Method for manufacturing a rolling or sliding bearing ring

Abstract

A method for manufacturing a rolling or sliding bearing ring (1) is disclosed, the method comprising forming (S2) a metal ring member (1') by depositing metal using a directed energy deposition (DED) operation; and applying (S3) a load carrying surface (11) to the formed metal ring member (1') by using a further DED operation.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a rolling bearing ring or a sliding bearing ring according to claim 1. This invention also relates to a rolling bearing ring or a sliding bearing ring according to claim 10. Background Technology

[0002] Rolling bearings and plain bearings are well-known mechanical components used to carry loads while allowing relative rotation between their bearing rings. Rolling bearings carry loads via rolling elements (such as balls and rollers), while plain bearings (also known as sliding bearings) carry loads via sliding surfaces.

[0003] Bearing rings are typically manufactured from rolled / forged steel substrates through processes such as surface cutting, grinding, and honing until the final bearing ring assembly is provided. Bearing rings often also undergo heat treatment to increase their surface hardness, thereby achieving high fatigue resistance, especially on the load-bearing surfaces. This results in a long service life.

[0004] It is also known, for example, to provide bearing rings made of more expensive materials to offer enhanced performance. For example, bearing rings can be made of stainless steel, thus providing corrosion-resistant rings. Because stainless steel is relatively expensive, larger bearings (such as bearings with an outer diameter greater than 500 mm) may be very expensive to produce due to the high material cost, or even impossible to produce due to limitations in the reduction ratio.

[0005] Instead of using expensive materials (such as stainless steel), bearing rings can be made from cheaper materials and coated with high-performance materials to provide additional properties (such as corrosion resistance). Therefore, in this case, the base ring is manufactured in a conventional manner using hot forming processes (such as forging and / or rolling), followed by coating. However, when producing large-size bearings, the volume is often very limited, leading to high costs and long leadtimes for the bearing rings.

[0006] The lead time for procuring components of large bearings (such as bearing races) is typically 8 to 12 months. The costs associated with such procurement are also very high because the volumes are very small and require large tonnages of high-quality steel. Furthermore, if production encounters problems, new orders need to be placed (again, 8 to 12 months). This can be mitigated by accumulating inventory, which can lead to high costs, and it's uncertain whether the accumulated inventory will actually be needed.

[0007] Therefore, the object of the present invention is to provide bearing rings in a cost-effective and faster manner compared to the manufacturing methods mentioned above. Summary of the Invention

[0008] This objective is achieved by a method for manufacturing rolling bearing rings or sliding bearing rings, the method comprising:

[0009] - Metal ring components are formed by depositing metal using Directed Energy Deposition (DED) operations; and

[0010] - The load-carrying surface is applied to the formed metal ring component by using an additional DED operation.

[0011] Based on this method, bearing rings can be easily and quickly manufactured simply using DED (Dual Engraving and Deposition) operations. DED is used here as a form of 3D printing for bearing rings. Therefore, in the first step, a metal ring component is formed or 3D printed using DED. Metal can be deposited onto a carrier material, which can subsequently be removed. Alternatively, the carrier material can be part of the bearing ring and can remain on it. The carrier material can be, for example, a thin metal film of the same material as the metal ring component.

[0012] In the second step, a DED is also used to apply the carrier-bearing surface to the ring component. Here, a DED is used to coat the formed ring component.

[0013] Laser cladding (DED) is a surface welding operation that metallurgically bonds the material of a load-bearing surface to a metal ring component (and / or metallurgically bonds the material of the ring component to a carrier material), thereby providing a DED-bonded surface on the metal ring component (and / or on the carrier material). Other examples of DED besides laser cladding include plasma transferred arc (PTA), electron beam melting (EBM), and selective laser melting (SLM).

[0014] The DED process can deposit material at very high deposition rates (up to 10 kg per hour). Therefore, bearing rings can be manufactured in a shorter time compared to previous methods, and can be manufactured on demand, for example, based on user / customer requirements. Furthermore, the DED process provides manufacturing with dimensional stability, resulting in small tolerances regarding post-machining, and thus reducing post-machining, further improving manufacturing in terms of time and cost. For example, using 3D printing, especially DED, the delivery cycle for procuring bearing rings can be reduced to 3 to 4 weeks compared to the previous 8 to 12 weeks.

[0015] Furthermore, the manufacturing method offers the advantage of easily producing bearing rings of different types and sizes using the same starting material (i.e., material). Therefore, the manufacturing method can be adapted to different bearing types and sizes based on user or customer requirements.

[0016] The DED operation used to form the metal ring component and / or apply the load-bearing surface can be a wire and / or steel metal powder DED operation. In particular, it has been recognized that a steel surface can be applied to a metal ring component made of any metal (e.g., a low-cost metal) through a wire and / or powder-based DED operation, wherein the metal surface is preferably a high-performance steel surface. Therefore, rolling or sliding bearing rings with extended service life can be achieved in a cost-effective and time-efficient manner. Furthermore, by using DED, a steel material layer of any desired thickness can be applied to the metal ring component, which means further improvement in performance.

[0017] Furthermore, the material of the load-carrying surface can be selected based on the specific application, such as for pulp and paper applications, wind turbines, metal and mining industry applications, etc. This provides enhanced flexibility because the material of the load-carrying surface is adapted to the corresponding application. As used herein, a load-carrying surface refers to a surface designed to withstand loads (typically alternating loads) during use. Preferably, the load-carrying surface is the raceway surface of a rolling bearing ring or a sliding bearing ring. However, the load-carrying surface can also be, for example, the inner circumferential surface of an inner bearing ring and / or the outer circumferential surface of an outer bearing ring. Moreover, the load-carrying surface can be any surface of a rolling or sliding bearing ring designed to bear loads having a substantially direct, surface-pointing main force component.

[0018] Additionally, when using wire and / or steel powder DED operations, the only stock required is the barrels containing the wire / powder for the printing process. This stock can be much smaller compared to previous manufacturing methods, as the same type of stock can be used for all bearing types and sizes.

[0019] The steel wire and / or steel metal powder used for metal ring components may contain low-strength steel, particularly S355J2, 42CrMo4, 21CrMoV5-11, 16CrMo4 and / or 25CrMo4.

[0020] Therefore, ring members can be produced cost-effectively using low-cost materials such as structural steel (e.g., S355J2, 42CrMo4, low-alloy low-carbon steel). The ring member can thus be formed using relatively inexpensive materials, while the required strength and other properties of the bearing ring can be provided by the load-bearing surfaces deposited on the ring member. For example, cheaper materials such as standard steels that are not stainless steel, such as steels with a chromium (Cr) content of less than 10 wt%, can be used for the ring member.

[0021] Steel wire and / or steel metal powder used for load-bearing surfaces can contain carbon (C) and boron (B) as hardening mechanisms. That is, it has been recognized that DEDs (e.g., laser cladding) containing only C as a hardening mechanism may not provide a surface with sufficient surface hardness without a high risk of cracking. In particular, it has been found that raceway surfaces coated with only C as a hardening mechanism may not provide sufficient surface hardness (especially for more demanding applications) without a high risk of cracking in the raceway surface. Therefore, by also providing B as a hardening mechanism, it has been recognized that high surface hardness suitable for more demanding applications can be achieved while also reducing the risk of cracking. For example, it has been found that when steel metal powder and / or steel wire contain both C and B as hardening mechanisms, a load-bearing surface with a surface hardness of at least 55 HRC (such as 55 HRC to 58 HRC) can be achieved. Optionally, the steel wire and / or steel metal powder may contain 0.10 wt% to 0.50 wt% of C and 0.50 wt% to 1.50 wt% of B. For example, it has been found that by using the above-mentioned amounts of C and B, typically by making the amount of B in the steel metal powder higher than the amount of C, a higher surface hardness can be achieved. According to one example embodiment, the total wt% of C and B is in the range of 0.6 wt% to 1.7 wt%, such as essentially 0.2 wt% of C and 0.9 wt% of B.

[0022] Alternatively, the steel wire and / or steel metal powder can be stainless steel wire and / or stainless steel metal powder, respectively. Therefore, a corrosion-resistant surface can be provided through DED operation, which translates to a high-performance surface compared to, for example, low-cost materials used in previously formed ring components.

[0023] The load-bearing surface can be applied by using a DED (Damaged Surface Erection) layer, such as 2 to 20 layers. Providing more than one layer (such as 2 to 20 layers) has been shown to achieve high-performance surfaces with satisfactory thickness for more demanding applications. This also reduces the amount of heat transferred to the previously formed ring component, meaning a reduced risk of cracking in the ring component.

[0024] Forming metal ring components by depositing metal using directional energy deposition (DED) involves depositing multiple layers using DED. These multiple layers can be, for example, hundreds of layers.

[0025] Therefore, the metal ring component can be constructed by depositing it layer by layer until the desired thickness of the metal ring component is achieved. This means that any desired thickness of the metal ring component, and therefore the bearing ring, can be achieved by adjusting the number of layers.

[0026] Furthermore, as viewed radially in a rolling or sliding bearing ring, the ratio between the ring component and the surface bearing the applied load can be variable. By selecting a specific ratio, the characteristics of the bearing ring can be further adjusted. For example, the load-bearing capacity can be enhanced or reduced by increasing or decreasing the percentage of the load-bearing surface within the total ratio. The same applies to the cost of the bearing ring; that is, the total cost of the bearing ring can be increased or decreased by increasing or decreasing the percentage of cost-effective materials in the ring components.

[0027] Optionally, the speed at which the load is applied to the bearing surface via DED (i.e., the DED speed, such as the laser cladding speed) can range from 0.5 m / min to 1000 m / min. According to one example embodiment, the DED speed is higher than 1 m / min, such as higher than 20 m / min, for example, 80 to 120 m / min, which means a reduced risk of cracking in the metal ring component. That is, higher DED speeds (such as laser cladding speeds) have been found to reduce the risk of cracking. Therefore, by using, for example, higher laser cladding speeds, improved rolling bearing rings or sliding bearing rings can be provided.

[0028] Optionally, when the DED operation is laser cladding, the laser power used when applying the load to the bearing surface can be from 1 kW to 30 kW, particularly from 5 kW to 16 kW.

[0029] Optionally, the application speed can be varied during the application of the wire material and / or steel metal powder to the carrier material and / or metal ring member. Therefore, one or more layers with different radial thicknesses can be applied. For example, while applying the load-bearing surface, the carrier material and / or metal ring member can be rotated relative to the rotation axis of the metal ring member, wherein the rotation speed can be varied during the application of the wire and / or steel metal powder to the carrier material and / or metal ring member. By varying the speed, less heat can be transferred to the carrier material and / or metal ring member and subsequent layers of the metal ring member and / or load-bearing surface during DED operation. According to one example embodiment, the speed is varied by reducing the speed at least once during the application of layers to the metal ring member and / or load-bearing surface. Therefore, a relatively high speed can be used when, for example, the first layer is applied directly to the metal ring member, and thus a relatively low speed can be used when one or more additional layers are applied on the first layer. This also applies to the layers of the metal ring member. Therefore, the first layer will be thinner than one or more additional layers. This allows less heat to be transferred to the metal ring component, thereby reducing the risk of cracks forming in the metal ring component during DED (e.g., laser cladding) operations.

[0030] Furthermore, by varying the application speed, a surface with a variable radius can be provided with a load-bearing surface of substantially uniform thickness. For example, a rolling bearing ring or a sliding bearing ring can have a spherical surface with a variable radius, thereby allowing the application speed to be varied to provide a load-bearing surface of substantially uniform thickness thereon. Thus, the application speed can be varied to achieve a constant surface velocity during DED operation. This also applies to the formation of the metal ring component. Optionally, as viewed in the radial direction of the rolling bearing ring or sliding bearing ring, the final thickness of the applied load-bearing surface can be from 0.25 μm to 10 μm.

[0031] According to another aspect, a rolling bearing ring or sliding bearing ring for a rolling bearing or a sliding bearing is provided, wherein the rolling bearing ring or sliding bearing ring has been manufactured by a method according to any embodiment of the method described above.

[0032] The ring of a rolling bearing can be any type of rolling bearing. For example, a rolling bearing can be a ball bearing or a roller bearing, including but not limited to spherical roller bearings, tapered roller bearings, toroidal roller bearings, cylindrical roller bearings, spherical ball bearings, deep groove ball bearings, and angular contact ball bearings. The ring of a sliding bearing can be any type of sliding bearing (such as a spherical sliding bearing).

[0033] According to another aspect, a rolling bearing or sliding bearing comprising at least one rolling bearing ring or sliding bearing ring as described above is provided.

[0034] Further preferred embodiments are defined in the dependent claims, as well as in the specification and drawings. Thus, elements described or shown in combination with other elements may exist alone or in combination with other elements without departing from the scope of protection. Attached Figure Description

[0035] In the following description, preferred embodiments of the invention are illustrated in the accompanying drawings, which are merely exemplary and not intended to limit the scope of protection. The scope of protection is defined only by the appended claims.

[0036] The attached diagram shows:

[0037] Figure 1 Cross-sectional view of a rolling bearing ring or a sliding bearing ring;

[0038] Figure 2 :include Figure 1 A schematic side view of a rolling bearing with rings;

[0039] Figure 3 : Figure 1 A cross-sectional view of the rolling bearing ring or the sliding bearing ring; and

[0040] Figure 4 Used for manufacturing according to Figures 1 to 3 A flowchart of a method for manufacturing rolling bearing rings or sliding bearing rings.

[0041] List of reference numerals

[0042] 1. Rolling bearing ring or sliding bearing ring

[0043] 1' Metal ring component

[0044] 2 Outer ring

[0045] 3 Rolling elements

[0046] 10 Rolling bearings

[0047] 11 Load-bearing surface

[0048] A. Rotation axis

[0049] h1 Thickness of the load-bearing surface

[0050] h2 Thickness of the metal ring component

[0051] S1 to S4 Method Steps Detailed Implementation

[0052] In the following text, elements that are the same or have similar functions are indicated by the same reference numerals.

[0053] Figure 1 A cross-sectional view of a rolling bearing ring or sliding bearing ring 1, which can be used in a rolling bearing or a sliding bearing, is shown. The cross-sectional view is defined by a plane extending along the axis of rotation A of the rolling bearing ring or sliding bearing ring 1. The rolling bearing ring or sliding bearing ring 1 includes a metal ring member 1'. The rolling bearing ring or sliding bearing ring also includes a load-bearing surface 11 disposed on the metal ring member 1'.

[0054] In order to provide a time- and cost-efficient way to manufacture the bearing ring 1, the metal ring component 1' and the load-bearing surface 11 are formed by DED operation.

[0055] Therefore, the metal ring member 1' is first formed by applying a layer of metallic material to a carrier material (not shown). After forming the metal ring member 1' and / or the load-bearing surface 11, the carrier material can remain on the bearing ring 1 or can be removed from the bearing ring 1. Then, the load-bearing surface 11 is applied to the metal ring member 1' via a DED operation.

[0056] The load-bearing surface 11 here is a raceway surface, such as the raceway surface used for rolling elements (i.e., balls and / or rollers). As shown, the raceway surface 11 may have a spherical shape. Thus, the rolling bearing ring or sliding bearing ring 1 can be misaligned relative to the outer ring 2 (see Figure 1). Figure 2 Therefore, a rolling bearing or sliding bearing 10 (such as a rolling bearing ring or a sliding bearing ring 1) includes a rolling bearing ring or a sliding bearing ring 1. Figure 2 The rolling bearing shown is capable of accommodating shaft deflections during use. Other forms of bearing rings 1 can also be formed.

[0057] Figure 2 The diagram shows a rolling bearing ring 1 (e.g., as shown in the image). Figure 1 The image shows a side view of the rolling bearing 10. The rolling bearing ring 1 is the inner ring of the rolling bearing 10. The rolling bearing 10 also includes the outer ring 2 mentioned above and a plurality of rolling elements 3 disposed between the outer ring 2 and the rolling bearing ring 1. It should be noted that, alternatively, the outer ring 2 is provided with a load-bearing surface 11 as described above.

[0058] Figure 3 It shows according to Figure 1A cross-sectional view of a portion of a rolling or sliding bearing ring 1. As already mentioned, it includes a load-bearing surface 11 and a metal ring member 1', both formed using DED (Dual Engraving and Deposition). The load-bearing surface 11 has a radial thickness h1, which can be, for example, 0.25 mm to 10 mm. The radial direction of the ring 1 is perpendicular to and intersects the axis of rotation A of the rolling or sliding bearing ring 1. The metal ring member 1' has a radial thickness h2 that is substantially greater than the radial thickness h1, such as 10 mm to 500 mm. The thicknesses h1 and h2 can be adjusted according to the intended application of the bearing ring 1. For example, relative to the thickness h2 of the metal ring member 1', the thickness h1 of the load-bearing surface 11 can be increased for applications with higher loads, while the thickness h1 of the load-bearing surface 11 can be decreased for applications with lower loads.

[0059] Furthermore, it should be noted that the metal ring member 1' and the load-bearing surface 11 can be composed of multiple single layers applied on top of each other using a DED operation.

[0060] exist Figure 4 The image shows the materials used in manufacturing. Figures 1 to 3 The flowchart of the method for bearing ring 1.

[0061] In the first step S1, a carrier material is provided, on which the metal ring component 1' can be formed. This step S1 is optional, and it should be noted that other methods of forming the metal ring component 1' are also possible, such as using a mold.

[0062] In the second step S2, a layer of the metal ring component 1' is applied or deposited using a DED operation. During this DED operation (e.g., laser cladding), steel wire and / or steel metal powder are melted layer by layer to form the metal ring component 1'. This step S2 can be performed until the desired thickness h2 of the metal ring component 1' is reached.

[0063] In the third step S3, the load-bearing surface 11 is also applied to the metal ring component 1' using a DED operation. This can be accomplished using the same machine or equipment as in step S2, except that the steel wire and / or steel metal powder used need to be changed to provide different features or properties to the load-bearing surface 11 and the metal ring component 1'. Therefore, steps S2 and S3 require only one production site.

[0064] It should be noted that the layers of the metal ring member 1' and the load-bearing surface 11 may also comprise different materials. For example, the layers of the metal ring member 1' may consist of alternating layers of two or more materials (such as different types of steel). The same applies to the load-bearing surface 11. This provides the advantage that additional features, properties, and / or characteristics can be added to the metal ring member 1' and / or the load-bearing surface 11.

[0065] After the desired thickness h1 of the load-bearing surface 11 has been reached, the method can either end or continue to step S4, in which the carrier material from step S1 can be removed. It should be noted that, when using a carrier material, it can also be removed after step S2 and before step S3.

[0066] In summary, the manufacturing method and corresponding bearing rings described in this paper provide a flexible approach to manufacturing bearing rings in terms of type and size. For example, the layer thickness and material can be adjusted according to the specific requirements of the intended application. Furthermore, bearing rings can be easily manufactured using the same manufacturing equipment by simply changing the added wire / powder.

Claims

1. A method for manufacturing a rolling bearing ring or a sliding bearing ring (1), the method comprising: - The (S2) metal ring structure (1') is formed by depositing metal using directional energy deposition (DED) operation; as well as - The load-bearing surface (11) is applied (S3) to the formed metal ring member (1') by using an additional DED operation.

2. The method according to claim 1, characterized in that, The DED operation used to form the metal ring member (1') and / or apply the load-bearing surface (11) is a steel wire and / or steel metal powder DED operation.

3. The method according to claim 2, characterized in that, The steel wire and / or steel metal powder used for the metal ring component (1') contain low-strength steel, particularly S355J2 and / or 42CrMo4.

4. The method according to claim 2 or 3, characterized in that, The steel wire and / or steel metal powder used for the load-bearing surface (11) contain carbon (C) and boron (B) as a hardening mechanism.

5. The method according to claim 4, characterized in that, The steel wire and / or steel metal powder used for the load-bearing surface (1) contains 0.10 wt% to 0.50 wt% C and 0.50 wt% to 1.20 wt% B.

6. The method according to any one of claims 2 to 5, characterized in that, The steel wire and / or steel metal powder used for the load-bearing surface (11) are stainless steel wire and / or stainless steel metal powder, respectively.

7. The method according to any one of the preceding claims, characterized in that, Applying the load to the bearing surface (11) includes applying more than one layer, such as 2 to 20 layers, by using a DED.

8. The method according to any one of the preceding claims, characterized in that, The metal ring component (1') is formed by depositing metal using directional energy deposition (DED) operation, which includes depositing multiple layers using DED.

9. The method according to any one of the preceding claims, characterized in that, As viewed in the radial direction of the rolling or sliding bearing ring (1), the ratio between the metal ring member (1') and the applied load-bearing surface (11) is variable.

10. A rolling bearing ring or sliding bearing ring (1) for a rolling bearing or sliding bearing (10), characterized in that, The rolling bearing ring or sliding bearing ring (1) has been manufactured by the method according to any one of the preceding claims.

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