Bearing and method for processing a bearing
By applying a chemically plated nickel-phosphorus layer and a nickel bonding layer to the inner and outer ring surfaces of the bearing, the problems of high-temperature oxidation and wear were solved, enabling stable operation of the bearing in high-temperature environments and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2026-03-31
AI Technical Summary
Existing bearings are prone to high-temperature oxidation in high-temperature and water vapor environments, resulting in severe wear. Furthermore, high-temperature lubricating greases are expensive, leading to bearing failure and high costs, making it difficult to promote them on a large scale.
A chemically plated nickel-phosphorus layer and a nickel bonding layer are applied to the inner and outer ring surfaces of the bearing to form a coating. The coating has good corrosion resistance and wear resistance, and can operate stably in high-temperature environments, avoiding the use of high-temperature lubricating grease.
It improves bearing life, reduces manufacturing and maintenance costs, and is suitable for high-temperature and corrosive environments, with a lifespan at least 2-3 times longer.
Smart Images
Figure CN121761032A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of mechanical equipment, and more specifically to a bearing and a method for processing the bearing. Background Technology
[0002] Bearings are used to support rotating parts in mechanical equipment. Generally, a bearing consists of an inner ring, an outer ring, a cage, and rollers, which convert the sliding friction between the rotating shaft and the bearing housing into rolling friction, reducing friction loss. During operation, bearings are typically lubricated using lubricating oil or grease.
[0003] In some cases, certain bearings (such as deep groove ball bearings) need to operate in high-temperature environments with a certain amount of water vapor. For example, bearings in some high-temperature kiln equipment operate at low speeds and light loads, but the ambient temperature may reach 250 to 300 degrees Celsius. The presence of water vapor in the environment makes ordinary bearing components prone to high-temperature oxidation, resulting in the formation of softer iron oxides on the surface. Simultaneously, the crushing wear during bearing operation causes the raceways and rolling elements to continuously wear down and enlarge, and the continuous accumulation of wear debris eventually leads to bearing seizure and failure. Furthermore, for such extreme high-temperature applications, it is difficult to use ordinary lubricating oils or greases for continuous lubrication, as there are almost no high-temperature greases available, and the few that can withstand around 250 degrees Celsius are extremely expensive, making bearings costly and hindering widespread adoption.
[0004] Therefore, a technical solution is still needed to address the technical problems caused by the aforementioned high-temperature oxidation. Summary of the Invention
[0005] To address the above problems, according to a first aspect of the present invention, a bearing is provided, comprising an inner ring, an outer ring, and rollers, wherein at least a portion of the surface of the inner ring and / or at least a portion of the surface of the outer ring is provided with a coating, the coating comprising an electroless nickel-phosphorus plating layer and a nickel bonding layer, the nickel bonding layer being located between the electroless nickel-phosphorus plating layer and the body material of the inner ring or the outer ring, wherein the mass percentage of phosphorus in the electroless nickel-phosphorus plating layer is 2% to 13%.
[0006] The bearing according to the first aspect of the present invention is a rolling bearing, such as a deep groove ball bearing, and the electroless nickel-phosphorus plating process disclosed in the present invention is specifically developed for rolling bearings. As described above, according to the first aspect of the present invention, the mass percentage of phosphorus in the electroless nickel-phosphorus plating layer is limited to 2% to 13%. Further, the surface treatment of the rolling bearing rings (i.e., the inner and outer rings) also includes providing a pre-plating nickel bonding layer (also referred to as an impact nickel layer or a nickel plating underlayer) to enhance coating adhesion.
[0007] As detailed below, the bearing according to the first aspect of the present invention can be used in high-temperature conditions, eliminating the need for high-temperature grease and maintenance.
[0008] Specifically, the bearing according to the present invention does not require the application of lubricating oil or grease, and the raceway surfaces of its inner and outer rings exhibit low friction. The electroless nickel-phosphorus plating coating, when rubbed against steel, has a sliding friction coefficient of 0.25-0.4, and an even lower rolling friction coefficient. Simultaneously, the coating is uniform and dense, exhibiting good corrosion resistance and high hardness in the plated state. If post-plating heat treatment is performed, the hardness can be further increased, reaching approximately HV1000, demonstrating excellent wear resistance. Furthermore, the electroless nickel-phosphorus plating coating exhibits outstanding oxidation stability; according to relevant data, the coating remains stable at temperatures below 300°C without high-temperature oxidation or yellowing. Therefore, the bearing can operate stably for extended periods in high-temperature and corrosive environments, resulting in a long service life. Additionally, the uniform coating thickness eliminates the need for further machining of the inner and outer rings of the bearing.
[0009] According to the applicant's research and experimental results, the above-mentioned coating provides high-temperature oxidation resistance, wear resistance, and corrosion resistance on bearings. Bearings according to the invention can withstand ambient temperatures of 250°C to 300°C. Furthermore, in rolling contact tests on bearings according to the invention, it has been found that, for applications in high-temperature kiln equipment mentioned in the background art, the lifespan of bearings according to the invention can be increased by at least 2-3 times compared to the current service life of approximately 3 to 6 months for general bearings, under actual load and after introducing high temperatures and corrosion into the test bearing. Another significance of the invention is that bearings according to the invention can be based on ordinary bearing steel, and by using a coating to improve friction resistance, high-temperature resistance, and corrosion resistance, the use of expensive high-temperature steel is avoided, facilitating widespread adoption.
[0010] The bearings according to the present invention may have one or more of the following features, individually or in combination.
[0011] According to one embodiment, preferably, the mass percentage of phosphorus in the electroless nickel-phosphorus plating layer is 3% to 10%.
[0012] According to one embodiment, preferably, the mass percentage of phosphorus in the electroless nickel-phosphorus plating layer is 3% to 7%.
[0013] According to one embodiment, preferably, the thickness of the electroless nickel-phosphorus plating layer ranges from 2 to 15 micrometers.
[0014] According to one embodiment, preferably, the thickness of the electroless nickel-phosphorus plating layer ranges from 3 to 7 micrometers.
[0015] According to one embodiment, preferably, the thickness of the nickel bonding layer ranges from 0.2 to 2 micrometers.
[0016] According to one embodiment, preferably, the thickness of the nickel bonding layer ranges from 0.5 to 1 micrometer.
[0017] According to one embodiment, preferably, the hardness of the electroless nickel-phosphorus plating layer is in the range of HV 450-1000, more preferably HV 450–800.
[0018] According to one embodiment, preferably, the coating is subjected to post-plating heat treatment, the temperature range of the post-plating heat treatment being 180-300°C and the heat treatment time being 1-24 hours, preferably, the temperature range of the post-plating heat treatment being 180-260°C and the heat treatment time being 1-16 hours.
[0019] According to one embodiment, preferably, the main body material of the inner ring and the outer ring is standard bearing steel, the roller is made of standard bearing steel or martensitic stainless steel or ceramic, and the cage is made of low carbon steel or stainless steel.
[0020] According to one embodiment, preferably, the bearing is a deep groove ball bearing.
[0021] According to a second aspect of the present invention, a method for processing a bearing is provided, comprising the steps of: providing an inner ring and an outer ring of the bearing; applying a nickel bonding layer to at least a portion of the surface of the inner ring and / or at least a portion of the surface of the outer ring; and applying a chemically plated nickel-phosphorus layer on the nickel bonding layer, wherein the nickel bonding layer and the chemically plated nickel-phosphorus layer define a coating.
[0022] The bearings obtained by the method according to the second aspect of the present invention will have the advantages of the bearings according to the first aspect of the present invention.
[0023] The method according to the present invention may also have the following features.
[0024] According to one embodiment, preferably, the coating is applied at least to the raceways of the inner ring and the raceways of the outer ring. Attached Figure Description
[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. The drawings are merely illustrative of some embodiments of the present invention and are not intended to limit the scope of the present invention to all embodiments.
[0026] Figure 1 This is a cross-sectional schematic diagram of a bearing according to an embodiment of the present invention.
[0027] Figure 2 This is a schematic cross-sectional view of the coating on the inner and outer raceway surfaces of a bearing according to an embodiment of the present invention.
[0028] List of reference numerals
[0029] 1. Main material of the inner or outer ring
[0030] 2. Electroless nickel-phosphorus plating
[0031] 3 Nickel bonding layer
[0032] 10 Inner Circle
[0033] 20 outer ring
[0034] 21 grooves
[0035] 30 rollers
[0036] 50 coating
[0037] 100 bearing Detailed Implementation
[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0039] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, “an” or “a” and similar terms do not necessarily indicate a quantity limitation. Terms such as “comprising” or “including” indicate that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to direct connections but can include indirect connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described object changes.
[0040] The present invention will be described in detail below by way of example embodiments.
[0041] Figure 1 This is a cross-sectional schematic diagram of the bearing 100 according to an embodiment of the present invention. Figure 2A schematic cross-sectional view of the coating 50 on the raceway surface of the inner ring 10 or outer ring 20 of a bearing 100 according to the present invention is shown. The bearing 100 according to the present invention can be a deep groove ball bearing whose rollers are spherical, such as... Figure 1 As shown. According to an embodiment of the invention, the inner ring 10, outer ring 20, and roller 30 of the bearing 100 can all be made of standard bearing steel (e.g., 52100 or GCR15). The standard bearing steel material can be hardened and tempered to a hardness of HRC 54 to 65, particularly HRC 58 to 62. According to other embodiments of the invention, the roller can be made of hardened stainless steel bearing steel (e.g., 440C, 420, etc.), wherein the roller can be made of martensitic stainless steel. Alternatively, the roller can also be made of ceramic materials (e.g., Si3N4, Al2O3, PSZ(Y2O3-ZrO2) etc.). As will be detailed below, the bearing according to the invention can operate stably for a long time in high-temperature and corrosive environments without using expensive high-temperature resistant bearing steel as the main material of the inner and outer rings.
[0042] According to an embodiment of the present invention, the bearing 100 has a coating 50 on both the raceway of its inner ring 10 and the raceway of its outer ring 20. For example... Figure 1 Specifically, coating 50 can also be applied to the entire surface of the inner ring 10 and the outer ring 20. According to an embodiment of the invention (not shown), coating 50 can also be applied to at least a portion of the surface of the inner ring 10 and / or at least a portion of the surface of the outer ring 20 to improve the high-temperature resistance and corrosion resistance of the respective surface portions. Figure 2 As shown, the coating 50 includes a chemically plated nickel-phosphorus layer 2 and a nickel bonding layer 3. The chemically plated nickel-phosphorus layer 2 forms the surface of the corresponding raceway, and the nickel bonding layer 3 is located between the chemically plated nickel-phosphorus layer 2 and the body material 1 of the inner or outer ring. In other words, at least on the raceway surface of the bearing inner ring, an inner ring raceway coating is provided, the chemically plated nickel-phosphorus layer of the inner ring raceway coating forms the surface of the inner ring raceway, and the nickel bonding layer of the inner ring raceway coating is located between the chemically plated nickel-phosphorus layer of the inner ring raceway coating and the body material of the inner ring. At least on the raceway surface of the bearing outer ring, an outer ring raceway coating is provided, the chemically plated nickel-phosphorus layer of the outer ring raceway coating forms the surface of the outer ring raceway, and the nickel bonding layer of the outer ring raceway coating is located between the chemically plated nickel-phosphorus layer of the outer ring raceway coating and the body material of the outer ring.
[0043] A bearing according to an embodiment of the present invention can be formed, for example, by the following steps: First, an inner ring and an outer ring of the bearing are provided; then, the inner ring and / or the outer ring are electroplated to form a nickel bonding layer on at least a portion of the surface of the inner ring and / or at least a portion of the surface of the outer ring; subsequently, the inner ring and the outer ring are chemically plated to form a chemically plated nickel-phosphorus layer on the respective nickel bonding layer; finally, the inner ring, outer ring, rollers, cage, and other components are assembled into a bearing. For example, the entire inner ring and the entire outer ring can be electroplated and chemically plated to form coatings on the respective surfaces, particularly on the raceway surfaces of the inner and outer rings, thereby reducing the manufacturing cost of the bearing. According to an embodiment of the present invention, the mass percentage of phosphorus in the chemically plated nickel-phosphorus layer can be from 2% to 13%. According to another embodiment of the present invention, after applying the chemically plated nickel-phosphorus layer, a post-plating heat treatment can also be applied to the coating. Figure 1 As shown, according to one embodiment of the present invention, the entire surface of the inner ring 10 and outer ring 20 of the plated bearing is coated with a coating 50. For example, the groove 21 of the outer ring 20 for supporting a dust cover (not shown) is also coated with a coating 50. Thus, the entire surface of the inner ring 10 and outer ring 20 of the bearing is protected by a coating.
[0044] For the bearing according to the present invention, by using a chemically plated nickel-phosphorus layer as the raceway surface of the inner and outer rings, the raceway surface can achieve high smoothness and a low coefficient of friction, thereby possessing self-lubricating properties and enabling the bearing to operate effectively for a long time without the need for adding lubricating oil or grease. Simultaneously, the chemically plated nickel-phosphorus layer provides resistance to high-temperature oxidation corrosion, allowing the bearing to operate continuously in high-temperature and certain humidity environments. Furthermore, the applicant discovered during the research process that, on the one hand, by setting the mass percentage of phosphorus in the chemically plated nickel-phosphorus layer to 2% to 13%, the coating on the raceway can achieve high hardness. On the other hand, compared to conventional surface pretreatment such as acid pickling or alkaline washing only on the surface of the inner and outer ring body materials, by applying a nickel bonding layer between the chemically plated nickel-phosphorus layer and the inner or outer ring body materials, the adhesion between the chemically plated nickel-phosphorus layer and the inner or outer ring body materials can be further increased. In particular, when the main body material of the inner or outer ring is made of the aforementioned standard bearing steel or similar materials, the electroless nickel-phosphorus plating layer on the nickel bonding layer is less likely to detach from the raceway surface of the inner or outer ring when subjected to pressure and friction from the roller surface. Therefore, the bearing can have a longer service life in high-temperature and corrosive operating environments. According to the applicant's test results, the bearing according to the present invention can operate continuously for one year in an environment of approximately 250 to 300 degrees Celsius and high humidity without bearing failure.
[0045] Meanwhile, the coating used in rolling bearings must be able to withstand the maximum contact stress generated during the rolling of the rolling elements. Analysis of actual application conditions indicates that the maximum contact stress the coating can withstand during actual use is approximately 1200 MPa. For the protective coating formed according to this invention, a rolling test was conducted on the bearing, where a maximum contact stress of approximately 1600 MPa was applied. After a test period of 19 hours, no coating peeling or failure was observed. Optical microscopy revealed that the coating was intact with almost no wear.
[0046] Therefore, as mentioned above, the bearings according to the present invention can be used in high-temperature and certain corrosive environments, eliminating the need for high-temperature resistant bearing steel to manufacture the inner and outer rings, thus significantly reducing the manufacturing cost of the bearings. Furthermore, the bearings according to the present invention do not require the addition of high-temperature lubricating oil or grease before or during use, further reducing not only the manufacturing cost of the bearings but also the maintenance costs of the mechanical equipment incorporating them.
[0047] According to one embodiment of the present invention, the mass percentage of phosphorus in the electroless nickel-phosphorus plating layer is 3% to 10%. According to another embodiment of the present invention, the mass percentage of phosphorus in the electroless nickel-phosphorus plating layer is 3% to 7%. By setting the mass percentage of phosphorus in the electroless nickel-phosphorus plating layer to 3% to 10%, the coating of the raceway can have increased hardness. Further, by setting the mass percentage of phosphorus in the electroless nickel-phosphorus plating layer to 3% to 7%, the coating of the raceway can have further increased hardness, preventing wear of the raceway coating. Accordingly, according to one embodiment of the present invention, the hardness of the electroless nickel-phosphorus plating layer is HV450–1000. According to another embodiment of the present invention, the hardness of the electroless nickel-phosphorus plating layer is HV 450–800. It should be noted that, according to the present invention, the electroless nickel-phosphorus plating layer, in addition to the phosphorus in the aforementioned proportions, only includes nickel and unavoidable impurities.
[0048] According to one embodiment of the present invention, the thickness of the electroless nickel-phosphorus plating layer is 2 to 15 micrometers. According to another embodiment of the present invention, the thickness of the electroless nickel-phosphorus plating layer is 3 to 7 micrometers. The applicant discovered during the research process that by setting the thickness range of the electroless nickel-phosphorus plating layer to 2 to 15 micrometers, it is possible to ensure that the electroless nickel-phosphorus plating layer has strong corrosion resistance. Furthermore, by setting the thickness range of the electroless nickel-phosphorus plating layer to 3 to 7 micrometers, it is possible to ensure that the electroless nickel-phosphorus plating layer has strong corrosion resistance while also ensuring that it has high overall strength and is not easily broken under the pressure of a roller.
[0049] According to one embodiment of the invention, the thickness of the nickel bonding layer is 0.2 to 2 micrometers. According to another embodiment of the invention, the thickness of the nickel bonding layer is 0.5 to 1 micrometer. By setting the thickness range of the nickel bonding layer to 0.2 to 2 micrometers, the electroless nickel-phosphorus plating layer can be more firmly attached to the raceway of the inner or outer ring of the bearing. Furthermore, by setting the thickness range of the nickel bonding layer to 0.5 to 1 micrometer, the overall coating can also have higher strength and be less prone to cracking under roller surface pressure. It should be noted that, according to the invention, the nickel bonding layer includes only nickel and unavoidable impurities. On the other hand, according to embodiments of the invention, the nickel bonding layer itself can have a non-uniform thickness, and the aforementioned thickness of the nickel bonding layer refers to the average thickness of the nickel bonding layer. Even when the nickel bonding layer has a non-uniform thickness, it can still enhance the adhesion between the electroless nickel-phosphorus plating layer and the body material of the inner or outer ring.
[0050] According to one embodiment of the present invention, the coatings on the inner and outer rings of the bearing are subjected to post-plating heat treatment, wherein the temperature range of the post-plating heat treatment is 180-300°C, and the heat treatment time is 1-24 hours. According to another embodiment of the present invention, the temperature range of the post-plating heat treatment is 180-260°C, and the heat treatment time is 1-16 hours. The above-mentioned post-plating heat treatment can further improve the coating properties, including removing hydrogen embrittlement, increasing the coating hardness to a certain extent, and enhancing the coating adhesion.
[0051] According to one embodiment of the present invention, the bearing may be provided with a cage for holding the rollers, for separating the rolling elements (rollers), and for preventing premature failure caused by reverse friction between the rollers.
[0052] Furthermore, according to one embodiment of the present invention, the bearing may be provided with a dust cover, which may be made of low carbon steel, so as to block the influence of external dust particles and other contaminants on the inner and outer raceways and rolling elements at a lower cost.
[0053] The foregoing description, with reference to preferred embodiments, details exemplary embodiments of the bearings and bearing processing methods proposed in this invention. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the concept of this invention, and various combinations can be made to the various technical features and structures proposed in this invention without exceeding the protection scope of this invention.
Claims
1. A bearing comprising an inner ring, an outer ring and rollers, wherein, At least a part of a surface of the inner ring and / or at least a part of a surface of the outer ring is provided with a coating, the coating comprising an electroless nickel-phosphorus layer and a nickel bonding layer, the nickel bonding layer being located between the electroless nickel-phosphorus layer and the main material of the inner ring or the outer ring, wherein the mass percentage of phosphorus in the electroless nickel-phosphorus layer is 2% to 13%.
2. The bearing of claim 1, wherein, The coating is provided on the raceway of the inner ring and the raceway of the outer ring.
3. The bearing of claim 1, wherein, The mass percentage of phosphorus in the electroless nickel-phosphorus layer is 3% to 10%, preferably the mass percentage of phosphorus in the electroless nickel-phosphorus layer is 3% to 7%.
4. The bearing of claim 1, wherein, The thickness of the electroless nickel-phosphorus layer is 2 to 15 microns, preferably the thickness of the electroless nickel-phosphorus layer is 3 to 7 microns.
5. The bearing of claim 1, wherein, The thickness of the nickel bonding layer is 0.2 to 2 microns, preferably the thickness of the nickel bonding layer is 0.5 to 1 micron.
6. The bearing of claim 1, wherein, The coating is subjected to post-plating heat treatment, the temperature of the post-plating heat treatment ranges from 180-300℃, and the heat treatment time is 1-24 hours, preferably the temperature of the post-plating heat treatment ranges from 180-260℃, and the heat treatment time is 1-16 hours.
7. The bearing of claim 1, wherein, The hardness of the electroless nickel-phosphorus layer is HV 450-1000, preferably HV 450-800.
8. The bearing of any one of claims 1 to 7, wherein, The main material of the inner ring and the outer ring is standard bearing steel, the roller is made of standard bearing steel or martensitic stainless steel or ceramic, the retainer is made of low-carbon steel or stainless steel, and / or the bearing is a deep groove ball bearing.
9. A method of processing a bearing, comprising the steps of: providing an inner ring and an outer ring of a bearing, applying a nickel bond layer on at least a portion of a surface of the inner ring and / or at least a portion of a surface of the outer ring, and applying an electroless nickel phosphorous layer on the nickel bond layer, wherein, The nickel bonding layer and the electroless nickel-phosphorus layer define a coating.
10. The method of claim 9, wherein, The coating is applied at least on the raceway of the inner ring and the raceway of the outer ring. The coating is applied at least on the raceway of the inner ring and the raceway of the outer ring.