An ultra-high pressure spherical sealing structure with anti-extrusion function

Abstract

This invention relates to an ultra-high pressure spherical sealing structure with anti-extrusion function, belonging to the field of static strength testing of aerospace products. External aerospace products are divided into flange structures and nozzle structures. When the external aerospace product is a flange structure, the spherical sealing structure includes a sealing flange, a spherical retaining ring, an O-ring, fasteners, and a connecting nozzle. The sealing flange is vertically aligned with the external aerospace product. A sealing groove is provided at the connection point between the sealing flange and the external aerospace product. The spherical retaining ring is placed in the sealing groove of the sealing flange. The O-ring is embedded in the bottom of the spherical retaining ring. After the sealing flange and the external aerospace product are connected, fasteners are threaded through the sealing flange and the external aerospace product from top to bottom. The connecting nozzle is coaxially welded to the top of the sealing flange. During testing, the spherical retaining ring effectively prevents the high-pressure test fluid medium from extruding and damaging the O-ring.

Description

Technical Field

[0001] This invention belongs to the field of static strength testing of aerospace products and relates to an ultra-high pressure spherical sealing structure with anti-extrusion function. Background Technology

[0002] To ensure the high performance and safe and reliable operation of rocket engines, pump housings, valve housings, and conduits used in aerospace products must undergo static strength testing after manufacturing to verify the static strength of the structure and the welding quality of the welds. The test pressure for static strength testing is generally 1.2 to 1.5 times the working pressure of the aerospace product. Simultaneously, the sealing structure used in the test must not damage the sealing surface of the aerospace product, and it should be easy for workers to use and disassemble. Existing spherical sealing structures can be broadly classified into two categories: hard metal seals and rubber packing seals. Hard metal seals achieve sealing by creating line contact between a metal ball head and the spherical surface; however, this sealing structure can damage the spherical surface of the aerospace product after repeated disassembly and assembly, and it is only suitable for sealing applications with small diameters. Rubber packing seals have a more complex spherical sealing groove structure and require complex machining processes. They also suffer from damage to the sealing surface of the aerospace product after repeated disassembly and assembly, and the rubber packing is easily extruded under high-pressure conditions. Therefore, how to provide a new sealing structure with excellent machinability, that does not damage the spherical surface of the aerospace product during disassembly and assembly, and that has strong ultra-high-pressure sealing capabilities is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose an ultra-high pressure spherical sealing structure with anti-extrusion function. During the test, the spherical retaining ring can effectively prevent the high pressure test fluid medium from extruding and damaging the O-ring rubber ring.

[0004] The solution of the present invention is:

[0005] An ultra-high pressure spherical sealing structure with anti-extrusion function is disclosed. The external aerospace product can be either a flange structure or a nozzle structure. When the external aerospace product is a flange structure, the spherical sealing structure includes a sealing flange, a spherical retaining ring, an O-ring, fasteners, and a connecting nozzle. The sealing flange is vertically aligned axially with the external aerospace product. A sealing groove is provided at the connection point between the sealing flange and the external aerospace product. The spherical retaining ring is placed within the sealing groove of the sealing flange. The O-ring is embedded in the bottom of the spherical retaining ring. After the sealing flange and the external aerospace product are connected, fasteners are threaded through the sealing flange and the external aerospace product from top to bottom. The connecting nozzle is coaxially welded to the top of the sealing flange.

[0006] In the aforementioned ultra-high pressure spherical sealing structure with anti-extrusion function, the external aerospace product has a through hole along the axial direction; the sealing flange is connected to the inner wall of the through hole of the external aerospace product; the side wall of the sealing flange is a spherical structure; the inner wall of the top of the through hole of the external aerospace product is a spherical structure with the same shape as the sealing flange, so as to achieve adaptive connection.

[0007] In the aforementioned ultra-high pressure spherical sealing structure with anti-extrusion function, a through hole is provided at the axis of the sealing flange. This through hole connects to the nozzle, enabling the channel communication between the internal cavity of the external aerospace product and the nozzle.

[0008] In the aforementioned ultra-high pressure spherical sealing structure with anti-extrusion function, the sealing groove is set on the spherical sidewall of the sealing flange; the cross-section of the sealing groove is a right-angled triangular structure; and the transition between the two corners of the sealing groove and the spherical sidewall of the sealing flange is provided with a radius of R1.

[0009] In the aforementioned ultra-high pressure spherical sealing structure with anti-extrusion function, the diameter of the spherical sidewall of the sealing flange is 0.4 mm smaller than the diameter of the inner spherical wall of the external aerospace product; and after the sealing flange is docked and fixed with the external aerospace product, the root of the large-diameter end of the spherical sidewall of the sealing flange is 1 mm higher than the top of the external aerospace product.

[0010] In the aforementioned ultra-high pressure spherical sealing structure with anti-extrusion function, the bottom end of the spherical sidewall of the sealing flange is provided with a vertical diameter section with a length of 4mm; the outer wall of the bottom end of the diameter section is provided with a 1.5x45° chamfer; and the inner diameter of the diameter section is 0.15mm smaller than the inner wall diameter of the external aerospace product.

[0011] In the aforementioned ultra-high pressure spherical sealing structure with anti-extrusion function, the diameter of the spherical retaining ring is 0.5-0.8 mm larger than the diameter of the spherical sidewall of the sealing flange; during docking, the spherical retaining ring first contacts the inner wall of the external aerospace product; when the fasteners are tightened, the spherical retaining ring is compressed and tightly fits against the inner wall of the external aerospace product.

[0012] In the aforementioned ultra-high pressure spherical sealing structure with anti-extrusion function, a spherical groove is provided on the lower surface of the spherical retaining ring, and the diameter of the groove is equal to the diameter of the O-ring; thus, the O-ring is embedded in the groove of the spherical retaining ring.

[0013] In the aforementioned ultra-high pressure spherical sealing structure with anti-extrusion function, when the external aerospace product is a nozzle structure, the spherical sealing structure includes a sealing flange, a spherical retaining ring, an O-ring, and fasteners. The sealing flange integrates a nozzle at its top, forming a single integrated structure. The sealing flange is coaxially connected to the top of the external aerospace product. The spherical retaining ring and the O-ring are both located at the connection point between the sealing flange and the external aerospace product. Fasteners are sequentially fitted from top to bottom onto the sealing flange and the outer wall of the external aerospace product, and are screwed and fixed to the outer wall of the external aerospace product.

[0014] In the aforementioned ultra-high pressure spherical sealing structure with anti-extrusion function, when the external aerospace product is a flange structure, the fastener is a hexagonal head bolt; when the external aerospace product is a nozzle structure, the fastener is an outer nut structure.

[0015] The beneficial effects of this invention compared to the prior art are:

[0016] (1) The present invention provides rounded corners of R1 at both the inlet and outlet of the sealing groove to prevent damage to the spherical surface of aerospace products. The advantage of this sealing groove is that it has good machinability;

[0017] (2) The sealing flange of the present invention has a straight section of about 4mm below the small section, and the end of the straight section has a 1.5x45° chamfer to achieve circumferential limiting of the sealing flange and prevent the sealing flange (1) from circumferentially flipping relative to the spherical surface of the aerospace product during installation and damaging the spherical surface of the product.

[0018] (3) The diameter of the spherical retaining ring of the present invention is 0.5-0.8 mm larger than the diameter of the spherical sidewall of the sealing flange. During assembly, the spherical retaining ring contacts the spherical surface of the product first. After the fasteners are tightened, the spherical retaining ring is compressed and fits tightly against the metal spherical surface of the product. This structure has two functions: first, it can prevent the spherical surface of the aerospace product from being damaged by excessive force when the operator tightens the fasteners during installation; second, it makes the spherical retaining ring fit tightly against the metal spherical surface, improving the ability of the spherical retaining ring to prevent the O-ring from being squeezed out and damaged under high pressure conditions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the spherical sealing structure of the present invention when the external aerospace product is a flange structure;

[0020] Figure 2 This is a schematic diagram of the spherical sealing structure of the present invention when the external aerospace product is a nozzle structure.

[0021] In the picture

[0022] 1-Sealing flange; 2-Spherical retaining ring; 3-O-ring; 4-Fastener; 5-Connecting nozzle. Detailed Implementation

[0023] The present invention will be further described below with reference to the embodiments.

[0024] This invention provides an ultra-high pressure spherical sealing structure with anti-extrusion function. The sealing structure is fixed to the mechanical interface of the aerospace product by fastener 4. During the test, the ultra-high pressure fluid test medium acts on the O-ring 3. The O-ring 3 tends to be extruded and destroyed. Through structural design, the spherical retaining ring 2 can fit tightly with the spherical surface of the aerospace product, effectively reducing this tendency and improving the ultra-high pressure sealing capability of the structure.

[0025] The ultra-high pressure spherical sealing structure is designed based on the structural form of external aerospace products. External aerospace products are divided into two types: flange structures and nozzle structures. When the external aerospace product is a flange structure, such as... Figure 1 As shown, the spherical sealing structure includes a sealing flange 1, a spherical retaining ring 2, an O-ring 3, a fastener 4, and a connector 5. The sealing flange 1 is vertically aligned axially with the external aerospace product. A sealing groove is provided at the connection point between the sealing flange 1 and the external aerospace product. The spherical retaining ring 2 is placed in the sealing groove of the sealing flange 1. The O-ring 3 is embedded in the bottom of the spherical retaining ring 2. After the sealing flange 1 is connected to the external aerospace product, the fastener 4 passes through the sealing flange 1 and the external aerospace product sequentially from top to bottom, and is threaded in place. The connector 5 is coaxially welded to the top of the sealing flange 1.

[0026] The external aerospace product has a through hole along its axial direction; the sealing flange 1 is aligned with the inner wall of the through hole of the external aerospace product; the side wall of the sealing flange 1 is a spherical structure; the inner wall of the top of the through hole of the external aerospace product is a spherical structure with the same shape as the sealing flange 1, achieving adaptive alignment. A connector is welded onto the sealing flange 1 for filling and draining fluid during hydraulic strength testing. When installing this structure, first check the spherical retaining ring 2 and O-ring 3 for cracks, aging, etc., and check the fasteners 4 for deformation, cracks, damage, etc. If any are found, replace them. Then, sequentially insert the spherical retaining ring 2 and O-ring 3 into the sealing groove of the sealing flange 1, align the sealing flange 1 with the aerospace product, and tighten the fasteners 4 to complete the installation. A through hole is provided at the axis of the sealing flange 1, which aligns with the connector 5, enabling communication between the inner cavity of the external aerospace product and the connector 5.

[0027] The sealing groove is located on the spherical sidewall of sealing flange 1; the cross-section of the sealing groove is a right-angled triangular structure; the transition points between the two corners of the sealing groove and the spherical sidewall of sealing flange 1 are both rounded with R1 to prevent damage to the spherical surface of aerospace products. The advantage of this sealing groove is its good machinability.

[0028] The diameter of the spherical sidewall of sealing flange 1 is 0.4 mm smaller than the diameter of the inner spherical wall of the external aerospace product; and after sealing flange 1 is docked and fixed to the external aerospace product, the root of the large-diameter end of the spherical sidewall of sealing flange 1 is 1 mm higher than the top of the external aerospace product. The function of this structure is to ensure that sealing flange 1 and the spherical surface of the aerospace product are completely fitted together.

[0029] The bottom end of the spherical sidewall of sealing flange 1 has a vertical diameter section with a length of 4mm; the outer wall of the bottom end of the diameter section has a 1.5x45° chamfer; and the inner diameter of the diameter section is 0.15mm smaller than the inner diameter of the outer aerospace product. The function of this structure is to circumferentially limit the sealing flange 1, preventing it from circumferentially rotating relative to the spherical surface of the aerospace product during installation and damaging the spherical surface of the product.

[0030] The diameter of the spherical retaining ring 2 is 0.5-0.8 mm larger than the diameter of the spherical sidewall of the sealing flange 1. During assembly, the spherical retaining ring 2 first contacts the inner wall of the external aerospace product. When the fastener 4 is tightened, the spherical retaining ring 2 is compressed and tightly fitted to the inner wall of the external aerospace product. This structure serves two purposes: firstly, it prevents damage to the spherical surface of the aerospace product caused by excessive force applied by the operator when tightening the fastener 4 during installation; secondly, it ensures a tight fit between the spherical retaining ring 2 and the metal spherical surface, improving the ability of the spherical retaining ring 2 to prevent the O-ring 3 from being squeezed out and damaged under high-pressure conditions.

[0031] The lower surface of the spherical retaining ring 2 has a spherical groove with a diameter equal to that of the O-ring 3, allowing the O-ring 3 to be embedded in the groove of the spherical retaining ring 2. When the center of the spherical groove is close to the spherical retaining ring, the compression of the O-ring 3 decreases; conversely, the compression of the O-ring 3 increases. This structure serves two purposes: first, it increases the contact area of ​​the O-ring 3, reducing the stress level of the O-ring 3 and the spherical retaining ring 2 under high-pressure conditions, thus improving the service life of the seal; second, by adjusting the position of the center of the spherical groove, the compression of the O-ring 3 can be adjusted to approximately 25% without changing the installation space.

[0032] When the external aerospace product has a nozzle structure, such as Figure 2 As shown, the spherical sealing structure includes a sealing flange 1, a spherical retaining ring 2, an O-ring 3, and fasteners 4. The sealing flange 1 integrates a connector at its top, forming a single unit. The sealing flange 1 is coaxially connected to the top of the external aerospace product. The spherical retaining ring 2 and the O-ring 3 are both located at the connection point between the sealing flange 1 and the external aerospace product. The fasteners 4 are sequentially fitted from top to bottom onto the sealing flange 1 and the outer wall of the external aerospace product, and are screwed to the outer wall of the external aerospace product for secure fixing.

[0033] In summary, when the external aerospace product is a flange structure, fastener 4 is a hexagonal head bolt; when the external aerospace product is a nozzle structure, fastener 4 is an outer sleeve nut structure.

[0034] The advantages of the above technical solution are: the straight segment provides circumferential restraint for the sealing flange 1, preventing the sealing flange 1 from circumferentially rotating relative to the spherical surface of the aerospace product during installation and damaging the spherical surface of the aerospace product.

[0035] The fourth technical solution of the present invention is: a spherical retaining ring 2 is provided on the back side of the O-ring 3 that bears pressure. The small end of the spherical retaining ring 2 has a spherical groove. The diameter of the spherical surface is equal to the diameter of the O-ring 3. When the center of the spherical surface is close to the spherical retaining ring, the compression of the O-ring 3 becomes smaller. Conversely, the compression of the O-ring 4 becomes larger.

[0036] One of the advantages of the above technical solution is that by adjusting the position of the center of the spherical groove of the spherical retaining ring 2, the compression of the O-ring 3 can be adjusted to about 20% without changing the installation space, thus expanding the application range of the sealing structure.

[0037] The second advantage of the above technical solution is that the O-ring 3 and the spherical groove of the spherical retaining ring 2 are in contact, which can effectively reduce the stress level of the contact surface under high pressure conditions and improve the service life of the O-ring 3 and the spherical retaining ring 2.

[0038] The third advantage of the above technical solution is that under high pressure conditions, the sealing flange 1 and the fastener 4 will undergo elastic deformation, which will create a gap between the spherical retaining ring 2 and the spherical surface of the aerospace product. At this time, the O-ring 3 will transmit the high pressure test pressure to the spherical groove surface of the spherical retaining ring 2. The two protrusions at the opening of the spherical groove of the spherical retaining ring 2 will deform along the gap, which will compensate for the leakage gap caused by the elastic deformation of the metal parts and improve the ultra-high pressure sealing capability of the structure.

[0039] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. An ultra-high pressure spherical sealing structure with anti-extrusion function, characterized in that: The external aerospace product is a flange structure. The spherical sealing structure includes a sealing flange (1), a spherical retaining ring (2), an O-ring (3), fasteners (4), and a connector (5). The sealing flange (1) is vertically aligned with the external aerospace product. A sealing groove is provided at the connection between the sealing flange (1) and the external aerospace product. The spherical retaining ring (2) is placed in the sealing groove of the sealing flange (1). The O-ring (3) is embedded in the bottom of the spherical retaining ring (2). After the sealing flange (1) is connected to the external aerospace product, the fasteners (4) pass through the sealing flange (1) and the external aerospace product from top to bottom and are threaded. The connector (5) is coaxially welded to the top of the sealing flange (1). The external aerospace product has a through hole along the axial direction; the sealing flange (1) is connected to the inner wall of the through hole of the external aerospace product; the side wall of the sealing flange (1) is a spherical structure; the inner wall of the top of the through hole of the external aerospace product is a spherical structure with the same shape as the sealing flange (1) to achieve adaptive docking; The sealing groove is set on the spherical sidewall of the sealing flange (1); the cross section of the sealing groove is a right-angled triangular structure; the transition between the two corners of the sealing groove and the spherical sidewall of the sealing flange (1) is provided with a radius of R1; The spherical retaining ring (2) has a spherical groove on its lower surface, and the diameter of the groove is equal to the diameter of the O-ring (3); so that the O-ring (3) can be embedded in the groove of the spherical retaining ring (2).

2. The ultra-high pressure spherical sealing structure with anti-extrusion function according to claim 1, characterized in that: A through hole is provided at the axis of the sealing flange (1), which is connected to the connector (5) to realize the channel connection between the inner cavity of the external aerospace product and the connector (5).

3. The ultra-high pressure spherical sealing structure with anti-extrusion function according to claim 1, characterized in that: The diameter of the spherical sidewall of the sealing flange (1) is 0.4 mm smaller than the diameter of the inner spherical wall of the external aerospace product; and after the sealing flange (1) is docked and fixed with the external aerospace product, the root of the large diameter end of the spherical sidewall of the sealing flange (1) is 1 mm higher than the top of the external aerospace product.

4. The ultra-high pressure spherical sealing structure with anti-extrusion function according to claim 3, characterized in that: The bottom end of the spherical sidewall of the sealing flange (1) is provided with a vertical diameter section with a length of 4mm; the outer wall of the bottom end of the diameter section is provided with a 1.5x45° chamfer; and the inner diameter of the diameter section is 0.15mm smaller than the inner wall diameter of the external aerospace product.

5. The ultra-high pressure spherical sealing structure with anti-extrusion function according to claim 4, characterized in that: The diameter of the spherical retaining ring (2) is 0.5-0.8 mm larger than the diameter of the spherical sidewall of the sealing flange (1). When docking, the spherical retaining ring (2) first contacts the inner wall of the external aerospace product. When the fastener (4) is tightened, the spherical retaining ring (2) is compressed and tightly fits the inner wall of the external aerospace product.

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