A fluorine rubber O-ring seal

Abstract

The utility model relates to sealing device technical field especially relates to a kind of fluorine rubber O type sealing ring, including the circular core part in cross section center and the multiple radial extension arc protrusions that are evenly distributed along the circumference of core part;The thickness of arc protrusion gradually increases from the root portion connected with core part to radial outer end, and all arc protrusions are symmetrically distributed relative to the axis of core part, so that the overall cross section is radially symmetric star structure;Compared with prior art, through the unique star cross section structure design, i.e. circular core part and circumferentially evenly distributed arc protrusion, arc protrusion thickness gradually increases from root portion to radial outer end, so that sealing ring when being subjected to medium pressure, arc protrusion can better elastically deform, increase the contact area with sealing surface, improve sealing performance;The radial outer end of arc protrusion is provided with circular-arc end face and through-hole, and circular-arc end face can reduce the friction and wear between sealing ring and sealing surface.

Description

Technical Field

[0001] This utility model relates to the field of sealing device technology, and in particular to a fluororubber O-ring. Background Technology

[0002] Fluororubber O-rings are O-ring sealing elements made primarily of fluororubber through molding or extrusion. They have a circular cross-section, a simple and compact structure, and are easy to install. They can be adapted to various sealing groove designs. By pre-compressing (extrusion deformation during installation), contact pressure is formed between the sealing surfaces. When there is medium pressure in the system, the sealing ring will move towards the low-pressure side, further increasing the contact pressure, thereby achieving dynamic or static sealing.

[0003] Traditional O-rings have a circular cross-section, which has the following shortcomings under high pressure or frequent diameter changes: stress concentration occurs when the cross-section is under pressure, making it prone to permanent deformation or extrusion; the single circular arc contact surface is prone to leakage due to wear in dynamic sealing; and it has high requirements for the dimensional accuracy of the mounting groove and poor adaptability; therefore, it is urgent to improve it. Utility Model Content

[0004] To address the technical problems existing in the background art, this utility model proposes a fluororubber O-ring.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A fluororubber O-ring is characterized in that it includes a circular core located at the center of the cross-section and a plurality of radially extending arc-shaped protrusions evenly distributed along the circumference of the core; the thickness of the arc-shaped protrusions gradually increases from the root of the core to the radially outer end, and all the arc-shaped protrusions are centrally symmetrically distributed with respect to the axis of the core, so that the overall cross-section has a radially symmetrical star-shaped structure.

[0007] Preferably, the radial outer end of the arc-shaped protrusion is a circular arc-shaped end face, and a through hole is formed in the middle of each circular arc-shaped end face in a direction parallel to the axis of the core.

[0008] Preferably, a plurality of pits are provided on the high-pressure side contact surface of the arc-shaped protrusion; the high-pressure side contact surface is defined as the outer surface of the arc-shaped protrusion on the side with higher medium pressure when the sealing ring is installed.

[0009] Preferably, the high-pressure side contact surface is determined according to the following rules: when the sealing ring is used for piston sealing, the high-pressure side is the inner arc-shaped protrusion surface near the piston rod; when the sealing ring is used for shaft sealing, the high-pressure side is the outer arc-shaped protrusion surface near the housing wall.

[0010] Preferably, the arrangement of the pits avoids the central region of the sealing contact strip formed by the high-pressure side contact surface of the arc-shaped protrusion, and is distributed in a spiral pattern along the edge region of the sealing contact strip.

[0011] Preferably, the fluororubber has a Shore A hardness of 65-75 degrees and a compression set of no more than 40% at 200°C.

[0012] Preferably, the working contact surface of the sealing ring is covered with a fuel corrosion resistant protective layer; the protective layer is formed by any of the following processes:

[0013] Perfluoroelastomer (FFKM) coating process: An FFKM layer with a thickness of 20μm-100μm is coated onto the surface of a fluororubber matrix, wherein the fluorine content of the FFKM layer is ≥70wt%; or

[0014] Surface deep fluorination process: Plasma fluorination treatment is performed on the surface of the fluororubber matrix to form a modified layer with a fluorination depth of 5μm-10μm, and the fluorine-carbon atomic ratio (F / C) on the surface of the modified layer is ≥1.5;

[0015] The protective layer is used to block the penetration of esters and hydroxyl components in biodiesel or alcohol-containing fuels, so that the volume swelling rate of the sealing ring is ≤10% after being immersed in B100 biodiesel at 40°C for 168 hours.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] Compared with existing technologies, the unique star-shaped cross-section structure design, consisting of a circular core and circumferentially distributed arc-shaped protrusions, with the thickness of the arc-shaped protrusions gradually increasing from the root to the radially outer end, allows the sealing ring to undergo better elastic deformation under medium pressure, increasing the contact area with the sealing surface and improving sealing performance. The radially outer end of the arc-shaped protrusion features a circular arc-shaped end face and a through hole. The circular arc-shaped end face reduces friction and wear between the sealing ring and the sealing surface, while the through hole forms an elastic buffer zone in the maximum stress area of ​​the sealing ring, effectively decomposing concentrated stress during radial compression and solving the root cracking problem under high-pressure alternating loads, thus extending service life. Furthermore, recesses are provided on the high-pressure side contact surface of the arc-shaped protrusion, spirally distributed along the edge of the sealing contact zone, avoiding the central area. This design allows the medium stored in the recesses to form a lubricating film under high pressure, reducing friction and wear on the high-pressure side contact surface. Simultaneously, the spirally distributed recesses promote uniform distribution and flow of the medium, improving the stability of the sealing ring under high pressure. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the fluororubber O-ring proposed in this utility model;

[0019] Figure 2 This is a schematic diagram of the first cross-sectional structure of the fluororubber O-ring proposed in this utility model.

[0020] Figure 3 This is a schematic diagram of the second cross-sectional structure of the fluororubber O-ring proposed in this utility model.

[0021] In the diagram: 1-Sealing ring, 11-Core, 12-Arch-shaped protrusion, 13-Through hole, 14-Dent. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] like Figures 1-3 As shown, this embodiment provides a fluororubber O-ring, including a circular core 11 located at the center of the cross-section and a plurality of radially extending arc-shaped protrusions 12 evenly distributed around the core 11; the thickness of the arc-shaped protrusions 12 gradually increases from the root of the core 11 to the radially outer end, and all the arc-shaped protrusions 12 are centrally symmetrically distributed with respect to the axis of the core 11, so that the overall cross-section has a radially symmetrical star structure.

[0024] Overall, four arc-shaped protrusions 12 are evenly distributed around the core 11. The arc-shaped protrusions 12 are centrally symmetrical with respect to the axis of the core 11, and the overall cross-section has a radially symmetrical star-shaped structure. The thickness of the arc-shaped protrusions 12 gradually increases from the root of the core 11 to the radially outer end. This structural design allows the arc-shaped protrusions 12 to undergo better elastic deformation when the sealing ring 1 is subjected to external pressure, increasing the contact area with the sealing surface and thus improving the sealing performance.

[0025] like Figures 2-3 As shown, in this embodiment, the radial outer end of the arc-shaped protrusion 12 is a circular arc-shaped end face, and a through hole 13 is provided in the middle of each circular arc-shaped end face along a direction parallel to the axis of the core 11.

[0026] Specifically, the radial outer end of the arc-shaped protrusion 12 is an arc-shaped end face. A through hole 13 is provided in the middle of each arc-shaped end face along a direction parallel to the axis of the core 11. The arc-shaped end face design can reduce the friction and wear between the sealing ring 1 and the sealing surface, and improve the service life of the sealing ring 1. The through hole 13 can form an elastic buffer zone between the root and the end transition zone of the maximum stress area of ​​the sealing ring 1, effectively decompose the concentrated stress during radial compression, and also solve the problem of root cracking of the sealing ring 1 under high pressure alternating loads such as hydraulic impact, thus improving its service life.

[0027] like Figures 2-3 As shown, in this embodiment, a plurality of pits 14 are provided on the high-pressure side contact surface of the arc-shaped protrusion 12; the high-pressure side contact surface is defined as the outer surface of the arc-shaped protrusion 12 on the side with higher medium pressure when the sealing ring 1 is installed.

[0028] By providing multiple pits 14 on the high-pressure side contact surface of the arc-shaped protrusion 12, the high-pressure side contact surface is defined as the outer surface of the arc-shaped protrusion 12 on the side of the sealing ring 1 that bears the higher medium pressure in the installation state; by providing pits 14 on this surface, a certain amount of medium can be stored to form a lubricating film, thereby reducing friction and wear between the high-pressure side contact surface and the sealing surface, and improving the lubrication effect and sealing stability.

[0029] like Figures 2-3 As shown, in this embodiment, the high-pressure side contact surface is determined according to the following rules: when the sealing ring 1 is used for piston sealing, the high-pressure side is the inner arc-shaped protrusion 12 surface near the piston rod; when the sealing ring 1 is used for shaft sealing, the high-pressure side is the outer arc-shaped protrusion 12 surface near the housing wall.

[0030] When this sealing ring 1 is used for piston sealing: the high-pressure side is the inner arc-shaped protrusion 12 surface near the piston rod. At this time, the inner arc-shaped protrusion 12 surface bears a high medium pressure. A pit 14 is set on this surface. This design allows the pit 14 to store a certain amount of medium under high pressure environment, forming a lubricating film, reducing the friction and wear between the high-pressure side contact surface and the sealing surface, making the lubricating film more evenly distributed on the sealing contact strip, and improving the lubrication effect and sealing stability.

[0031] When the sealing ring 1 is used for shaft sealing: the high-pressure side is the outer arc-shaped protrusion 12 surface close to the housing wall. At this time, the outer arc-shaped protrusion 12 surface bears a high medium pressure. A pit 14 is set on the outer arc-shaped protrusion 12 surface. The high-pressure side contact surface is accurately determined and the pit 14 is set for different application scenarios, so that the structural design of the sealing ring 1 is more reasonable, can better adapt to different sealing conditions, and improve the sealing effect and reliability.

[0032] like Figures 2-3As shown, in this embodiment, the arrangement of the pits 14 avoids the central region of the sealing contact strip formed by the high-pressure side contact surface of the arc-shaped protrusion 12, and is distributed in a spiral pattern along the edge region of the sealing contact strip.

[0033] Specifically, when this sealing ring 1 is used for piston sealing: the high-pressure side is the inner arc-shaped protrusion 12 surface near the piston rod. At this time, the inner arc-shaped protrusion 12 surface bears a high medium pressure. A pit 14 is set on this surface. The arrangement of the pits 14 avoids the central area of ​​the sealing contact strip formed by the high-pressure side contact surface of the arc-shaped protrusion 12, and is distributed in a spiral line along the edge area of ​​the sealing contact strip. This design allows the pits 14 to store a certain amount of medium under high pressure, forming a lubricating film, reducing friction and wear between the high-pressure side contact surface and the sealing surface. The spiral distribution of the pits 14 helps the medium to flow along the spiral direction, making the lubricating film more evenly distributed on the sealing contact strip, improving the lubrication effect and sealing stability.

[0034] When the sealing ring 1 is used for shaft sealing: the high-pressure side is the outer arc-shaped protrusion 12 surface near the housing wall. At this time, the outer arc-shaped protrusion 12 surface bears a high medium pressure. A pit 14 is set on the outer arc-shaped protrusion 12 surface. The pit 14 is also arranged in a spiral pattern along the edge area, avoiding the central area of ​​the sealing contact zone. The high-pressure side contact surface is accurately determined and the pit 14 is set for different application scenarios, so that the structural design of the sealing ring 1 is more reasonable, which can better adapt to different sealing conditions and improve the sealing effect and reliability.

[0035] Since the recesses 14 avoid the central area of ​​the sealing contact strip, they maintain good sealing performance in the central area. The recesses 14 in the edge area store the medium to form a lubricating film, reducing friction and wear in the edge area. At the same time, the spiral distribution of the recesses 14 is conducive to the flow and distribution of the medium, avoiding the formation of local high pressure in the edge area, thereby improving the stability of the sealing ring 1 under high pressure and reducing the possibility of leakage.

[0036] like Figure 1 As shown, in this embodiment, the fluororubber has a Shore A hardness of 65-75 degrees and a compression set of no more than 40% at a high temperature of 200°C.

[0037] Specifically, the fluororubber O-ring 1 has a Shore A hardness of 70 and a compression set of 35% at 200°C. This hardness and compression set allow the O-ring 1 to maintain good elasticity in high-temperature environments and prevent permanent deformation, ensuring reliable sealing performance under high-temperature conditions. For example, in high-temperature equipment, the O-ring 1 is exposed to high temperatures for extended periods. The high Shore A hardness and low compression set ensure that the O-ring 1 does not lose its elasticity due to high temperatures, thus maintaining a continuous and effective sealing function.

[0038] like Figure 1 As shown, in this embodiment, the working contact surface of the sealing ring 1 is covered with a fuel corrosion resistant protective layer; the protective layer is formed by any of the following processes:

[0039] FFKM coating process for perfluoroelastomer rubber: An FFKM layer with a thickness of 20μm-100μm is coated onto the surface of a fluororubber matrix, wherein the fluorine content of the FFKM layer is ≥70wt%; or

[0040] Surface deep fluorination process: Plasma fluorination treatment is performed on the surface of the fluororubber matrix to form a modified layer with a fluorination depth of 5μm-10μm, and the fluorine-carbon atom ratio F / C on the surface of the modified layer is ≥1.5;

[0041] The protective layer is used to block the penetration of esters and hydroxyl components in biodiesel or alcohol-containing fuels, so that the volume swelling rate of the sealing ring 1 after being immersed in B100 biodiesel at 40°C for 168 hours is ≤10%.

[0042] Specifically, the working contact surface of the sealing ring 1 is covered with a fuel corrosion resistant protective layer. This layer is created using a perfluoroelastomer (FFKM) coating process, where a 50μm thick FFKM layer is coated onto the fluororubber substrate. The fluorine content of the FFKM layer is 75wt%. This protective layer effectively prevents esters and hydroxyl components in biodiesel or alcohol-containing fuels from penetrating into the fluororubber substrate. Testing showed that the volume swelling rate of the sealing ring 1 after immersion in B100 biodiesel at 40℃ for 168 hours was 8%, meeting the usage requirements. Alternatively, a surface deep fluorination process can be used, where the fluororubber substrate surface undergoes plasma fluorination treatment to form a modified layer with a fluorination depth of 8μm. The fluorine-to-carbon atomic ratio (F / C) on the modified layer surface is 1.8, achieving similarly good fuel corrosion resistance and effectively improving the service life of the sealing ring 1 in special media environments.

[0043] Of course, those skilled in the art will recognize that this invention is not limited to the details of the exemplary embodiments described above, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0044] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0045] The technologies, shapes, and structures not described in detail in this utility model are all known technologies.

Claims

1. A fluororubber O-ring, characterized in that, It includes a circular core (11) located at the center of the cross section and multiple radially extending arc-shaped protrusions (12) evenly distributed around the core (11); the thickness of the arc-shaped protrusions (12) gradually increases from the root of the core (11) to the radially outer end, and all the arc-shaped protrusions (12) are centrally symmetrically distributed with respect to the axis of the core (11), so that the overall cross section has a radially symmetrical star structure.

2. The fluororubber O-ring according to claim 1, characterized in that, The radial outer end of the arc-shaped protrusion (12) is a circular arc-shaped end face, and a through hole (13) is provided in the middle of each circular arc-shaped end face in a direction parallel to the axis of the core (11).

3. The fluororubber O-ring according to claim 1, characterized in that, Multiple pits (14) are provided on the high-pressure side contact surface of the arc-shaped protrusion (12); the high-pressure side contact surface is defined as the outer surface of the arc-shaped protrusion (12) on the side with higher medium pressure when the sealing ring (1) is installed.

4. The fluororubber O-ring according to claim 3, characterized in that, The high-pressure side contact surface is determined according to the following rules: when the sealing ring (1) is used for piston sealing, the high-pressure side is the inner arc-shaped protrusion (12) surface close to the piston rod; when the sealing ring (1) is used for shaft sealing, the high-pressure side is the outer arc-shaped protrusion (12) surface close to the housing wall.

5. The fluororubber O-ring according to claim 3, characterized in that, The arrangement of the pits (14) avoids the central area of ​​the sealing contact strip formed by the high-pressure side contact surface of the arc protrusion (12) and is distributed in a spiral pattern along the edge area of ​​the sealing contact strip.

6. The fluororubber O-ring according to any one of claims 1-5, characterized in that, The fluororubber has a Shore A hardness of 65-75 degrees and a compression set of no more than 40% at 200°C.

7. The fluororubber O-ring according to any one of claims 1-5, characterized in that, The working contact surface of the sealing ring (1) is covered with a fuel corrosion resistant protective layer; the protective layer is formed by any of the following processes: Perfluoroelastomer (FFKM) coating process: An FFKM layer with a thickness of 20μm-100μm is coated onto the surface of a fluororubber matrix, wherein the fluorine content of the FFKM layer is ≥70wt%; or Surface deep fluorination process: Plasma fluorination treatment is performed on the surface of the fluororubber substrate to form a modified layer with a fluorination depth of 5μm-10μm, and the fluorine-carbon atomic ratio (F / C) on the surface of the modified layer is ≥1.5; The protective layer is used to block the penetration of esters and hydroxyl components in biodiesel or alcohol-containing fuels, so that the volume swelling rate of the sealing ring (1) after being immersed in B100 biodiesel at 40°C for 168 hours is ≤10%.

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