CN219712065U

CN219712065U - Sliding bearing and transmission device

Info

Publication number: CN219712065U
Application number: CN202223610887.5U
Authority: CN
Inventors: 张国强; 郑青春; 龚颖; 倪志伟
Original assignee: COB PRECISION PARTS Inc
Current assignee: COB PRECISION PARTS Inc
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-09-19
Anticipated expiration: 2032-12-29

Abstract

The present utility model provides a slide bearing and a transmission device, the slide bearing comprising: a base layer; the support layer is positioned on the base layer; and the sliding layer is positioned on the supporting layer, wherein the hardness gradient is gradually decreased from the base layer to the supporting layer. The sliding bearing is a multi-layer sliding bearing, and the layers are metallurgically bonded to form an integrated sliding bearing, so that the use of nonferrous metals is saved, and the bearing cost is obviously reduced; the bonding strength between each layer is stronger, and the risk of falling off of the sliding layer and the matrix shaft does not exist. The middle supporting layer arranged between the base layer and the sliding layer can be used as a blocking layer, so that the diffusion of elements of the base layer to the sliding layer is blocked or reduced, and the wear resistance of the sliding layer is ensured; the hardness gradient between the layers allows the support layer to provide flexible support for the sliding layer, and particularly reduces wear of the sliding layer under high loads, thereby extending the life of the sliding bearing.

Description

Sliding bearing and transmission device

Technical Field

The present utility model relates to a sliding bearing, in particular for a gearbox of a wind power plant.

The utility model also relates to a transmission, in particular a planetary gear, comprising the sliding bearing.

Background

In sliding friction devices (e.g., sliding bearings), aluminum alloys and copper alloys are widely used as wear-resistant materials. For sliding bearings, a blank is usually made by continuous casting or centrifugal casting, and then turned into a finished sleeve. Casting defects are often generated by adopting a casting mode, so that a method for increasing the processing amount is generally adopted; moreover, the energy consumption of casting is high, and the environmental pollution is also high. In addition, the material costs are also high for large-sized bushings or bushes.

Because the copper alloy and the aluminum alloy have low hardness and insufficient rigidity, the bearing load bearing performance is difficult to ensure under the working condition of heavy load and high-speed service. A preferred mode is to sinter, roll, clad or build up weld on the steel substrate, so that good wear resistance is achieved while sufficient bearing capacity is ensured, a large amount of nonferrous metals are saved, and cost is reduced.

CN108787809B discloses a rolled bearing with a welded seam, which is formed by sintering a steel back and an alloy layer, and the open seam of the rolled bearing is welded to form a closed bearing, and is sleeved on the shaft by hot pressing. There is a risk of weld failure and delamination of the slide bearing under high load long term operation.

Disclosure of Invention

The utility model aims to provide a sliding bearing which is easy to maintain, high in wear resistance and long in service life. Accordingly, another object of the present utility model is to provide a transmission, in particular a planetary gear transmission, comprising a sliding bearing as described above, which transmission is particularly applicable to wind power plants (e.g. gearboxes of wind power plants).

According to an aspect of the present utility model, there is provided a sliding bearing comprising: a base layer; a support layer, the support layer being located on the base layer; and the sliding layer is positioned on the supporting layer, and the hardness gradient is gradually decreased from the base layer, the supporting layer to the sliding layer.

In one embodiment, the base layer is formed with a groove, and the support layer and the sliding layer are sequentially disposed in the groove.

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.

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.

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, nickel and nickel-based alloys.

In one embodiment, the sliding bearing further comprises a running-in layer on the sliding layer, the running-in layer being formed of a polymeric material.

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

In one embodiment, the sliding bearing is a planar structure.

According to another aspect of the present utility model, there is provided a sliding bearing comprising: a base layer; a support layer, the support layer being located on the base layer; the sliding layer is positioned on the supporting layer, wherein a groove is formed in the base layer, and the supporting layer and the sliding layer are sequentially arranged in the groove.

In one embodiment, the gradient of hardness decreases from the base layer, the support layer, and the sliding layer in sequence.

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

According to a further aspect of the present utility model there is provided a transmission comprising a shaft, a gear supported on the shaft and a slide bearing as described above, wherein the base layer is provided by the shaft, the support layer and the slide layer being in turn provided on an outer surface of the shaft, the gear being supported on the slide layer.

The sliding bearing is a multi-layer sliding bearing, and the layers are metallurgically bonded to form an integrated sliding bearing, so that the use of nonferrous metals is saved, and the bearing cost is obviously reduced; the bonding strength between each layer is stronger, and the risk of falling off of the sliding layer and the matrix shaft does not exist. The middle supporting layer arranged between the base layer and the sliding layer can be used as a blocking layer, so that the diffusion of elements of the base layer to the sliding layer is blocked or reduced, and the wear resistance of the sliding layer is ensured; the hardness gradient between the layers allows the support layer to provide flexible support for the sliding layer, and particularly reduces wear of the sliding layer under high loads, thereby extending the life of the sliding bearing.

In addition, by disposing the support layer and the sliding layer in the grooves formed in the base layer, it is possible to further save materials, save processing steps, reduce material costs and manufacturing costs and increase the bonding strength between the respective layers of the sliding bearing, thereby increasing the structural strength of the sliding bearing itself as well as the service life and wear resistance.

Drawings

For a better understanding of the above and other objects, features, advantages and functions of the present utility model, reference should be made to the preferred embodiments illustrated in the accompanying drawings. Like reference numerals refer to like parts throughout the drawings. It will be appreciated by persons skilled in the art that the drawings are intended to schematically illustrate preferred embodiments of the utility model, and that the scope of the utility model is not limited in any way by the drawings, and that the various components are not drawn to scale.

Fig. 1 is a side sectional view of a sliding bearing according to an embodiment of the present utility model.

Fig. 2 is a side sectional view of a sliding bearing according to another embodiment of the present utility model.

Detailed Description

Specific embodiments of the present utility model will now be described in detail with reference to the accompanying drawings. What has been described herein is merely a preferred embodiment according to the present utility model, and other ways of implementing the utility model will occur to those skilled in the art on the basis of the preferred embodiment, and are within the scope of the utility model.

The sliding bearing and the corresponding transmission device of the present utility model are described herein by way of example in relation to a wind power plant, i.e. the sliding bearing and the transmission device may be applied to a wind power plant (e.g. a gearbox of a wind power plant), but are not limited thereto, but may also be applied to other industries and applicable machine equipment (e.g. automobiles, ships, aircraft etc. and their transmissions, gearboxes or any parts requiring sliding friction etc.).

As for the transmission devices such as gearboxes of wind power plants, planetary gear transmission devices are taken as an example, which comprise sun gears, planet carriers, drive shafts, support shafts, etc., which are also known in principle from the prior art and are therefore not described in detail here. The sliding bearing and its related structure will be described with emphasis.

In some conventional technologies, the integral copper sleeve sliding bearing is fixed on the shaft in a mechanical mode, the copper sleeve is usually manufactured in a casting mode, the machining allowance of a copper sleeve blank is large, and the copper sleeve body is large in copper consumption. In contrast, the metal-based multilayer composite bearing provided by the utility model saves the use amount of copper, thereby obviously reducing the material cost of the sliding bearing shaft sleeve, and has the characteristics of saving materials and cost, saving energy and protecting environment.

Fig. 1 shows a partial view of a sliding bearing between a gear wheel and a shaft 1 of a wind power plant in a side view in section. The gears are, for example, planetary gears and are supported on the shaft 1 by means of plain bearings. For this purpose, a sliding bearing is provided on the shaft 1 between the inner bore of the gear and the shaft 1, which is a multi-layer bearing and comprises a base layer 1, a support layer 2 and a sliding layer 3. Wherein the base layer is provided by the shaft 1, i.e. the shaft 1 itself serves both as a base support for the plain bearing, while the outer layer surface (which may also be referred to as skin layer) of the shaft 1 also serves as part of the plain bearing (i.e. the base layer 1 of the plain bearing); that is, the surface layer of the shaft 1 serves as a base support layer of the slide bearing, and thus the shaft 1 may also be referred to as a base shaft. The support layer 2 and the sliding layer 3 are sequentially applied on the base shaft 1 in the radial direction from inside to outside, and since the support layer 2 is located between the base layer 1 and the sliding layer 3, the support layer 2 may also be referred to as an intermediate support layer 2; the sliding layer 3 is located at the radially outermost layer, constituting the sliding surface of the bearing, and the sliding layer 3 is therefore also referred to as surface sliding layer 3. The support layer 2 is applied directly to the substrate shaft 1 (or the base layer 1), and the sliding layer 3 is applied directly to the support layer 2, whereby the support layer 2 and the sliding layer 3 form a multi-layer sliding bearing with the shaft 1.

For the support layer 2 and the sliding layer 3, the term "applying" means that the support layer 2 is bonded to the base shaft 1 (or the base layer 1) and further the sliding layer 3 is bonded to the upper support layer 2 using various methods. These application methods or bonding methods include electroplating, spraying, powder metallurgy, casting, cladding, laser welding, build-up welding, and the like, as well as other suitable application methods. Wherein spraying includes, but is not limited to, air spraying, airless spraying, high pressure spraying, electrostatic spraying, arc spraying, flame spraying, plasma spraying, explosion spraying, etc., such as, but not limited to, atomized spraying, thermal spraying, automated spraying, multiple sets of spraying, etc. The base layer 1, the support layer 2 and the sliding layer 3 form a unitary or one-piece sliding bearing via the above-described application method; the integral or unitary sliding bearing herein refers to 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 mechanical bonding or mechanical assembly as in conventional techniques.

The advantage of forming the integrated sliding bearing by metallurgical bonding is that the base layer 1 and the supporting layer 2 and the sliding layer 3 have stronger bonding strength, and the layers together form a single part (namely the integrated and seamless multi-layer sliding bearing), thereby omitting the assembly of the shaft sleeve and the shaft in the conventional technology, further saving the installation time, and greatly reducing the time cost and the labor cost of the assembly. That is, the sliding bearing provided by the present utility model is composed of the base shaft 1, the supporting layer 2 and the sliding layer 3 (i.e., the supporting layer 2 and the sliding layer 3 are sequentially applied on the shaft 1), is a multi-layer integral sliding bearing, saves the use of precious metals (e.g., nonferrous metals) compared with the conventional way of thermally sleeving the integral copper shaft sleeve on the shaft, and significantly reduces the cost of the bearing, for example, the sliding layer uses less nonferrous metals (e.g., copper) compared with the amount of copper used in the conventional integral copper shaft sleeve. The bearing and the matrix shaft are integrated, the risk that the sliding layer and the matrix shaft fall off is avoided, and the anti-fatigue and anti-creep performance is excellent.

It is noted that the above-described application method or bonding method is only exemplary and not limiting, and that a person skilled in the art may apply the support layer 2 and the sliding layer 3 by other suitable methods, as long as a metallurgical bond between the base layer 1, the support layer 2 and the sliding layer 3 is achieved to form a monolithic multilayer sliding bearing.

The material and dimensions of the shaft 1 are not particularly limited and may be selected according to the particular engineering application. For example, the shaft 1 may be made of steel, so that the shaft 1 may be a steel shaft as is well known in the art, and the length and outer diameter thereof may be sufficient to meet the dimensional requirements of the desired finished bearing. For example, the material of the steel shaft 1 is selected from the following group of materials: 20CrMnTi, 20CrMnMo, 18CrNiMo7-6, 34CrNiMo6, 45# steel, 40Cr, 40CrMo, 42CrMoA, etc. For example, the outer diameter of the shaft 1 may range from 100mm to 800mm, preferably from 200mm to 500mm, by way of example only, and may be selected to have other suitable dimensions depending on the actual engineering needs.

Further, the characteristics of the shaft 1 such as hardness and strength are not particularly limited. For example, the hardness of the shaft 1 may be 20HRC to 40HRC, preferably 25HRC to 35HRC, such as 20HRC, 25HRC, 26HRC, 27HRC, 28HRC, 29HRC, 30HRC, 31HRC, 32HRC, 33HRC, 34HRC, 35HRC, 36HRC, 37HRC, 38HRC, 39HRC, 40HRC or any other suitable value, such as HB280. In addition, the surface roughness of the outer circumferential surface of the shaft 1 is, for example, ra 1.6 μm to 12.5 μm, so that the support layer 2 is applied on the shaft 1, for example, the roughness may 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.

It is pointed out that the specific choices and values of the above-mentioned materials, dimensions, surface roughness and hardness of the shaft 1 are only examples and are not limiting, and that a person skilled in the art can flexibly choose, change and adjust them according to the specific engineering application.

The material and dimensions of the support layer 2 are not particularly limited and may be selected according to the specific engineering application. For example, the material of the support layer 2 may be selected from the group consisting of aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, and copper alloys may be preferably selected, more preferably, cuAl alloys, cuSn alloys, cuSi alloys, cuMn alloys, cuZn alloys, cuCr alloys, or CuNi alloys, for example.

For example, the support layer 2 may employ a CuAl alloy, and the CuAl alloy has the following mass percent (or weight percent) content: 6 to 15 percent of Al, 0 to 7.5 percent of Fe, 0 to 8.5 percent of Ni, 0 to 10.0 percent of Mn, 0 to 2.0 percent of Zn and the balance of Cu.

For example, the support layer 2 may employ a CuSn alloy, and the CuSn alloy has the following mass percent (or weight percent) content: 4 to 25% of Sn, 0 to 5% of Ni, 0 to 0.6% of P, 0 to 1.0% of Zn, 0 to 10% of Fe and the balance of Cu.

For example, the support layer 2 may employ a CuSi alloy, and the CuSi alloy has the following mass percent (or weight percent) content: 1.0 to 6.0% of Si, 0 to 4.0% of Mn, 0 to 0.5% of P, 0 to 10% of Fe, 0 to 12% of Zn and the balance of Cu.

For example, the support layer 2 may employ a CuMn alloy, and the CuMn alloy has the following mass percent (or weight percent) content: mn 6.0% to 16.0%, al 5% to 12%, ni 0% to 6%, fe 0% to 10%, and the balance Cu.

For example, the support layer 2 may employ a CuZn alloy, and the CuZn alloy has the following mass percent (or weight percent) content: 5.0 to 50.0% of Zn, 0 to 15.0% of Al, 0 to 10.0% of Mn, 0 to 5.0% of As, 0 to 5.0% of Sb, 0 to 10.0% of Si, 0 to 25.0% of Ni, 0 to 5.0% of Pb, 0 to 5.0% of Fe, 0 to 5.0% of Sn, and the balance of Cu.

For example, the support layer 2 may employ a CuCr alloy, and the CuCr alloy has the following mass percent (or weight percent) 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.

For example, the support layer 2 may employ a CuNi alloy, and the CuNi alloy has the following mass percent (or weight percent) content: 0.1 to 45.0% of Ni, 0 to 5.0% of Fe, 0 to 5.0% of Zn, 0 to 5.0% of Mn, 0 to 5.0% of Cr, 0 to 5.0% of Si, 0 to 5.0% of Nb, and the balance of Cu.

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

The material and dimensions of the sliding layer 3 are also not particularly limited and may be selected according to the specific engineering application. For example, the material of the sliding layer 3 may be selected from the group consisting of aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, and copper alloys and aluminum alloys may be preferably selected.

For example, the sliding layer 3 may employ a CuSn alloy having the following mass percent (or weight percent) content: 6 to 15% of Sn, 0.05 to 0.5% of P, 0 to 0.5% of Zn, 0 to 5% of Fe and the balance of Cu. More preferably, the CuSn alloy has the following mass percent (or weight percent) content: 9 to 14% of Sn, 0 to 3.0% of Ni, 0.05 to 0.5% of P, 0 to 0.5% of Zn, 0 to 4% of Fe and the balance of Cu.

For example, the sliding layer 3 may contain Al, sn, cu, and other alloy elements, and have the following mass percent (or weight percent) contents: 5 to 35% of Sn, 0.5 to 2.0% of Cu, 0 to 1.5% of Ni, 0 to 4% of Fe and the balance of Al. And the sliding layer 3 also preferably has the following mass percent (or weight percent) content: 10 to 25% of Sn, 0.5 to 1.5% of Cu, 0 to 0.5% of Ni and the balance of Al.

In addition, the above-mentioned material composition of the supporting layer 2 (i.e., the weight percentages of the various copper alloys and the material contents thereof selected for the supporting layer 2) is also applicable to the sliding layer 3, and will not be described herein.

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

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

It should be noted that the specific choice and values of dimensions of the above-mentioned materials, thicknesses, etc. of the support layer 2 and the sliding layer 3 are merely examples and are not limiting, and that they can be flexibly chosen, altered and adapted by a person skilled in the art according to the specific engineering application.

In addition, the supporting layer 2 is disposed between the base shaft 1 and the sliding layer 3, and may serve as a blocking layer, blocking or reducing diffusion of elements of the base shaft 1 into the sliding layer 3, for example, reducing diffusion of steel elements of the steel shaft 1 into the sliding layer 3, ensuring integrity of chemical components of the sliding layer 3, so that the sliding layer 3 is not diffused and disturbed by elements of the base shaft 1, and further ensuring characteristics of the sliding layer 3, for example, maintaining wear resistance of the sliding layer 3.

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

Further, the bonding strength of the sliding layer 3 to the supporting layer 2 may be greater than 150MPa, more preferably may be greater than 170MPa, even more preferably may be greater than 200MPa, for example 160MPa, 170MPa, 180MPa, 190MPa, 200MPa, 210MPa, 220MPa, 230MPa, 240MPa, 250MPa or more or any other suitable value.

Furthermore, in the sliding bearing, there is a decreasing hardness gradient between the layers, i.e. the hardness of the base shaft 1 (or base layer 1) is greatest; secondly, the hardness of the support layer 2 is smaller than that of the base shaft 1 (or the base layer 1); again, the hardness of the sliding layer 3 is smaller than the hardness of the supporting layer 2.

For example, the hardness of the support layer 2 may be 20% to 90%, more preferably 35% to 90%, 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 of the hardness of the substrate shaft 1 (or the base layer 1) based on the hardness of the substrate shaft 1 as a reference. Further, the hardness of the sliding layer 3 may be 15% to 90%, 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 of the hardness of the supporting layer 2.

Whereas, as described above, the hardness of the base shaft 1 (or the base layer 1) may be 20HRC to 40HRC, preferably 25HRC to 35HRC; accordingly, the hardness of the support layer 2 and the sliding layer 3 can be calculated accordingly, according to the decreasing proportion of the hardness gradient and the specific values described above, and are not specifically calculated here. It should be noted that the hardness of the various layers described herein may be a single specific hardness value or may be a range of hardness values. For example, the hardness of the sliding layer 3 may be 15% to 90% of the hardness of the supporting layer 2, where the hardness of the supporting layer 2 may be a specific hardness value, for example, the hardness of the supporting layer 2 may be 18HRC, and the hardness of the sliding layer 3 may be 2.7HRC to 16.2HRC (i.e., 15% to 90% of 18 HRC). In actual mass production, the hardness of each layer may have a certain machining tolerance or the hardness of each layer may vary over a range, for example, the hardness of the support layer 2 may fluctuate over a range of 15 to 18HRC, and the hardness of the sliding layer 3 may be 2.25HRC to 16.2HRC (i.e., over a range of 15% to 90% of 15HRC to 18 HRC), that is, the hardness of the support layer 2 fluctuates over a range, and the hardness of the sliding layer 3 in turn varies over a certain proportion of the hardness of the support layer 2.

In a sliding bearing, the advantage of having a decreasing hardness gradient between the layers is that a buffer gradient is provided between the layers. For example, the outermost sliding layer 3 has a softer hardness, which serves as a sliding surface and a friction surface for sliding friction with a harder engaging member (for example, the above-described gear); the intermediate support layer 2 serves to support the sliding layer 3 and thus has a relatively high hardness, which is soft and thus cannot effectively support the sliding layer 3, and which is too high in hardness and thus is disadvantageous for long-term sliding friction of the sliding layer 3, so that the force transmission between the outermost sliding layer 3 and the base layer 1 generates a direct impact, especially in the case of high loads. That is, the intermediate support layer 2 is provided such that a buffer is provided between the softer sliding layer 3 and the harder base layer 1 to absorb energy of the sliding layer 3 during sliding friction, so that the support layer 2 further buffers the sliding layer 3 when the sliding layer 3 is pressed like a damper spring and generates a repulsive force to the sliding layer 3, avoiding direct transmission of the force of the sliding layer 3 to the base layer 1. If the intermediate support layer 2 is not provided, the force of the sliding layer 3 acts directly on the harder base layer 1 without any damping, so that the sliding layer 3 is always forced to wear directly with prolonged sliding friction. In contrast, the hardness setting of the support layer 2 and the hardness gradient between the 3 layers allow the support layer 2 to provide flexible support for the sliding layer 3, and in particular to reduce wear of the sliding layer 3 at high loads, thereby extending the life of the sliding bearing.

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

The hardness gradient may be achieved by the choice of the respective materials of the respective layers, for example, if the base layer 1 is composed of a first material and the material, the base layer 1 is directly made of the choice of the material to obtain the first hardness or hardness range directly upon application of the material to form the base layer 1; similarly, if the support layer 2 is of a second material and material composition, the support layer 2 directly obtains a second hardness or hardness range directly through the choice of the material; if the sliding layer 3 is made of a third material and the material composition, the sliding layer 3 directly obtains a third hardness or hardness range directly through the choice of the material.

Alternatively and additionally, the hardness gradient may also be obtained indirectly by heat treating the individual layers. The heat treatment may include various methods employed in the art, such as bulk heat treatment including, for example, annealing, normalizing, quenching, tempering, heat treatment, surface heat treatment including, for example, case hardening and chemical heat treatment, and other common and commonly used heat treatment methods, such that the individual layers achieve the desired hardness or hardness range.

It is noted that the two above-described methods of obtaining the hardness gradient may be implemented separately for each layer or may be combined as long as the desired hardness or hardness range can be obtained. For example, the base layer 1 may be obtained by the selection of materials alone, or the first hardness or hardness range may be obtained indirectly by the heat treatment alone when the base layer 1 is formed by applying materials, or the first hardness or hardness range may be obtained by a combination of the selection of materials and the heat treatment. Similarly, the hardness or hardness range of the support layer 2 may be obtained directly after the support layer 2 is formed by applying the selected material, or may be obtained by further heat treatment after the support layer 2 is formed by applying the material. Similarly, the hardness or hardness range of the sliding layer 3 may be obtained directly after the sliding layer 3 is formed by applying the selected material, or may be obtained by further heat treatment after the sliding layer 3 is formed by applying the material.

For example, the base layer 1 is a steel shaft, and the material itself has high hardness; the support layer 2 and the sliding layer 3 may be selected from aluminium-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, some of which have a relatively small hardness with respect to the steel shaft, for example, when the support layer 2 and the sliding layer 3 are made of copper alloys, the two layers directly obtain a relatively soft hardness. It should be noted that the supporting layer 2 and the sliding layer 3 are both selected from aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, but the specific material composition of the two is different to produce different layers and different hardness. For example, the support layer 2 and the sliding layer 3 may be selected from different specific material compositions and/or the same heat treatment to obtain different hardness; or the supporting layer 2 and the sliding layer 3 can be selected from different specific material compositions and/or different heat treatments to obtain different hardness; or in extreme cases, the supporting layer 2 and the sliding layer 3 may be made of the same specific material composition and may be subjected to different heat treatments, and may also have different hardness.

Furthermore, in a sliding bearing, the individual layers have a decreasing iron (Fe) content (weight% or wt.%) between them or the Fe content has a decreasing composition gradient between them, i.e. the iron (Fe) content of the base shaft 1 (or base layer 1) is greatest; secondly, the Fe content of the support layer 2 is smaller than that of the substrate shaft 1 (or the base layer 1); again, the Fe content of the sliding layer 3 is smaller than the Fe content of the supporting layer 2. It should be noted here that the materials used for the support layer 2 and the sliding layer 3 described above refer to the materials before the support layer 2 and the sliding layer 3 are applied, and the mass percentages of the respective elements in the alloy materials listed above refer to the mass percentages of the materials before they are applied. While the decreasing iron (Fe) content between the various layers described herein refers to the Fe content contained by the various layers after formation (i.e., after application of the material).

This is because, upon application (e.g., welding) of the support layer 2 to the shaft 1, a molten material interface is formed between the support layer 2 and the shaft 1, where a portion of the iron in the shaft 1 may melt or diffuse into the support layer 2 through the material interface therebetween; similarly, when the sliding layer 3 is applied to the supporting layer 2, a molten material interface is formed between the sliding layer 3 and the supporting layer 2, and a portion of the iron in the supporting layer 2 may be melted or diffused into the sliding layer 3 through the material interface therebetween. Wherein the Fe content in the sliding layer 3 should be as small as possible because the sliding layer 3 acts as a sliding friction layer, wherein an increase in the Fe component adversely affects the wear resistance of the sliding layer 3. For example, the substrate shaft 1 (or the base layer 1) may be made of steel, i.e. the Fe content is very high, so that when the support layer 2 is applied, a part of the iron melts into or diffuses into the support layer 2; the support layer 2 is selected from the group consisting of aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, and the like, and the Fe content of these alloys is relatively small in itself, and a portion of the iron in the support layer 2 melts into or diffuses into the sliding layer 3 when the sliding layer 3 is applied. In contrast, the Fe content melted into or diffused into the sliding layer 3 from the support layer 2 is much smaller than the Fe content diffused into the support layer 2 from the substrate axis 1. Further, the supporting layer 2 and the sliding layer 3 are selected from aluminum-based alloy, tin-based alloy, copper and copper-based alloy, nickel and nickel-based alloy, and the like, and the content of Fe in the materials is relatively small; further, the Fe content additionally diffused into the support layer 2 and the sliding layer 3 is considered, so that after molding, the Fe content in the sliding layer 3 is smaller than that of the support layer 2.

For example, the Fe content of the support layer 2 may be 5% or less, preferably 4% or less, 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 of values by weight. The Fe content of the sliding layer 3 is 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 of values. The support layer 2 may be made of a material having a relatively high Fe content, and for example, the Fe content of the support layer 2 may be 90% or less, for example 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or any other value or range of values. In summary, whatever material is used for the support layer 2 and the sliding layer 3 (including, but not limited to, aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, and any other suitable material), it is within the scope of the present disclosure that the Fe content of the support layer 2 is less than the Fe content of the base shaft 1 and that the Fe content of the sliding layer 3 is less than the Fe content of the support layer 2.

In addition, in practice, it is relatively important that the Fe content of the sliding layer 3 should be as small as possible because, as the outermost sliding friction layer, the increase in Fe component therein adversely affects the wear resistance of the sliding layer 3, so that in alternative embodiments, the Fe content of the sliding layer 3 may be of great concern such 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%, e.g., 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.

In summary, it can be seen that the support layer 2 itself can serve both as a barrier layer to block diffusion of harmful elements in the shaft 1 into the sliding layer 3 and as a buffer layer and support layer between the base layer 1 and the sliding layer 3. In particular, the material of the support layer 2 may be selected from the group consisting of aluminum-based alloys, tin-based alloys, copper and copper-based alloys, nickel and nickel-based alloys, and copper alloys may be preferably selected, which alloys contain less Fe on the one hand, thereby reducing the diffusion of Fe into the sliding layer 3, and on the other hand, the support layer 2 formed of these alloys provides a hardness gradient between the base layer 1 and the sliding layer 3, thereby achieving a cushioning and supporting effect of the support layer 2.

A transmission including the sliding bearing and a method of manufacturing the same are described below. The transmission device comprises a shaft 1, a gear supported on the shaft 1, a supporting layer 2 and a sliding layer 3 arranged between the shaft 1 and the gear, wherein the shaft 1 is the base layer 1, the supporting layer 2 is applied on the outer surface of the shaft 1, and the sliding layer 3 is applied on the supporting layer 2.

The method of manufacturing the shaft 1 of the transmission comprises the steps of:

(1) Providing a shaft 1, and machining the shaft 1 to have a predetermined length, outer diameter and surface roughness;

(2) Optionally, cleaning the surface of the shaft 1;

(3) Applying the material of the support layer 2 to the surface of the shaft 1 to form the support layer 2;

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

(5) Applying the material of the sliding layer 3 on the support layer 2 to form the sliding layer 3;

(6) The sliding layer 3 is processed.

In step (1), preferably the shaft 1 is a round steel or forged steel round billet and the billet is machined to a predetermined length and outer diameter, wherein the predetermined outer diameter is 0.1 to 5.5mm smaller than the outer diameter of the finished shaft, such as 1.5mm, 2.0mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm or any other suitable value, which is aimed at leaving a predetermined dimensional space for the support layer 2 and the sliding layer 3 applied on the shaft 1; the finished shaft refers to the shaft after the support layer 2 and the sliding layer 3 are applied. After the finished shaft has been formed, the gear is supported on the shaft 1. The term "machining" may include machining or any other suitable manufacturing method as long as the corresponding parameters, such as length, outer diameter and surface roughness, thickness, can be achieved. The dimensions (e.g. length and outer diameter etc.), materials and hardness of the shaft 1 are not particularly limited and may be selected as described above,

It is to be noted that the base layer 1 may be provided by the shaft 1, and the support layer 2 and the sliding layer 3 of the sliding bearing are applied on the outer surface of the shaft 1 such that the support layer 2 and the sliding layer 3 are formed around the shaft 1 to be formed in a cylindrical shape or a ring shape, but is not limited thereto. The sliding bearing may have other shapes, for example, the sliding bearing may have a multi-layer planar structure, that is, only includes a planar base layer 1, a planar support layer 2, and a planar sliding layer 3, which are laminated in order; alternatively, for example, the sliding bearing may be a cylindrical structure such as a conventional bush-type sliding bearing including a bush in which a journal of a shaft is supported, the base layer 1 may be provided by an inner peripheral surface of the bush, and the supporting layer 2 and the sliding layer 3 may be applied in a ring-cylindrical shape in order on the inner peripheral surface of the bush, in which case, when the shaft is supported in the sliding bearing, an outer peripheral surface of the shaft is in contact with the sliding layer 3, with sliding friction therebetween.

The term "apply" is not particularly limited and various methods described above may be employed, for example, as long as the corresponding parameters such as bonding strength, hardness can be achieved.

In the embodiment of the shaft 1 shown in the figures and described above as a basic layer, in the formed slide bearing the slide bearing is provided with a lubrication medium (e.g. lubricant, lubricating oil) conveying structure, which is a bore or a groove. In a preferred embodiment, an axial bore and a radial bore are provided in the shaft 1, the lubricant being fed in from the axial bore of the shaft end face, the lubricant being fed via the axial bore to the axial sections and then via the radial bore into the region of the sliding surface of the sliding bearing, the lubricant then being distributed from this region over the entire sliding surface. The axial bores are preferably distributed over an axial plurality of sections, which sections are each provided with radial through bore communication.

In a variant embodiment, the sliding layers may be applied in sections spaced apart from each other along the axial direction of the shaft. Here, it is advantageous that the axial gap between the sliding layer and the sliding layer may form a natural oil groove, in which radial holes are provided, communicating with the axial holes to form lubrication channels, so that better lubrication of the sliding layer may be achieved. Wherein the width of the oil groove is larger than the diameter of the radial hole.

In view of the above-described lubrication medium conveying structure, the manufacturing process of the sliding bearing and the shaft 1 is: (1) machining the shaft 1; (2) applying a support layer 2 on the shaft 1; (3) applying a sliding layer 3 on the support layer 2; (4) processing oil outlet holes or oil grooves on the shaft 1; (5) working the end face and the outer peripheral face of the shaft 1.

In another variant embodiment, a running-in layer may be provided on the sliding layer 3. In this case, the running-in layer constitutes the outermost layer of the sliding bearing, and is used as a sliding friction layer in place of the sliding layer 3 or in combination with the sliding layer 3 to perform sliding friction with an external member. For example, the gear may be disposed on the running-in layer while sliding on the running-in layer. The provision of the running-in layer improves the friction properties of the sliding bearing.

The running-in layer is preferably a polymer material, and the polymer material comprises resin and an additive. The resin is at least one of polyamide, polyurethane, polyester, polyphenylene sulfide, fluorine-containing polymer, polyether-ether-ketone, polyimide resin, alkyd resin, polyacrylate, epoxy resin, phenolic resin and organic silicon resin, and the additive is at least one of graphite, carbon nano tube, polytetrafluoroethylene, ultra-high molecular weight polyethylene, molybdenum disulfide, tungsten disulfide, zinc sulfide, calcium fluoride, boron nitride, metallic lead, metallic silver, metallic bismuth and metallic tin.

The sliding bearing of the present utility model is described below by way of example.

Example 1:

the shaft 1 is made of 40Cr material, and the hardness is HRC32. The shaft 1 was first machined to a predetermined length as required, and then the outer diameter was machined to a size 1.5mm smaller than the finished shaft, with a surface roughness of Ra3.2μm. The supporting layer 2 was made of CuZn25Al5Mn4Fe3 material, which was applied on the outer circumferential surface of the shaft 1, and the Fe content in the supporting layer 2 formed was 4.5wt.%. The hardness of the supporting layer 2 was HB180, the thickness was 1.0mm, and the bonding strength of the supporting layer 2 to the shaft 1 was 260MPa. After the support layer 2 was formed, the sliding layer 3 was directly applied to the surface thereof, the sliding layer 3 was made of CuSn10, and the material was applied to the outer peripheral surface of the support layer 2, and the content of Fe in the sliding layer 3 formed was 0.2wt.%. The hardness of the sliding layer 3 was HB90, and the thickness was 1.0mm. The sliding layer 3 was then machined to a thickness of 0.5mm, thereby forming a unitary sliding bearing. An oil passage (e.g., an oil hole or an oil groove) communicating with the sliding layer 3 and the supporting layer 2 and each other is formed in the shaft 1 for lubrication of the sliding layer 3.

Example 2:

the shaft 1 is made of 40Cr material, and the hardness is HRC32. The shaft 1 was first machined to a predetermined length as required, and then the outer diameter was machined to a size smaller than the finished shaft by 2.0mm, with a surface roughness of Ra3.2μm. The supporting layer 2 was made of CuAl10Fe5Ni5 material, which was applied on the outer circumferential surface of the shaft 1, and the Fe content in the supporting layer 2 formed was 5.0wt.%. The hardness of the supporting layer 2 was HB170, the thickness was 1.0mm, and the bonding strength of the supporting layer 2 to the shaft 1 was 230MPa. After the support layer 2 was formed, the sliding layer 3 was directly applied to the surface thereof, the sliding layer 3 was made of CuSn10, and the material was applied to the outer peripheral surface of the support layer 2, and the content of Fe in the sliding layer 3 formed was 0.25wt.%. The hardness of the sliding layer 3 was HB90, and the thickness was 1.5mm. The sliding layer 3 was then machined to a thickness of 1.0mm, thereby forming a unitary sliding bearing. An oil passage (e.g., an oil hole or an oil groove) communicating with the sliding layer 3 and the supporting layer 2 and each other is formed in the shaft 1 for lubrication of the sliding layer 3.

Example 3:

the shaft 1 was made of 42CrMoA material and had a hardness of HB280. The shaft 1 was first machined to a predetermined length as required, and then the outer diameter was machined to a size smaller than the finished shaft by 2.5mm, with a surface roughness of Ra3.2μm. The supporting layer 2 was made of CuAl10Fe5Ni5 material, which was applied on the outer circumferential surface of the shaft 1, and the Fe content in the supporting layer 2 formed was 4.5wt.%. The hardness of the support layer 2 was HB170, and the thickness was 2.0mm. The bonding strength of the support layer 2 to the shaft 1 was 250MPa. After the support layer 2 was formed, the sliding layer 3 was directly applied to the surface thereof, the sliding layer 3 was made of CuSn12Ni2, and the material was applied to the outer peripheral surface of the support layer 2, and the content of Fe in the sliding layer 3 formed was 0.3wt.%. The hardness of the sliding layer 3 was HB120, and the thickness was 1.0mm. The sliding layer 3 was then machined to a thickness of 0.5mm, thereby forming a unitary sliding bearing. An oil passage (e.g., an oil hole or an oil groove) communicating with the sliding layer 3 and the supporting layer 2 and each other is formed in the shaft 1 for lubrication of the sliding layer 3.

Example 4:

the shaft 1 was made of 42CrMoA material and had a hardness of HB280. The shaft 1 was first machined to a predetermined length as required, and then the outer diameter was machined to a size smaller than the finished shaft by 2.5mm, with a surface roughness of Ra6.4μm. The support layer 2 was made of CuSn12Ni2 material, which was applied on the outer circumferential surface of the shaft 1, and the Fe content in the support layer 2 formed was 3.0wt.%. The hardness of the support layer 2 was HB120, and the thickness was 2.0mm. The bonding strength of the support layer 2 to the shaft 1 was 200MPa. After the support layer 2 was formed, the sliding layer 3 was directly applied to the surface thereof, the sliding layer 3 was made of AlSn20Cu, and the material was applied to the outer peripheral surface of the support layer 2, and the content of Fe in the sliding layer 3 formed was 0.2wt.%. The hardness of the sliding layer 3 was HB40, and the thickness was 1.0mm. The sliding layer 3 was then machined to a thickness of 0.5mm, thereby forming a unitary sliding bearing. An oil passage (e.g., an oil hole or an oil groove) communicating with the sliding layer 3 and the supporting layer 2 and each other is formed in the shaft 1 for lubrication of the sliding layer 3.

Example 5:

the shaft 1 was made of 42CrMoA material and had a hardness of HB280. The shaft 1 was first machined to a predetermined length as required, and then the outer diameter was machined to a size smaller than the finished shaft by 2.5mm, with a surface roughness of Ra6.4μm. The supporting layer 2 was made of CuAl9 material, which was applied on the outer circumferential surface of the shaft 1, and the Fe content in the supporting layer 2 was formed to be 2.5wt.%. The hardness of the support layer 2 was HB110, and the thickness was 2.0mm. The bonding strength of the support layer 2 to the shaft 1 was 190MPa. After the support layer 2 was formed, the sliding layer 3 was directly applied to the surface thereof, the sliding layer 3 was made of a babbitt alloy, and the material was applied to the outer peripheral surface of the support layer 2, and the content of Fe in the sliding layer 3 formed was 0.3wt.%. The hardness of the sliding layer 3 was HB25, and the thickness was 1.0mm. The sliding layer 3 was then machined to a thickness of 0.5mm, thereby forming a unitary sliding bearing. An oil passage (e.g., an oil hole or an oil groove) communicating with the sliding layer 3 and the supporting layer 2 and each other is formed in the shaft 1 for lubrication of the sliding layer 3.

It should be noted that the 5 examples described above are only a few examples and are not limiting. And the materials used in these examples, as well as other parameters (e.g., hardness, length, outer diameter, thickness, roughness, strength, fe content, etc.), are examples only and not limiting, and these materials and parameters may be interchanged with one another, combined. Of course, any other suitable materials and parameters may be selected and set by those skilled in the art.

Other examples and embodiments may be flexibly arranged and selected by those skilled in the art according to actual engineering needs and fall within the scope of the utility model.

The sliding bearing according to another embodiment of the present utility model will be described below with reference to fig. 2, and the difference between fig. 2 and fig. 1 is mainly that the specific structures of the base layer 1 and the support layer 2 and the sliding layer 3 are the same, that is, all the descriptions above with respect to fig. 1 are applicable to fig. 2, and will not be repeated here.

Fig. 2 shows that the base layer 1 has a groove in which the support layer 2 and the sliding layer 3 are disposed, and that the sliding layer 3 is flush with the outer surface of the base layer 1. The following description will be made taking the shaft 1 as an example of the base layer 1, but not limited thereto, the base layer 1 may be planar or plate-shaped, and the support layer 2 and the sliding layer 3 are also planar or plate-shaped and disposed in the groove of the base layer 1.

Specifically, the shaft 1 is recessed inward in the radial direction on the outer peripheral surface of its intermediate 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.

The process of forming the sliding bearing of fig. 2 is described below. Machining a concave annular groove in the middle section of the shaft 1, wherein the middle section is a section needing sliding friction with a matching component, and the matching component is a section sliding friction with the shaft 1, such as a gear; that is, an intermediate section is set on the shaft 1 according to the size of the fitting member and the section size of the fitting member with which the shaft 1 is slidably friction-fitted, and an annular groove is machined on the intermediate section. Wherein the depth of the annular groove is now greater than the final thickness after the formation of the support layer 2, less than the total thickness after the application of the support layer 2 and the sliding layer 3 and greater than the final total thickness after the formation of the support layer 2 and the sliding layer 3, the depth being set such that a machining allowance is left for the final formation of the support layer 2 and the sliding layer 3. In addition, the outer diameter of the shaft 1 is also larger than the outer diameter of the final molded finished shaft 1 at this time because the shaft 1 needs to be machined to a predetermined size together with the sliding layer 3 formed in the groove of the shaft after the sliding layer 3 is applied, and thus, a machining allowance needs to be set for the finished shaft at this time. As in the embodiment of fig. 1, this tooling allowance is not limited and can be reasonably set according to actual engineering needs.

After forming the grooves, the support layer 2 and the sliding layer 3 are sequentially applied into the grooves by the application method and process described above, as described above. It should be noted that in the present embodiment, only the supporting layer 2 and the sliding layer 3 need be applied to the grooves of the shaft section where sliding friction is required, and this embodiment saves materials, reduces material costs, and also reduces the machining process after application, compared to the embodiment of fig. 1 where the supporting layer 2 and the sliding layer 3 need be applied to the entire shaft/shaft partial portion. Further, as in the embodiment of fig. 1, when the support layer 2 and the sliding layer 3 are applied, the material thickness of the applied support layer 2 and the thickness of the finally formed support layer 2 may be the same without processing the formed support layer, or the material thickness of the applied support layer 2 may be greater than the thickness of the finally formed support layer 2, so that the support layer 2 is processed after being formed; the thickness of the material of the applied sliding layer 3 is larger than the thickness of the final shaped sliding layer 3, because after the material of the sliding layer 3 has been applied, it is necessary to machine the sliding layer 3, i.e. to remove a part of the sliding layer 3, so as to form the desired sliding surface roughness.

By providing the grooves, the support layer 2 and the sliding layer 3 can be kept in the grooves in molten liquid form after application, wherein the sliding layer 3 is, after application to the support layer 2 in the grooves, above and above the outer surface of the shaft 1. Due to the arrangement of the grooves, when the sliding layer 3 is applied, the molten sliding layer 3 flows only in the vicinity of the grooves and flows onto the shaft surface around the grooves without overflowing onto the end faces of the both ends of the shaft; in contrast, in one embodiment of fig. 1, since the supporting layer 2 and the sliding layer 3 are applied over the entire shaft 1, the melted liquid supporting layer 2 and the sliding layer 3 overflow on or near and around the end surfaces of both end portions of the shaft, thereby forming coating rounded corners at the end surfaces due to liquid tension, which cannot meet the requirements of actual engineering use due to non-uniformity of materials contained therein, etc., and need to be processed and removed.

After the sliding layer 3 is cured, since the machining allowance is reserved for the shaft 1 and the sliding layer 3 as described above, the shaft 1 and the sliding layer 3 are machined so that the sliding layer 3 is machined to a predetermined thickness while the shaft 1 is machined to a predetermined outer diameter size. It should be noted that in the present embodiment, the final machining and forming of the shaft 1 and the sliding layer 3 are performed simultaneously, that is, the shaft 1 and the sliding layer 3 are simultaneously machined to a finished product by only one machining pass or only one machining process; further, since the molten liquid of the sliding layer 3 flows only in the vicinity of the grooves in the present embodiment, it is not necessary to process both end surfaces of the shaft, but only the outer peripheral surface of the shaft 1.

In contrast, in the embodiment of fig. 1, it is necessary to first machine the shaft 1 to have a predetermined length, outer diameter, and surface roughness; then, after the support layer 2 and the sliding layer 3 are applied, the sliding layer 3 is processed to a predetermined thickness; furthermore, machining of both end faces of the shaft is required to remove the rounded corners. It follows that the embodiment of fig. 1 requires at least 3 machining steps to be performed at 3 different points in time, whereas the embodiment of fig. 2 requires only one machining step to simultaneously machine the shaft and the sliding layer 3 after the sliding layer 3 has been applied, e.g. machining the shaft to a predetermined outer diameter and surface roughness in a single machining step while machining the sliding layer 3 to a predetermined thickness and surface roughness, whereby it can be seen that the surface roughness of the finished shaft may be equal to the surface roughness of the sliding layer and that no additional machining of the two end faces of the shaft is required. In contrast, the embodiment of fig. 2 saves the number of machining processes and the amount of time, reducing machining and manufacturing costs.

Furthermore, in the embodiment of fig. 2, the circumferential annular groove in the shaft 1 has a bottom and two circumferential annular side walls or side surfaces, the shape of the groove functioning to receive the support layer 2 and the sliding layer 3 and to hold them firmly on the shaft. Further, in the embodiment of fig. 1, the support layer 2 and the sliding layer 3 are fixed only by bonding with the outer peripheral surface of the shaft, specifically, the support layer 2 is bonded on the outer peripheral surface of the shaft, and the sliding layer 3 is bonded on the surface of the support layer 2; whereas in the embodiment of fig. 2, the support layer 2 and the sliding layer 3 are bonded to both circumferential side walls of the groove, respectively, in addition to the outer surface of the shaft (i.e., the bottom 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.

In addition, as shown in fig. 2, both sidewalls of the groove may have a slope or inclination angle with respect to the bottom, and the inclination angle may be set to facilitate the processing of the groove on the one hand and further increase the surface of the sidewalls on the other hand, thereby further increasing the bonding surface areas of the support layer 2 and the sliding layer 3 with the shaft 1, so that the support layer 2 and the sliding layer 3 have a greater bonding strength with the shaft 1. The inclination angle may be, for example, 30 degrees, 45 degrees, 60 degrees, or 30 to 45 degrees, or 45 to 60 degrees, or any other suitable angle, the specific value of which is not particularly limited and may be suitably selected according to the specific engineering application.

The above description is focused on the arrangement and modification of the structure of the shaft 1 and the sliding bearing in fig. 2, with the difference that other aspects of the embodiment of fig. 1 are equally applicable to the embodiment of fig. 2, such as material selection of the support layer 2 and the sliding layer 3, the arrangement of the individual components in the material, the arrangement of the hardness gradient, the additional arrangement of the running-in layer, etc., which are not repeated here.

In addition, it is shown in fig. 2 that the support layer 2 and the sliding layer 3 are sequentially disposed in the groove, and the outermost sliding layer 3 is flush with the outer surface of the shaft 1 (i.e., flush with the groove), but not limited thereto, the outermost sliding layer 3 may be lower or higher than the outer surface of the shaft 1 without being flush therewith. In another alternative embodiment, not shown, the support layer 2 and the sliding layer 3 may protrude radially or in the height direction out of the groove of the base layer 1 to be higher than the groove, and the base layer 1 may be planar or plate-shaped, with the shaft 1 being described below as an example of the base layer 1, but not limited thereto, 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 approaches: (1) The supporting layer 2 and the sliding layer 3 are both higher than the outer surface of the shaft 1 and higher than the grooves; (2) Only the sliding layer 3 is above the outer surface of the shaft 1 and above the grooves, while the supporting layer 2 is below the outer surface of the shaft 1 and below the grooves. These two solutions differ from the embodiment of fig. 2 only in that the support layer 2 and the sliding layer 3 are not flush with the grooves, so that the description above for the embodiment of fig. 2 applies equally to these two solutions of this alternative embodiment and is not repeated here. These two schemes will be described with emphasis in the following.

In the 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 grooves, the grooves may be first machined and the outer diameter of the shaft 1 may be directly machined to the outer diameter of the final-formed finished shaft 1 before the support layer 2 and the sliding layer 3 are applied in the grooves, then the support layer 2 may be applied in the grooves, and the thickness of the applied support layer 2 may be the same as that of the final-formed support layer 2 without machining the formed support layer, or the thickness of the applied support layer 2 may be greater than that of the final-formed support layer 2, so that the support layer 2 is machined after being formed. After the support layer 2 is formed, at this time, the support layer 2 is higher than the outer surface of the shaft 1 and higher than the grooves, and then the sliding layer 3 is applied on the support layer 2, and the sliding layer 3 is machined, thereby machining the sliding layer 3 to a predetermined thickness. Alternatively, it is also possible to machine the shaft 1 not before the support layer 2 and the sliding layer 3 are applied in the grooves, but after the sliding layer 3 is finally formed, to machine the shaft 1 and the sliding layer 3 at the same time, thereby machining the sliding layer 3 to a predetermined thickness while machining the shaft 1 to a predetermined outer diameter size.

In the scheme (2), only the sliding layer 3 is higher than the outer surface of the shaft 1 and higher than the groove, and the supporting layer 2 is lower than the outer surface of the shaft 1 and lower than the groove, so that the groove may be first machined and the outer diameter of the shaft 1 may be directly machined to the outer diameter of the final-formed finished shaft 1 before the supporting layer 2 and the sliding layer 3 are applied in the groove, then the supporting layer 2 may be applied in the groove, and the material thickness of the applied supporting layer 2 may be the same as that of the final-formed supporting layer 2 without machining the formed supporting layer, or the material thickness of the applied supporting layer 2 may be larger than that of the final-formed supporting layer 2, so that it is machined after the supporting layer 2 is formed. After the support layer 2 is formed, at this time, the support layer 2 has a height lower than the outer surface of the shaft 1 and lower than the grooves, and then the sliding layer 3 is applied on the support layer 2 and the sliding layer 3 is machined, thereby machining the sliding layer 3 to a predetermined thickness. Alternatively, it is also possible to machine the shaft 1 not before the support layer 2 and the sliding layer 3 are applied in the grooves, but after the sliding layer 3 is finally formed, to machine the shaft 1 and the sliding layer 3 at the same time, thereby machining the sliding layer 3 to a predetermined thickness while machining the shaft 1 to a predetermined outer diameter size.

In both the embodiment of fig. 2 and in these alternative embodiments, no matter whether the sliding layer 3 is flush with the outer surface of the shaft 1 (i.e. flush with the grooves), and no matter what number and order of machining processes are to be performed on the shaft 1, the supporting layer 2 and the sliding layer 3, it is only necessary to ensure that the thickness of the sliding layer 3 can meet the actual engineering requirements, for example the various thicknesses described above in relation to the sliding layer 3 are not repeated here.

The sliding bearing has the advantages that the sliding bearing is a multi-layer sliding bearing comprising a plurality of metal layers, and the layers are metallurgically combined to form an integrated sliding bearing, so that a bearing sleeve in the conventional technology is omitted, the use of precious metals (such as nonferrous metals) is saved, and the bearing cost is remarkably reduced; the assembly of the shaft sleeve and the shaft is eliminated, the installation time is saved, and the time cost and the labor cost of the assembly are greatly reduced; the layers of the bearing and the matrix shaft form a whole, the layers have stronger bonding strength, and the risk that the sliding layer and the matrix shaft fall off does not exist.

In addition, an intermediate support layer is arranged between the base layer (such as a matrix shaft) and the sliding layer, and the intermediate support layer can serve as a blocking layer to block or reduce diffusion of elements of the matrix shaft to the sliding layer, such as steel element diffusion of a steel shaft to the sliding layer, so that the integrity of chemical components of the sliding layer is ensured, the sliding layer is not diffused and disturbed by the elements of the matrix shaft, and further the wear resistance and the like of the sliding layer are ensured.

The decreasing hardness gradient from the base layer to the sliding layer, particularly the hardness of the support layer, provides a flexible support for the sliding layer, particularly at high loads, which reduces wear of the sliding layer and thus extends the life of the sliding bearing. Furthermore, the provision of the hardness gradient reduces stresses (e.g., thermal stresses) at the material interface between the various layers, thereby increasing the fatigue strength and creep resistance and life of the sliding bearing.

In particular, 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, nickel and nickel-based alloys, and preferably copper alloys, the selection of these alloy materials having the dual technical effect: on the one hand, these materials themselves contain less Fe, thereby reducing the diffusion of Fe into the outer sliding layer, minimizing the adverse effect of the Fe component on the wear resistance of the sliding layer; on the other hand, the support layer formed of these alloys can provide a desired hardness gradient between the base layer and the sliding layer, thereby achieving cushioning and supporting effects of the support layer.

Through the advantages, the sliding bearing provided by the utility model has the advantages of low cost, simple structure, easiness in manufacturing, easiness in maintenance, high wear resistance and long service life.

The foregoing description of various embodiments of the utility model has been presented for the purpose of illustration to one of ordinary skill in the relevant art. It is not intended that the utility model be limited to the exact embodiment disclosed or as illustrated. As above, many alternatives and modifications of the present utility model will be apparent to those of ordinary skill in the art in light of the above teachings. Thus, while some alternative embodiments have been specifically described, those of ordinary skill in the art will understand or relatively easily develop other embodiments. The present utility model is intended to embrace all alternatives, modifications and variations of the present utility model described herein and other embodiments that fall within the spirit and scope of the utility model described above.

Reference numerals:

1. shaft (basic unit)

2. Support layer

3. Sliding layer

Claims

1. A sliding bearing comprising:

a base layer (1);

a support layer (2) on the base layer (1);

a sliding layer (3) on the supporting layer (2),

characterized in that the hardness gradient is gradually decreased from the base layer (1), the supporting layer (2) to the sliding layer (3).

2. The sliding bearing according to claim 1, wherein the base layer (1) is formed with grooves in which the support layer (2) and the sliding layer (3) are disposed in sequence.

3. The sliding bearing according to claim 1 or 2, wherein 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).

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

5. A sliding bearing according to claim 1 or 2, further comprising a running-in layer on the sliding layer (3).

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

7. The sliding bearing according to claim 1 or 2, wherein the sliding bearing is of planar construction.

8. A transmission comprising a shaft, a gear wheel supported on the shaft and a sliding bearing according to any one of claims 1 to 6, wherein the base layer (1) is provided by the shaft, the support layer (2) and the sliding layer (3) being in turn arranged on the outer surface of the shaft, the gear wheel being supported on the sliding layer (3).