adapted to the mounting groove of the hydraulic support pipe joint, and the dimensions of the mounting groove are 50mm×45mm×5mm.

[0016] According to one aspect of the hydraulic support pipe joint sealing device of this utility model, the physical properties of the hydrolyzed polyurethane material include:

[0017] The hardness of the hydrolyzed polyurethane material is 95±2A;

[0018] The tensile strength of hydrolyzed polyurethane materials is ≥55 N / mm². 2 Elongation at break ≥430%;

[0019] The hydrolyzed polyurethane material has an elastic recovery rate of 49%, a tear strength of ≥125 N / mm, and an abrasion loss of 15 mm. 3 .

[0020] According to one aspect of the present invention, the hydraulic support pipe joint sealing device has a rounded corner in the transition area between the arc-shaped sealing surface of the D-shaped structure and the planar support back, with a radius of 0.5mm-1mm, to avoid stress concentration.

[0021] According to one aspect of the present invention, the hydraulic support pipe joint sealing device has an annular groove on the axial end face of the sealing body. The depth of the annular groove is 0.3mm-0.5mm, which is used to accommodate minor deformations that may occur during installation.

[0022] According to one aspect of the present invention, the hydraulic support pipe joint sealing device has a working temperature range of -40℃ to +120℃ and a compression permanent deformation rate of ≤8% under a hydraulic pressure of 10MPa.

[0023] According to one aspect of the present invention, the hydraulic support pipe joint sealing device has a D-shaped structure that is an integral structure.

[0024] The D-shaped structure is used to replace the traditional combination of split O-rings and polyoxymethylene retaining rings. It does not require distinguishing the direction or assembling multiple parts during installation, and can withstand mechanical impacts with an axial vibration frequency ≤50Hz and an amplitude ≤2mm generated by the movement of hydraulic supports.

[0025] The above-mentioned technical solutions adopted in this utility model embodiment can achieve the following beneficial effects: In the above-mentioned hydraulic support pipe joint sealing device, the hydraulic support pipe joint sealing device includes a sealing body, which is made of hydrolyzed polyurethane material, and the cross-section of the sealing body is a D-shaped structure. Traditional sealing materials are prone to hydrolytic aging and mechanical property decay under long-term immersion in hydraulic support emulsion, and are prone to material embrittlement, cracking or strength reduction, eventually losing their sealing ability. However, the hydrolyzed polyurethane molecular structure contains hydrolysis-resistant groups, which can resist the erosion of water and chemical media in the emulsion, avoiding the molecular chain breakage problem caused by hydrolysis of traditional materials, and can still maintain the integrity of the material after long-term use. In addition, the curvature radius of the arc surface is adapted to the inner wall of the pipe joint, which can convert the axial impact force of the high-pressure emulsion into radial expansion force. This force conversion makes the sealing surface pressure increase uniformly with the increase of liquid pressure, avoiding excessive material deformation or fatigue caused by local stress concentration. At the same time, the radial expansion force makes the sealing surface fit tightly with the inner wall of the joint, reducing local wear caused by liquid scouring.

[0026] Secondly, the planar support back forms surface contact with the mounting groove plane, providing rigid support. When high-pressure liquid attempts to force the seal body into the gap, the planar support back disperses the pressure through large-area contact, preventing the seal from deforming into the gap. This avoids the extrusion tearing problem caused by the lack of support in traditional O-rings, structurally protecting the material from mechanical damage.

[0027] Based on this, traditional seals, if the interference fit is insufficient, cannot form an effective pre-seal at low pressure, allowing liquid to easily leak from the gaps and erode the sealing surface, leading to premature material wear. If the interference fit is unreasonable, excessive compression at high pressure may cause permanent material deformation and loss of elasticity. A 15% interference fit creates a pre-compression contact pressure in the seal body after installation, forming an initial static seal. This pre-tightening force ensures no gaps at the sealing surface under low pressure, preventing premature erosion and corrosion of the material due to liquid leakage. Under high pressure, the sealing surface pressure increases synchronously with the system pressure. This pressure-adaptive characteristic ensures that the sealing surface remains in tight contact, preventing high-pressure liquid from breaking down the sealing surface and causing jet erosion, reducing localized damage to the material caused by high-pressure impact. This effectively solves the problem in existing technologies where the sealing performance of hydraulic support pipe joints is affected by the easily damaged materials used in the seals. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the original sealing section provided as an example of this utility model;

[0030] Figure 2 This is a schematic cross-sectional view of the sealing body provided as an example of this utility model;

[0031] Figure 3 This is a schematic diagram of the sealing assembly structure provided as an example of the present utility model;

[0032] Figure 4 This is a schematic diagram of the sealing tolerance provided as an example of the present invention.

[0033] Figure label:

[0034] 101-O-ring, 102-retaining ring, 200-sealing body, 201-arc sealing surface, 202-flat support back, 301-male end of connector, 302-female end of connector, 303-U-pin. Detailed Implementation

[0035] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0036] It should be understood that the steps described in the method embodiments of this utility model may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this utility model is not limited in this respect.

[0037] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc., mentioned in this utility model are only used to distinguish different devices, modules, or units, and are not used to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0038] It should be noted that the terms "a" and "a plurality of" used in this utility model are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0039] The names of the messages or information exchanged between the multiple devices in this embodiment of the invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0040] Hydraulic supports, as the core equipment for roof support, rely on the powerful hydraulic pressure provided by columns and jacks to achieve their support function. The hydraulic system consists of a main fluid supply system and a support hydraulic system. Powered by high-pressure emulsion supplied by a hydraulic pump station, it controls multiple hydraulic cylinders through various hydraulic valve groups, driving the supports to perform lifting, pushing, and other actions. In the hydraulic system, the fluid pipe joints are the weakest point in the seal. Vibration at the support's fluid pipe joints during fluid inflow and outflow causes uneven stress on the seals. During support movement, the fluid pipes are pulled back and forth, causing compression and deformation of the seals at the joints. Prolonged exposure to these adverse conditions makes the seals extremely prone to damage, leading to frequent leaks. Furthermore, workers must carry different sizes of fluid pipe joint seals for frequent replacement, resulting in high labor intensity and tedious work.

[0041] Currently, the hydraulic support pipe joint seal adopts a split-type structure, mainly composed of a nitrile rubber O-ring and a polyoxymethylene (POM) retaining ring. However, the existing seals frequently fail, primarily due to their poor wear and compression resistance. Furthermore, the split structure makes the seal prone to flipping under frequent tension, leading to seal damage after long-term operation. When the hydraulic support moves, the emulsion enters the support, causing severe vibration and significant tensile force at the pipe joint, resulting in O-ring wear and loss of resilience, thus affecting sealing performance.

[0042] To address the aforementioned problems, an exemplary embodiment of this utility model provides a hydraulic support pipe joint sealing device to solve the problem in the prior art where the sealing performance of the hydraulic support pipe joint is affected by the easy damage of the materials used for sealing the hydraulic support pipe joint.

[0043] The following will describe in detail, with reference to the accompanying drawings, a hydraulic support pipe joint sealing device according to an embodiment of the present invention.

[0044] Figure 1 This is a schematic diagram of the original sealing section provided as an example of this utility model. Figure 2 This is a schematic cross-sectional view of the sealing body 200 provided as an example of the present invention, as shown below. Figures 1-2 As shown, the hydraulic support pipe joint sealing device includes a sealing body 200, which is made of hydrolyzed polyurethane material and has a D-shaped cross-section. The radius of curvature of the arc-shaped sealing surface 201 is adapted to the inner wall of the pipe joint to convert the axial impact force of the high-pressure emulsion into a radial expansion force to achieve a hydraulic self-tightening seal. The planar support back 202 forms a surface contact with the corresponding plane of the mounting groove to provide anti-extrusion support. The sealing body 200 and the mounting groove are interference-fitted with an interference amount of 15%, which is used to form an initial static seal through pre-compression under zero pressure and to enhance the sealing performance through the hydraulic self-tightening effect under high pressure.

[0045] In practical applications, such as Figure 1 As shown, the original liquid pipe joint seal consists of an O-ring 101 and a retaining ring 102. The O-ring 101 is made of ordinary nitrile rubber, and the retaining ring 102 is made of polyoxymethylene. Nitrile rubber has low tensile strength and surface hardness (85A), making it prone to extrusion, deformation, and edge cutting on one side of the seal. High-temperature hydrolysis-resistant polyurethane material is selected to compensate for the original seal's insufficient hardness and strength. Furthermore, polyurethane material has good resilience and is less prone to failure in emulsion media. Comparing the advantages and disadvantages of the two materials, it is recommended to use high-temperature hydrolysis-resistant polyurethane material as the sealing material for the liquid pipe joint. Its physical properties are shown in Table 1.

[0046] Table 1 Comparison of Material Properties

[0047]

[0048] In practical applications, O-ring 101 is located on the pressure-receiving side. Under the periodic impact of high-pressure emulsion on the pipeline vibration and pulling during inlet and outlet, the liquid exerts an upward oblique force on O-ring 101. This force tends to extrude the relatively soft nitrile rubber O-ring from the gap in its mounting groove. Once partially extruded, it is highly susceptible to twisting and overturning under subsequent movement and pressure changes, leading to seal failure and rapid wear. The main function of retainer ring 102 is to physically prevent O-ring extrusion. However, it does not provide a sealing function itself, and as an independent component from O-ring 101, it may experience relative displacement under severe vibration and pipe deformation, reducing the protective effect. The two independent components are more prone to misalignment and separation under complex stress, increasing the risk of failure.

[0049] Therefore, as Figure 2 As shown, the hydraulic support pipe joint sealing device includes a sealing body 200, which is made of hydrolyzed polyurethane material and has a D-shaped cross-section. Traditional sealing materials, under long-term immersion in the hydraulic support emulsion, are prone to hydrolytic aging and mechanical property degradation, easily leading to material embrittlement, cracking, or strength reduction, ultimately losing their sealing ability. However, the hydrolyzed polyurethane molecular structure contains hydrolysis-resistant groups, which can resist the erosion of moisture and chemical media in the emulsion, avoiding the molecular chain breakage problems caused by hydrolysis in traditional materials, and maintaining material integrity even after long-term use. Furthermore, the curvature radius of the arc-shaped surface is adapted to the inner wall of the pipe joint, converting the axial impact force of the high-pressure emulsion into a radial expansion force. This force conversion causes the sealing surface pressure to increase uniformly with the increase of liquid pressure, avoiding excessive material deformation or fatigue caused by localized stress concentration. Simultaneously, the radial expansion force ensures a tight fit between the sealing surface and the inner wall of the joint, reducing localized wear caused by liquid scouring.

[0050] Secondly, the planar support back 202 forms surface contact with the mounting groove plane, providing rigid support. When high-pressure liquid attempts to force the sealing body 200 into the gap, the planar support back 202 disperses the pressure through large-area contact, preventing the seal from deforming into the gap and avoiding the extrusion tearing problem caused by the lack of support in traditional O-rings 101, thus structurally protecting the material from mechanical damage.

[0051] Based on this, traditional seals, if the interference fit is insufficient, cannot form an effective pre-seal at low pressure, allowing liquid to easily leak from the gaps and erode the sealing surface, leading to premature material wear. If the interference fit is unreasonable, excessive compression at high pressure may cause permanent material deformation and loss of elasticity. A 15% interference fit creates a pre-compression contact pressure on the sealing body 200 after installation, forming an initial static seal. This pre-tightening force ensures no gaps on the sealing surface under low pressure, preventing premature erosion and corrosion of the material due to liquid leakage. Under high pressure, the sealing surface pressure increases synchronously with the system pressure. This pressure-adaptive characteristic ensures that the sealing surface remains in tight contact, preventing high-pressure liquid from breaking down the sealing surface and causing jet erosion, reducing localized damage to the material caused by high-pressure impact. This effectively solves the problem in existing technologies where the sealing performance of hydraulic support pipe joints is affected by the easily damaged materials used in the seals.

[0052] For example, Figure 3 This is a schematic diagram of the sealing assembly structure provided as an example of the present invention. The male end 301 of the connector mates with the female end 302 of the connector, and a U-shaped pin 303 is sleeved on the male end of the connector. The sealing body 200 is located between the male end 301 and the female end 302 of the connector. The curvature center of the arc-shaped sealing surface is biased towards the inner side of the sealing body. The arc-shaped sealing surface is also used to disperse the impact force of the high-pressure liquid and convert the axial component of the liquid pressure into a radial sealing force, thereby reducing the tangential deformation of the sealing lip under vibration conditions.

[0053] Figure 4 This is a schematic diagram of the sealing tolerance provided as an example of the present invention, such as... Figure 4 As shown, according to one aspect of the hydraulic support pipe joint sealing device of this utility model, when the outer diameter φD of the sealing body 200 is ≤ 50mm, the tolerance of the outer diameter of the sealing body 200 is -0.4mm to -0.1mm. When the cross-sectional dimension CS of the sealing body 200 is ≤ 30mm, the tolerance of the sealing body 200 is +0.1mm to +0.3mm. When the height H of the sealing body 200 is ≤ 30mm, the tolerance is ±0.2mm.

[0054] In practical applications, such as Figure 4As shown, when the outer diameter φD of the sealing body 200 is ≤50mm, a negative tolerance of -0.4mm to -0.1mm is adopted, meaning that the actual outer diameter of the sealing body 200 is slightly smaller than the nominal size. This design reduces the interference resistance between the seal and the joint hole wall during assembly, avoids the seal being squeezed, scratched, or deformed during installation due to excessive interference, ensures smooth assembly, and reduces the risk of initial damage. When the cross-sectional dimension CS of the sealing body 200 is ≤30mm, a positive tolerance of +0.1mm to +0.3mm is adopted, meaning that the actual cross-sectional thickness is slightly larger than the nominal size. The increase in cross-sectional dimension enhances the elastic reserve capacity of the seal. Under the pressure of the hydraulic system, the seal can undergo more complete elastic deformation, tightly filling the tiny gaps in the joint mating surfaces, thereby improving the fit of the sealing surface and effectively preventing hydraulic oil leakage. When the height H of the sealing body 200 is ≤30mm, a symmetrical tolerance of ±0.2mm is adopted to strictly control the height dimension deviation. Height is a key parameter determining the compression of a seal: insufficient compression leads to inadequate sealing force and easy leakage; excessive compression causes the seal to be under excessive pressure for a long time, accelerating material aging, fatigue, or permanent deformation. A tolerance range of ±0.2mm ensures the height consistency of different seals, keeping the compression stable within a reasonable range after assembly. This avoids under-compression or over-compression problems caused by excessive height deviation, thereby extending the service life of the seal and reducing maintenance frequency.

[0055] Meanwhile, the hydraulic support operates in harsh environments with vibration, impact, and temperature fluctuations, making the dimensional stability of the seals crucial. The aforementioned tolerance design ensures a stable fit between the seals and the joint by precisely controlling deviations in the outer diameter, cross-section, and height. Negative tolerances in the outer diameter prevent loosening, positive tolerances in the cross-section enhance the fit, and stable heights guarantee constant compressive force. This synergistic effect reduces loosening and repeated impacts from compression of the seals under vibration or pressure fluctuations, lowers the risk of structural fatigue failure due to dimensional deviations, and improves the reliability of the sealing device under complex operating conditions.

[0056] For example, such as Figure 2 As shown, the axial dimension of the planar support back 202 is 30%-40% of the axial dimension of the D-shaped structure; the surface roughness Ra of the planar support back 202 is ≤0.8μm, which is used to ensure a tight fit with the mounting groove plane.

[0057] In practical applications, such as Figure 2As shown, the planar support back 202 provides axial support for the seal, preventing excessive deformation, extrusion, or failure of the seal under hydraulic pressure or vibration conditions. It should be understood that the aforementioned axial dimension is actually the width of the D-shaped structure. Setting the axial dimension to 30%-40% of the axial dimension of the D-shaped structure represents a precise balance between support effectiveness and spatial compatibility. This 30%-40% ratio ensures the support back has sufficient structural rigidity to withstand the axial force transmitted by the seal, effectively limiting excessive compression or lateral displacement of the seal under high pressure, and preventing permanent deformation or detachment of the sealing surface due to insufficient support. Furthermore, the size is not excessively enlarged, avoiding the support back occupying too much installation space and reserving reasonable elastic deformation space for the D-shaped seal body 200. The seal needs to achieve sealing by filling the fitting gap through a certain deformation. The appropriate clearance in the support back dimension ensures that the seal can fully conform to the sealing surface under pressure, rather than being excessively squeezed by the support back, leading to restricted deformation and seal failure. The installation groove space for hydraulic support pipe joints is usually compact, with a ratio of 30%-40% to avoid interference between the support back size and other parts of the groove, thus ensuring assembly feasibility.

[0058] Based on this, surface roughness is a key indicator for evaluating the fit quality between the planar support back 202 and the mounting groove plane. A low-roughness surface, specifically Ra ≤ 0.8 μm, can significantly reduce the microscopic gap between the support back and the groove plane. If the surface is rough, the gap will cause local suspension of the support back under stress, resulting in stress concentration. Under long-term vibration or high pressure, this can easily lead to local deformation and loosening of the support back, resulting in uneven stress on the seal. A tightly fitted surface can evenly distribute the pressure transmitted by the seal to the groove plane, preventing the support back from failing due to local overload.

[0059] For example, the dimensions of the sealing body 200 are adapted to the mounting groove of the hydraulic support pipe connector, and the dimensions of the mounting groove are 50mm × 45mm × 5mm.

[0060] For example, the physical properties of the hydrolyzed polyurethane material include: a hardness of 95±2A; and a tensile strength ≥55 N / mm². 2 The elongation at break is ≥430%. The elastic recovery rate of the hydrolyzed polyurethane material is 49%, the tear strength is ≥125 N / mm, and the abrasion is 15 mm3.

[0061] In practical applications, the aforementioned physical properties of hydrolyzed polyurethane materials work synergistically to achieve key technical effects for applications under complex conditions such as high pressure, vibration, and friction. A hardness of 95±2A balances rigidity and sealing adaptability. A Shore hardness of 95±2A falls into the category of high-hardness elastic materials. This high hardness ensures that the material is not prone to excessive compression deformation under high pressure, maintaining the stable structural shape of the sealing or supporting surface and preventing sealing gap or support failure due to collapse. The ±2A tolerance range ensures the consistency of material hardness, reducing performance differences between batches or different parts, ensuring uniform stress on each seal or component after assembly, and avoiding uneven wear due to excessive softness or assembly interference due to excessive hardness. High hardness serves as a basic rigid support while retaining the slight deformation capacity of elastic materials, ensuring a tight fit with the mating surfaces.

[0062] Additionally, ≥55N / mm 2 High tensile strength means the material has an extremely strong ability to resist tensile failure, capable of withstanding tensile forces during assembly or dynamic tensile loads caused by vibration and pressure fluctuations during operation, preventing breakage or tearing. An elongation at break of ≥430% indicates excellent flexibility and deformation capacity, allowing the material to adapt to dynamic deformations such as tension and bending under complex working conditions, avoiding cracking or breakage caused by rigidity and brittleness. The combination of high strength and high elongation overcomes the traditional contradiction of materials being either too hard and brittle or too soft and weak, ensuring that the material can resist damage under high loads while also buffering stress through deformation, extending its service life.

[0063] Secondly, the seal undergoes compressive deformation under hydraulic pressure. A 49% recovery rate ensures that the material partially returns to its original shape after unloading, reducing permanent deformation. Even after long-term use, it maintains the contact pressure with the sealing surface, avoiding the risk of leakage due to insufficient recovery and widening of the sealing gap. Under conditions of frequent vibration and pressure fluctuations, the material buffers stress through the cyclic deformation and recovery process, reducing material fatigue caused by continuous deformation and maintaining the stability of the sealing performance. During installation, the seal may come into contact with groove edges or sharp edges; high tear strength prevents cracks caused by localized friction and compression, reducing initial damage. Under high-pressure impact, vibration friction, or scratching by foreign objects, the material is less prone to tearing and propagation due to localized stress concentration, preventing seal breakage or functional failure and significantly extending its service life.

[0064] Finally, during the relative movement between the seal and the mating surface, the material surface experiences minimal wear, maintaining the integrity and roughness of the sealing surface over a long period and preventing the sealing gap from increasing due to wear. Low wear reduces the rate of performance degradation caused by material wear, extending the replacement cycle of seals or components, and lowering equipment maintenance costs and downtime risks.

[0065] For example, the transition area between the arc-shaped sealing surface 201 of the D-shaped structure and the planar support back 202 is also provided with a rounded corner, the radius of which is 0.5mm-1mm, to avoid stress concentration. The axial end face of the sealing body 200 is provided with an annular groove, the depth of which is 0.3mm-0.5mm, to accommodate minor deformations that may occur during installation.

[0066] In practical applications, when the curved surface bears the sealing pressure, it transmits force to the support back. However, a right-angle transition causes the force to accumulate at the corner, forming localized high stress. A 0.5mm-1mm radius fillet transforms the right-angle transition into a smooth curve, allowing the force to gradually disperse along the curve as it is transmitted from the curved sealing surface 201 to the planar support back 202. This prevents localized stress from exceeding the material's fatigue limit and reduces material cracking or fissures caused by repeated stress. During assembly, the seal may experience slight friction or collision with the mounting groove. The radius fillet prevents the transition area from being scratched or cut due to sharp edges, protecting the integrity of the material in its initial state and laying the foundation for long-term sealing performance. Under the vibration and impact conditions of the hydraulic support, the sealing body 200 will undergo slight periodic deformation. The radius fillet reduces localized stress peaks, decreases material fatigue accumulation, and extends the service life of the seal.

[0067] Furthermore, the 0.3mm-0.5mm depth provides ample space for minor deformations, preventing stress from being transmitted to the sealing surface due to unreleased stress and avoiding gaps caused by forced deformation. If deformation is concentrated on the axial end face, unaccommodated protrusions can lead to uneven contact pressure between the sealing body 200 and the mating component. The groove absorbs deformation, distributing the contact pressure more evenly across the sealing surface and ensuring a tight fit between the arc-shaped sealing surface 201 and the mating surface. The groove's ability to accommodate minor deformations appropriately reduces the machining precision requirements of the installation groove, minimizes assembly interference caused by manufacturing errors, and improves assembly feasibility and efficiency.

[0068] For example, at -40°C, the sealing material will not lose its elasticity, become brittle, or crack due to the extremely low temperature. If the material's low-temperature performance is insufficient, the sealing body 200 may experience brittle fracture during assembly or under pressure, leading to leakage due to damage to the sealing surface. The wide-temperature design ensures that the material maintains a certain degree of flexibility and elasticity at low temperatures, maintaining a tight fit with the sealing surface. At +120°C, the sealing material will not soften, swell, or break its molecular chains due to overheating. High-temperature environments accelerate material aging; if the sealing body 200 softens, it may deform excessively under hydraulic pressure or even be squeezed out of the sealing gap, leading to leakage. The wide-temperature design ensures that the material maintains structural stability and necessary elasticity at high temperatures, resisting the risk of failure.

[0069] Furthermore, the hydraulic support pipe joint is subjected to a working pressure of approximately 10 MPa for extended periods, requiring the sealing body 200 to maintain a tight seal with the mating surface to prevent media leakage. A deformation rate of ≤8% means that the sealing body 200, after being subjected to a long-term 10 MPa pressure, can still recover most of its original shape after pressure relief, maintaining effective pressure on the sealing surface. Even under repeated pressure fluctuations, the material is not prone to losing its sealing ability due to plastic accumulation, fundamentally preventing leakage caused by seal collapse and loosening. The low permanent deformation rate reflects the strong elastic recovery ability of the material's molecular chains, better resisting fatigue aging under long-term stress. In the high-frequency, long-cycle operation of the hydraulic support, the sealing body 200 is less prone to performance degradation due to repeated compression and rebound, significantly extending the seal replacement cycle and reducing maintenance costs and equipment downtime risks.

[0070] For example, such as Figure 1 As shown, the dimensional tolerances and assembly positions of the O-ring 101 and the retaining ring 102 must be strictly matched. If the retaining ring 102 deviates in size or is misaligned during installation, it will cause uneven stress on the O-ring 101, or even scratches from the edge of the retaining ring 102, leading to leakage. The difference in the coefficient of friction and coefficient of thermal expansion between the polyoxymethylene retaining ring 102 and the O-ring 101 may cause relative displacement during vibration or temperature changes, weakening the support effect. The split design requires additional installation space for the retaining ring 102, increasing the complexity of the joint structure. The D-shaped structure, through its integrated design, combines the sealing function with the support and anti-extrusion function into a single unit, directly eliminating the component matching risks and structural redundancy of the split assembly, improving the stability of the sealing system from the design source. In addition, the O-ring 101 needs to be distinguished by its installation direction, and the retaining ring 102 needs to be precisely positioned outside the O-ring 101. The assembly steps are cumbersome, especially in complex environments such as downhole, where operational errors can easily lead to component misalignment, omission, or damage.

[0071] Furthermore, this design avoids sealing failures caused by operational errors such as missing retaining ring 102, reversed O-ring 101 installation, and component misalignment, significantly improving the assembly qualification rate. Vibration and impact can cause retaining ring 102 to loosen or shift, losing its support for O-ring 101. Under hydraulic pressure, O-ring 101 can easily be squeezed out of the sealing gap, leading to leakage. Simultaneously, repeated relative friction between separate components accelerates wear and shortens their lifespan.

[0072] The above description is merely an illustration of some embodiments of this utility model and the technical principles employed. Those skilled in the art should understand that the scope of this utility model is not limited to the specific combinations of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features of this utility model that have similar functions.

[0073] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A sealing device for a hydraulic support pipe joint, characterized in that, The hydraulic support pipe joint sealing device includes a sealing body made of hydrolyzed polyurethane material, and the sealing body has a D-shaped cross-section, the D-shaped structure comprising: An arc-shaped sealing surface, the radius of curvature of which is adapted to the inner wall of the liquid pipe joint, is used to convert the axial impact force of the high-pressure emulsion into a radial expansion force to achieve a hydraulic self-tightening seal. A planar support back, wherein the planar support back forms a surface contact with the corresponding plane of the mounting groove, for providing anti-extrusion support; The sealing body and the mounting groove are interference fit with an interference amount of 15%, which is used to form an initial static seal through pre-compression under zero pressure and to enhance the sealing performance through hydraulic self-tightening effect under high pressure.

2. The hydraulic support pipe joint sealing device according to claim 1, characterized in that, The curvature center of the arc-shaped sealing surface is biased towards the inner side of the sealing body. The arc-shaped sealing surface is also used to disperse the impact force of high-pressure liquid and convert the axial component of the liquid pressure into radial sealing force, thereby reducing the tangential deformation of the sealing lip under vibration conditions.

3. The hydraulic support pipe joint sealing device according to claim 1, characterized in that, When the outer diameter φD of the sealing body is ≤50mm, the outer diameter tolerance of the sealing body is -0.4mm to -0.1mm; When the cross-sectional dimension CS of the sealing body is ≤30mm, the tolerance of the sealing body is +0.1mm to +0.3mm; When the height H of the sealing body is ≤30mm, the tolerance is ±0.2mm.

4. The hydraulic support pipe joint sealing device according to claim 1, characterized in that, The axial dimension of the planar support back is 30%-40% of the axial dimension of the D-shaped structure; the surface roughness Ra of the planar support back is ≤0.8μm to ensure a tight fit with the mounting groove plane.

5. The hydraulic support pipe joint sealing device according to claim 1, characterized in that, The dimensions of the sealing body are adapted to the mounting groove of the hydraulic support pipe joint, and the dimensions of the mounting groove are 50mm×45mm×5mm.

6. The hydraulic support pipe joint sealing device according to claim 1, characterized in that, The physical properties of the hydrolyzable polyurethane material include: The hardness of the hydrolyzed polyurethane material is 95±2A; The hydrolyzed polyurethane material has a tensile strength ≥55 N / mm2 and an elongation at break ≥430%. The hydrolyzed polyurethane material has an elastic recovery of 49%, a tear strength of > 125 N / mm, and an abrasion of 15 mm 3 .

7. The hydraulic support pipe joint sealing device according to claim 1, characterized in that, The transition area between the arc-shaped sealing surface of the D-shaped structure and the planar support back is also provided with rounded corners, the radius of which is 0.5mm-1mm, to avoid stress concentration.

8. The hydraulic support pipe joint sealing device according to claim 1, characterized in that, The axial end face of the sealing body is provided with an annular groove, the depth of which is 0.3mm-0.5mm, to accommodate minor deformations that may occur during installation.

9. The hydraulic support pipe joint sealing device according to claim 1, characterized in that, The operating temperature range of the sealing body is -40℃ to +120℃, and the compression permanent deformation rate is ≤8% under 10MPa hydraulic pressure.

10. The hydraulic support pipe joint sealing device according to any one of claims 1-9, characterized in that, The D-shaped structure is an integral structure; The D-shaped structure is used to replace the traditional combination of split O-rings and polyoxymethylene retaining rings. It does not require distinguishing directions or assembling multiple parts during installation, and can withstand mechanical impacts with axial vibration frequencies ≤50Hz and amplitudes ≤2mm generated by the movement of hydraulic supports.

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