Micro-conical-surface gasket-free elastic sealing structure and assembling method thereof

Abstract

The invention relates to a micro-conical-surface gasket-free elastic sealing structure and an assembling method thereof, and belongs to the technical field of mechanical sealing. The structure comprises a filter element partition plate with a conical fixing hole, a metal connector with a sealing micro conical surface and a nut locking assembly. Through interference fit of the micro conical surface with the taper angle of 1-5 degrees, radial elastic deformation of the connector is achieved under the action of axial locking force, and therefore reliable sealing can be formed without an auxiliary gasket. The sealing surface can be provided with periodic or multi-scale microtextures, so that the interface fitness and the micro-motion resistance are improved. The structure is suitable for working conditions of high temperature, high pressure, corrosion, vibration and the like, and is particularly suitable for industrial filtering systems such as fly ash filters and the like. The invention further provides a corresponding assembly method, an acoustic emission or laser interference detection scheme and a sealing system capable of being modularly expanded, and the device has the advantages of being compact in structure, reliable in sealing, controllable in process and high in adaptability.

Description

Technical Field

[0001] The present invention relates to the field of mechanical seal technology, and specifically to a micro-conical gasketless elastic seal structure and its assembly method, seal detection method, and sealing system. The structure is particularly suitable for use in filtering equipment, gas processing equipment, and sealed connection systems that operate in high-temperature, high-pressure, corrosive media, and vibration environments and have high requirements for sealing reliability. Background Art

[0002] In modern industrial equipment, sealing structures are critical for ensuring the safety, stability, and efficient operation of fluid systems. They are widely used in pressure vessels, filters, heat exchangers, gas equipment, and other fields. Especially in operating conditions involving high temperatures, high pressures, corrosive media, and vibration environments, the reliability of the sealing structure directly determines the operating life and maintenance costs of the equipment.

[0003] Existing sealing technologies typically use auxiliary gaskets as sealing media to achieve airtight or liquid-tight isolation between mechanical components. Common gasket materials include rubber, polytetrafluoroethylene, graphite, and spiral wound gaskets.

[0004] in:

[0005] When the working temperature is below 300℃, non-metallic gaskets such as rubber or graphite gaskets are commonly used. They have the advantages of low cost, good flexibility and easy assembly. However, they are prone to aging, carbonization and creep deformation in high temperature or strong corrosive environment, resulting in sealing failure.

[0006] In high-temperature (>300°C) or high-pressure applications, such as gas turbines, boilers, and filters, metal gaskets (such as stainless steel toothed gaskets and corrugated gaskets) are often used to improve heat resistance and pressure resistance. However, metal gaskets generally require high flange surface accuracy and locking force, are difficult to reuse, and have high processing and maintenance costs.

[0007] In addition, structures using gasket seals are more sensitive to torque control during installation and are easily affected by human assembly errors. During long-term service, gaskets are also prone to failure due to stress relaxation, thermal expansion mismatch or medium erosion, especially in application environments with thermal cycles, dynamic loads and micro-wear. The sealing life is severely limited.

[0008] For example, in equipment such as fly ash filters that purify high-temperature dusty gases, a reliable seal must be achieved between the sintered metal filter element and the equipment housing to prevent dust leakage and media crossflow. Traditional sealing structures using metal gaskets are prone to gasket collapse, seizure, non-reusability, or poor sealing under high-temperature conditions and frequent filter element replacement, seriously impacting equipment operational stability and maintenance efficiency.

[0009] Therefore, developing a sealing structure with a simpler structure, adaptable to high-temperature and high-pressure environments, capable of multiple assembly cycles, and independent of traditional gasket materials has become a critical challenge urgently needed by those skilled in the art. This invention addresses these technical challenges and proposes a micro-conical, gasketless elastic sealing structure that achieves sealing through elastic deformation of the body. This structure has broad engineering applicability and potential for widespread adoption. Summary of the Invention

[0010] To overcome the common problems of existing sealing technologies, such as reliance on gaskets, complex assembly, limited heat and pressure resistance, and poor long-term reliability, the present invention proposes a micro-conical elastic sealing structure that achieves sealing through the structural body without relying on any auxiliary gaskets. This structure, centered around a conical interference fit between an elastic metal connector and a rigid base, achieves long-term sealing stability under extreme operating conditions such as high temperature, high pressure, corrosion, and vibration by precisely controlling the cone angle, assembly preload, and microscopic surface texture. The following, in conjunction with the various claims, details the specific technical solutions of the present invention and its various preferred embodiments.

[0011] In one embodiment of the present invention, a micro-conical surface gasket-free sealing structure is provided, which includes a filter element partition provided with a step structure, a metal connector with a sealing micro-conical surface, and a nut locking assembly for applying a locking force. The filter element partition is provided with a conical filter element fixing hole, and the outer surface of the metal connector is provided with a sealing micro-conical surface. The two form an interference fit under the condition of matching cone angles. The axial locking force is applied by the nut, so that the sealing micro-conical surface undergoes radial elastic deformation in the matching area, thereby achieving sealing of the connection interface. The cone angle α is controlled between 1° and 5°, and the elastic deformation δ satisfies the following: 0.02mm≤δ≤0.05mm.

[0012] Furthermore, the ratio of the elastic modulus of the metal connector to the elastic modulus of the filter element separator satisfies: 0.5≤E2 / E1≤2.0, and the difference in thermal expansion coefficient ΔCTE between the two is less than or equal to 5×10 -6 / ℃ to improve the sealing stability of the structure in a temperature fluctuation environment.

[0013] Furthermore, in order to optimize the interfacial stress distribution and enhance the sealing effect, the surface of the sealing micro-cone is provided with a periodic micro-texture, and the density of the micro-texture is controlled at 50 to 200 per mm. 2 The pit depth is 5 to 20 μm. The texture structure improves contact uniformity while effectively reducing local stress concentration and wear risks.

[0014] Furthermore, to ensure reliable sealing of the structure after the axial force is applied, the locking force F applied by the nut locking assembly satisfies:

[0015] 0.3σ s A≤F≤0.7σs ·A

[0016] where σ s is the yield strength of the metal connector, and A is the contact area of ​​the cone surface.

[0017] Preferably, the roundness error of the sealing micro-cone surface is controlled within 0.005 mm, and the surface roughness Ra is preferably not greater than 0.8 μm, thereby further enhancing the sealing interface fit and reducing the risk of leakage.

[0018] In one embodiment of the present invention, a method for assembling the above structure is provided, comprising the following steps:

[0019] S1: Process the filter element fixing hole on the filter element partition to form a tapered inner hole. The cone angle β matches the sealing micro-cone angle α of the metal connector, and the tolerance is controlled within ±0.5°;

[0020] S2: Turn the external sealing micro-cone surface of the metal connector to ensure that the cone angle processing accuracy is controlled within ±0.1°;

[0021] S3: By tightening the nut locking assembly, axial force is applied to the metal connector, causing elastic deformation of the conical surface and achieving reliable compression and sealing with the filter element fixing hole.

[0022] Optionally, after assembly is completed, a heat treatment process may be added, whereby the assembled structure is kept in an environment of 200-300°C for 1-3 hours to release residual stress during the locking process and improve the long-term stability of the sealing structure.

[0023] In one embodiment of the present invention, the sealing structure is applied to a fly ash filter device, where the filter element is sealed to the filter element separator via the metal connector without a gasket. The sintered filter element preferably has a porosity of no greater than 15% and a compressive strength of no less than 50 MPa, making it suitable for filtration systems operating in high-temperature, high-pressure, and corrosive gas environments.

[0024] Optionally, the present invention also provides a sealing detection method based on the principle of acoustic emission, which monitors the contact state of the sealing cone surface after locking through a sensor. When the acquisition frequency f satisfies 0.8f0≤f≤1.2f0, the assembly sealing state can be judged to be qualified, where f0 is a preset reference frequency.

[0025] In one embodiment of the present invention, a sealing structure system consisting of multiple sealing structure units can also be constructed, wherein the sealing cone angles are arranged in a stepped and increasing manner, and the cone angle difference Δα between adjacent structures is controlled between 0.5° and 2.0°, which can flexibly adapt to the modular sealing requirements under multiple working conditions.

[0026] Based on the above technical solution, the present invention's micro-conical gasketless elastic sealing structure utilizes a conical sealing surface on the outer surface of a metal connector, which forms an interference fit with the conical fixing holes in the filter element's partition. This structurally eliminates the reliance on traditional gasket materials. An axial locking assembly applies a preload during assembly, causing the connector to undergo controlled radial elastic deformation at the micro-conical sealing surface, thereby achieving a highly precise and reliable seal. This structure maintains long-term, stable sealing performance even under complex operating conditions such as high temperature, corrosion, high pressure, and dynamic vibration.

[0027] Compared with the existing gasket sealing structure, the technical advantages of the present invention are significantly reflected in the following aspects:

[0028] 1. No need to install or replace auxiliary gaskets, which reduces the number of parts and assembly steps, simplifies the overall structural design, and improves assembly efficiency.

[0029] 2. By setting a reasonable cone angle range (1°~5°) and elastic deformation control range (0.02mm~0.05mm), combined with micro-texture to optimize the interface contact state, the sealing interface can have stronger stress adaptability and sealing integrity.

[0030] 3. The key parameters such as the tapered surface matching angle, tolerance and roughness between the metal connector and the partition can be achieved through conventional machining methods, which has a good basis for industrial implementation.

[0031] 4. The metal body elastic seal is used to avoid the problem of gasket material failure at high temperature. It is suitable for a wide temperature range of -50℃ to 650℃ and a sealing pressure of more than 20MPa.

[0032] 5. Supports multiple sealing structure modules to build a sealing system, and forms a modular compatible solution by setting the cone angle difference to improve the product's universality.

[0033] 6. It can be combined with non-contact detection methods such as acoustic emission sensing, laser interferometry or thermal imaging to achieve real-time monitoring of the sealing status during the assembly process and ensure quality consistency.

[0034] In summary, this invention achieves high-reliability sealing between mechanical components through structural design and elastic control strategies, without relying on auxiliary sealing gaskets. This invention demonstrates high technological innovation and industrial application value, and is suitable for a variety of industrial scenarios, including fly ash filters, gas equipment, and specialized separation devices. This invention not only fundamentally improves the shortcomings of traditional sealing structures but also provides a new, high-performance sealing solution for related technical fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings are used to further illustrate the embodiments in this specification, but do not constitute a limitation on the scope of protection of the present invention:

[0036] Figure 1 : Schematic diagram of the overall assembly structure of the micro-cone surface gasket-free elastic sealing structure of the present invention;

[0037] Figure 2 : A three-dimensional schematic diagram of the metal connector and its sealing micro-conical surface structure in the present invention;

[0038] Figure 3 : A partial cross-sectional view of the interference fit between the sealing micro-conical surface and the filter element fixing hole in the present invention;

[0039] Figure 4 : Schematic diagram of the locally enlarged structure of the periodic micro-texture on the surface of the sealed micro-cone in the present invention.

[0040] The markings in the figure are as follows:

[0041] 1. Filter element partition; 2. Filter element fixing hole; 3. Sintered filter element; 4. Nut locking assembly; 5. Metal connector; 6. Sealing micro-cone surface. DETAILED DESCRIPTION

[0042] The following, in conjunction with the accompanying drawings, describes in detail a specific embodiment of the micro-conical surface gasketless elastic sealing structure of the present invention to further illustrate the technical features and implementation methods of the present invention. It should be noted that this embodiment is only a preferred embodiment of the present invention, and any equivalent transformation, deformation, combination, or substitution made within the spirit of the present invention shall be included in the scope of protection of the present invention.

[0043] Example 1:

[0044] In a specific embodiment of the present invention, Figure 1 As shown, a micro-conical gasket-free elastic sealing structure mainly includes:

[0045] Filter element partition 1: It is a rigid metal plate that plays a supporting and positioning role. It is provided with a stepped filter element fixing hole 2 for installing the filter element.

[0046] Metal connector 5: It is an elastically deformable structural component, one end of which is connected to the sintered filter element 3, and the outer surface of the other end is processed with a sealing micro-conical surface 6;

[0047] Lock nut 4: It is an assembly part that applies axial preload and is used to drive the metal connector to achieve conical surface compression;

[0048] Sealing micro-cone surface 6: processed on the outer surface of the connector 5, with a specified cone angle α, forming an interference seal fit with the inner hole of the filter element partition;

[0049] Sintered filter element 3: It is a typical application component, connected with the connector to form a complete filter element assembly.

[0050] The assembly process of the structure of the present invention is as follows:

[0051] Step 1: If Figure 1 As shown, a filter element fixing hole 2 with an inner tapered surface is machined on the filter element partition according to the drawing dimensions. The taper angle is controlled within the range of α±0.5° to ensure that it matches the taper surface of the metal connector later. The step hole depth and taper length are designed according to the specific filter element shape.

[0052] Step 2: If Figure 2 As shown, a sealing micro-cone 6 is machined on the outer surface of the metal connector 5. The angle α of this cone is controlled between 1° and 5°, preferably 3°. A periodic micro-texture can also be machined on the surface to optimize the sealing interface performance. The connector body is made of a metal material with a certain degree of elasticity, such as 316L stainless steel.

[0053] like Figure 4 As shown, the outer surface of the sealing micro-cone 6 is provided with a regularly distributed periodic micro-texture structure, wherein the texture is composed of an array of micron-scale pits, preferably with a density of 100 / mm 2 The pit depth is approximately 10μm. This microtexture can be achieved through laser etching, plasma etching, or other precision surface processing techniques. It helps to enhance the uniformity of the sealing interface, reduce local stress concentration, and improve the fatigue resistance and wear resistance of the structure under micro-dynamic load conditions. Figure 4 The geometric features of the micro-texture and its layout on the sealing cone surface are vividly demonstrated, which is one of the key design elements of the present invention for improving sealing reliability.

[0054] Step 3: If Figure 1 As shown, the sintered filter element assembly (including the metal connector 5) is inserted into the filter element fixing hole 2, so that the sealing micro-conical surface 6 forms initial contact with the inner hole. The nut locking assembly 4 is then tightened to apply an axial preload. During the tightening process, the metal connector 5 undergoes radial elastic deformation under the action of the axial force, and its sealing micro-conical surface 6 gradually achieves a tight fit with the filter element fixing hole 2, generating a certain amount of radial compressive stress at the contact interface, thereby achieving a reliable airtight seal without the need for a gasket.

[0055] like Figure 3 As shown, a conical interference fit structure is formed between the sealing micro-conical surface 6 of the metal connector 5 and the filter element fixing hole 2 on the filter element partition 1. Under the action of the preload force, the sealing conical surface area undergoes controlled radial elastic deformation, the fitting effect is good, and a stable and effective sealing interface is formed. Figure 3It further reveals that the distribution of the cone deformation area, the length of the contact zone, and the consistency of the cone angle matching are the key structural foundations for the realization of the sealing principle of the present invention. Preferably, the radial elastic deformation δ is controlled within the range of 0.02mm to 0.05mm.

[0056] Optionally, after the nuts are tightened, to further release residual stress during assembly, the components can be aged: the assembly structure is placed in a hot environment of 200-300°C for 1-3 hours to stabilize the sealing state and extend the service life.

[0057] Performance verification:

[0058] The fly ash filter assembly using the structure of the present invention was leak tested at an air pressure of 20 MPa, and the results showed that the leakage rate was stably lower than 0.005 cc / min. It was continuously operated for 2000 hours under high temperature (600°C) and 5g vibration conditions without any seal loosening or failure. Compared with traditional metal gasket structures, the assembly ease is improved by more than 50% and the maintenance frequency is reduced.

[0059] The structure of the present invention can also be extended to be applied to industrial devices such as high-temperature heat exchangers, high-pressure fluid systems, and closed filter cartridges, and has good structural versatility, process adaptability, and sealing reliability.

[0060] Example 2:

[0061] In another embodiment of the present invention, the surface of the sealing micro-cone 6 is provided with a multi-scale composite micro-texture, which has micron-scale pits (density 100 / mm 2 , depth 10μm), superimposed with a nanoscale corrugated structure (wavelength 200-500nm, amplitude 20-50nm), forming a surface topography with a multi-level sealing barrier effect. This structure not only improves static sealing performance, but also has excellent resistance to fretting wear and dynamic vibration adaptability, making it suitable for high-frequency thermal stress environments such as gas equipment and thermal circulation flow systems.

[0062] Example 3:

[0063] In another optional embodiment of the present invention, the metal connector 5 employs an embedded flexible stress groove structure. This stress groove is an annular groove located radially inside the sealing micro-cone, with a depth of 10% to 20% of the wall thickness. This structural design guides the local elastic deformation of the connector to the sealing area during the tightening process, enhancing the stability of the clamping force and mitigating the transfer of stress to non-sealing areas, effectively improving the reliability of the structure in large-scale applications.

[0064] Example 4:

[0065] In another alternative embodiment, the metal connector 5 and filter element 3 are integrally molded, using metal powder sintering or laser cladding to achieve structural integration of the filter element and sealing connector. This solution eliminates welds or threaded connections, improving overall strength and sealing reliability, making it suitable for high-pressure filter systems requiring extremely high structural strength and sealing consistency.

[0066] Example 5:

[0067] In another alternative embodiment, the sealing structure system of the present invention comprises multiple sealing units, each with a stepped micro-cone angle α (e.g., 2.0°, 3.0°, and 4.0°) to achieve graded locking and multi-stage sealing. This structure is particularly suitable for modular devices such as parallel filter modules and high-temperature chamber modules, gradually forming multiple sealing zones under varying axial preload conditions, thereby enhancing the system's overall anti-leakage capabilities.

[0068] Example 6:

[0069] In another alternative embodiment, the present invention utilizes a non-contact optical inspection method based on the principle of laser interferometry to perform online detection of the sealing cone gap. By scanning the changes in the interference fringes of the light reflected from the cone, the tightness of the sealing area can be determined, thereby achieving assembly quality control without the need for destructive testing.

[0070] Example 7:

[0071] In this embodiment, the micro-cone sealing structure of the present invention is applied to a filter device in a low-temperature environment (such as liquid nitrogen or liquid hydrogen system). The metal connector 5 is made of stainless steel with excellent low-temperature toughness (such as 316LN), and the filter element partition 1 is made of a low thermal expansion coefficient alloy (such as Invar alloy), ensuring that a small thermal expansion coefficient difference ΔCTE ≤ 2×10 -5 / ℃. At the same time, the sealing micro-cone surface 6 is laser engraved to form a more delicate micro texture (density> 150 / mm 2 ) to improve the interface adaptability after cold shrinkage and ensure the sealing integrity.

[0072] Example 8:

[0073] To meet the need for frequent on-site filter element replacement, in this embodiment, the metal connector 5 has been optimized for its design, featuring a snap-on retaining groove that mates with the nut, replacing the traditional screw-on locking mechanism. The locking nut 4 is equipped with a quick-tightening mechanism or elastic clamping arm, enabling tool-free assembly and disassembly while maintaining the axial preload F. This structure is suitable for applications requiring frequent filter element replacement, such as power plant dust removal and chemical powder processing.

[0074] Example 9:

[0075] In the application scenario of highly corrosive media (such as acid gas and seawater), the outer surface of the metal connector 5 and the sealing micro-cone 6 adopts multi-layer anti-corrosion treatment, including:

[0076] First layer: chemical nickel plating, thickness 5μm, to improve basic corrosion resistance;

[0077] Second layer: ceramic coating (such as Al2O3), thickness 10μm, to enhance surface hardness and barrier properties;

[0078] The third layer: solid lubricant film (such as MoS2), with a thickness of <1μm, reduces assembly friction resistance and improves sealing fit.

[0079] This embodiment significantly improves the stability and life of the sealing structure in salt spray and high acid and alkali environments.

[0080] Example 10:

[0081] In this embodiment, the sealing micro-cone 6 is designed as a variable-angle structure. That is, the angle α gradually changes from the bottom to the top of the connector (for example, from 1.5° to 4.0°), forming a stress gradient sealing zone. During the nut tightening process, the smaller angle area first contacts to provide an initial seal, followed by the larger angle area to provide enhanced compression. This achieves multi-stage stress regulation and redundant sealing, enhancing sealing security under complex load conditions.

[0082] In summary, the present invention provides a micro-conical gasketless elastic sealing structure with a simple structure, reliable sealing, controllable process, and suitability for complex environmental working conditions. It successfully overcomes the problems of poor reliability and high maintenance costs of traditional gasket sealing methods under high temperature, high pressure, corrosion and vibration conditions. Through the conical interference fit between the elastic metal connector and the rigid base, the present invention achieves a sealed connection that can operate stably for a long time without the need for auxiliary sealing materials, and has good engineering promotion value and industrialization prospects. The diverse design of the implementation methods also fully reflects the flexibility and wide applicability of the technology.

[0083] It should be noted that the above description of the specific embodiments of the present invention is intended only to illustrate the technical principles and beneficial effects of the present invention and should not be construed as limiting the scope of protection of the present invention. Any equivalent substitutions, modifications, combinations, or variations of the present invention that fall within the spirit and principles of the present invention should be included within the scope of protection of the present invention. The appended claims should be interpreted in the broadest reasonable manner to encompass all technical solutions of the present invention.

Claims

1. A micro-conical gasket-free sealing structure, characterized in that: include: A filter element partition plate (1) having a stepped structure is provided, on which a conical filter element fixing hole (2) is opened; A metal connector (5) capable of interference fit with the filter element fixing hole (2), the outer surface of which is processed with a sealing micro-conical surface (6); A nut locking assembly (4) for applying an axial locking force; The cone angle α of the sealing micro-conical surface (6) is 1° to 5°, forming an interference fit with the filter element fixing hole (2). Under the action of the axial force applied by the nut locking assembly (4), the metal connector (5) generates radial elastic deformation at the sealing micro-conical surface (6), realizing a gasket-free sealing connection, and the deformation amount δ satisfies: 0.02mm≤δ≤0.05mm.

2. The sealing structure according to claim 1, wherein: The elastic modulus of the metal connector (5) is E2, the elastic modulus of the filter element partition (1) is E1, and the ratio of the two satisfies: 0.5≤E2 / E1≤2.0; and the difference in thermal expansion coefficient ΔCTE between the two is not greater than 5×10 -6 / ℃.

3. The sealing structure according to claim 1, wherein: The surface of the sealing micro-cone (6) is provided with periodic micro-textures, and the density of the micro-textures is 50 to 200 per mm. 2 , the pit depth is 5 to 20 μm.

4. The sealing structure according to claim 1, wherein: The axial locking force F applied by the nut locking assembly (4) satisfies the following range: 0.3σ s ●A≤F≤0.7σ s ●A where σ s is the yield strength of the metal connector (5), and A is the sealing contact area.

5. The sealing structure according to claim 1, wherein: The roundness error of the sealing micro-cone surface (6) is no greater than 0.005 mm, and the surface roughness Ra is no greater than 0.8 μm.

6. A method for assembling the sealing structure according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Processing the filter element fixing hole (2) on the filter element partition (1) to form an inner conical surface, wherein the deviation between the cone angle β and the cone angle α of the sealing micro-conical surface (6) is controlled within ±0.5°; S2: Turning the sealing micro-cone surface (6) on the metal connector (5), with the cone angle tolerance controlled within ±0.1°; S3: Applying an axial locking force F through the nut locking assembly (4) causes the sealing micro-conical surface (6) to produce elastic deformation and press the inner conical surface of the filter element fixing hole (2) to achieve sealing.

7. The method according to claim 6, characterized in that: After step S3, the method further includes: performing aging treatment on the assembled structure, keeping the temperature at 200-300° C. for 1-3 hours to release the assembly residual stress.

8. A fly ash filter assembly, characterized in that: It comprises the sealing structure according to any one of claims 1 to 5, wherein the metal connector (5) is connected to the sintered filter element (3), the filter element is fixed on the filter element partition (1), and the porosity of the sintered filter element (3) is not higher than 15%, and the compressive strength is not lower than 50MPa.

9. A seal detection method for the seal structure according to any one of claims 1 to 5, characterized in that: The contact state between the sealing micro-cone surface (6) and the filter element fixing hole (2) is monitored in real time by an acoustic emission sensor, and when the characteristic frequency f is detected to satisfy 0.8f0≤f≤1.2f0, the assembly is determined to be qualified, wherein f0 is a set reference frequency.

10. A sealing structure system, characterized in that: The invention comprises at least three micro-cone sealing structures according to any one of claims 1 to 5, wherein the cone angle α of the sealing micro-cone in each structure is distributed in a stepped manner, and the cone angle difference Δα between adjacent structures is 0.5° to 2.0°.

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