Process for the production of integrated shafts by cold metal transfer cladding

Abstract

The application belongs to the technical field of manufacturing of wind power gear box and its shaft, and particularly relates to a process for preparing an integrated shaft by cold metal transfer cladding. The preparation of the integrated shaft comprises the following steps: step S1: cleaning the surface of the shaft to remove oxides and oil stains; step S2: using a cold metal transfer surfacing process to cladding a transition layer alloy on the surface of the shaft; step S3: processing and detecting the transition layer to ensure that the surface meets the preset flatness and geometric accuracy, and is free of cracks, un-fused or hole defects; step S4: using a cold metal transfer surfacing process to cladding a wear-resistant layer alloy on the transition layer; and step S5: processing and detecting the wear-resistant layer to ensure that the surface is free of cracks, un-fused or hole defects, and meets the design roughness requirement. The process can be used to prepare a planetary shaft of a wind power gear box, significantly improving performance and reducing cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of manufacturing wind power gearboxes and shafts thereof, and particularly relates to a process for preparing an integrated shaft by cold metal transfer cladding. Background Art

[0002] In recent years, with the increasing global emphasis on renewable energy, the development and utilization of wind power, a clean and sustainable form of energy, has experienced rapid growth. Gearboxes, a core component of wind turbines, play a crucial role in converting the rotational motion of the wind rotor into the speed required by the generator. Sliding bearings, a crucial component within gearboxes, have a direct impact on the reliability and efficiency of the entire system.

[0003] In traditional sliding bearing design, such as Figure 1 The planetary axis shown is the same as Figure 2 The alloy sleeves shown are connected via an interference fit and secured with bolts or pins. While this method is widely used, it presents several problems in practice. First, the radial and bending forces experienced during operation, as well as thermal expansion caused by temperature rise, can easily lead to bearing deformation and displacement, especially under extreme operating conditions. Second, the thick walls of the alloy sleeves not only increase material costs but also affect overall economic efficiency. Furthermore, the bonding strength of traditional connection methods is often insufficient in complex operating conditions, particularly in situations such as oil hole blockage, which can easily cause bearing slippage or displacement, accelerating the failure process. Coupled with the long design life of wind turbine gearboxes (20 years on land and 25 years offshore), the limitations of traditional sliding bearing design significantly increase the risk of failure and maintenance costs throughout their lifecycle.

[0004] In view of the above problems, developing a new bearing technology that overcomes the limitations of traditional sliding bearings, achieves longer service life, lower maintenance frequency and higher operating efficiency, while also having good economy and environmental adaptability will be of great practical significance to the development of the wind power industry. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention provides a process for preparing an integrated shaft by cold metal transfer cladding.

[0006] A first aspect of the present invention is to provide a process for preparing an integrated shaft, comprising the following steps:

[0007] Step S1: Clean the surface of the shaft to remove oxides and oil stains;

[0008] Step S2: using a cold metal transfer cladding process to clad the transition layer alloy on the surface of the shaft;

[0009] Step S3: Processing and inspecting the transition layer to ensure that its surface meets the preset flatness and geometric accuracy and is free of cracks, unfused parts, or holes;

[0010] Step S4: using a cold metal transfer cladding process to clad the wear-resistant layer alloy on the transition layer;

[0011] Step S5: Process and inspect the wear-resistant layer to ensure that its surface has no cracks, unfused or hole defects, and meets the designed roughness requirements.

[0012] As a further optimization solution for the preparation process of the above-mentioned integrated shaft, in step S2, a cold metal transfer cladding process is used to clad the transition layer alloy on the surface of the shaft with the following parameters:

[0013] Current: 180-220A;

[0014] Voltage: 22-26V;

[0015] Surfacing speed: 15-25mm / s;

[0016] Gas protection: He, flow rate 15-20L / min; or other single or mixed protective gases with equivalent flow rate;

[0017] Preheat the shaft to 100-150℃ before surfacing welding, and control the temperature of the surfacing area not to exceed 400℃ during the surfacing welding process. Forced air cooling is performed after surfacing welding.

[0018] The transition layer alloy includes but is not limited to the following components and mass ratio ranges:

[0019] Co (cobalt): 50-60%;

[0020] Cr (chromium): 20-30%;

[0021] W (tungsten): 10-20%;

[0022] C (carbon): 0.5-1.5%;

[0023] Other elements: less than 2%.

[0024] As a further optimization solution for the manufacturing process of the above-mentioned integrated shaft, in step S4, a cold metal transfer cladding process is used to clad the wear-resistant layer alloy on the transition layer with the following parameters:

[0025] Current: 220-260A;

[0026] Voltage: 22-26V;

[0027] Surfacing speed: 15-25mm / s;

[0028] Gas protection: He, flow rate 15-20L / min; or other single or mixed protective gases with equivalent flow rate;

[0029] Preheat the shaft to 100-150℃ before surfacing welding, and control the temperature of the surfacing area not to exceed 400℃ during the surfacing welding process. Forced air cooling is performed after surfacing welding.

[0030] The wear-resistant layer alloy includes but is not limited to the following components and mass ratio ranges:

[0031] Cu (copper): 80-85%

[0032] Sn (tin): 10-13%

[0033] Ni (nickel): 0.5-3%

[0034] Other elements: less than 2%.

[0035] As a further optimization solution for the preparation process of the above-mentioned integrated shaft, the material of the shaft is selected from steel or cast iron.

[0036] As a further optimization solution for the preparation process of the above-mentioned integrated shaft, the shaft is a planetary shaft of a wind power gearbox.

[0037] As a further optimization solution for the preparation process of the above-mentioned integrated shaft, the total thickness of the transition layer alloy and the wear-resistant layer alloy is 1 to 3 mm.

[0038] As a further optimization scheme for the preparation process of the above-mentioned integrated shaft, the thickness ratio of the transition layer alloy to the wear-resistant layer alloy is 3:7~7:3.

[0039] As a further optimization solution for the preparation process of the above-mentioned integrated shaft, in step S2, the uneven parts of the transition layer surface are removed by mechanical processing such as turning or grinding; and magnetic particle testing or penetrant testing is used to ensure that the transition layer has no cracks, unfused or hole defects.

[0040] As a further optimization scheme for the preparation process of the above-mentioned integrated shaft, in step S5, the uneven parts of the surface are removed by mechanical processing such as turning or grinding; the wear-resistant layer is ultrasonically tested to ensure that there are no delamination, voids or cracks inside; and the surface quality of the wear-resistant layer is checked using a surface roughness meter to ensure that it meets the designed roughness requirements.

[0041] A second aspect of the present invention is to provide a wind turbine gearbox, wherein a planetary shaft is rotatably mounted in the wind turbine gearbox, and the planetary shaft is manufactured according to the manufacturing process of the above-mentioned integrated shaft.

[0042] Beneficial effects

[0043] The integrated shaft cold metal transfer cladding manufacturing process proposed in the invention not only significantly improves the performance of the shaft, but also effectively reduces costs, enhances environmental adaptability and operating efficiency, and plays an important role in promoting the sustainable development of the wind power industry. The present invention provides excellent ductility, thermal stability, corrosion resistance and high hardness through the refined selection of transition layer alloys and wear-resistant layer alloys, especially the combined use of nickel-based alloys and cobalt-based alloys, thereby enhancing the shaft's ability to resist thermal expansion, mechanical stress and wear. The present invention ensures the uniformity and density of the alloy layer by precisely controlling parameters such as current, voltage, speed and gas protection, reduces defects such as cracks, unfused or holes, and further improves the overall performance and reliability of the shaft. The present invention reduces the impact of thermal stress through effective control of the preheating and cooling processes. Compared with traditional sliding bearings and shafts, this integrated shaft reduces the wall thickness of the alloy sleeve, reduces material costs, simplifies the assembly process, and reduces manufacturing and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Schematic diagram of the structure of a traditional planetary shaft.

[0045] Figure 2 Schematic diagram of the structure of a traditional alloy sleeve.

[0046] Figure 3 Schematic diagram of the structure of the shaft manufactured by the present invention. DETAILED DESCRIPTION

[0047] The present invention is further illustrated below by means of specific examples. These examples are exemplary and are intended to illustrate the problem and explain the present invention, but are not intended to be limiting.

[0048] The present invention provides a process for preparing an integrated shaft, that is, a process for manufacturing an integrated shaft by cold metal transfer cladding. A transition layer alloy and another wear-resistant layer alloy are sequentially clad on the surface of the shaft by cold metal transfer cladding, and the total thickness of the alloy layer in the radial direction is 1-3 mm. The shaft manufactured by this technology is as follows: Figure 3 As shown, it is a composite of a shaft and a bearing, which is essentially different from the traditional sliding bearing and shaft being separated into two parts.

[0049] As described above, the present invention utilizes a cold metal transfer hardfacing process to clad a transition layer alloy and a wear-resistant layer alloy on the shaft surface. In a specific embodiment, a planetary shaft, which can be made of either steel or cast iron, is clamped to a hardfacing device and cold metal transfer hardfacing is performed according to pre-set parameters. After the first transition layer is clad, machining and testing are performed. Once quality assurance is achieved, a second wear-resistant layer is hardfacing welded, followed by further machining and testing.

[0050] Axis preprocessing

[0051] Clean the surface of the shaft by grinding and chemically cleaning to remove any remaining oxides and oils.

[0052] Selection of transition layer alloy materials

[0053] A chromium-based alloy, a nickel-based alloy, or other nonferrous metal alloy is selected. Preferably, the composition and mass ratio of the transition layer alloy are as follows:

[0054] Co (cobalt): 50-60%;

[0055] Cr (chromium): 20-30%;

[0056] W (tungsten): 10-20%;

[0057] C (carbon): 0.5-1.5%;

[0058] Other elements are less than 2%.

[0059] The alloy has good ductility, thermal stability and corrosion resistance, and can effectively cope with thermal expansion and mechanical stress, ensuring a tight bond with the planetary shaft.

[0060] Transition layer surfacing parameter setting

[0061] Current: 180-220A, suitable for transition layer alloys.

[0062] Voltage: 22-26V, keep the arc stable.

[0063] Speed: 15-25mm / s, ensuring the uniformity and density of the alloy layer.

[0064] Gas protection: Use He gas (or other single or mixed protective gases with equivalent flow rate), and control the flow rate at 15-20L / min to prevent oxidation and splashing.

[0065] Before surfacing the transition layer, preheat the planetary shaft to 100-150°C to reduce thermal stress.

[0066] During the surfacing process, the temperature of the surfacing area should be controlled not to exceed 400℃ to avoid degradation of material properties. After surfacing, the area should be kept warm and then cooled by forced air.

[0067] Transition layer processing and testing

[0068] Rough machining: Use turning or grinding to remove the uneven parts of the transition layer surface to ensure the flatness and geometric accuracy of the transition layer surface.

[0069] Non-destructive testing: Magnetic particle testing (MT) or penetrant testing (PT) is used to ensure that the transition layer is free of cracks, unfused or holes.

[0070] Selection of wear-resistant layer alloy materials

[0071] A copper-based alloy, an aluminum-based alloy, or other nonferrous metal alloy wear-resistant layer alloy is selected. Preferably, the alloy composition and mass ratio range are as follows:

[0072] Cu (copper): 80-85%

[0073] Sn (tin): 10-13%

[0074] Ni (nickel): 0.5-3%

[0075] Other elements are less than 2%.

[0076] This alloy has extremely high hardness and wear resistance, which can significantly increase the service life of bearings.

[0077] Wear-resistant layer surfacing parameter setting

[0078] Current: 220-260A, suitable for wear-resistant layer alloy.

[0079] Voltage: 22-26V, keep the arc stable.

[0080] Speed: 15-25mm / s, ensuring the uniformity and density of the alloy layer.

[0081] Gas protection: Use He gas (or other single or mixed protective gases with equivalent flow rate), and control the flow rate at 15-20L / min to prevent oxidation and splashing.

[0082] Before surfacing the wear-resistant layer, preheat the planetary shaft to 100-150℃ to reduce thermal stress.

[0083] During the surfacing process, the temperature of the surfacing area should be controlled not to exceed 400℃ to avoid degradation of material properties. After surfacing, the area should be kept warm and then cooled by forced air.

[0084] Wear-resistant layer processing and testing

[0085] Finishing: After the wear-resistant layer is surfacing, use turning or grinding to remove the uneven parts of the surface.

[0086] Ultrasonic Testing (UT): Ultrasonic testing of the wear-resistant layer to ensure there are no obvious internal defects such as delamination, voids or cracks.

[0087] Surface roughness testing: Use a surface roughness tester to check the surface quality of the wear-resistant layer to ensure that it meets the designed roughness requirements. Low surface roughness helps reduce friction and wear.

[0088] In summary, the present invention utilizes cold metal transfer welding to clad the planetary shaft with a transition layer alloy and a wear-resistant layer alloy, creating an integrated structure. This effectively addresses the failure issues associated with traditional sliding bearings and improves bearing reliability and cost-effectiveness. Through meticulous process parameter control and quality testing, the alloy layer is ensured to be robust and reliable, meeting the long-term operational requirements of wind turbine gearboxes.

[0089] The above embodiments are exemplary and intended to illustrate the technical concepts and features of the present invention so that those skilled in the art can understand the present invention and implement it accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A process for preparing an integrated shaft by cold metal transfer cladding, characterized in that: The following steps are involved: Step S1: Clean the surface of the shaft to remove oxides and oil stains; Step S2: using a cold metal transfer cladding process to clad the transition layer alloy on the surface of the shaft; Step S3: Processing and inspecting the transition layer to ensure that its surface meets the preset flatness and geometric accuracy and is free of cracks, unfused parts, or holes; Step S4: using a cold metal transfer cladding process to clad the wear-resistant layer alloy on the transition layer; Step S5: Processing and inspecting the wear-resistant layer to ensure that its surface has no cracks, unfused or hole defects and meets the designed roughness requirements; In step S2, a cold metal transfer cladding process is used to clad the transition layer alloy on the surface of the shaft with the following parameters: Current: 180-220A; Voltage: 22-26V; Surfacing speed: 15-25mm / s; Gas protection: He, flow rate 15-20L / min; or other single or mixed protective gases with equivalent flow rate; Preheat the shaft to 100-150℃ before surfacing welding, and control the temperature of the surfacing area not to exceed 400℃ during the surfacing welding process. Keep the shaft warm and then cool after surfacing welding. The transition layer alloy includes the following components and mass ratios: Co (cobalt): 50-60%; Cr (chromium): 20-30%; W (tungsten): 10-20%; C (carbon): 0.5-1.5%; Other elements: less than 2%; In step S4, a cold metal transfer cladding process is used to clad the wear-resistant layer alloy on the transition layer with the following parameters: Current: 220-260A; Voltage: 22-26V; Surfacing speed: 15-25mm / s; Gas protection: He, flow rate 15-20L / min; or other single or mixed protective gases with equivalent flow rate; Preheat the shaft to 100-150℃ before surfacing welding, and control the temperature of the surfacing area not to exceed 400℃ during the surfacing welding process. Forced air cooling is performed after surfacing welding. The wear-resistant layer alloy includes the following components and mass ratios: Cu (copper): 80-85%; Sn (tin): 10-13%; Ni (nickel): 0.5-3%; Other elements: less than 2%; The total thickness of the transition layer alloy and the wear-resistant layer alloy is 1~3 mm; The thickness ratio of the transition layer alloy to the wear-resistant layer alloy is 3:7~7:

3.

2. The process for preparing an integrated shaft by cold metal transfer cladding according to claim 1, characterized in that: The material of the shaft is selected from steel or cast iron.

3. The process for preparing an integrated shaft by cold metal transfer cladding according to claim 2, characterized in that: The shaft is a planetary shaft of a wind power gearbox.

4. The process for preparing an integrated shaft by cold metal transfer cladding according to claim 1, characterized in that: In step S2, the uneven parts on the surface of the transition layer are removed by machining such as turning or grinding; and magnetic particle testing or penetrant testing is used to ensure that the transition layer has no cracks, unfused or hole defects.

5. The process for preparing an integrated shaft by cold metal transfer cladding according to claim 1, characterized in that: In step S5, the uneven parts of the surface are removed by mechanical processing such as turning or grinding; the wear-resistant layer is ultrasonically tested to ensure that there are no delamination, voids or cracks inside; and the surface quality of the wear-resistant layer is checked using a surface roughness meter to ensure that it meets the designed roughness requirements.

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