plain bearing

Abstract

The application provides a sliding bearing, comprising a base layer, a support layer on the base layer, and a sliding layer on the support layer, wherein the hardness gradient of the base layer, the support layer and the sliding layer decreases in turn. The sliding bearing of the application is a multilayer sliding bearing, which is integrated by metallurgical bonding between the layers, thereby saving non-ferrous metals and significantly reducing the cost of the bearing; the bonding strength between the layers is strong, and the sliding layer and the base layer cannot fall off. The intermediate support layer between the base layer and the sliding layer can be used as a barrier layer to block or reduce the diffusion of elements from the base layer to the sliding layer, thereby ensuring the wear resistance of the sliding layer; the hardness gradient between the layers provides flexible support for the sliding layer by the support layer, especially under high load, which can reduce the wear of the sliding layer, thereby prolonging the service life of the sliding bearing.

Description

Technical Field

[0001] This invention relates to a sliding bearing, and more particularly to a sliding bearing for a gearbox in a wind power generation device.

[0002] Furthermore, the present invention relates to a transmission device including the aforementioned sliding bearing, particularly a planetary gear transmission device.

[0003] Furthermore, the present invention relates to a method for manufacturing the aforementioned transmission device. Background Technology

[0004] In sliding friction devices (such as sliding bearings), aluminum alloys and copper alloys are widely used as wear-resistant materials. For sliding bearings, blanks are typically made using continuous casting or centrifugal casting, and then machined into finished bushings. Casting often results in casting defects, so increasing the machining process is usually employed; furthermore, casting consumes a lot of energy and causes significant environmental pollution. In addition, the material cost is also high for large-sized bushings or bearing shells.

[0005] Because copper and aluminum alloys have relatively low hardness and insufficient stiffness, it is difficult to guarantee the bearing capacity under heavy load and high-speed service conditions. A better approach is to sinter, roll, clad, or weld them onto a steel substrate. This ensures sufficient load-bearing capacity while also providing excellent wear resistance, and saves a significant amount of non-ferrous metals, thus reducing costs.

[0006] CN108787809B discloses a rolled bearing with a welded seam, which is formed by sintering a steel backing and an alloy layer. The open seam of the rolled bearing is welded to form a closed bearing, which is then hot-pressed onto a shaft. Under high load and long-term operation, there is a risk of weld failure and delamination of the sliding bearing. Summary of the Invention

[0007] The object of this invention is to provide a sliding bearing that is easy to maintain, highly wear-resistant, and has a long service life. Correspondingly, another object of this invention is to provide a transmission device, particularly a planetary gear transmission device, including the aforementioned sliding bearing, which is particularly applicable to wind power generation equipment (e.g., the gearbox of a wind power generation equipment). Furthermore, yet another object of this invention is to provide a method for manufacturing the aforementioned transmission device.

[0008] According to one aspect of the present invention, a sliding bearing is provided, comprising: a base layer; a support layer located on the base layer; and a sliding layer located on the support layer, wherein a decreasing hardness gradient is provided from the base layer, the support layer to the sliding layer.

[0009] In one embodiment, a groove is formed on the base layer, and the support layer and the sliding layer are sequentially disposed in the groove.

[0010] In one embodiment, the hardness of the support layer is 20% to 90% of the hardness of the base layer, and the hardness of the sliding layer is 15% to 90% of the hardness of the support layer.

[0011] In one embodiment, the hardness of the support layer is 35% to 90% or 40% to 65% of the hardness of the base layer, and the hardness of the sliding layer is 30% to 60% of the hardness of the support layer.

[0012] In one embodiment, the support layer and the sliding layer are selected from the group consisting of aluminum-based alloys, tin-based alloys, copper and copper-based alloys, and nickel and nickel-based alloys.

[0013] In one embodiment, the support layer is formed of a CuAl alloy having the following contents: Al 6% to 15%, Fe 0% to 7.5%, Ni 0% to 8.5%, Mn 0% to 10.0%, Zn 0% to 2.0%, and the balance being Cu.

[0014] In one embodiment, the support layer is formed of a CuSn alloy having the following contents: Sn 4% to 25%, Ni 0% to 5%, P 0% to 0.6%, Zn 0% to 1.0%, Fe 0% to 10%, and the balance being Cu.

[0015] In one embodiment, the support layer is formed of a CuSi alloy having the following contents: Si 1.0% to 6.0%, Mn 0% to 4.0%, P 0% to 0.5%, Fe 0% to 10%, Zn 0% to 12%, and the balance being Cu.

[0016] In one embodiment, the support layer is formed of a CuMn alloy having the following contents: Mn 6.0% to 16.0%, Al 5% to 12%, Ni 0% to 6%, Fe 0% to 10%, and the balance being Cu.

[0017] In one embodiment, the support layer is formed of a CuZn alloy having the following contents: Zn 5.0% to 50.0%, Al 0% to 15.0%, Mn 0% to 10.0%, As 0% to 5.0%, Sb 0% to 5.0%, Si 0% to 10.0%, Ni 0% to 25.0%, Pb 0% to 5.0%, Fe 0% to 5.0%, Sn 0% to 5.0%, with the balance being Cu.

[0018] In one embodiment, the support layer is formed of a CuCr alloy having the following content: Cr from 0.1% to 10.0%, Zr from 0% to 5.0%, other impurities from 0% to 5.0%, and the balance being Cu.

[0019] In one embodiment, the support layer is formed of a CuNi alloy having the following contents: Ni 0.1% to 45.0%, Fe 0% to 5.0%, Zn 0% to 5.0%, Mn 0% to 5.0%, Cr 0% to 5.0%, Si 0% to 5.0%, Nb 0% to 5.0%, and the balance being Cu.

[0020] In one embodiment, the sliding layer is formed of a CuSn alloy having the following content: Sn 6% to 15%, P 0.05% to 0.5%, Zn 0% to 0.5%, Fe 0% to 5%, and the balance being Cu.

[0021] In one embodiment, the sliding layer is formed of a CuSn alloy having the following contents: Sn 9% to 14%, Ni 0% to 3.0%, P 0.05% to 0.5%, Zn 0% to 0.5%, Fe 0% to 4%, and the balance being Cu.

[0022] In one embodiment, the sliding layer is formed of an alloy material having the following content: Sn 5% to 35%, Cu 0.5% to 2.0%, Ni 0% to 1.5%, Fe 0% to 4%, and the balance being Al.

[0023] In one embodiment, the sliding layer is formed of an alloy material having the following content: Sn 10% to 25%, Cu 0.5% to 1.5%, Ni 0% to 0.5%, and the balance being Al.

[0024] In one embodiment, the Fe content decreases sequentially from the base layer, the support layer to the sliding layer.

[0025] In one embodiment, the Fe content of the support layer is less than or equal to 90%, and the Fe content of the sliding layer is less than or equal to 5%.

[0026] In one embodiment, the Fe content of the support layer is less than or equal to 85%, and the Fe content of the sliding layer is less than or equal to 3%.

[0027] In one embodiment, the sliding bearing further includes a running-in layer located on the sliding layer, the running-in layer being formed of a polymer material.

[0028] In one embodiment, the Fe content of the sliding layer is less than or equal to 5%.

[0029] In one embodiment, the sliding layer is flush with or higher than the groove.

[0030] In one embodiment, the sliding bearing has a planar structure.

[0031] According to another aspect of the invention, a transmission device is provided, comprising a shaft, a gear supported on the shaft, and a sliding bearing as described above, wherein the base layer is provided by the shaft, the support layer and the sliding layer are sequentially disposed on the outer surface of the shaft, and the gear is supported on the sliding layer.

[0032] The sliding bearing of this invention is a multi-layered sliding bearing, with these layers metallurgically bonded to form an integral sliding bearing. This saves on the use of non-ferrous metals and significantly reduces bearing costs. The layers have strong bonding strength, eliminating the risk of the sliding layer detaching from the base material. An intermediate support layer between the base material and the sliding layer acts as a barrier layer, preventing or reducing the diffusion of elements from the base material into the sliding layer, thus ensuring the wear resistance of the sliding layer. The hardness gradient between the layers allows the support layer to provide flexible support to the sliding layer, particularly reducing wear under high loads and extending the life of the sliding bearing.

[0033] In addition, by setting the support layer and the sliding layer in the groove formed in the base layer, it is possible to further save materials, reduce processing steps, reduce material and manufacturing costs, and increase the bonding strength between the various layers of the sliding bearing, thereby increasing the structural strength, service life and wear resistance of the sliding bearing itself. Attached Figure Description

[0034] To better understand the above and other objects, features, advantages, and functions of the present invention, reference can be made to the preferred embodiments shown in the accompanying drawings. The same reference numerals in the drawings refer to the same parts. Those skilled in the art should understand that the drawings are intended to schematically illustrate preferred embodiments of the invention and do not limit the scope of the invention in any way; the parts in the drawings are not drawn to scale.

[0035] Figure 1 This is a side sectional view of a sliding bearing according to an embodiment of the present invention.

[0036] Figure 2 This is a side sectional view of a sliding bearing according to another embodiment of the present invention. Detailed Implementation

[0037] Now, with reference to the accompanying drawings, specific embodiments of the present invention will be described in detail. The embodiments described herein are merely preferred embodiments of the invention; those skilled in the art can conceive of other ways to implement the invention based on these preferred embodiments, and such other ways also fall within the scope of the invention.

[0038] In this paper, the sliding bearing and corresponding transmission device of the present invention are described using wind power generation equipment as an example. The sliding bearing and transmission device can be applied to wind power generation equipment (e.g., the gearbox of wind power generation equipment), but are not limited thereto. They can also be applied to other industries and applicable machinery and equipment (e.g., automobiles, ships, airplanes, etc. and their transmissions, gearboxes, or any parts that require sliding friction).

[0039] For transmission devices such as gearboxes in wind power generation equipment, taking planetary gear transmission as an example, it includes a sun gear, planet gears, planet carrier, drive shaft, support shaft, etc. Since this type of planetary gear transmission is already known in principle by existing technology, it will not be described in detail here. The following will focus on describing sliding bearings and their related structures.

[0040] In some conventional technologies, integral copper bushing sliding bearings are mechanically fixed to the shaft. However, the copper bushing is usually made by casting, resulting in a large machining allowance for the copper bushing blank and a large amount of copper used in the bushing body. In contrast, the metal-based multilayer composite bearing provided by this invention saves on the amount of copper used, thereby significantly reducing the material cost of the sliding bearing bushing. It features material and cost savings, energy saving, and environmental protection.

[0041] Figure 1 A partial side sectional view shows a sliding bearing between a gear and shaft 1 in a wind power transmission device. The gear is, for example, a planetary gear, and is supported on shaft 1 by the sliding bearing. The sliding bearing is disposed on shaft 1 and located between the inner bore of the gear and shaft 1. The sliding bearing is a multi-layered bearing comprising a base layer 1, a support layer 2, and a sliding layer 3. The base layer is provided by shaft 1; that is, shaft 1 itself serves as both the base support for the sliding bearing and its outer surface (also called the surface layer) is part of the sliding bearing (i.e., the base layer 1 of the sliding bearing). In other words, the surface layer of shaft 1 serves as the base support layer of the sliding bearing, therefore shaft 1 can also be called the base shaft. The support layer 2 and the sliding layer 3 are sequentially applied to the base shaft 1 from the inside to the outside in the radial direction. Since the support layer 2 is located between the base layer 1 and the sliding layer 3, the support layer 2 can also be called the intermediate support layer 2. The sliding layer 3 is located at the outermost radial layer, constituting the sliding surface of the bearing; therefore, the sliding layer 3 is also called the surface sliding layer 3. The support layer 2 is applied directly to the base shaft 1 (or base layer 1), while the sliding layer 3 is applied directly to the support layer 2, thereby forming a multi-layer sliding bearing with the shaft 1.

[0042] For the support layer 2 and the sliding layer 3, the term "apply" refers to using various methods to bond the support layer 2 to the base shaft 1 (or base layer 1) and further bond the sliding layer 3 to the upper support layer 2. These application methods or bonding methods include electroplating, spraying, powder metallurgy, casting, cladding, laser welding, welding, and other suitable application methods. Among them, spraying includes, but is not limited to, air spraying, airless spraying, high-pressure spraying, electrostatic spraying, arc spraying, flame spraying, plasma spraying, and explosive spraying, such as, but not limited to, atomized spraying, thermal spraying, automatic spraying, and multi-group spraying. Through the above application methods, the base layer 1, the support layer 2, and the sliding layer 3 form an integral or one-piece sliding bearing; the integral or one-piece sliding bearing mentioned here refers to the metallurgical bonding between the base layer 1 and the support layer 2, and between the support layer 2 and the sliding layer 3, rather than the mechanical joining or mechanical assembly in conventional technologies.

[0043] The advantage of forming an integral sliding bearing through metallurgical bonding is that there is a strong bonding strength between the base layer 1 and the support layer 2, as well as between the support layer 2 and the sliding layer 3. These layers together form a single part (i.e., a complete and seamless integral multi-layer sliding bearing), thus eliminating the need for assembly of the bushing and shaft in conventional technologies, thereby saving installation time and significantly reducing assembly time and labor costs. In other words, the sliding bearing provided by this invention is composed of a base shaft 1, a support layer 2, and a sliding layer 3 (i.e., the support layer 2 and the sliding layer 3 are applied sequentially to the shaft 1). It is a multi-layer integral sliding bearing. Compared with the conventional method of heat-fitting an integral copper bushing onto the shaft, it saves the use of precious metals (e.g., non-ferrous metals), significantly reducing bearing costs. For example, compared with the amount of copper used in a conventional integral copper bushing, the sliding layer uses less non-ferrous metal (e.g., copper). The bearing and the base shaft are an integral unit, eliminating the risk of the sliding layer detaching from the base shaft, and exhibiting excellent fatigue and creep resistance.

[0044] It should be noted that the above application or bonding methods are merely exemplary and not restrictive. Those skilled in the art can use other suitable methods to apply the support layer 2 and the sliding layer 3, as long as the metallurgical bonding between the base layer 1, the support layer 2 and the sliding layer 3 can be achieved to form an integral multi-layer sliding bearing.

[0045] There are no special restrictions on the material and dimensions of shaft 1, and they can be selected according to the specific engineering application. For example, shaft 1 can be made of steel, allowing the use of steel shafts well-known in the art, provided that its length and outer diameter meet the dimensional requirements of the finished bearing. For example, the material of steel shaft 1 can be selected from the following material group: 20CrMnTi, 20CrMnMo, 18CrNiMo7-6, 34CrNiMo6, 45# steel, 40Cr, 40CrMo, 42CrMoA, etc. For example, the outer diameter of shaft 1 ranges from φ100mm to φ800mm, preferably from φ200mm to φ500mm. This is just an example; other suitable dimensions can be selected according to actual engineering needs.

[0046] Furthermore, there are no specific limitations on the hardness and strength properties of shaft 1. For example, the hardness of shaft 1 can be from 20 HRC to 40 HRC, preferably from 25 HRC to 35 HRC, such as 20 HRC, 25 HRC, 26 HRC, 27 HRC, 28 HRC, 29 HRC, 30 HRC, 31 HRC, 32 HRC, 33 HRC, 34 HRC, 35 HRC, 36 HRC, 37 HRC, 38 HRC, 39 HRC, 40 HRC, or any other suitable value, such as HB280. Additionally, the surface roughness of the outer peripheral surface of shaft 1 is, for example, Ra 1.6 μm to 12.5 μm, to facilitate the application of the support layer 2 to shaft 1. For example, the roughness can be Ra 1.6 μm, Ra 3.2 μm, Ra 6.3 μm, Ra 6.4 μm, Ra 12.5 μm, or any other suitable value.

[0047] It should be noted that the specific selection and values ​​of the material, dimensions, surface roughness and hardness of shaft 1 are merely examples and are not restrictive. Those skilled in the art can flexibly select, change and adjust them according to specific engineering applications.

[0048] There are no special restrictions on the material and size of the support layer 2, and it can be selected according to the specific engineering application. For example, the material of the support layer 2 can be selected from the group consisting of aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, and preferably copper alloys, more preferably such as CuAl alloys, CuSn alloys, CuSi alloys, CuMn alloys, CuZn alloys, CuCr alloys or CuNi alloys.

[0049] For example, the support layer 2 can be made of CuAl alloy, and the CuAl alloy has the following mass percentage (or weight percentage) content: Al 6% to 15%, Fe 0% to 7.5%, Ni 0% to 8.5%, Mn 0% to 10.0%, Zn 0% to 2.0%, and the balance Cu.

[0050] For example, the support layer 2 can be made of CuSn alloy, and the CuSn alloy has the following mass percentage (or weight percentage) content: Sn 4% to 25%, Ni 0% to 5%, P 0% to 0.6%, Zn 0% to 1.0%, Fe 0% to 10%, and the balance Cu.

[0051] For example, the support layer 2 can be made of CuSi alloy, and the CuSi alloy has the following mass percentage (or weight percentage) content: Si is 1.0% to 6.0%, Mn is 0% to 4.0%, P is 0% to 0.5%, Fe is 0% to 10%, Zn is 0% to 12%, and the balance is Cu.

[0052] For example, the support layer 2 can be made of CuMn alloy, and the CuMn alloy has the following mass percentage (or weight percentage) content: Mn is 6.0% to 16.0%, Al is 5% to 12%, Ni is 0% to 6%, Fe is 0% to 10%, and the balance is Cu.

[0053] For example, the support layer 2 can be made of CuZn alloy, and the CuZn alloy has the following mass percentage (or weight percentage) content: Zn 5.0% to 50.0%, Al 0% to 15.0%, Mn 0% to 10.0%, As 0% to 5.0%, Sb 0% to 5.0%, Si 0% to 10.0%, Ni 0% to 25.0%, Pb 0% to 5.0%, Fe 0% to 5.0%, Sn 0% to 5.0%, with the balance being Cu.

[0054] For example, the support layer 2 can be made of CuCr alloy, and the CuCr alloy has the following mass percentage (or weight percentage) content: Cr is 0.1% to 10.0%, Zr is 0% to 5.0%, other impurities are 0% to 5.0%, and the balance is Cu.

[0055] For example, the support layer 2 can be made of CuNi alloy, and the CuNi alloy has the following mass percentage (or weight percentage) content: Ni 0.1% to 45.0%, Fe 0% to 5.0%, Zn 0% to 5.0%, Mn 0% to 5.0%, Cr 0% to 5.0%, Si 0% to 5.0%, Nb 0% to 5.0%, and the balance Cu.

[0056] Furthermore, the support layer 2 can have various thicknesses depending on the specific engineering application. For example, preferably, the thickness of the support layer 2 can be from 0.05 mm to 3.0 mm, more preferably, the thickness of the support layer 2 can be from 0.5 mm to 2.0 mm, such as 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, or any other suitable value.

[0057] There are no special restrictions on the material and size of the sliding layer 3, and it can be selected according to the specific engineering application. For example, the material of the sliding layer 3 can be selected from the group consisting of aluminum-based alloys, tin-based alloys, copper and copper-based alloys, and nickel and nickel-based alloys, and copper alloys and aluminum alloys can be preferred.

[0058] For example, the sliding layer 3 can be made of CuSn alloy, which has the following mass percentage (or weight percentage) content: Sn 6% to 15%, P 0.05% to 0.5%, Zn 0% to 0.5%, Fe 0% to 5%, and the balance Cu. More preferably, the CuSn alloy has the following mass percentage (or weight percentage) content: Sn 9% to 14%, Ni 0% to 3.0%, P 0.05% to 0.5%, Zn 0% to 0.5%, Fe 0% to 4%, and the balance Cu.

[0059] For example, the sliding layer 3 may contain alloying elements such as Al, Sn, and Cu, and have the following mass percentage (or weight percentage) content: Sn 5% to 35%, Cu 0.5% to 2.0%, Ni 0% to 1.5%, Fe 0% to 4%, with the balance being Al. Furthermore, the sliding layer 3 preferably has the following mass percentage (or weight percentage) content: Sn 10% to 25%, Cu 0.5% to 1.5%, Ni 0% to 0.5%, with the balance being Al.

[0060] Furthermore, the material composition of the support layer 2 described above (i.e., the various copper alloys selected for the support layer 2 and their weight percentage content) also applies to the sliding layer 3, and will not be repeated here.

[0061] Furthermore, the sliding layer 3 can have various thicknesses depending on the specific engineering application. For example, the thickness of the sliding layer 3 can be from 0.05 mm to 3 mm, preferably from 0.05 mm to 2.5 mm, more preferably from 0.5 mm to 1.3 mm, and even more preferably from 0.5 mm to 1 mm, such as 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, or any other suitable value. The advantages of the above-mentioned thickness range of the sliding layer 3 are that it enables the sliding layer 3 to have good sliding characteristics, is easy to manufacture in terms of process technology, and has a sufficient lifespan.

[0062] Furthermore, as described above, the total thickness of the support layer 2 and the sliding layer 3 can be from 0.1 mm to 5.5 mm, preferably from 1 mm to 3.3 mm, more preferably from 1 mm to 3 mm, for example, the total thickness can be 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm or any other suitable value.

[0063] It should be noted that the specific selection and values ​​of the materials, thicknesses, and other dimensions of the support layer 2 and the sliding layer 3 are merely examples and are not restrictive. Those skilled in the art can flexibly select, change, and adjust them according to specific engineering applications.

[0064] In addition, the support layer 2 is disposed between the base shaft 1 and the sliding layer 3, and can be used as a barrier layer to block or reduce the diffusion of elements from the base shaft 1 to the sliding layer 3. For example, it reduces the diffusion of steel-based elements from the steel shaft 1 to the sliding layer 3, ensuring the integrity of the chemical composition of the sliding layer 3, so that the sliding layer 3 is not diffused and interfered with by the elements of the base shaft 1, thereby ensuring the properties of the sliding layer 3, such as maintaining the wear resistance of the sliding layer 3.

[0065] In the sliding bearing, the bonding strength between the support layer 2 and the base layer 1, as well as between the sliding layer 3 and the support layer 2, is increased. This can be achieved, for example, by the application method described above. The bonding strength between the support layer 2 and the base shaft 1 can be greater than 150 MPa, more preferably greater than 200 MPa, such as 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa, 260 MPa, 270 MPa, or greater.

[0066] Furthermore, the bonding strength between the sliding layer 3 and the support layer 2 can be greater than 150 MPa, more preferably greater than 170 MPa, and even more preferably greater than 200 MPa, such as 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa or greater or any other suitable value.

[0067] Furthermore, in the sliding bearing, there is a decreasing hardness gradient between the layers, that is, the hardness of the base shaft 1 (or base layer 1) is the greatest; secondly, the hardness of the support layer 2 is less than that of the base shaft 1 (or base layer 1); and thirdly, the hardness of the sliding layer 3 is less than that of the support layer 2.

[0068] For example, using the hardness of the base shaft 1 (or base layer 1) as a reference, the hardness of the support layer 2 can be 20% to 90% of the hardness of the base shaft 1, more preferably 35% to 90%, and even more preferably 40% to 65%, such as 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or any other suitable value. Furthermore, the hardness of the sliding layer 3 can be 15% to 90% of the hardness of the support layer 2, more preferably 30% to 60%, such as 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or any other suitable value.

[0069] As mentioned above, the hardness of the substrate shaft 1 (or base layer 1) can be from 20 HRC to 40 HRC, preferably from 25 HRC to 35 HRC. Accordingly, based on the decreasing ratio and specific values ​​of the hardness gradient, the hardness of the support layer 2 and the sliding layer 3 can be calculated accordingly, which will not be specifically calculated here. It should be noted that the hardness of each layer mentioned herein can be a single specific hardness value or a hardness range. For example, the hardness of the sliding layer 3 can be 15% to 90% of the hardness of the support layer 2. Here, the hardness of the support layer 2 can be a specific hardness value, for example, if the hardness of the support layer 2 is 18 HRC, then the hardness of the sliding layer 3 can be 2.7 HRC to 16.2 HRC (i.e., 15% to 90% of 18 HRC). In actual mass production, the hardness of each layer may have certain processing tolerances or the hardness of each layer may fluctuate within a range. For example, the hardness of the support layer 2 may fluctuate within the range of 15 to 18 HRC, while the hardness of the sliding layer 3 may be between 2.25 HRC and 16.2 HRC (i.e., within the range of 15% to 90% of 18 HRC). In other words, the hardness of the support layer 2 fluctuates within a certain range, and the hardness of the sliding layer 3 changes within a certain proportion of the hardness of the support layer 2.

[0070] In sliding bearings, the advantage of a decreasing hardness gradient between layers is that it provides a buffer gradient between them. For example, the outermost sliding layer 3 has a softer hardness and serves as both a sliding and friction surface, engaging in sliding friction with a harder mating component (e.g., the gear mentioned above). The middle support layer 2 supports the sliding layer 3 and therefore has a relatively high hardness. If its hardness is too soft, it cannot effectively support the sliding layer 3; if its hardness is too high, it is detrimental to the long-term sliding friction of the sliding layer 3, causing a direct impact on the force transmission between the outermost sliding layer 3 and the base layer 1, especially under high loads. In other words, the middle support layer 2 is designed to provide a buffer between the softer sliding layer 3 and the harder base layer 1 to absorb the energy of the sliding layer 3 during sliding friction. Thus, the support layer 2 acts like a damping spring, further buffering the sliding layer 3 when it is compressed and generating a rebound force on the sliding layer 3, preventing the force of the sliding layer 3 from being directly transmitted to the base layer 1. Without the intermediate support layer 2, the force of the sliding layer 3 acts directly on the harder base layer 1 without any buffering or vibration reduction. As a result, with prolonged sliding friction, the sliding layer 3 is constantly under stress and directly wears away. Conversely, the hardness setting of the support layer 2 and the hardness gradient between the three layers allow the support layer 2 to provide flexible support for the sliding layer 3. Especially under high loads, it can reduce the wear of the sliding layer 3, thereby extending the life of the sliding bearing.

[0071] Furthermore, the hardness gradient reduces stress at material interfaces (e.g., thermal stress), such as stress at the interfaces between layers, thereby improving the fatigue strength, creep resistance, and lifespan of the sliding bearing. Tests have shown that the lifespan of the sliding bearing has increased by 10% to 50%, for example, by 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 30%, 35%, 40%, 45%, and 50%.

[0072] The hardness gradient can be achieved by selecting the materials for each layer. For example, if the base layer 1 uses a first material and its composition, the base layer 1 directly obtains the first hardness or hardness range when the material is applied to form the base layer 1. Similarly, if the support layer 2 uses a second material and its composition, the support layer 2 directly obtains the second hardness or hardness range through the selection of the material. If the sliding layer 3 uses a third material and its composition, the sliding layer 3 directly obtains the third hardness or hardness range through the selection of the material.

[0073] Alternatively and additionally, the hardness gradient can also be indirectly obtained by heat treatment of the individual layers. Heat treatment can include various methods employed in the art, such as overall heat treatment and surface heat treatment. Overall heat treatment includes, for example, annealing, normalizing, quenching, tempering, and heat treatment. Surface heat treatment includes, for example, surface quenching and chemical heat treatment, as well as other common and frequently used heat treatment methods, to enable the individual layers to obtain the desired hardness or hardness range.

[0074] It should be noted that the two methods described above for obtaining the hardness gradient can be implemented individually for each layer or in combination, as long as the desired hardness or hardness range can be obtained. For example, the base layer 1 can obtain its first hardness or hardness range solely through material selection, or it can indirectly obtain its first hardness or hardness range through heat treatment while forming the base layer 1 by applying the material, or it can obtain its first hardness or hardness range through a combination of material selection and heat treatment. Similarly, the hardness or hardness range of the support layer 2 can be obtained directly after forming the support layer 2 by applying the selected material, or it can be obtained by further heat treatment after forming the support layer 2 by applying the material. Similarly, the hardness or hardness range of the sliding layer 3 can be obtained directly after forming the sliding layer 3 by applying the selected material, or it can be obtained by further heat treatment after forming the sliding layer 3 by applying the material.

[0075] For example, base layer 1 is a steel shaft, whose material itself has high hardness; support layer 2 and sliding layer 3 can be selected from aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys. Some of these materials have relatively low hardness compared to the steel shaft. For example, when support layer 2 and sliding layer 3 are made of copper alloys, these two layers directly acquire a softer hardness during their formation. It should be noted that although support layer 2 and sliding layer 3 are both selected from aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, their specific material compositions are different to produce different layers and different hardnesses. For example, support layer 2 and sliding layer 3 can use different specific material compositions and / or the same heat treatment to obtain different hardnesses; or support layer 2 and sliding layer 3 can use different specific material compositions and / or different heat treatments to obtain different hardnesses; or, in extreme cases, support layer 2 and sliding layer 3 can use the same specific material composition but undergo different heat treatments to obtain different hardnesses.

[0076] Furthermore, in the sliding bearing, there is a decreasing iron (Fe) content (by weight, wt.%) or a decreasing Fe content composition gradient between the layers. Specifically, the base shaft 1 (or base layer 1) has the highest iron (Fe) content; secondly, the support layer 2 has a lower Fe content than the base shaft 1 (or base layer 1); and thirdly, the sliding layer 3 has a lower Fe content than the support layer 2. It should be noted that the materials used for support layer 2 and sliding layer 3 mentioned above refer to the materials used before the application of support layer 2 and sliding layer 3, and the mass percentage of each element in the alloy materials listed above refers to the mass percentage of the material before application. The decreasing iron (Fe) content described here refers to the Fe content contained in each layer after its formation (i.e., after the application of the material).

[0077] This is because when the support layer 2 is applied (e.g., welded) to the shaft 1, a molten material interface is formed between the support layer 2 and the shaft 1. At this time, some of the iron in the shaft 1 will melt or diffuse into the support layer 2 through the material interface between the two. Similarly, when the sliding layer 3 is applied to the support layer 2, a molten material interface is formed between the sliding layer 3 and the support layer 2. At this time, some of the iron in the support layer 2 will melt or diffuse into the sliding layer 3 through the material interface between the two. The Fe content in the sliding layer 3 should be as low as possible, because as a sliding friction layer, an increased Fe content will adversely affect the wear resistance of the sliding layer 3. For example, the base shaft 1 (or base layer 1) can be made of steel, which has a very high Fe content. Therefore, when the support layer 2 is applied, some iron melts into or diffuses into the support layer 2. The support layer 2 is selected from materials such as aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, etc., and these alloys themselves have relatively low Fe content. When the sliding layer 3 is applied, some iron in the support layer 2 melts into or diffuses into the sliding layer 3. In contrast, the Fe content that melts into or diffuses from the support layer 2 into the sliding layer 3 is much less than the Fe content that diffuses from the base shaft 1 into the support layer 2. Furthermore, the support layer 2 and the sliding layer 3 themselves are selected from materials such as aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, etc., and these materials themselves have relatively low Fe content. In addition, considering the additional Fe content that diffuses into the support layer 2 and the sliding layer 3, after molding, the Fe content in the sliding layer 3 is less than the Fe content in the support layer 2.

[0078] For example, the Fe content of the support layer 2, by weight percentage, can be less than or equal to 5%, preferably less than or equal to 4%, for example, 5%, 4.5%, 4.0%, 3.5%, 3.0%, 2.5%, 2.0%, 1.5%, 1.0%, 0.5%, or any other value or range. The Fe content of the sliding layer 3 is less than that of the support layer 2 and can be less than or equal to 5%, preferably less than or equal to 3%, preferably less than or equal to 2%, more preferably less than or equal to 0.5%, for example, 3%, 2.5%, 2.0%, 1.5%, 1.0%, 0.5%, 0.45%, 0.4%, 0.35%, 0.3%, 0.25%, 0.2%, 0.15%, 0.1%, or any other value or range. Furthermore, the support layer 2 can be formed of a material with a relatively high Fe content. For example, the Fe content of the support layer 2 can be less than or equal to 90%, such as less than or equal to 85%, less than or equal to 80%, less than or equal to 75%, less than or equal to 70%, less than or equal to 65%, less than or equal to 60%, less than or equal to 55%, less than or equal to 50%, less than or equal to 45%, less than or equal to 40%, less than or equal to 35%, less than or equal to 30%, less than or equal to 25%, or any other value or range. In summary, regardless of the materials used for the support layer 2 and the sliding layer 3 (these materials include, but are not limited to, the aforementioned aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, and may also include any other suitable materials), as long as the Fe content of the support layer 2 is less than the Fe content of the substrate shaft 1 and the Fe content in the sliding layer 3 is less than the Fe content of the support layer 2, they all fall within the protection scope of this disclosure.

[0079] In addition, in practice, it is relatively important that the Fe content of the sliding layer 3 be as low as possible. This is because as the outermost sliding friction layer, an increase in the Fe content of the sliding layer 3 will adversely affect its wear resistance. Therefore, in alternative embodiments, the Fe content of the sliding layer 3 can be the focus, so that the Fe content of the sliding layer 3 is less than 5%, preferably less than or equal to 3%, preferably less than or equal to 2%, more preferably less than or equal to 0.5%, for example, 3%, 2.5%, 2.0%, 1.5%, 1.0%, 0.5%, 0.45%, 0.4%, 0.35%, 0.3%, 0.25%, 0.2%, 0.15%, 0.1%, or any other value or range of values.

[0080] In summary, the support layer 2 can function as both a barrier layer to prevent harmful elements in the shaft 1 from diffusing into the sliding layer 3, and a buffer and support layer between the base layer 1 and the sliding layer 3. Specifically, the material of the support layer 2 can be selected from the group consisting of aluminum-based alloys, tin-based alloys, copper and copper-based alloys, and nickel and nickel-based alloys, with copper and copper alloys being preferred. On the one hand, these alloys contain less Fe, thus reducing the Fe diffusing into the sliding layer 3; on the other hand, the support layer 2 formed by these alloys provides a hardness gradient between the base layer 1 and the sliding layer 3, thereby achieving the buffering and support functions of the support layer 2.

[0081] The following describes a transmission device including the sliding bearing and its manufacturing method. The transmission device includes a shaft 1, a gear supported on the shaft 1, and a support layer 2 and a sliding layer 3 disposed between the shaft 1 and the gear. The shaft 1 is the aforementioned base layer 1, the support layer 2 is applied to the outer surface of the shaft 1, and the sliding layer 3 is applied to the support layer 2.

[0082] The manufacturing method of shaft 1 of the transmission device includes the following steps:

[0083] (1) Provide shaft 1 and process shaft 1 to have a predetermined length, outer diameter and surface roughness;

[0084] (2) Optionally, clean the surface of shaft 1;

[0085] (3) Apply the material of the support layer 2 to the surface of the shaft 1 to form the support layer 2;

[0086] (4) Optionally, the support layer 2 is processed;

[0087] (5) Apply the material of the sliding layer 3 to the support layer 2 to form the sliding layer 3;

[0088] (6) Process the sliding layer 3.

[0089] In step (1), preferably, shaft 1 is a round steel or forged steel billet, and the billet is machined to a predetermined length and outer diameter, wherein the predetermined outer diameter is 0.1 to 5.5 mm smaller than the outer diameter of the finished shaft, for example, 1.5 mm, 2.0 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or any other suitable value. This is done to leave a predetermined space for the support layer 2 and sliding layer 3 applied to shaft 1; the finished shaft refers to the shaft after the support layer 2 and sliding layer 3 have been applied. After the finished shaft is formed, the gear is supported on shaft 1. The term "machining" can include machining or any other suitable manufacturing method, as long as the corresponding parameters, such as length, outer diameter, surface roughness, and thickness, can be achieved. There are no specific limitations on the dimensions (e.g., length and outer diameter), material, and hardness of shaft 1, and they can be selected as described above.

[0090] It should be noted that the base layer 1 can be provided by the shaft 1, and the support layer 2 and sliding layer 3 of the sliding bearing are applied to the outer surface of the shaft 1, such that the support layer 2 and sliding layer 3 are formed around the shaft 1 in a cylindrical or annular shape, but are not limited thereto. The sliding bearing can also be other shapes. For example, the sliding bearing can be a multi-layer planar structure, that is, it only includes a planar base layer 1, a planar support layer 2, and a planar sliding layer 3 stacked sequentially. Alternatively, for example, the sliding bearing can be a cylindrical structure, such as a conventional bearing bush type sliding bearing, which includes a bearing bush, the journal of the shaft is supported in the annular cylindrical bearing bush, the base layer 1 can be provided by the inner circumferential surface of the bearing bush, and the support layer 2 and sliding layer 3 can be annular in shape and applied sequentially to the inner circumferential surface of the bearing bush. In this case, when the shaft is supported in the sliding bearing, the outer circumferential surface of the shaft contacts the sliding layer 3, and sliding friction occurs between them.

[0091] The term “apply” is not specifically limited and can be applied by various methods, such as those described above, as long as the corresponding parameters, such as bond strength and hardness, can be achieved.

[0092] In the embodiment shown in the figure and described above, where shaft 1 serves as the base layer, the formed sliding bearing is provided with a lubricating medium (e.g., lubricant, lubricating oil) delivery structure, which is a hole or groove. In a preferred embodiment, shaft 1 is provided with axial holes and radial holes. The lubricant is delivered from the axial holes on the shaft end face, passing through the axial holes to various axial sections, and then through the radial holes to the sliding surface region of the sliding bearing. The lubricant then distributes from that region to the entire sliding surface. The axial holes are preferably distributed in multiple axial sections, all of which are connected by radial through holes.

[0093] In a variant embodiment, the sliding layers can be applied in segments, spaced apart from each other along the axial direction of the shaft. Advantageously, the axial gap between the sliding layers can form natural oil grooves, each groove containing radial holes that communicate with the axial holes to form lubrication channels, thereby achieving better lubrication of the sliding layers. The width of the oil grooves is greater than the diameter of the radial holes.

[0094] Considering the above-mentioned lubricating medium conveying structure, the manufacturing process of the sliding bearing and shaft 1 is as follows: (1) machining shaft 1; (2) applying support layer 2 to shaft 1; (3) applying sliding layer 3 to support layer 2; (4) machining oil holes or oil grooves on shaft 1; (5) machining the end face and outer peripheral surface of shaft 1.

[0095] In another variant embodiment, a running-in layer can be provided on the sliding layer 3. In this case, the running-in layer constitutes the outermost layer of the sliding bearing, serving as a sliding friction layer in place of the sliding layer 3 or in combination with the sliding layer 3, and engaging in sliding friction with external components. For example, a gear can be disposed on the running-in layer and slide on it. The provision of the running-in layer improves the frictional performance of the sliding bearing.

[0096] The running-in layer is preferably a polymer material, which includes resin and additives. The resin is at least one of polyamide, polyurethane, polyester, polyphenylene sulfide, fluoropolymer, polyetheretherketone, polyimide resin, alkyd resin, polyacrylate, epoxy resin, phenolic resin, and silicone resin. The additives are at least one of graphite, carbon nanotubes, polytetrafluoroethylene, ultra-high molecular weight polyethylene, molybdenum disulfide, tungsten disulfide, zinc sulfide, calcium fluoride, boron nitride, lead, silver, bismuth, and tin.

[0097] The sliding bearing of the present invention is described below by way of example.

[0098] Example 1:

[0099] Shaft 1 is made of 40Cr material with a hardness of HRC32. First, shaft 1 is machined to the desired length, and then its outer diameter is machined to be 1.5 mm smaller than the finished shaft size, with a surface roughness of Ra3.2 μm. Support layer 2 is made of CuZn25Al5Mn4Fe3 material and applied to the outer circumference of shaft 1, resulting in a support layer 2 with an Fe content of 4.5 wt.%. Support layer 2 has a hardness of HB180, a thickness of 1.0 mm, and a bonding strength between support layer 2 and shaft 1 of 260 MPa. After forming support layer 2, sliding layer 3 is directly applied to its surface. Sliding layer 3 is made of CuSn10 material and applied to the outer circumference of support layer 2, resulting in a sliding layer 3 with an Fe content of 0.2 wt.%. Sliding layer 3 has a hardness of HB90 and a thickness of 1.0 mm. Sliding layer 3 is then machined to a thickness of 0.5 mm, thus forming an integral sliding bearing. Oil passages (e.g., oil holes or oil grooves) are machined on shaft 1 to communicate with and connect with sliding layer 3 and support layer 2, for the lubrication of sliding layer 3.

[0100] Example 2:

[0101] Shaft 1 is made of 40Cr material with a hardness of HRC32. First, shaft 1 is machined to the desired length, and then its outer diameter is machined to be 2.0 mm smaller than the finished shaft size, with a surface roughness of Ra3.2 μm. Support layer 2 is made of CuAl10Fe5Ni5 material and is applied to the outer circumference of shaft 1, resulting in a support layer 2 with an Fe content of 5.0 wt.%. Support layer 2 has a hardness of HB170, a thickness of 1.0 mm, and a bonding strength between support layer 2 and shaft 1 of 230 MPa. After forming support layer 2, sliding layer 3 is directly applied to its surface. Sliding layer 3 is made of CuSn10 material and is applied to the outer circumference of support layer 2, resulting in a sliding layer 3 with an Fe content of 0.25 wt.%. Sliding layer 3 has a hardness of HB90 and a thickness of 1.5 mm. Sliding layer 3 is then machined to a thickness of 1.0 mm, thus forming an integral sliding bearing. Oil passages (e.g., oil holes or oil grooves) are machined on shaft 1 to communicate with and connect with sliding layer 3 and support layer 2, for the lubrication of sliding layer 3.

[0102] Example 3:

[0103] Shaft 1 is made of 42CrMoA material with a hardness of HB280. First, shaft 1 is machined to the desired length, and then its outer diameter is machined to be 2.5 mm smaller than the finished shaft size, with a surface roughness of Ra3.2 μm. Support layer 2 is made of CuAl10Fe5Ni5 material and applied to the outer circumference of shaft 1, resulting in a support layer 2 with an Fe content of 4.5 wt.%. Support layer 2 has a hardness of HB170 and a thickness of 2.0 mm. The bonding strength between support layer 2 and shaft 1 is 250 MPa. After forming support layer 2, sliding layer 3 is directly applied to its surface. Sliding layer 3 is made of CuSn12Ni2 material and applied to the outer circumference of support layer 2, resulting in a sliding layer 3 with an Fe content of 0.3 wt.%. Sliding layer 3 has a hardness of HB120 and a thickness of 1.0 mm. Then, sliding layer 3 is machined to a thickness of 0.5 mm, thus forming an integral sliding bearing. Oil passages (e.g., oil holes or oil grooves) are machined on shaft 1 to communicate with and connect with sliding layer 3 and support layer 2, for the lubrication of sliding layer 3.

[0104] Example 4:

[0105] Shaft 1 is made of 42CrMoA material with a hardness of HB280. First, shaft 1 is machined to the desired length, and then its outer diameter is machined to be 2.5 mm smaller than the finished shaft size, with a surface roughness of Ra6.4 μm. Support layer 2 is made of CuSn12Ni2 material and applied to the outer circumference of shaft 1, resulting in a support layer 2 with an Fe content of 3.0 wt.%. Support layer 2 has a hardness of HB120 and a thickness of 2.0 mm. The bonding strength between support layer 2 and shaft 1 is 200 MPa. After forming support layer 2, sliding layer 3 is directly applied to its surface. Sliding layer 3 is made of AlSn20Cu material and applied to the outer circumference of support layer 2, resulting in a sliding layer 3 with an Fe content of 0.2 wt.%. Sliding layer 3 has a hardness of HB40 and a thickness of 1.0 mm. Then, sliding layer 3 is machined to a thickness of 0.5 mm, thus forming an integral sliding bearing. Oil passages (e.g., oil holes or oil grooves) are machined on shaft 1 to communicate with and connect with sliding layer 3 and support layer 2, for the lubrication of sliding layer 3.

[0106] Example 5:

[0107] Shaft 1 is made of 42CrMoA material with a hardness of HB280. First, shaft 1 is machined to the desired length, and then its outer diameter is machined to be 2.5 mm smaller than the finished shaft size, with a surface roughness of Ra6.4 μm. Support layer 2 is made of CuAl9 material and applied to the outer circumference of shaft 1, resulting in a support layer 2 with an Fe content of 2.5 wt.%. Support layer 2 has a hardness of HB110 and a thickness of 2.0 mm. The bonding strength between support layer 2 and shaft 1 is 190 MPa. After forming support layer 2, sliding layer 3 is directly applied to its surface. Sliding layer 3 is made of Babbitt alloy and applied to the outer circumference of support layer 2, resulting in a sliding layer 3 with an Fe content of 0.3 wt.%. Sliding layer 3 has a hardness of HB25 and a thickness of 1.0 mm. Sliding layer 3 is then machined to a thickness of 0.5 mm, thus forming an integral sliding bearing. Oil passages (e.g., oil holes or oil grooves) are machined on shaft 1 to communicate with and connect with sliding layer 3 and support layer 2, for the lubrication of sliding layer 3.

[0108] It should be noted that the above five examples are only a portion of the embodiments and are not limiting. Furthermore, the materials and other parameters used in these examples (e.g., hardness, length, outer diameter, thickness, roughness, strength, Fe content, etc.) are merely illustrative and not limiting, and these materials and parameters can be interchanged and combined with each other. Of course, those skilled in the art can select and set any other suitable materials and parameters.

[0109] Those skilled in the art can flexibly set and select other examples and embodiments according to actual engineering needs, and all of them fall within the protection scope of this invention.

[0110] The following reference Figure 2 A sliding bearing according to another embodiment of the present invention is described. Figure 2 and Figure 1 The main difference lies in the specific structure of the base layer 1, the support layer 2, and the sliding layer 3; all other aspects are the same, as mentioned above. Figure 1 All descriptions apply Figure 2 This will not be elaborated upon here.

[0111] Figure 2 The diagram shows a base layer 1 with a groove, a support layer 2 and a sliding layer 3 disposed within the groove, and the sliding layer 3 being flush with the outer surface of the base layer 1. The following description uses a shaft 1 as an example of the base layer 1, but is not limited thereto. The base layer 1 can be planar or plate-shaped, and the support layer 2 and sliding layer 3 can also be planar or plate-shaped and disposed within the groove of the base layer 1.

[0112] Specifically, the shaft 1 is recessed in the radial direction on the outer peripheral surface of its middle section to form an annular groove, the support layer 2 and the sliding layer 3 are disposed in the groove, and the sliding layer 3 is flush with the outer surface of the shaft 1.

[0113] The following description Figure 2 The forming process of the sliding bearing. A concave annular groove is machined in the middle section of shaft 1. This middle section is the section that needs to slide and rub against the mating component, such as a gear. That is, the middle section is set on shaft 1 according to the size of the mating component and the size of the section where the mating component slides and rubs against shaft 1, and the annular groove is machined in the middle section. The depth of the annular groove is greater than the final thickness of the support layer 2 after forming, less than the total thickness of the support layer 2 and sliding layer 3 after application, and greater than the final total thickness of the support layer 2 and sliding layer 3 after forming. This depth setting leaves machining allowance for the final forming of the support layer 2 and sliding layer 3. Furthermore, the outer diameter of shaft 1 is also greater than the outer diameter of the final formed finished shaft 1. This is because after applying the sliding layer 3, shaft 1 and the sliding layer 3 formed in the groove of the shaft need to be machined together to a predetermined size; therefore, machining allowance is needed for the finished shaft. Figure 1 The implementation method is the same, and there is no limit to this machining allowance. It can be set reasonably according to the actual engineering needs.

[0114] After the groove is formed, as described above, the support layer 2 and the sliding layer 3 are sequentially applied into the groove using the aforementioned application method and process. It should be noted that in this embodiment, only the support layer 2 and the sliding layer 3 need to be applied to the groove of the shaft section where sliding friction is required. Figure 1 Compared to the previous implementation method which required applying the support layer 2 and sliding layer 3 to the entire shaft / partial shaft area, this implementation method saves materials, reduces material costs, and also reduces post-application processing steps. Furthermore, compared to... Figure 1 The implementation method is the same. When applying the support layer 2 and the sliding layer 3, the material thickness of the applied support layer 2 can be the same as the thickness of the final formed support layer 2 without processing the formed support layer, or the material thickness of the applied support layer 2 can be greater than the thickness of the final formed support layer 2, so that the support layer 2 is processed after it is formed; while the material thickness of the applied sliding layer 3 is greater than the thickness of the final formed sliding layer 3. This is because after the material of the sliding layer 3 is applied, the sliding layer 3 needs to be machined, that is, a part of the sliding layer 3 is removed, so as to form the desired sliding surface roughness.

[0115] By creating grooves, the support layer 2 and the sliding layer 3 can be held in a molten liquid state within the grooves after application. Specifically, after the sliding layer 3 is applied to the support layer 2 within the grooves, the molten sliding layer 3 extends beyond and above the outer surface of the shaft 1. Due to the groove design, when the sliding layer 3 is applied, the molten sliding layer 3 flows only near the grooves and onto the shaft surface around the grooves without overflowing onto the end faces of the two ends of the shaft; in contrast, in… Figure 1 In one embodiment, since the support layer 2 and the sliding layer 3 are applied to the entire shaft 1, the molten liquid support layer 2 and the sliding layer 3 will overflow onto or near the end faces of the two ends of the shaft, thereby forming a coating fillet at the end face due to liquid tension. This fillet cannot meet the requirements of actual engineering use due to uneven material content, etc., and needs to be removed by processing.

[0116] After the sliding layer 3 has solidified, as mentioned above, the shaft 1 and the sliding layer 3 have pre-reserved machining allowances. Therefore, the shaft 1 and the sliding layer 3 are machined to achieve a predetermined thickness for the sliding layer 3, and the shaft 1 is machined to a predetermined outer diameter. It should be noted that in this embodiment, the final machining of the shaft 1 and the sliding layer 3 is performed simultaneously. That is, the shaft 1 and the sliding layer 3 are machined into finished products in only one machining pass or one machining process. Furthermore, since the molten liquid of the sliding layer 3 only flows near the groove in this embodiment, it is not necessary to machine the two end faces of the shaft, but only the outer peripheral surface of the shaft 1 needs to be machined.

[0117] In contrast, Figure 1In this implementation, the shaft 1 needs to be machined first to have a predetermined length, outer diameter, and surface roughness; then, after applying the support layer 2 and the sliding layer 3, the sliding layer 3 is machined to a predetermined thickness; furthermore, the two end faces of the shaft need to be machined to remove the aforementioned fillets. It can be seen that... Figure 1 The implementation method requires performing at least three processing steps at three different time points, while Figure 2 The proposed implementation only requires a single machining step after the sliding layer 3 is applied to simultaneously shape the shaft and the sliding layer 3. For example, in a single machining step, the shaft is machined to a predetermined outer diameter and surface roughness, while the sliding layer 3 is machined to a predetermined thickness and surface roughness. This demonstrates that the surface roughness of the finished shaft can be equal to the surface roughness of the sliding layer, and no additional machining is required on the two end faces of the shaft. In contrast, Figure 2 The implementation method saves on the number of processing steps and time, and reduces processing and manufacturing costs.

[0118] In addition, Figure 2 In this embodiment, the circumferential annular groove in shaft 1 has a bottom and two circumferential annular sidewalls or side surfaces. The shape of the groove serves to receive the support layer 2 and the sliding layer 3 and firmly hold them on the shaft. Furthermore, in Figure 1 In this embodiment, the support layer 2 and the sliding layer 3 are fixed only by being bonded to the outer peripheral surface of the shaft. Specifically, the support layer 2 is bonded to the outer peripheral surface of the shaft, while the sliding layer 3 is bonded to the surface of the support layer 2; and in Figure 2 In this embodiment, in addition to being bonded to the outer surface of the shaft (i.e., the bottom of the groove), the support layer 2 and the sliding layer 3 are also bonded to the two circumferential sidewalls of the groove, which increases the bonding surface area with the shaft, thereby more firmly bonding the support layer 2 and the sliding layer 3 to the shaft.

[0119] In addition, such as Figure 2 As shown, the two sidewalls of the groove can have a certain slope or inclination angle relative to the bottom. The inclination angle facilitates the processing of the groove and further increases the surface area of ​​the sidewalls, thereby increasing the contact surface area between the support layer 2 and the sliding layer 3 and the shaft 1, resulting in greater bonding strength between the support layer 2 and the sliding layer 3 and the shaft 1. This inclination angle can be, for example, 30 degrees, 45 degrees, 60 degrees, or 30 to 60 degrees, 30 to 45 degrees, 45 to 60 degrees, or any other suitable angle. There is no specific limitation on the specific value of this angle; it can be appropriately selected according to the specific engineering application.

[0120] The above text focuses on describing Figure 2 and Figure 1 The difference lies in the structural arrangement and modification of shaft 1 and the sliding bearing. It should be noted that... Figure 1Other aspects of the implementation method are also applicable. Figure 2 The implementation methods, such as the material selection of the support layer 2 and the sliding layer 3, the proportion of each component in the material, the setting of the hardness gradient, and the additional settings of the running-in layer, will not be repeated here.

[0121] in addition, Figure 2 The diagram shows a support layer 2 and a sliding layer 3 sequentially disposed in a groove, with the outermost sliding layer 3 flush with the outer surface of the shaft 1 (i.e., flush with the groove). However, this is not a limitation; the outermost sliding layer 3 may be lower than or higher than the outer surface of the shaft 1 without being flush with it. In another alternative embodiment not shown, the support layer 2 and the sliding layer 3 may protrude radially or vertically beyond the groove of the base layer 1 and be higher than the groove. The following description uses the shaft 1 as an example of the base layer 1, but is not limited to this. The base layer 1 may be planar or plate-shaped, and the support layer 2 and the sliding layer 3 may also be planar or plate-shaped and disposed in the groove of the base layer 1. This alternative embodiment includes two schemes: (1) both the support layer 2 and the sliding layer 3 are higher than the outer surface of the shaft 1 and higher than the groove; (2) only the sliding layer 3 is higher than the outer surface of the shaft 1 and higher than the groove, while the support layer 2 is lower than the outer surface of the shaft 1 and lower than the groove. These two schemes are similar to... Figure 2 The only difference in the embodiment is that the support layer 2 and the sliding layer 3 are not flush with the groove, therefore the above description is for... Figure 2 The description of the embodiments also applies to these two alternative embodiments, and will not be repeated here. The two embodiments will be described in detail below.

[0122] In scheme (1), since both the support layer 2 and the sliding layer 3 are higher than the outer surface of the shaft 1 and higher than the groove, the groove can be machined first and the outer diameter of the shaft 1 can be directly machined to the outer diameter of the final formed shaft 1 before applying the support layer 2 and the sliding layer 3 to the groove. Then, the support layer 2 is applied to the groove, and the material thickness of the applied support layer 2 can be the same as the thickness of the final formed support layer 2 without processing the formed support layer. Alternatively, the material thickness of the applied support layer 2 can be greater than the thickness of the final formed support layer 2, so that the support layer 2 is processed after it is formed. After the support layer 2 is formed, its height is higher than the outer surface of the shaft 1 and higher than the groove. Then, the sliding layer 3 is applied to the support layer 2 and machined to achieve a predetermined thickness. Alternatively, the shaft 1 can be machined without applying the support layer 2 and the sliding layer 3 to the groove. Instead, the shaft 1 and the sliding layer 3 can be machined simultaneously after the sliding layer 3 is finally formed, so that the sliding layer 3 is machined to a predetermined thickness and the shaft 1 is machined to a predetermined outer diameter.

[0123] In scheme (2), only the sliding layer 3 is higher than the outer surface of the shaft 1 and higher than the groove, while the support layer 2 is lower than the outer surface of the shaft 1 and lower than the groove. Therefore, before applying the support layer 2 and the sliding layer 3 to the groove, the groove can be machined first, and the outer diameter of the shaft 1 can be directly machined to the outer diameter of the final formed shaft 1. Then, the support layer 2 is applied to the groove, and the material thickness of the applied support layer 2 can be the same as the thickness of the final formed support layer 2 without processing the formed support layer, or the material thickness of the applied support layer 2 can be greater than the thickness of the final formed support layer 2, so that the support layer 2 is processed after it is formed. After the support layer 2 is formed, the height of the support layer 2 is lower than the outer surface of the shaft 1 and lower than the groove. Then, the sliding layer 3 is applied to the support layer 2, and the sliding layer 3 is machined to a predetermined thickness. Alternatively, the shaft 1 can be machined without applying the support layer 2 and the sliding layer 3 to the groove. Instead, the shaft 1 and the sliding layer 3 can be machined simultaneously after the sliding layer 3 is finally formed, so that the sliding layer 3 is machined to a predetermined thickness and the shaft 1 is machined to a predetermined outer diameter.

[0124] exist Figure 2 In both the embodiments and the alternative embodiments, regardless of whether the sliding layer 3 is flush with the outer surface of the shaft 1 (i.e., flush with the groove), and regardless of the quantity and order of the processing technology applied to the shaft 1, the support layer 2 and the sliding layer 3, as long as the thickness of the sliding layer 3 can meet the actual engineering needs, such as the various thicknesses described above for the sliding layer 3, will not be repeated here.

[0125] The advantages of this invention are that the sliding bearing of this invention is a multi-layer sliding bearing comprising multiple metal layers, which are metallurgically bonded to form an integral sliding bearing. This eliminates the need for bearing bushings in conventional technologies, saving the use of precious metals (such as non-ferrous metals) and significantly reducing bearing costs. It also eliminates the assembly of bushings and shafts, saving installation time and greatly reducing assembly time and labor costs. Each layer of the bearing forms an integral whole with the base shaft, and the layers have strong bonding strength, eliminating the risk of the sliding layer detaching from the base shaft.

[0126] In addition, an intermediate support layer is set between the base layer (e.g., the matrix shaft) and the sliding layer. The intermediate support layer can be used as a barrier layer to block or reduce the diffusion of elements from the matrix shaft into the sliding layer. For example, it reduces the diffusion of steel-based elements from the steel shaft into the sliding layer, ensuring the integrity of the chemical composition of the sliding layer. This prevents the sliding layer from being diffused and interfered with by elements from the matrix shaft, thereby ensuring the wear resistance of the sliding layer.

[0127] From the base layer to the sliding layer, there is a decreasing hardness gradient between each layer. In particular, the hardness setting of the support layer allows it to provide flexible support for the sliding layer, which can reduce wear on the sliding layer, especially under high loads, thereby extending the life of the sliding bearing. In addition, the hardness gradient reduces the stress (e.g., thermal stress) at the material interfaces between the layers, thereby improving the fatigue strength, creep resistance, and life of the sliding bearing.

[0128] Specifically, the material of the intermediate support layer is selected from the group consisting of aluminum-based alloys, tin-based alloys, copper and copper-based alloys, and nickel and nickel-based alloys, with copper alloys being preferred. The selection of these alloy materials has a dual technical effect: on the one hand, these materials themselves contain less Fe, thereby reducing the Fe that diffuses into the outer sliding layer and minimizing the adverse effects of Fe composition on the wear resistance of the sliding layer; on the other hand, the support layer formed by these alloys can provide the desired hardness gradient between the base layer and the sliding layer, thereby realizing the buffering and support function of the support layer.

[0129] In addition, by setting the support layer and the sliding layer in the groove formed in the base layer, it is possible to further save materials, reduce processing steps, reduce material and manufacturing costs, and increase the bonding strength between the various layers of the sliding bearing, thereby increasing the structural strength, service life and wear resistance of the sliding bearing itself.

[0130] Based on the above advantages, the present invention provides a sliding bearing that is low-cost, simple in structure, easy to manufacture, easy to maintain, highly wear-resistant, and has a long service life.

[0131] The above description of various embodiments of the present invention is provided for illustrative purposes to a person skilled in the art. It is not intended to limit the invention to a single disclosed embodiment. As taught above, those skilled in the art will understand various alternatives and variations of the invention. Therefore, although some alternative embodiments have been specifically described, those skilled in the art will understand or relatively easily develop other embodiments. The present invention is intended to include all alternatives, modifications, and variations of the invention described herein, as well as other embodiments falling within the spirit and scope of the invention described above.

[0132] Figure label:

[0133] 1st axis (base layer)

[0134] 2 Support layer

[0135] 3. Sliding layer.

Claims

1. A sliding bearing, comprising: Grassroots (1); Support layer (2), which is located on the base layer (1); A sliding layer (3) is located on the support layer (2). The base layer (1), the support layer (2), and the sliding layer (3) have a decreasing hardness gradient. The hardness of the support layer (2) is 20% to 90% of the hardness of the base layer (1), and the hardness of the sliding layer (3) is 15% to 90% of the hardness of the support layer (2). The support layer (2) and the sliding layer (3) are selected from the group consisting of aluminum-based alloys, tin-based alloys, copper and copper-based alloys, and nickel and nickel-based alloys. The support layer also serves as a barrier layer to block or reduce the diffusion of elements from the base layer into the sliding layer. The Fe content decreases sequentially from the base layer (1), the support layer (2) to the sliding layer (3).

2. The sliding bearing according to claim 1, wherein, A groove is formed on the base layer (1), and the support layer (2) and the sliding layer (3) are sequentially disposed in the groove.

3. The sliding bearing according to claim 1, wherein, The hardness of the support layer (2) is 35% to 90% or 40% to 65% of the hardness of the base layer (1), and the hardness of the sliding layer (3) is 30% to 60% of the hardness of the support layer (2).

4. The sliding bearing according to claim 1, wherein, The support layer (2) is formed of CuAl alloy, which has the following contents: Al is 6% to 15%, Fe is 0% to 7.5%, Ni is 0% to 8.5%, Mn is 0% to 10.0%, Zn is 0% to 2.0%, and the balance is Cu.

5. The sliding bearing according to claim 1, wherein, The support layer (2) is formed of CuSn alloy, which has the following contents: Sn is 4% to 25%, Ni is 0% to 5%, P is 0% to 0.6%, Zn is 0% to 1.0%, Fe is 0% to 10%, and the balance is Cu.

6. The sliding bearing according to claim 1, wherein, The support layer (2) is formed of CuSi alloy, which has the following contents: Si is 1.0% to 6.0%, Mn is 0% to 4.0%, P is 0% to 0.5%, Fe is 0% to 10%, Zn is 0% to 12%, and the balance is Cu.

7. The sliding bearing according to claim 1, wherein, The support layer (2) is formed of CuMn alloy, which has the following contents: Mn is 6.0% to 16.0%, Al is 5% to 12%, Ni is 0% to 6%, Fe is 0% to 10%, and the balance is Cu.

8. The sliding bearing according to claim 1, wherein, The support layer (2) is formed of a CuZn alloy having the following contents: Zn 5.0% to 50.0%, Al 0% to 15.0%, Mn 0% to 10.0%, As 0% to 5.0%, Sb 0% to 5.0%, Si 0% to 10.0%, Ni 0% to 25.0%, Pb 0% to 5.0%, Fe 0% to 5.0%, Sn 0% to 5.0%, with the balance being Cu.

9. The sliding bearing according to claim 1, wherein, The support layer (2) is formed of a CuCr alloy, which has the following content: Cr is 0.1% to 10.0%, Zr is 0% to 5.0%, other impurities are 0% to 5.0%, and the balance is Cu.

10. The sliding bearing according to claim 1, wherein, The support layer (2) is formed of a CuNi alloy having the following contents: Ni 0.1% to 45.0%, Fe 0% to 5.0%, Zn 0% to 5.0%, Mn 0% to 5.0%, Cr 0% to 5.0%, Si 0% to 5.0%, Nb 0% to 5.0%, and the balance being Cu.

11. The sliding bearing according to claim 1, wherein, The sliding layer (3) is formed of CuSn alloy, which has the following contents: Sn is 6% to 15%, P is 0.05% to 0.5%, Zn is 0% to 0.5%, Fe is 0% to 5%, and the balance is Cu.

12. The sliding bearing according to claim 1, wherein, The sliding layer (3) is formed of CuSn alloy, which has the following contents: Sn is 9% to 14%, Ni is 0% to 3.0%, P is 0.05% to 0.5%, Zn is 0% to 0.5%, Fe is 0% to 4%, and the balance is Cu.

13. The sliding bearing according to claim 1 or 2, wherein, The sliding layer (3) is formed of an alloy material having the following contents: Sn is 5% to 35%, Cu is 0.5% to 2.0%, Ni is 0% to 1.5%, Fe is 0% to 4%, and the balance is Al.

14. The sliding bearing according to claim 1 or 2, wherein, The sliding layer (3) is formed of an alloy material having the following contents: Sn is 10% to 25%, Cu is 0.5% to 1.5%, Ni is 0% to 0.5%, and the balance is Al.

15. The sliding bearing according to claim 1, wherein, The Fe content of the support layer (2) is less than or equal to 90%, and the Fe content of the sliding layer (3) is less than or equal to 5%.

16. The sliding bearing according to claim 15, wherein, The Fe content of the support layer (2) is less than or equal to 85%, and the Fe content of the sliding layer (3) is less than or equal to 3%.

17. The sliding bearing according to claim 1 or 2 further includes a running-in layer located on the sliding layer (3), the running-in layer being formed of a polymer material.

18. The sliding bearing according to claim 1 or 2, wherein, The Fe content of the sliding layer (3) is less than or equal to 5%.

19. The sliding bearing according to claim 2, wherein, The sliding layer (3) is flush with or higher than the groove.

20. The sliding bearing according to claim 1 or 2, wherein, The sliding bearing has a planar structure.

21. A transmission device comprising a shaft, a gear supported on the shaft, and a sliding bearing according to any one of claims 1 to 19, wherein, The base layer (1) is provided by the shaft, the support layer (2) and the sliding layer (3) are sequentially disposed on the outer surface of the shaft, and the gear is supported on the sliding layer (3).

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