A shield-shaped textured structure on the surface of a water-lubricated silicon carbide bearing based on biomimetic texture.

Abstract

This invention relates to the field of fluid machinery lubrication and friction reduction technology, specifically to a shield-shaped textured structure on the surface of a water-lubricated silicon carbide bearing based on biomimetic texture. It includes a SiC workpiece and multiple sets of biomimetic textures on the surface of the SiC workpiece. The biomimetic texture, viewed from above, is a shield-shaped curved concave surface. The bottom shape of the biomimetic texture consists of a descending uniformly accelerated convex curve and a vertical line. The shield-shaped texture can generate a significant dynamic pressure effect. The uniformly accelerated convex curve shape at the bottom can generate a constant external force, ensuring that the fluid has sufficient stable kinetic energy. Furthermore, the uniformly accelerated convex curve texture area has a larger proportion of high-pressure area. The presence of the convergence zone at the tip where the fluid converges at the texture outlet and the bottom of the convex curve enhances the fluid's inertial effect, forming a significant "ball effect" vortex, improving the load-bearing capacity of the friction pair surface, reducing the shear force on the friction pair surface, and achieving the purpose of lubrication and friction reduction.

Description

Technical Field

[0001] This invention relates to the field of fluid machinery lubrication and friction reduction technology, specifically to a shield-shaped textured structure on the surface of a water-lubricated silicon carbide bearing based on biomimetic texture. Background Technology

[0002] Water-lubricated SiC bearings are a new type of sliding bearing characterized by being pollution-free, energy-saving, inexpensive, and simple in structure. They have broad application prospects in marine turbines, wet ore processing equipment, and ocean current generators. SiC water-lubricated bearings can operate directly in water, using water as a lubricant, simplifying the mechanical seal system structure and reducing oil leakage pollution. Compared to metal bearing materials, SiC bearings offer better wear resistance, corrosion resistance, and high-temperature resistance, resulting in a longer service life in water-lubricated environments. Furthermore, SiC bearings possess a certain degree of self-lubrication, forming a hydrodynamic lubricating water film to reduce direct friction between friction pairs and provide a certain load-bearing capacity.

[0003] Surface texture is an effective means of improving the fluid lubrication performance between friction pairs, enabling self-lubrication of material surfaces and reducing premature failure of mechanical equipment and energy consumption caused by friction and wear. Research has found that through natural evolution, many organisms have optimized various microstructures with specific shapes, distributions, and scales on their body surfaces, allowing them to better adapt to their surroundings. These microstructures possess functions such as wear resistance, hydrophobicity, drag reduction, and anti-fouling, providing more possibilities for surface texture research. Pangolin scales have a shield-like structure with a central keel-like protrusion, and their scale structure effectively prevents soil adhesion during burrowing, exhibiting excellent friction-reducing and wear-resistant properties.

[0004] The complex morphological structures of biological surfaces are an ideal source of inspiration for biomimicry. Some features are the result of multi-dimensional coupling. Currently, many scholars studying biomimetic textures have only greatly simplified the surface geometry. The simplified structural dimensions are too singular, thus losing some of their effectiveness. Therefore, this invention proposes a three-dimensional curved surface biomimetic texture coupled to SiC bearings to improve the tribological performance of friction pairs in water-lubricated environments. Summary of the Invention

[0005] The purpose of this invention is to provide a shield-shaped textured structure for the surface of a water-lubricated silicon carbide bearing based on biomimetic texture. This structure can be applied to the surface of SiC bearings in water-lubricated environments. Due to the biomimetic three-dimensional curved pits with a gradient change in depth along the fluid flow direction, a good dynamic pressure effect is generated. It can also form a significant eddy current "ball" effect in the textured area, reducing the friction force between friction pairs and improving the bearing capacity. Compared with a smooth sample, the friction coefficient of the shield-shaped textured sample is reduced by 52.68%, and the bearing capacity is increased by 212.03%.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0007] A shield-shaped textured structure for the surface of a water-lubricated silicon carbide bearing based on biomimetic texture includes a SiC workpiece and multiple sets of biomimetic textures on the surface of the SiC workpiece. The biomimetic texture is viewed from above as a shield-shaped curved surface pit, and the bottom shape of the biomimetic texture is composed of a descending uniformly accelerated convex curve and a vertical line.

[0008] Furthermore, the middle section of the shield-shaped texture is defined as a longitudinal section (AA section). The shape of the longitudinal section consists of two line segments: a curve and a vertical line. When x is in the interval [0, L), the section line is a uniformly accelerated convex curve; when x = L, the section line is a vertical line. The equation of the section is as follows:

[0009]

[0010] Where x is the horizontal coordinate of the biomimetic texture profile line, z is the vertical coordinate of the biomimetic texture AA profile, L is the length of the biomimetic texture, and H is the height of the biomimetic texture.

[0011] The top view of the biomimetic texture is composed of a straight line and a quadratic curve, and the shape of the graphic is represented by the following formula:

[0012]

[0013] Where x is the horizontal coordinate of the top view of the biomimetic texture, y is the vertical coordinate of the top view of the biomimetic texture, L is the length of the biomimetic texture, and W is the width of the biomimetic texture.

[0014] Furthermore, the fluid movement direction of the biomimetic texture is: from the flat straight end to the tip of the curve.

[0015] Furthermore, the biomimetic texture has a length L of 900 μm, a width W of 600 μm, a depth H of 60 μm, and a texture depth of 1 / 15 of the texture length.

[0016] Furthermore, the biomimetic texture is arranged in a circular array on the friction sample, and the specific arrangement dimensions are shown in the figure. The textured area occupies 6% of the surface area of ​​the SiC workpiece.

[0017] Furthermore, the biomimetic textured pits are all composed of gradually curved surfaces, which can reduce the shear resistance experienced by the fluid.

[0018] The beneficial effects of this invention are:

[0019] This invention utilizes a micron-scale biomimetic texture on the surface of SiC material. When the friction pair surfaces of the SiC specimen move relative to each other at a certain speed, the hydrophilicity of SiC causes a water film to be adsorbed between the two surfaces, protecting the friction pair surfaces. Water flows in from the texture inlet and, along the direction of fluid movement, exhibits a phenomenon where the pressure first decreases and then increases due to the presence of the texture, indicating that the shield-shaped texture can generate a significant dynamic pressure effect. The uniformly accelerated convex curve shape at the bottom generates a constant external force, ensuring sufficient stable kinetic energy for the fluid. Furthermore, the uniformly accelerated convex curve texture region has a larger proportion of high-pressure areas. The convergence zone at the tip where the fluid converges at the texture outlet and the presence of the convex curve bottom enhance the fluid's inertial effect, forming a significant "ball effect" vortex, improving the load-bearing capacity of the friction pair surface, reducing the shear force on the friction pair surface, and achieving the purpose of lubrication and friction reduction. Specifically, it includes:

[0020] 1. Improved lubrication performance of friction pairs: The biomimetic shield-shaped textured structure can form textured pits on the bearing surface. The gradient changes in the shape and depth of these pits can effectively improve the fluid lubrication effect between friction pairs. By forming complex flow patterns, the shield-shaped texture can reduce the friction coefficient of the friction pair and reduce frictional force.

[0021] 2. Enhanced bearing load capacity: The recessed design of the shield-shaped texture creates a vortex effect within the textured area, resulting in a dynamic pressure effect. This dynamic pressure effect effectively increases the bearing's load capacity. The depth gradient variation of the shield-shaped texture creates different dynamic pressure effects at different locations, further enhancing the load capacity.

[0022] 3. Improved bearing wear and corrosion resistance: SiC material itself has high hardness and wear resistance, which can reduce bearing wear. The recessed design of the shield-shaped texture provides an additional lubricating film, reducing direct contact between friction pairs and further reducing wear. In addition, the shield-shaped texture can also prevent corrosive substances in fluids from eroding SiC bearings, improving the bearing's corrosion resistance.

[0023] 4. Reduced Energy Consumption and Equipment Failure: The lubrication and hydrodynamic effects of the shield-shaped texture can reduce the friction between friction pairs. By reducing friction losses, energy consumption of mechanical equipment can be reduced, improving energy utilization efficiency. Simultaneously, due to the reduction in friction losses, the temperature rise of mechanical equipment is also reduced, thereby lowering the risk of equipment failure.

[0024] 5. Simplified mechanical seal system structure and reduced environmental pollution: SiC water-lubricated bearings eliminate the need for complex mechanical seal systems, reducing friction and wear on the seals and improving the reliability of the sealing system. Simultaneously, SiC water-lubricated bearings use water as a lubricant, reducing oil leakage and environmental pollution.

[0025] In summary, the shield-shaped textured structure on the surface of water-lubricated silicon carbide bearings based on biomimetic texture optimizes the performance and application prospects of SiC water-lubricated bearings from multiple aspects, such as improving lubrication performance, enhancing load-bearing capacity, improving wear resistance and corrosion resistance, reducing energy consumption and mechanical equipment failure, simplifying the sealing system, and reducing environmental pollution.

[0026] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the shield-shaped textured structure on the surface of the silicon carbide sliding bearing of the present invention;

[0029] Figure 2 This is a schematic diagram of a single biomimetic texture structure.

[0030] Figure 3 This is a schematic diagram illustrating the principle of the biomimetic texture friction test of this invention.

[0031] Figure 4 This is a model diagram of the biomimetic texture friction test specimen of the present invention;

[0032] Figure 5 This is a structural diagram of the biomimetic texture friction test specimen of the present invention;

[0033] Figure 6 This is a fluid pressure cloud diagram of the biomimetic textured sample of the present invention;

[0034] Figure 7 This is a streamline diagram of the velocity of a single biomimetic textured fluid in this invention;

[0035] Figure 8 This is a diagram showing the friction coefficient of the biomimetic texture of the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] like Figure 1-7 As shown

[0039] The shield-shaped textured structure on the surface of a water-lubricated silicon carbide bearing based on biomimetic texture described in this embodiment includes a SiC workpiece and multiple sets of biomimetic textures on the surface of the SiC workpiece. The biomimetic pit is viewed as a shield-shaped curved surface pit from a top view. The bottom shape of the biomimetic texture is composed of a descending uniformly accelerated convex curve and a vertical line.

[0040] In this embodiment, the middle section of the shield-shaped texture is defined as the longitudinal section (AA section). The shape of the longitudinal section consists of two line segments: a curve and a vertical line. When x is in the interval [0, L), the section line is a uniformly accelerated convex curve; when x = L, the section line is a vertical line. The equation of the section is as follows:

[0041]

[0042] The cross-sectional view described in the above equation is as follows: Figure 2 As shown in (a), x is the horizontal coordinate of the biomimetic texture profile line, z is the vertical coordinate of the biomimetic texture AA profile, L is the length of the biomimetic texture, and H is the height of the biomimetic texture.

[0043] The shape of the biomimetic texture in its top view is as follows: Figure 2 As shown in (b), the figure consists of a straight line and a quadratic curve, and its shape is as follows:

[0044]

[0045] The top view lines described in the above equation are as follows: Figure 2 As shown in (c), x is the horizontal coordinate of the top view of the biomimetic texture, y is the vertical coordinate of the top view of the biomimetic texture, L is the length of the biomimetic texture, and W is the width of the biomimetic texture.

[0046] In this embodiment, the fluid movement direction of the biomimetic texture is: from the flat straight end to the tip of the curve.

[0047] In this embodiment, the biomimetic texture has a length L of 900 μm, a width W of 600 μm, a depth H of 60 μm, and a texture depth of 1 / 15 of the texture length.

[0048] In this embodiment, the biomimetic texture is arranged in a circular array on the friction sample, and the specific arrangement dimensions are shown in the figure. The textured area occupies 6% of the surface area of ​​the SiC workpiece.

[0049] In this embodiment, the biomimetic textured pits are all composed of gradually curved surfaces, which can reduce the shear resistance experienced by the fluid.

[0050] Example 2

[0051] like Figure 1-5 As shown

[0052] A shield-shaped textured structure for the surface of a water-lubricated silicon carbide bearing based on biomimetic texture includes an annular column with a base SiC material sample having a radius of 2.5 mm to 25 mm and a height of 12 mm. The biomimetic texture is processed on the annular surface of the sample by laser etching and is evenly arranged in 11 rows × 27 columns along the circumference. The area occupancy of the biomimetic texture is 6% (the ratio of the surface area of ​​the annular surface of the SiC sample).

[0053] (1) Preparation of biomimetic textures

[0054] The surface of the specimen was processed using a fiber laser marking machine (Leip LM-20).

[0055] (2) Friction and wear test

[0056] Rotary friction tests were conducted on a disc-to-disc friction and wear tester: friction specimens with a SiC matrix texture of size R2.5mm to R25mm and height of 12mm were subjected to rotary friction with friction specimens with a SiC matrix smooth surface of size R2.4mm to R25mm and height of 15mm.

[0057] Test conditions: Load 100N, rotational speeds 400r / min, 500r / min, 600r / min, 700r / min, 800r / min, 900r / min, 1000r / min, 1100r / min, 1200r / min, 1300r / min, 1400r / min, 1500r / min, 1600r / min, 1700r / min, 1800r / min, 1900r / min, 2000r / min.

[0058] (3) Comparative analysis of friction test results

[0059] All textured surfaces showed an increase in load-bearing capacity and shear force with increasing rotational speed, but the rate of increase in load-bearing capacity was much greater than that of shear force, thus the coefficient of friction decreased. At different rotational speeds, the shield-shaped texture exhibited the highest load-bearing capacity and the lowest coefficient of friction, as shown in the friction coefficient comparison diagram below. Figure 8 As shown.

[0060] In summary, this invention proposes a shield-shaped textured structure for the surface of a water-lubricated silicon carbide bearing based on biomimetic texture. Laser processing is performed on the SiC bearing surface, and the biomimetic texture occupies 6% of the area. The shield-shaped texture can generate a significant dynamic pressure effect. The uniformly accelerated convex curve shape at the bottom generates a constant external force, ensuring sufficient stable kinetic energy for the fluid. Furthermore, the uniformly accelerated convex curve textured region has a larger proportion of high-pressure areas. The presence of the convergence zone at the tip where the fluid converges at the texture outlet and at the bottom of the convex curve enhances the fluid's inertial effect, forming a significant "ball effect" vortex. This improves the load-bearing capacity of the friction pair surface, reduces the shear force on the friction pair surface, and achieves the purpose of lubrication and friction reduction.

[0061] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A biomimetic texture based water lubricated silicon carbide bearing surface asperity texture structure, characterized in that, It includes a SiC workpiece and multiple sets of biomimetic textures on the surface of the SiC workpiece. The biomimetic textures are viewed from above as shield-shaped curved surface pit structures. The bottom shape of the biomimetic textures consists of a descending uniformly accelerated convex curve and a vertical line. The biomimetic texture has a longitudinal section in its middle section. The longitudinal section is composed of two line segments: a curve and a vertical line. When x is in the interval [0, L), the section line is a uniformly accelerated convex curve; when x = L, the section line is a vertical line. The equation of the section is as follows: wherein x is the lateral coordinate of the biomimicry texture profile line, z is the longitudinal coordinate of the biomimicry texture profile, L is the biomimicry texture length, and H is the biomimicry texture height. The top view of the biomimetic texture is composed of a straight line and a quadratic curve, and the shape of the graphic is represented by the following formula: where x is the lateral coordinate of the biomimicry texture top view, y is the longitudinal coordinate of the biomimicry texture top view, L is the biomimicry texture length, and W is the biomimicry texture width.

2. The biomimetic texture based water lubricated silicon carbide bearing surface of claim 1, wherein: The fluid movement direction of the biomimetic texture is from the flat straight end to the tip of the curve.

3. The biomimetic textured water lubricated silicon carbide bearing surface of claim 2, wherein: The length of the biomimetic texture L is 900 µm, the width W is 600 µm, the depth H is 60 µm, the texture depth is 1 / 15 of the texture length.

4. The biomimetic textured water lubricated silicon carbide bearing surface of claim 1, wherein: The shield-shaped texture is arranged in a circular array on the friction sample, and the area of ​​the shield-shaped texture occupies 6% of the surface area of ​​the SiC workpiece.

5. The biomimetic textured water lubricated silicon carbide bearing surface of claim 4, wherein: The biomimetic textured pits are all composed of gradually changing curved surfaces that can reduce the shear resistance experienced by the fluid.

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