Silicon carbide sealing ring with good sealing effect

Abstract

The utility model discloses a silicon carbide sealing ring that has good sealing effect, which comprises a silicon carbide ring body. An asymmetric micron-level texture is arranged on the sealing end face of the silicon carbide ring body. The texture comprises a texture area on the high-pressure side and a smooth sealing dam on the low-pressure side. A micro-dimple is arranged in the texture area to store medium and generate fluid dynamic pressure. In addition, a metal ring with a thermal expansion coefficient between the silicon carbide and the external mounting seat is fixedly installed on the outer surface of the other end of the silicon carbide ring body. The utility model has the beneficial effects that the asymmetric texture can enhance the dynamic pressure lubrication effect between the end faces, reduce friction and wear, and effectively inhibit medium leakage. The composite metal ring can reduce the internal stress of the silicon carbide ring body caused by thermal mismatch through the transition of the thermal expansion coefficient, prevent cracking, and thus realize the long service life and high reliability of the sealing ring under harsh working conditions.

Description

Technical Field

[0001] This utility model relates to the field of silicon carbide sealing ring technology, specifically a silicon carbide sealing ring with good sealing effect. Background Technology

[0002] Mechanical seals are key components widely used in rotating fluid equipment such as pumps, compressors, and agitators. Their performance directly affects the operating efficiency, safety, and reliability of the equipment. Silicon carbide ceramics, due to their high hardness, excellent wear resistance, outstanding chemical stability, and good thermal conductivity, have become one of the preferred materials for manufacturing mechanical seal rings, especially under harsh conditions such as high temperature, high pressure, and strong corrosion.

[0003] The end face morphology of a sealing ring is a core factor determining its sealing performance and service life. Traditional silicon carbide sealing rings typically have smooth, flat sealing faces, relying on an extremely thin liquid film formed between the face surfaces for lubrication and sealing. However, this design has inherent drawbacks: during equipment startup, shutdown, or low-pressure conditions, it is difficult to form a complete liquid film between the face surfaces, easily leading to dry friction or boundary lubrication, resulting in a sharp increase in friction and wear, and ultimately, seal failure and leakage. Conversely, under high-speed and high-pressure conditions, the hydrostatic pressure effect between the face surfaces may cause excessive opening force, leading to increased leakage.

[0004] Furthermore, silicon carbide sealing rings typically need to be installed in metal sealing seats or clamping rings. There is a significant difference in the coefficient of thermal expansion between silicon carbide and metal. When equipment experiences temperature changes during start-up, shutdown, or operation, this thermal mismatch generates enormous thermal stress within the silicon carbide ring, easily leading to cracks or even breakage in the brittle ring. This, in turn, affects the stability of the sealing effect.

[0005] Therefore, we propose a silicon carbide sealing ring with good sealing performance. Utility Model Content

[0006] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a silicon carbide sealing ring with excellent sealing performance. By setting an asymmetric texture on the sealing end face and combining it with a thermally matched metal ring, the hydrodynamic lubrication effect and thermal shock resistance of the silicon carbide sealing ring are synergistically improved, thereby enhancing sealing performance and service life, and effectively solving the problems in the background technology.

[0007] (II) Technical Solution To achieve the above objectives, the technical solution adopted by this utility model is as follows: a silicon carbide sealing ring with good sealing effect, comprising a silicon carbide ring body, wherein the sealing end face of the silicon carbide ring body is provided with an asymmetric micron-level texture, the asymmetric micron-level texture includes a textured area provided on the high-pressure side of the sealing end face and a smooth sealing dam provided on the low-pressure side, the textured area containing a plurality of micro-pits for storing media and generating fluid dynamic pressure; a metal ring is fixedly installed on the outer surface of the other end of the silicon carbide ring body.

[0008] Preferably, the micro-pits are circular or elliptical; the depth of the micro-pits is 5-50 μm and the diameter is 50-500 μm.

[0009] Preferably, the coefficient of thermal expansion of the metal ring is between that of the silicon carbide ring and the external mounting base on which the silicon carbide ring is mounted.

[0010] Preferably, the metal ring is a tungsten alloy ring.

[0011] Preferably, the metal ring is integrated with the silicon carbide ring body by sintering or brazing.

[0012] Preferably, the silicon carbide cyclic body is made of reaction-sintered silicon carbide or pressureless sintered silicon carbide.

[0013] (III) Beneficial Effects Compared with the prior art, this utility model provides a silicon carbide sealing ring with good sealing effect, which has the following beneficial effects: 1. This silicon carbide sealing ring with good sealing effect forms an efficient asymmetric hydrodynamic lubrication structure by setting a micro-dimpled textured area on the high-pressure side of the medium and maintaining a smooth sealing dam on the low-pressure side. This structure can actively pump the sealing medium to the end face, enhance the hydrodynamic effect, and thus form a more stable and load-bearing lubricating film between the end faces. It can effectively reduce the friction coefficient and wear between the end faces, extend the service life, and actively resist the leakage tendency of the medium, thereby improving the sealing effect.

[0014] 2. This silicon carbide sealing ring with good sealing effect has an asymmetric texture design, which enables the sealing ring to establish a lubricating film more quickly when the equipment starts up, stops or the load fluctuates, avoiding dry friction and improving adaptability under changing working conditions. At the same time, the smooth sealing dam area provides a reliable main sealing barrier, which works in conjunction with the dynamic pressure effect of the textured area to ensure a wide range of stable sealing performance.

[0015] 3. This silicon carbide sealing ring with good sealing effect has a metal ring fixedly installed at the end that mates with the external mounting base. The thermal expansion coefficient of the metal ring is between that of silicon carbide and the metal of the mounting base, thus creating a thermal expansion gradient transition zone. When the temperature changes, the metal ring can effectively compensate for the huge difference in thermal expansion between the silicon carbide ring and the metal base, reducing the thermal stress generated inside the brittle silicon carbide due to thermal mismatch. This avoids the risk of the silicon carbide ring cracking or "bursting" due to thermal stress concentration under alternating hot and cold conditions, and improves the reliability and service life of the product. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of a silicon carbide sealing ring with good sealing effect according to this utility model.

[0017] Figure 2 This is a partial structural schematic diagram of a silicon carbide sealing ring with good sealing effect according to the present invention.

[0018] Figure 3 This is a schematic diagram of the metal ring structure in a silicon carbide sealing ring with good sealing effect according to this utility model.

[0019] In the diagram: 1. Silicon carbide ring; 2. Metal ring; 3. Sealing end face; 4. Smooth sealing dam; 5. Textured area; 6. Micro-pits. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0021] This embodiment is a silicon carbide sealing ring with good sealing performance.

[0022] like Figure 1-3 As shown, this embodiment provides a silicon carbide sealing ring with good sealing effect, mainly including a silicon carbide ring body 1 and a metal ring 2 fixedly installed on the outer surface of its other end.

[0023] The silicon carbide ring 1 is preferably made of reaction-sintered silicon carbide or pressureless sintered silicon carbide. Both materials have high hardness, high wear resistance, and good chemical stability, which can meet the requirements of use under harsh working conditions. One end face of the silicon carbide ring 1 is a sealing end face 3 for mating with the grinding ring.

[0024] The core improvement of this invention lies in the configuration of the sealing end face 3. The sealing end face 3 is designed to have an asymmetric micron-level texture. Specifically, based on the characteristics of the medium pressure distribution in actual operation (the high-pressure side is usually located on the inner side of the sealing end face (closer to the rotation axis), and the low-pressure side is located on the outer side), a textured area 5 is provided in the region of the sealing end face 3 corresponding to the high-pressure side, while the region corresponding to the low-pressure side remains a smooth sealing dam 4. The textured area 5 contains multiple uniformly distributed micro-pits 6. These micro-pits 6 are preferably circular or elliptical, with a depth of 5-50 μm and a diameter of 50-500 μm. This ensures that the micro-pits can effectively store trace amounts of sealing medium and generate a significant hydrodynamic pressure effect when the sealing end face 3 rotates relative to it.

[0025] Working Principle and Beneficial Effects: When the sealing ring is working, its sealing end face 3 and the mating ring end face are tightly pressed together and rotate relative to each other under the action of fluid pressure and spring force. The micro-pits 6 in the textured area 5 on the high-pressure side can trap a small amount of sealing medium. As the relative motion continues, when the trapped medium flows out of the micro-pits 6, additional hydrodynamic pressure is generated due to the viscosity of the liquid and the formation of a converging wedge between the end faces. This hydrodynamic pressure slightly pushes the two end faces apart, forming a stable and more load-bearing lubricating film. This film can effectively reduce direct contact and dry friction between the end faces, reduce the coefficient of friction and wear, thereby extending the seal life. At the same time, the asymmetric design—that is, the high-pressure side texture generates dynamic pressure, and the low-pressure side smooth sealing dam 4 maintains the contact barrier—creates a "pump-in-block" effect, which can actively resist the leakage tendency of the medium from the high-pressure side to the low-pressure side, achieving a better sealing effect, especially under start-up, shutdown and variable operating conditions.

[0026] To overcome the thermal stress problem caused by the significant difference in thermal expansion coefficients between the silicon carbide ring 1 and the external mounting base, which is typically made of metal, this invention fixes a metal ring 2 to the outer surface of the other end of the silicon carbide ring 1. The thermal expansion coefficient of this metal ring 2 is carefully selected to fall between the thermal expansion coefficients of the silicon carbide ring 1 and the metal of the external mounting base (typically stainless steel, carbon steel, etc.). Preferably, the metal ring 2 is a tungsten alloy ring (such as a high-density tungsten alloy), because tungsten alloys not only have high strength and hardness, but also a relatively low thermal expansion coefficient (typically 4.5-6 × 10⁻⁶). -6 / ℃) is just between that of silicon carbide (approximately 4.5 × 10) -6 / ℃) and steel (approximately 11-18×10 -6 Between 0.5°C and 0.6°C, it is an ideal material for thermal expansion transition.

[0027] The metal ring 2 is firmly bonded to the silicon carbide ring 1 through processes such as sintering or high-temperature brazing, ensuring the connection strength and thermal conductivity between the two.

[0028] Working Principle and Beneficial Effects: When the operating temperature of the equipment changes, the silicon carbide ring 1, the metal ring 2, and the external mounting base all undergo thermal expansion and contraction. Since the coefficient of thermal expansion of the metal ring 2 is in the middle range, its deformation during temperature changes also falls between these two values. This design creates a gradient transition zone for thermal expansion, effectively buffering and coordinating the deformation difference between the silicon carbide and the mounting base metal, thereby reducing concentrated thermal stress generated within the brittle silicon carbide ring 1 due to thermal mismatch. This fundamentally avoids the risk of the silicon carbide sealing ring cracking or even "bursting" under thermal cycling conditions due to excessive thermal stress, improving the reliability and service life of the sealing ring under thermal shock environments.

[0029] It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A silicon carbide sealing ring with good sealing effect, comprising a silicon carbide ring body (1), characterized in that: The sealing end face (3) of the silicon carbide ring (1) is provided with an asymmetric micron-level texture. The asymmetric micron-level texture includes a textured area (5) on the high-pressure side of the sealing end face (3) and a smooth sealing dam (4) on the low-pressure side. The textured area (5) contains a plurality of micro-pits (6) for storing the medium and generating hydrodynamic pressure. A metal ring (2) is fixedly installed on the outer surface of the other end of the silicon carbide ring (1).

2. The silicon carbide sealing ring with good sealing effect according to claim 1, characterized in that: The micro-pits are circular or elliptical; the depth of the micro-pits is 5-50 μm and the diameter is 50-500 μm.

3. The silicon carbide sealing ring with good sealing effect according to claim 1, characterized in that: The coefficient of thermal expansion of the metal ring (2) is between that of the silicon carbide ring (1) and the external mounting base on which the silicon carbide ring (1) is mounted.

4. The silicon carbide sealing ring with good sealing effect according to claim 3, characterized in that: The metal ring (2) is a tungsten alloy ring.

5. A silicon carbide sealing ring with good sealing effect according to claim 4, characterized in that: The metal ring (2) is integrated with the silicon carbide ring (1) by sintering or brazing.

6. The silicon carbide sealing ring with good sealing effect according to claim 1, characterized in that: The silicon carbide cyclic body (1) is made of reaction-sintered silicon carbide or pressureless sintered silicon carbide.

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