A mesh texture structure based on the surface of a water-lubricated silicon carbide bearing
By designing a herringbone-shaped texture with intersecting radial grooves and guide grooves on the surface of SiC bearings, the problem of water film formation under high speed and high load is solved, thereby reducing the coefficient of friction, increasing the load-bearing capacity, and improving lubrication performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KUNMING UNIV OF SCI & TECH
- Filing Date
- 2023-10-20
- Publication Date
- 2026-07-17
AI Technical Summary
Under high speed and high load conditions, it is difficult for water-lubricated SiC bearings to form a water film, which leads to increased friction and wear and deterioration of lubrication performance.
A herringbone-shaped texture with intersecting radial and guide channels is designed, including radial grooves and trapezoidal guide channels, which are formed on the surface of SiC material by laser etching technology. The radial grooves are quadratic convex curves, and the guide channels are flat-bottomed trapezoids, which optimizes the formation and flow of water film.
It significantly improves the load-bearing capacity of the water film, reduces the coefficient of friction by 93.75%, increases the load-bearing capacity by 1930.8%, improves lubrication performance, and reduces friction and wear.
Smart Images
Figure CN117469302B_ABST
Abstract
Description
Technical Field
[0001] This invention discloses a mesh texture structure on the surface of a water-lubricated silicon carbide bearing, relating to the field of water-lubricated SiC bearing technology. Background Technology
[0002] Water-lubricated SiC bearings are a new type of bearing characterized by being pollution-free, energy-saving, inexpensive, and simple in structure, and have broad application prospects in fields such as marine turbines, wet ore beneficiation 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 with metal bearing materials, SiC bearing materials have better wear resistance, corrosion resistance, and high-temperature resistance, resulting in a longer service life in a water-lubricated environment. Furthermore, SiC bearings possess a certain degree of self-lubrication, forming a hydrodynamic lubricating water film to reduce direct friction between friction pairs, and the formed water film can also provide a certain load-bearing capacity.
[0003] Surface texturing, through various processes, involves machining specific geometric shapes onto the relatively smooth surfaces of friction pairs. This can significantly improve the load-bearing capacity of the friction pairs, enhance their tribological properties, extend their service life, and reduce premature failure of mechanical equipment and energy consumption caused by friction and wear.
[0004] However, under high speed and high load conditions, the water film on the grooved surface texture often becomes increasingly difficult to form, leading to deterioration of lubrication performance and thus exacerbating friction and wear, resulting in increased wear on the friction pair. Therefore, a herringbone-shaped texture with intersecting radial grooves and guide grooves was designed based on the grooved texture. The guide grooves allow water to be replenished in the radial grooves, enabling the formation of a high-load, low-shear flowing water film on the friction pair surface, thereby improving the lubrication performance of the grooved texture under high speed and high load conditions.
[0005] Content of this invention
[0006] Based on the aforementioned shortcomings and deficiencies, this invention proposes a herringbone-shaped texture with intersecting radial grooves and guide grooves, building upon the existing groove texture. This texture can be applied to the surface of SiC bearings in water-lubricated environments. It consists of radial grooves and trapezoidal guide grooves. The secondary convex curve of the radial grooves generates excellent dynamic pressure, significantly improving the water film's load-bearing capacity.
[0007] Specifically, the present invention is achieved through the following technical solutions:
[0008] A mesh texture structure based on the surface of a water-lubricated silicon carbide bearing includes a fishbone-shaped texture with several radial grooves and flow guide grooves intersecting on the surface of SiC material. The longitudinal cross-section of the radial grooves is a groove composed of a quadratic convex curve, and the trapezoidal flow guide groove is a flat-bottomed trapezoid with a cross-section that decreases in size along the direction of rotation when viewed from above.
[0009] The trapezoidal guide channel has three modes of operation:
[0010] Firstly, because the cross-section decreases continuously from the direction of fluid inflow to outflow, it has the effect of throttling and increasing fluid pressure, while also diffusing positive pressure;
[0011] Secondly, the trapezoidal guide channel can interrupt the negative pressure zone, thereby reducing the effective area of the negative pressure zone; thirdly, it connects the various radial channels, effectively replenishing the water in the radial channels;
[0012] The three mechanisms work together to increase the load-bearing capacity of the water film. Compared with the smooth sample, the herringbone textured sample has a 93.75% reduction in friction coefficient and a 1930.8% increase in load-bearing capacity.
[0013] Furthermore, the longitudinal section of the herringbone texture is formed by three line segments, each line segment including a curve and two vertical lines. The straight lines are perpendicular to each other, and the curve conforms to:
[0014]
[0015] Where x is the horizontal coordinate of the top view of the fishbone texture, y is the vertical coordinate of the top view of the fishbone texture, L1 is the length of the curved section, W1 is the width of the quadratic convex curve section and the inlet width of the trapezoidal guide channel, L2 is the length of the trapezoidal guide channel section, W2 is the outlet width of the trapezoidal guide channel, and H is the deepest depth of the fishbone texture.
[0016] Furthermore, the fluid movement direction of the fishbone-shaped texture is: from the long side of the trapezoidal guide channel to the short side of the trapezoidal guide channel.
[0017] Furthermore, L1 is 800 μm, W1 is 10 mm, L2 is 2.5 mm, W2 is 0.8 mm, and depth H is 30 μm.
[0018] Furthermore, the fishbone texture is arranged in a circular array on the friction sample, and the fishbone texture area occupies 43% of the surface area of the SiC material.
[0019] Furthermore, the radial surfaces of the fishbone-shaped texture are all secondary convex curved surfaces, and the guide grooves are all trapezoidal flat-bottomed grooves.
[0020] Beneficial effects:
[0021] This invention utilizes a micron-scale herringbone-shaped 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 and formed between the two surfaces, protecting the friction pair surfaces. The secondary convex curved grooves of the radial grooves can generate good dynamic pressure effects, significantly improving the load-bearing capacity of the water film. The trapezoidal guide channel has three functions: first, because the cross-section decreases continuously from the fluid inflow direction to the outflow direction, it has a throttling effect, increasing the fluid pressure and diffusing positive pressure; second, the trapezoidal guide channel can interrupt the negative pressure zone, thereby reducing the effective area of the negative pressure zone; and third, it connects all the radial grooves, effectively replenishing the water in the radial grooves. These three functions work together to increase the load-bearing capacity of the water film while reducing surface shear force and improving lubrication performance.
[0022] As can be seen from the above mechanism, the geometry of the herringbone texture and the matrix material of the friction pair will affect the lubrication and friction reduction performance of the parts.
[0023] Compared with the prior art, the advantages of the present invention are as follows:
[0024] (1) It adopts laser etching technology, which is a subtractive manufacturing process and is more widely applicable to various occasions.
[0025] (2) Using SiC as the matrix material and water as the lubricant avoids oil leakage pollution and the corrosion problems of traditional metal water environment, making it green, environmentally friendly and highly reliable.
[0026] (3) The fishbone texture can form a protective water film under SiC water lubrication. The fishbone texture can form a good dynamic pressure effect, which effectively enhances the bearing capacity of the sliding bearing and reduces the friction between the friction pairs.
[0027] 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
[0028] Figure 1 This is a schematic diagram of the fishbone-shaped textured structure on the surface of the silicon carbide hollow thrust sliding bearing of the present invention.
[0029] Figure 2 This is a schematic diagram of the fishbone-shaped texture unit structure of this invention.
[0030] Figure 3 This is a schematic diagram illustrating the principle of the fishbone-shaped texture friction test of the present invention.
[0031] Figure 4 This is a model diagram of the fishbone-shaped textured friction test specimen of the present invention.
[0032] Figure 5 This is a structural diagram of the fishbone-shaped textured friction test specimen of the present invention.
[0033] Figure 6 This is a fluid pressure cloud diagram of the fishbone-shaped textured sample of the present invention.
[0034] Figure 7 This is a comparison chart of the load-bearing capacity, shear capacity, and friction coefficient of the fishbone-textured surface and the smooth surface of the present invention at a rotation speed of 2000 r / min.
[0035] In the attached image:
[0036] 1-Water, 2-Experimental oil tank, 3-Upper specimen, 4-Lower specimen. Detailed Implementation
[0037] To more clearly illustrate the technical solution of the present invention, the present invention will be described in detail below with reference to embodiments.
[0038] Example
[0039] This embodiment discloses a fishbone-shaped texture on the surface of a water-lubricated silicon carbide (SiC) thrust sliding bearing, comprising SiC material and a fishbone-shaped texture formed by the intersection of several radial grooves and guide grooves on the surface of the SiC material. The longitudinal cross-section of the radial grooves is a groove composed of a quadratic convex curve, and the trapezoidal guide grooves are flat-bottomed trapezoids whose cross-section decreases from large to small along the direction of rotation when viewed from above.
[0040] Define the mid-section of the fishbone texture as the longitudinal section (AA section). The shape of the longitudinal section consists of three line segments: one curve and two vertical lines. When x is in the interval [0, L1), the section line is a quadratic convex curve; when x is in the interval [L1, L1+L2), the section line is a horizontal line; when x = L1+L2, the section line is a vertical line. The equation of the quadratic section is as follows:
[0041]
[0042] The top view lines described in the above equation are as follows: Figure 2 As shown in the figure, x is the horizontal coordinate of the top view of the herringbone texture, y is the vertical coordinate of the top view of the herringbone texture, L1 is the length of the quadratic convex curve, W1 is the width of the quadratic convex curve and the inlet width of the trapezoidal guide channel, L2 is the length of the trapezoidal guide channel, W2 is the outlet width of the trapezoidal guide channel, and H is the deepest depth of the herringbone texture.
[0043] The fluid movement direction of the fishbone-shaped texture is from the long side of the trapezoidal guide channel to the short side of the trapezoidal guide channel.
[0044] The length L1 of the secondary convex curve portion of the fishbone-shaped texture is 800 μm, the width of the secondary convex curve portion and the inlet width W1 of the trapezoidal guide channel are 10 mm, the length L2 of the trapezoidal guide channel portion is 2.5 mm, the outlet width W2 of the trapezoidal guide channel is 0.8 mm, and the depth H is 30 μm.
[0045] The fishbone 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 43% of the surface area of the SiC material.
[0046] The radial surfaces of the fishbone-shaped texture are all secondary convex curved surfaces, and the guide channels are all trapezoidal flat-bottomed channels. Together, they can enhance the load-bearing capacity of the water film.
[0047] In one specific embodiment, such as Figures 1 to 5 The diagram illustrates a fishbone-shaped textured structure on the surface of a water-lubricated silicon carbide thrust sliding bearing. The matrix SiC material sample consists of an annular column with a diameter of 2.5 mm to 25 mm and a height of 12 mm. The fishbone-shaped texture is laser-etched onto the annular surface of the sample, arranged in 36 columns evenly along the circumference. The biomimetic fishbone-shaped texture occupies 43% of the area (as a percentage of the surface area of the annular surface of the SiC sample).
[0048] Simulation dimensions: Friction samples with textured SiC substrates ranging from R2.5mm to R25mm and a height of 12mm were subjected to rotational friction against friction samples with smooth SiC substrates ranging from R2.4mm to R25mm and a height of 15mm.
[0049] Simulation conditions: rotation speed 2000 r / min, water film thickness 5 μm.
[0050] Simulation Calculation Results Analysis:
[0051] At 2000 r / min, the herringbone texture exhibits the highest load-bearing capacity and the lowest coefficient of friction. A comparison of its load-bearing capacity, shear capacity, and coefficient of friction with those of a smooth surface is shown in the figure below. Figure 7 As shown.
[0052] In summary, this invention proposes a herringbone-shaped textured structure on the surface of a water-lubricated silicon carbide thrust sliding bearing. Laser processing is performed on the SiC bearing surface, and the herringbone-shaped texture occupies 43% of the area. The secondary convex curved grooves of the radial slots generate excellent dynamic pressure, significantly improving the water film's load-bearing capacity. The trapezoidal guide channel has three functions: first, because the cross-section decreases continuously from fluid inflow to outflow, it throttles and increases fluid pressure, diffusing positive pressure; second, the trapezoidal guide channel can interrupt the negative pressure zone, thus reducing its effective area; and third, it connects all radial slots, effectively replenishing the water in the radial slots. These three functions collectively increase the water film's load-bearing capacity while reducing surface shear force and improving lubrication performance.
[0053] The above are merely some of the embodiments of this application and are not intended to limit the application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments shall still fall within the scope of protection of the technical solution of this application.
Claims
1. A mesh-textured structure on the surface of a water-lubricated silicon carbide bearing, characterized in that: It includes a fishbone-shaped texture with several radial grooves and flow guide grooves intersecting on the surface of SiC material. The longitudinal section of the radial grooves is a groove composed of a quadratic convex curve, and the trapezoidal flow guide groove is viewed from above as a flat-bottomed trapezoid with a cross section that decreases in size along the direction of rotation. The longitudinal section of the herringbone texture is formed by three line segments, each line segment including a curve and two vertical lines. The straight lines are perpendicular to each other, and the curve conforms to the following: Where x is the horizontal coordinate of the top view of the fishbone texture, y is the vertical coordinate of the top view of the fishbone texture, L1 is the length of the curved part, W1 is the width of the quadratic convex curve part and the inlet width of the trapezoidal guide channel, L2 is the length of the trapezoidal guide channel part, W2 is the outlet width of the trapezoidal guide channel, and H is the deepest depth of the fishbone texture. The L1 is 800 μm, W1 is 10 mm, L2 is 2.5 mm, W2 is 0.8 mm, and the depth H is 30 μm; The herringbone texture is arranged in a circular array on the friction sample, and the herringbone texture area occupies 43% of the surface area of the SiC material.
2. The mesh texture structure on the surface of a water-lubricated silicon carbide bearing according to claim 1, characterized in that: The fluid movement direction of the fishbone-shaped texture is from the long side of the trapezoidal guide channel to the short side of the trapezoidal guide channel.
3. The surface mesh texture structure of a water-lubricated silicon carbide bearing according to claim 1, characterized in that: The radial surfaces of the fishbone-shaped textures are all secondary convex curved surfaces, and the guide channels are all trapezoidal flat-bottomed channels.