A micro-conical gasketless elastic sealing structure

Abstract

This utility model relates to a micro-conical gasketless sealing structure, belonging to the field of mechanical seals. The structure includes a filter element diaphragm with a conical fixing hole, a metal connector with a sealing micro-conical surface, and a nut locking assembly. The metal connector and the fixing hole are interference-fitted by a micro-conical surface with a cone angle of 1° to 5°, undergoing radial elastic deformation under locking force to achieve a reliable seal without auxiliary gaskets. Periodic micro-textures can be provided on the surface of the sealing conical surface to enhance fit. This structure is suitable for high-temperature, high-pressure, vibrating, and corrosive media applications, and features a compact structure, reliable sealing, and convenient processing.

Description

Technical Field

[0001] This utility model relates to the field of mechanical seal technology, specifically to a micro-conical gasketless elastic sealing structure, which is particularly suitable for filtration equipment, gas treatment devices, and sealing connection systems that operate in high temperature, high pressure, corrosive media, and vibration environments and have high requirements for sealing reliability. Background Technology

[0002] In modern industrial equipment, sealing structures are crucial for ensuring the safety, stability, and efficient operation of fluid systems, and are widely used in pressure vessels, filters, heat exchangers, and gas equipment. Especially under conditions involving high temperature, high pressure, corrosive media, and vibration, the reliability of the sealing structure directly determines the equipment's service life and maintenance costs.

[0003] Existing sealing technologies typically use auxiliary gaskets as the sealing medium to achieve airtight or liquid-tight separation between mechanical components. Common gasket materials include rubber, polytetrafluoroethylene (PTFE), graphite, and spiral wound gaskets. Among them: In operating conditions with temperatures 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 highly corrosive environments, leading to sealing failure. In high-temperature (>300℃) 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 usually require high flange surface precision and locking force, and are difficult to reuse multiple times, resulting in high processing and maintenance costs.

[0004] In addition, gasket-sealed structures 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 media erosion. Especially in application environments with thermal cycling, dynamic loads, and fretting wear, the seal life is severely limited.

[0005] For example, in equipment involving the purification of high-temperature dust gases, such as fly ash filters, a reliable seal must be achieved between the sintered metal filter element and the equipment housing to prevent dust leakage or media cross-contamination. Traditional sealing structures using metal gaskets are prone to problems such as gasket crushing, jamming, inability to reuse, or incomplete sealing under high-temperature conditions and frequent filter element replacements, which seriously affects the operational stability and maintenance efficiency of the equipment.

[0006] Therefore, developing a sealing structure that is simpler in structure, adaptable to high-temperature and high-pressure environments, can be assembled multiple times, and does not rely on traditional gasket materials has become an important issue that urgently needs to be addressed by those skilled in the art. Based on the aforementioned technical challenges, this invention proposes a micro-conical surface gasketless elastic sealing structure that achieves sealing through the elastic deformation of the sealing body, possessing broad engineering applicability and promotional value. Utility Model Content

[0007] To overcome the problems of reliance on gaskets, complex assembly, limited temperature and pressure resistance, and poor long-term reliability commonly found in existing sealing technologies, this invention proposes a micro-conical elastic sealing structure that achieves sealing without relying on any auxiliary gaskets and utilizes the structural body itself. This structure is based on the cone-surface interference fit between an elastic metal connector and a rigid substrate. By precisely controlling the cone angle, assembly preload, and micro-surface texture, long-term sealing stability is achieved under extreme conditions such as high temperature, high pressure, corrosion, and vibration. The specific technical solutions and different preferred embodiments of this invention are described in detail below with reference to the claims.

[0008] In one embodiment of this utility model, a micro-conical gasketless sealing structure is provided. This structure includes a filter element separator with a stepped structure, a metal connector with a sealing micro-conical surface, and a nut locking assembly for applying a locking force. The filter element separator has a tapered filter element fixing hole, and the outer surface of the metal connector has a sealing micro-conical surface. The two form an interference fit under conditions of matching cone angles. An axial locking force is applied by the nut, causing the sealing micro-conical surface to undergo radial elastic deformation within the mating area, thus achieving a seal at the connection interface. The cone angle α is controlled between 1° and 5°, and the elastic deformation δ satisfies: 0.02mm ≤ δ ≤ 0.05mm.

[0009] 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 their coefficients of thermal expansion ΔCTE is less than or equal to 5 × 10⁻⁶. -6 / ℃, to improve the sealing stability of the structure under temperature fluctuations.

[0010] Furthermore, to optimize the interfacial stress distribution and enhance the sealing effect, the surface of the sealing microconical surface is provided with a periodic microtexture. The density of this microtexture is controlled between 50 and 200 per mm², and the pit depth is between 5 and 20 μm. This textured structure improves contact uniformity while effectively reducing localized stress concentration and the risk of wear.

[0011] Furthermore, to ensure a reliable seal of the structure after axial force is applied, the locking force F applied by the nut locking assembly satisfies: ; in Let A be the yield strength of the metal connector and A be the contact area of ​​the conical surface.

[0012] Preferably, the roundness error of the sealing microconical 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.

[0013] A guide structure is provided between the nut locking assembly and the metal connector.

[0014] In one embodiment of this utility model, an assembly method for the above-described structure is provided, comprising the following steps: S1: Machining the filter element fixing holes on the filter element separator to form a tapered inner hole, with the tapered angle β matching the sealing micro-taper angle α of the metal connector, and the tolerance controlled within ±0.5°; S2: The external sealing micro-conical surface of the metal connector is machined to ensure that the machining accuracy of the cone angle is controlled within ±0.1°; S3: By tightening the nut to lock the assembly, an axial force is applied to the metal connector, causing its conical surface to undergo elastic deformation and achieve a reliable compression seal with the filter element fixing hole.

[0015] Optionally, after assembly, an additional heat treatment process can be added, in which the assembled structure is kept at 200-300℃ for 1-3 hours to release residual stress during the locking process and improve the long-term stability of the sealing structure.

[0016] In one embodiment of this utility model, the sealing structure is applied in a fly ash filter device, and the filter element is connected to the filter element partition without gaskets through the metal connector. The porosity of the sintered filter element is preferably no higher than 15%, and its compressive strength is no less than 50 MPa, making it suitable for filtration systems in high-temperature, high-pressure, and corrosive gas environments.

[0017] Alternatively, this utility model also provides a sealing detection method based on the principle of acoustic emission. The method monitors the contact state of the sealing cone surface after locking by a sensor. When the sampling frequency f satisfies 0.8f0≤f≤1.2f0, the assembly sealing state can be determined to be qualified, where f0 is a preset reference frequency.

[0018] In one embodiment of this utility model, a sealing structure system composed of multiple such sealing structure units can also be constructed, with the sealing cone angle arranged in a stepped increasing manner, and the cone angle difference Δα between adjacent structures controlled between 0.5° and 2.0°, which can flexibly adapt to the modular sealing requirements under multiple working conditions.

[0019] Based on the above technical solution, the micro-conical gasketless elastic sealing structure of this utility model adopts a conical sealing surface on the outer surface of the metal connector, and forms an interference fit with the conical fixing hole in the filter element partition, thus eliminating the dependence on traditional gasket materials from the structural essence. By applying pre-tightening force during assembly through the axial locking component, the connector undergoes controlled radial elastic deformation at the sealing micro-conical surface, thereby achieving a high-precision and high-reliability sealing fit. This structure enables long-term stable sealing performance even under complex working conditions such as high temperature, corrosion, high pressure, and dynamic vibration.

[0020] Compared with existing gasket sealing structures, the technical advantages of this utility model are significantly reflected in the following aspects: 1. Simplified structure: No need to install or replace auxiliary shims, reducing the number of parts and assembly steps, simplifying the overall structural design, and improving assembly efficiency.

[0021] 2. Enhanced sealing performance: By setting a reasonable cone angle range (1°~5°) and elastic deformation control range (0.02mm~0.05mm), combined with microtexturing to optimize the interface contact state, the sealing interface has stronger stress self-adaptation capability and sealing integrity.

[0022] 3. Controllable machining and assembly precision: Key parameters such as the conical mating angle, tolerance, and roughness between the metal connector and the partition can all be achieved through conventional machining methods, providing a solid foundation for industrial implementation.

[0023] 4. Strong environmental adaptability: It adopts a metal body elastic seal, avoiding 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.

[0024] 5. Strong scalability and system integration: It supports the construction of multiple sealing structure modules into a sealing system, and forms a modular compatibility solution by setting the cone angle difference, thereby improving the product's versatility.

[0025] 6. Comprehensive quality monitoring and control methods: It can combine 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 consistent quality.

[0026] In summary, this invention achieves highly reliable sealing between mechanical components through structural design and flexible control strategies without relying on auxiliary sealing gaskets. It possesses significant technological innovation and industrial application value, and is suitable for various industrial applications such as fly ash filters, gas equipment, and special separation devices. This invention not only fundamentally improves upon the shortcomings of traditional sealing structures but also provides a novel, high-performance sealing solution for related technical fields. Attached Figure Description

[0027] To more clearly illustrate the technical solution of this utility model, 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 this invention: Figure 1 : A schematic diagram of the overall assembly structure of the micro-conical surface gasketless elastic sealing structure of the present invention; Figure 2 : A three-dimensional schematic diagram of the metal connector and its sealing micro-conical surface structure in this invention; Figure 3 : A partial cross-sectional view of the interference fit between the sealing microconical surface and the filter element fixing hole in this invention; Figure 4 : A partially enlarged schematic diagram of the periodic microtexture on the surface of the sealing microconical surface in this invention.

[0028] The markings in the diagram are explained as follows: 1. Filter element partition; 2. Filter element fixing hole; 3. Sintered filter element; 4. Nut locking assembly; 5. Metal connector; 6. Sealing micro-conical surface. Detailed Implementation

[0029] The following detailed description, with reference to the accompanying drawings, of the specific embodiments of the micro-conical gasketless elastic sealing structure of the present invention, further illustrates the technical features and implementation methods of the present invention. It should be noted that this embodiment is merely a preferred embodiment of the present invention, and all equivalent transformations, modifications, combinations, or substitutions made within the spirit and scope of the present invention should be included within the protection scope of the present invention.

[0030] Example 1: In one specific embodiment of this utility model, such as Figure 1 As shown, a micro-conical gasketless elastic sealing structure mainly includes: Filter element partition 1: It is a rigid metal plate that serves as a support and positioning element, and has stepped filter element fixing holes 2 for installing filter elements. Metal connector 5: It is a structural component that can be elastically deformed. One end of it is connected to the sintered filter element 3, and the outer circular surface of the other end is machined with a sealing micro-conical surface 6. Lock nut 4: An assembly that applies axial preload to drive the metal connector to achieve tapered surface clamping; Sealing micro-conical surface 6: Machined on the outer surface of connector 5, with a specified cone angle α, to form an interference seal fit with the inner hole of filter element partition; Sintered filter element 3: This is a typical application component, which is connected with the connector to form a complete filter element assembly.

[0031] The typical assembly process of the structure of this invention is as follows: Step 1: As Figure 1 As shown, filter element fixing holes 2 with inner conical surfaces are machined on the filter element separator according to the dimensions in the drawing. The cone angle is controlled within the range of α ±0.5° to ensure subsequent matching with the conical surface of the metal connector. The depth of the stepped hole and the length of the conical surface are designed according to the specific shape of the filter element.

[0032] Step Two: As Figure 2 As shown, a sealing micro-conical surface 6 is machined on the outer circular surface of the metal connector 5. The angle α of this conical surface is controlled between 1° and 5°, preferably 3°, and periodic microtextures can be further processed on its 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.

[0033] like Figure 4 As shown, the outer surface of the sealing microconical surface 6 is provided with a regularly distributed periodic microtexture structure. The texture consists of an array of micron-sized pits, preferably with a density of 100 pits / mm² and a pit depth of approximately 10 μm. This microtexture can be achieved through laser etching, plasma etching, or other precision surface processing techniques, which 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 fretting load conditions. Figure 4 The geometric features of the microtexture and its layout on the sealing cone surface are vividly illustrated, which is one of the key design elements of this invention to improve sealing reliability.

[0034] Step 3: As 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 makes initial contact with the inner hole. Then, the nut is tightened to lock the assembly 4, and an axial preload is applied. During the locking process, the metal connector 5 undergoes radial elastic deformation under the action of axial force, and its sealing micro-conical surface 6 gradually achieves tight contact with the filter element fixing hole 2, generating a certain radial compressive stress at the contact interface, thereby achieving a reliable airtight seal without the need for gaskets.

[0035] like Figure 3 As shown, the sealing micro-conical surface 6 of the metal connector 5 and the filter element fixing hole 2 on the filter element partition 1 form a conical interference fit structure. Under the action of pre-tightening force, the sealing conical surface area undergoes controlled radial elastic deformation, resulting in a good fit and forming a stable and effective sealing interface. Figure 3 The distribution of the conical deformation region, the length of the contact zone, and the consistency of the cone angle matching are further revealed, which are the key structural foundations for realizing the sealing principle of this invention. Preferably, the radial elastic deformation δ is controlled within the range of 0.02mm to 0.05mm.

[0036] Optionally, after the nuts are tightened, in order to further release residual stress from the assembly process, the components can be aged: the assembly structure is placed in a hot environment of 200-300℃ for 1-3 hours to stabilize the sealing state and improve service life.

[0037] Performance verification: The fly ash filter assembly using the structure of this utility model was tested for leakage under 20MPa air pressure, and the results showed that the leakage rate was consistently below 0.005cc / min; it operated continuously for 2000 hours under high temperature (600℃) and 5g vibration conditions without any loosening or failure of the seal; compared with the traditional metal gasket structure, the ease of assembly is improved by more than 50%, and the number of maintenance times is reduced.

[0038] The structure of this invention can also be extended to industrial devices such as high-temperature heat exchangers, high-pressure fluid systems, and sealed filter cartridges, and has good structural versatility, process adaptability, and sealing reliability.

[0039] Example 2: In another embodiment of this invention, the sealing microconical surface 6 is provided with a multi-scale composite microtexture, which superimposes a nanoscale corrugated structure (wavelength 200~500nm, amplitude 20~50nm) on top of micron-level pits (density 100 pits / mm², depth 10μm), forming a surface morphology 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 systems.

[0040] Example 3: In another optional embodiment of this utility model, the metal connector 5 adopts an embedded flexible stress groove structure. The stress groove is an annular groove, located in the radially adjacent area inside the sealing micro-conical surface, with a depth of 10% to 20% of the wall thickness. Through this structural design, the local elastic deformation of the connector can be guided to concentrate in the sealing area during the locking process, enhancing the stability of the clamping force, reducing the transmission of stress in the non-sealing area, and effectively improving the reliability of the structure in large-size applications.

[0041] Example 4: In another alternative embodiment, the metal connector 5 and the filter element 3 are integrally molded, and the filter element and the sealing connector are manufactured as a single unit through metal powder sintering or laser cladding processes. This solution eliminates welds or threaded interfaces at the connection points, improves overall strength and sealing reliability, and is suitable for high-pressure filter systems with extremely high requirements for structural strength and sealing consistency.

[0042] Example 5: In another optional embodiment, the sealing structure system of the present invention consists of multiple sealing units, and the cone angle α of the sealing micro-cone surface of each unit is distributed in a stepped manner, for example, set to 2.0°, 3.0°, and 4.0°, to achieve graded locking and multi-stage sealing functions. This structure is particularly suitable for combined devices such as parallel filter modules and high-temperature chamber modules, and can gradually form multi-stage sealing zones under different axial pre-tightening conditions, thereby improving the overall leakage resistance of the system.

[0043] Example 6: In another optional embodiment, this invention employs a non-contact optical inspection method to perform online detection of the mating gap of the sealing conical surface based on the principle of laser interference. By scanning the changes in the interference fringes of the reflected light from the conical surface, the tightness of the sealing area is determined, thereby achieving assembly quality control without the need for destructive testing.

[0044] Example 7: In this embodiment, the micro-conical sealing structure of this invention is applied to a filtration device in a low-temperature environment (such as liquid nitrogen or liquid hydrogen systems). The metal connector 5 is made of stainless steel with excellent low-temperature toughness (such as 316LN), and the filter element separator 1 is made of an alloy with a low coefficient of thermal expansion (such as Invar alloy), ensuring that a small difference in the coefficient of thermal expansion ΔCTE ≤ 2 × 10⁻⁶ at -196°C is maintained. -5 / ℃. Meanwhile, the sealing microconical surface 6 is laser-engraved to form a finer microtexture (density >150 particles / mm²) to improve the interface adaptability after cold shrinkage and ensure the integrity of the seal.

[0045] Example 8: To meet the need for frequent filter element replacements on-site, the external structure of the metal connector 5 is optimized in this embodiment. It is designed as a snap-fit ​​limiting groove that engages with the nut, replacing the traditional tightening method. The locking nut 4 is equipped with a quick-tightening mechanism or an elastic clamping arm, enabling tool-free assembly and disassembly while ensuring axial preload F. This structure is suitable for scenarios requiring frequent filter element replacement, such as power plant dust removal systems and chemical powder processing.

[0046] Example 9: In applications involving highly corrosive media (such as acidic gases and seawater), the outer surfaces of the metal connector 5 and the sealing micro-conical surface 6 undergo multi-layer anti-corrosion treatment, including: First layer: electroless nickel plating, 5μm thick, to improve the base corrosion resistance; The second layer is a ceramic coating (such as Al2O3) with a thickness of 10μm, which enhances surface hardness and barrier performance. The third layer is a solid lubricant film (such as MoS2) with a thickness of <1μm, which reduces assembly friction resistance and improves sealing fit.

[0047] This embodiment significantly improves the stability and lifespan of the sealing structure in salt spray and high acid / alkali environments.

[0048] Example 10: In this embodiment, the sealing micro-conical surface 6 is designed as a variable cone angle structure, meaning that the cone angle α gradually changes from the bottom to the top of the connector (e.g., from 1.5° to 4.0°), forming a stress gradient sealing band. During the nut tightening process, the smaller cone angle area that first comes into contact provides an initial seal, while the larger cone angle area provides enhanced clamping force, thereby achieving multi-stage stress adjustment and redundant sealing, improving sealing safety under complex load environments.

[0049] In summary, this invention provides a micro-conical gasketless elastic sealing structure that is simple in structure, reliable in sealing, controllable in process, and suitable for complex environmental conditions. It successfully overcomes the problems of poor reliability and high maintenance costs associated with traditional gasket sealing methods under high temperature, high pressure, corrosion, and vibration conditions. Through the cone-surface interference fit between the elastic metal connector and the rigid substrate, this invention achieves a long-term stable sealing connection without the need for auxiliary sealing materials, demonstrating good engineering application value and industrialization prospects. The diverse implementation methods also fully reflect the flexibility and wide applicability of this technology.

[0050] It should be noted that the above description of the specific embodiments of this utility model is only used 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. All equivalent substitutions, modifications, combinations, or variations made to the present invention 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 sense to cover all technical solutions of the present invention.

Claims

1. A micro-dome gasketless resilient sealing structure, characterized by, include: A filter element partition (1) is provided with a tapered filter element fixing hole (2); The metal connector (5) has a sealing micro-conical surface (6) on its outer surface, and forms an interference fit with the filter element fixing hole (2); Nut locking assembly (4) is used to apply axial locking force to the metal connector (5); The cone angle α of the sealing micro-cone surface (6) is 1° to 5°. Under the action of locking force, the metal connector (5) generates radial elastic deformation at the sealing micro-cone surface (6) to achieve gasket-free sealing connection, and the deformation amount δ satisfies: 0.02mm≤δ≤0.05mm.

2. The seal structure of claim 1, wherein: The elastic modulus of the metal connector (5) is E2, and the elastic modulus of the filter element partition (1) is E1. The ratio of the two satisfies: 0.5≤E2 / E1≤2.

0.

3. The seal structure of claim 1, wherein: The difference in thermal expansion coefficient ΔCTE between the metal connector (5) and the filter element partition (1) is no greater than 5×10-6 / ℃.

4. The seal structure of claim 1, wherein: The sealing micro-cone surface (6) is provided with periodic micro-texture, and the micro-texture density is 50-200 / mm 2 , and the pit depth is 5-20 μm.

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

6. The sealed structure of claim 1, wherein: A guide structure is provided between the nut locking assembly (4) and the metal connector (5).

7. The sealed structure of claim 1, wherein: The metal connector (5) is fixedly connected to the filter element (3). The filter element is a sintered structure with a porosity of no more than 15% and a compressive strength of no less than 50MPa.

8. The sealed structure of claim 1, wherein: The metal connector (5) and the filter element (3) are integrally formed.

9. The sealed structure of claim 1, wherein: The sealing microconical surface (6) has a variable cone angle structure, and its cone angle gradually changes along the axial direction.

10. The sealing structure according to claim 1, characterized in that: The sealing structure consists of multiple sealing units and is used in fly ash filter assemblies. The cone angles of the multiple sealing units are arranged in a stepped manner, and the cone angle difference Δα between adjacent structures is 0.5° to 2.0°.

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