Method for producing bearing components
By using polymer binders and bio-based filler materials to manufacture porous carbon and silicon carbide composite materials, the problems of fragility and high cost of ceramic bearing components have been solved, enabling the production of high-performance, low-carbon-emission bearing components.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AB SKF SKF PATENT DEPARTMENT
- Filing Date
- 2024-10-23
- Publication Date
- 2026-05-26
AI Technical Summary
Existing ceramic bearing components are fragile under high load and high temperature conditions, have high production costs, and have a large CO2 footprint, making it difficult to simultaneously improve fracture toughness and reduce carbon emissions.
By using a green body based on polymer binder and bio-based filler material, and through a manufacturing method of porous carbon body and silicon carbide composite material, combined with impregnation of liquid or gaseous substances, a C/Si/SiC composite material is formed to improve the mechanical properties of bearing components and reduce carbon emissions.
It enables the cost-effective production of bearing components with improved fracture toughness and CO2 balance, resulting in less wear, improved lubricant tolerance, and higher operating temperature, chemical stability, and aging stability.
Smart Images
Figure CN122095192A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for manufacturing bearing components according to the preamble of claim 1. Background Technology
[0002] Bearings are generally known to allow relative rotational motion between two components. Under harsh operating conditions, such as high loads combined with high temperatures, thin lubricating films, and / or insufficient lubrication, bearing components may suffer from surface-initiated fatigue, also known as micropitting, which can further lead to dents, surface-initiated spalling, and seizing.
[0003] Under such challenging conditions, it may be necessary to use at least one component in the bearing made of a more durable material. Ceramics are particularly characterized by their hardness and wear resistance, chemical stability, and temperature resistance. However, the production of ceramics is energy-intensive, making ceramic bearing components relatively expensive and resulting in a relatively large CO2 footprint. Furthermore, depending on the application, the ceramic used may be too brittle and therefore prone to breakage under heavy loads.
[0004] Therefore, the object of the present invention is to provide a method for producing bearing components that enables the bearing components to have improved fracture toughness and is cost-effective with improved CO2 balance. Summary of the Invention
[0005] This objective is achieved by the method for producing bearing components according to claim 1.
[0006] The following provides a method for manufacturing bearing components, which includes the following steps:
[0007] Provide green blanks,
[0008] The green body is converted into porous carbon body, thereby providing the green body and / or carbon body with the desired shape of the bearing component, and
[0009] Impregnate the carbon body with at least one liquid and / or gaseous substance.
[0010] To improve the fracture toughness of bearing components while cost-effectively producing them and achieving improved CO2 balance, the green blank contains at least one polymer-based binder and at least one carbonizable bio-based filler material. Specifically, the polymer used may be a bio-based polymer, such as lignin, a non-bio-based polymer, such as PEEK, and / or mixtures thereof.
[0011] Bearing components can be, in particular, sliding bearing components or rolling bearing components. For example, a bearing component can be an outer ring, an inner ring, a housing, a portion of a housing, a bearing sleeve, a raceway, or the like.
[0012] For example, the green body can be provided directly in the desired shape of the bearing component. Alternatively, the desired shape of the bearing component can be formed from the provided green body. Or, additionally, the desired shape of the bearing component can also be machined from carbon. Since the volume of the green body may change when it is converted into porous carbon, forming from carbon ensures that the bearing component has the desired dimensions. The volume changes that may occur when the green body is converted into carbon can depend on the polymer-based binder used, the bio-based filler material used, the green body manufacturing process, etc.
[0013] The liquid or gaseous substance can be a metal, a semi-metal, a metal salt, a polymer, a hydrocarbon, or the like. Furthermore, the substance can be a mixture of several substances. For example, the substance can contain silicon, aluminum, magnesium, titanium, copper, alloys, and / or semi-metallic substances such as silicon tetrachloride, which are particularly suitable for impregnating carbon bodies. Specifically, if the carbon body is to be impregnated with a mixture of several substances, at least one substance can be the main substance, and other substances can be present as additives, up to 20% by weight. For example, silicon can be used as the main substance, and metals and / or metal alloys as additives. Additives can be particularly suitable for modifying the material properties of finished bearing components. For example, appropriate selection of additives can improve the sliding behavior of the surface and / or the surface layer.
[0014] Bio-based filler materials can be, in particular, wood, cellulose, cellulose fibers, lignin, and / or other natural fibers. For example, wood can consist of wood processing waste such as sawdust, wood flour, or the like. Other natural fibers can be, in particular, waste products such as biomass waste, paper waste, and waste from the grain industry, such as rice husks, shells, or bracts. Depending on the size of the starting material, bio-based filler materials can be directly pressed together with a polymer-based binder, or the bio-based filler material can be pulverized using a suitable process to achieve the desired particle size. Because bio-based filler materials are sustainable, the CO2 balance of bearing components or their production can be improved. Furthermore, bearing components made at least partially from green bodies containing at least partially bio-based filler materials have improved mechanical properties, such as improved strength.
[0015] Furthermore, the mechanical properties of finished bearing components, such as fracture toughness or strength, can be adapted by appropriately selecting the polymer binder content, particle size, and other process parameters, such as temperature, pressure, and atmospheric composition, during the production of the green blank.
[0016] Polymer-based binders preferably comprise at least one thermosetting plastic and / or a crosslinkable thermoplastic. Thermosetting binders advantageously retain their shape under the influence of heat, thus the shape of the green body is substantially preserved when it is converted into porous carbon. This particularly makes it possible to obtain green bodies that are structurally stable enough to be converted into porous carbon without distortion.
[0017] Alternatively or additionally, phenolic resins, lignin, and / or dimensionally stable, crosslinkable, curable plastics such as PEEK can be used as polymer-based adhesives. Mixtures of thermoplastic and thermosetting adhesives can also be used as adhesives.
[0018] According to a preferred embodiment, the green compact is produced through extrusion, pressing, cutting, turning, milling, 3D printing, and / or other additive manufacturing processes. This makes it possible to provide green compacts that can have any shape. Depending on the type of biofiller material, the green compact may still be surrounded by loose particles of filler material after the binder has hardened or dried. Therefore, depending on the manufacturing process of the green compact, it may be necessary to at least partially remove the green compact from the filler material residue, for example if the green compact is formed in a powder bed, and / or separate it from the loose, uncured particles. It should be noted, however, that this step may be omitted for other manufacturing processes of the green compact. Furthermore, (fine) cleaning of the green compact can be followed to remove the attached particle residue. Cleaning can be performed, for example, by vacuuming away the loose particles with a vacuum cleaner. However, the type of cleaning is not limited, and all known methods can be used.
[0019] Furthermore, depending on the manufacturing process selected for the green body, at least one additive may be added to the mass of at least one polymer-based binder and at least one carbonizable bio-based filler material, the additive being suitable for adapting the mass to the selected manufacturing process. For example, if the green body is formed by 3D printing, at least one additive for 3D printing may be added to at least one polymer-based binder and at least one carbonizable bio-based filler material.
[0020] Preferably, the proportion of bio-based filler material in the green body is between at least 5% and 90% by weight. Depending on the application, the proportion of bio-based filler material in the green body is even more preferably between 40% and 90% by weight. In particular, the bio-based filler material may have a particle size between 0.0001 and 2.0 mm, preferably between 0.05 and 0.5 mm.
[0021] According to a further preferred embodiment, the green body is converted into porous carbon body by pyrolysis. The pyrolysis process is preferably carried out in a nearly oxygen-free atmosphere. A nearly oxygen-free atmosphere is specifically understood to have less than 3% residual oxygen. This can be, for example, a protective gas atmosphere and / or a vacuum. For example, the protective gas atmosphere can contain argon, nitrogen, or other suitable gases or gas mixtures. Furthermore, the pyrolysis process can be carried out at a temperature of at least 400°C, particularly between 500°C and 3000°C. This allows for the sufficient conversion of the carbonaceous material to form porous carbon body.
[0022] Furthermore, the carbon body can be impregnated with at least silicon. Preferably, the carbon body can be impregnated with liquid and / or gaseous silicon. In particular, the liquid and / or gaseous silicon can contain additives. Silicon carbide is formed by impregnating porous carbon body with silicon. Silicon carbide ceramics are particularly characterized by their hardness and wear resistance, chemical stability, and temperature resistance. Compared with materials commonly used in bearing components, especially sliding bearing components, such as bronze or coated bronze, silicon carbide has improved properties. Improved CO2 balance can also be achieved with the biofiller materials used.
[0023] When porous carbon bodies are impregnated with silicon, the carbon can react with the silicon to form SiC (silicon carbide). The carbon bodies, located above the melting point of silicon and essentially above the surface of the silicon bath, absorb silicon through capillary action. This typically results in the composite material containing unreacted carbon and free silicon in addition to SiC. Therefore, this is called a C / Si / SiC composite material.
[0024] A further advantage of bearing components manufactured using the described method is the ability to use less lubricant, resulting in less wear and improved bearing component life. Furthermore, bearing components obtained using the above method can exhibit improved resistance to contaminated lubricants, can be used at higher application temperatures, and have improved chemical stability. Additionally, bearing components obtained using the above method can exhibit improved aging stability compared to known plastic-coated bearing components.
[0025] Furthermore, the method may include at least one optional post-processing step, particularly polishing, honing, grinding, or the like, to obtain the bearing component.
[0026] In addition, a green body produced according to the above method is proposed, wherein the green body comprises at least one polymer-based binder and at least one carbonizable bio-based filler material.
[0027] Further advantages and advantageous embodiments are specified in the description, drawings, and claims. In particular, the combinations of features specified in the description and drawings are purely exemplary, and therefore features may also exist individually or in other combinations. Attached Figure Description
[0028] In the following description, the invention will be presented in more detail using embodiments illustrated in the accompanying drawings. The embodiments and combinations shown are purely exemplary and are not intended to limit the scope of the invention. The scope of protection is defined only by the appended claims.
[0029] They show:
[0030] Figure 1 A flowchart of a method for manufacturing bearing components according to one embodiment.
[0031] Figure 2 Green blanks used in the production of bearing components, and
[0032] Figure 3 : according to Figure 1 Bearing components manufactured using [method / method]. Detailed Implementation
[0033] In the following text, identical or functionally equivalent parts are referred to by the same reference numerals.
[0034] Figure 1 The steps for manufacturing a bearing component according to one embodiment are shown. The bearing component may be, in particular, a sliding bearing component or a rolling bearing component. For example, the bearing component may be an outer ring, an inner ring, a housing, a portion of a housing, a bearing sleeve, a raceway, or the like.
[0035] First, in the first step S1, a composite material is produced by mixing at least one polymer-based binder and at least one bio-based filler material together.
[0036] Bio-based filler materials can be, in particular, wood, cellulose, cellulose fibers, lignin, and / or other natural fibers, such as wood processing waste, biomass waste, paper waste, waste from the grain industry, and the like, and the polymer-based binder is preferably a thermosetting plastic, such as phenolic resin and / or lignin, which represents a bio-based binder. Alternatively, other dimensionally stable, crosslinkable, curable plastics, such as PEEK, or mixtures of thermoplastic and thermosetting binders may also be used.
[0037] Preferably, the proportion of bio-based filler material in the composite material is between 5% by weight and 90% by weight, and has a particle size between 0.0001 and 2.0 mm, preferably between 0.05 and 0.5 mm.
[0038] In step S2, a green blank of the bearing component is produced from the composite material through extrusion, pressing, cutting, turning, milling, 3D printing, and / or other additive manufacturing processes, followed by curing of the binder. Depending on the type of biofiller material, the green blank may still be surrounded by loose particles of filler material after the binder has cured or dried. Depending on the manufacturing process of the green blank, it can therefore be removed from the powder bed of filler material or separated from the loose, uncured particles. Furthermore, a (fine) cleaning of the green blank can follow to remove any attached particle residue. Cleaning can be performed, for example, by vacuuming away the loose particles. However, the type of cleaning is not limited, and all known methods can be used.
[0039] Subsequently, in step S3, the green body is converted into porous carbon body by pyrolysis. This can preferably be carried out in an oxygen-free atmosphere. A protective gas atmosphere, such as that composed of argon, nitrogen, or other suitable gases or gas mixtures, and / or a vacuum, can be used. The pyrolysis process is advantageously carried out at a temperature of at least 400°C. This allows for the full conversion of the carbonaceous material to form porous carbon body. Alternatively, the desired shape of the bearing component can also be machined from the carbon body first.
[0040] Finally, to obtain the bearing component, the carbon body is impregnated with at least liquid silicon in step S4. Specifically, the liquid silicon may contain additives such as metals, metal alloys, metal salts, or the like. Alternatively, the carbon body may be impregnated with gaseous silicon. When the carbon body is impregnated with silicon, silicon carbide is formed in particular. Silicon carbide ceramics are characterized by their hardness and wear resistance, chemical stability, and temperature resistance. This typically results in the composite material containing unreacted carbon and free silicon in addition to SiC. Therefore, this is referred to as a C / Si / SiC composite material.
[0041] Additives can be particularly suitable for modifying the material properties of finished bearing components. For example, appropriate selection of additives can improve the sliding behavior of the surface layer of the formed silicon carbide ceramic. Alternatively, the green body 1 can also be impregnated with other liquid or gaseous substances such as metals, semi-metals, metal salts, polymers, hydrocarbons, or the like. Furthermore, the green body can also be impregnated with a mixture of several substances.
[0042] Figure 2 The green blank 1 obtained after step S2 is shown, and Figure 3 The finished bearing component 2 is shown. (As shown from...) Figure 2 and Figure 3 The comparison shows that when green body 1 is converted into porous carbon body through pyrolysis, it does not lose its basic shape. However, the volume may change when green body 1 is converted into porous carbon body. The possible volume change when green body 1 is converted into carbon body can depend on the polymer-based binder used, the bio-based filler used, the manufacturing process of the green body, etc.
[0043] In summary, a manufacturing process for bearing components is proposed that makes it possible to obtain bearing components that not only have improved fracture toughness, but can also be produced cost-effectively with improved CO2 balance.
[0044] Because bio-based filler materials are sustainable, the CO2 balance of bearing components and their production can be improved. Compared to materials commonly used in bearing components, particularly sliding bearing components, such as bronze or bronze-coated bearings, silicon carbide offers improved performance. The bio-based filler materials used also contribute to the improved CO2 balance. Other advantages of bearing components manufactured using the described process include the ability to use less lubricant, resulting in less wear and improved bearing component lifespan.
[0045] Furthermore, bearing components obtained using the above method can exhibit improved resistance to contaminated lubricants, can be used at higher application temperatures, and have improved chemical stability. Additionally, bearing components obtained using the above method can exhibit improved aging stability compared to known plastic-coated bearing components.
[0046] List of reference numerals
[0047] S1-S4 Process Steps
[0048] 1. Green body
[0049] 2 Bearing components
Claims
1. A method for manufacturing a bearing component (2), wherein the method comprises the following steps: Provide (S2) green blank (1), The green body (1) is transformed (S3) into porous carbon body, wherein the green body (1) and / or carbon body are provided with the desired shape of the bearing component, and Impregnate (S4) carbon body with at least one liquid and / or gaseous substance. Its features The green body (1) comprises at least one polymer-based binder and at least one carbonizable bio-based filler material.
2. The method according to claim 1, wherein the bio-based filler material comprises wood, cellulose, cellulose fibers, lignin and / or natural fibers.
3. The method according to claim 1 or 2, wherein the polymer-based adhesive comprises at least one thermosetting plastic and / or a crosslinkable thermoplastic plastic.
4. The method according to any one of the preceding claims, wherein the green body (1) is produced by extrusion, pressing, cutting, turning, milling, 3D printing and / or additive manufacturing processes.
5. The method according to any one of the preceding claims, wherein the proportion of bio-based filler material in the green body (1) is at least 5% by weight, preferably between 5% and 90% by weight.
6. The method according to any one of the preceding claims, wherein the conversion of green body (1) to porous carbon body comprises pyrolysis of green body (1).
7. The method of claim 6, wherein the pyrolysis process is carried out in an oxygen-free atmosphere, particularly in a protective gas atmosphere and / or under vacuum.
8. The method according to claim 6 or 7, wherein the pyrolysis process is carried out at a temperature of at least 400°C.
9. The method according to any one of the preceding claims, wherein the carbon body is at least impregnated with silicon.
10. The method according to any one of the preceding claims, wherein the method further comprises at least one optional post-processing step, particularly polishing, honing, grinding, etc., to obtain the bearing component.
11. A green blank (1) for the method of manufacturing a bearing component (2) according to any one of claims 1 to 10, wherein the green blank (1) comprises at least one polymer-based binder and at least one carbonizable bio-based filler material.