Cold metal transfer cladding process for preparing integrated shaft and planetary shaft and its application

Abstract

A process for preparing an integrated shaft by cold metal transfer cladding, an integrated shaft and its application, comprising the following steps: step S1: cleaning the surface of the shaft to remove oxides and oil stains; step S2: using a thermal spraying process to spray a transition layer alloy on the shaft surface to form a transition layer; step S3: using a cold metal transfer cladding process to clad a wear-resistant layer alloy on the transition layer on the shaft surface to form a wear-resistant layer; step S4: processing and testing the wear-resistant layer on the shaft surface to ensure that the surface has no cracks, unfused or hole defects, and meets the designed roughness requirements, and an integrated shaft is prepared. The process for preparing an integrated shaft by cold metal transfer cladding, an integrated shaft and its application described in the present invention have a reasonable process design, and the prepared integrated shaft is used to prepare the planetary shaft of a wind power gearbox, which can significantly improve the performance of the wind power gearbox and reduce the cost.

Description

Technical Field

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

[0002] In recent years, as the world pays more and more attention to renewable energy, the development and utilization of wind energy as a clean and sustainable energy form has been rapidly developed. One of the core components of wind power equipment, the gearbox, plays a key role in converting the rotational motion generated by the wind wheel into the speed required by the generator. Among them, the sliding bearing is an important component inside the gearbox, and its performance directly affects the reliability and efficiency of the entire system.

[0003] In traditional sliding bearing design, Figure 1 The planetary axis shown is similar to Figure 2 The alloy sleeves shown are connected by interference fit and fixed by bolts or pins. Although this method is widely used, it exposes many problems in practical applications.

[0004] First, the radial force, bending force and thermal expansion caused by temperature rise during operation can easily cause deformation and displacement of the bearing, especially under extreme working conditions. Secondly, the thick wall thickness of the alloy sleeve not only increases the material cost, but also affects the overall economy. In addition, the bonding force under the traditional connection method is often insufficient when facing complex working conditions, especially in cases such as oil hole blockage, which can easily cause the bearing to slip or displace, thereby accelerating the failure process. In addition, the design life of wind turbine gearboxes is relatively long (20 years on land and 25 years at sea), and the limitations of traditional sliding bearing design significantly increase the risk of failure and maintenance costs throughout the life cycle.

[0005] In view of the above problems, developing a new type of bearing technology to overcome the limitations of traditional sliding bearings, achieve longer service life, lower maintenance frequency and higher operating efficiency, while having good economy and environmental adaptability will be of great practical significance to the development of the wind power industry.

[0006] Therefore, the present invention proposes a cold metal transfer cladding manufacturing process for an integrated shaft, which can not only significantly improve the performance of the shaft, but also effectively reduce the cost. The integrated shaft prepared by the above manufacturing process is applied to the planetary shaft, and the planetary shaft is rotatably installed in the wind power gearbox, which enhances the environmental adaptability and operating efficiency, and plays an important role in promoting the sustainable development of the wind power industry. Summary of the invention

[0007] Purpose of the invention: In order to overcome the above shortcomings, the purpose of the present invention is to provide a process for preparing an integrated shaft by cold metal transfer cladding, an integrated shaft and its application. The integrated shaft prepared by the above process not only significantly improves the performance of the shaft, but also effectively reduces the cost. When it is applied to the planetary shaft in the wind power gearbox, it can enhance the environmental adaptability and operating efficiency, which plays an important role in promoting the sustainable development of the wind power industry and has broad application prospects.

[0008] The objective of the present invention is achieved through the following technical solutions: A process for preparing an integrated shaft by cold metal transfer cladding comprises the following steps: Step S1: Clean the surface of the shaft to remove oxides and oil stains; Step S2: using a thermal spraying process to spray a transition layer alloy onto the shaft surface to form a transition layer; Step S3: using a cold metal transfer cladding process to melt the wear-resistant layer alloy onto the transition layer on the shaft surface to form a wear-resistant layer; Step S4: Process and inspect the wear-resistant layer on the shaft surface to ensure that the surface has no cracks, unfused or hole defects and meets the designed roughness requirements, thereby preparing an integrated shaft.

[0009] The process of the integrated shaft described in the present invention has reasonable process steps. The surface of the shaft is first cleaned to remove oxides and oil stains, which can increase the adhesion of subsequent coatings and ensure the uniformity of coating quality. Then, a thermal spraying process is used to spray a transition layer alloy on the shaft surface to form a transition layer. The thermal spraying process is to spray the transition layer alloy onto the shaft surface at a high temperature and high speed to form a good bond with the base material. The presence of the transition layer can relieve the stress caused by differences in thermal expansion coefficient, chemical composition, etc. between the shaft and the wear-resistant layer, improve the bonding strength and service life of the wear-resistant layer, and the transition layer alloy can also play a certain protective role. Then, a cold metal transfer cladding process is used to melt the wear-resistant layer alloy on the transition layer on the shaft surface to form a wear-resistant layer. The cold metal transfer cladding process has a lower heat input and can accurately control the temperature and thickness of the cladding layer during the cladding process, which is beneficial to avoid performance changes and deformation of the shaft base material due to excessive heat input, and ensure the dimensional accuracy and mechanical properties of the integrated shaft. The cladding of the wear-resistant layer alloy can significantly improve the wear resistance of the shaft surface. Finally, processing and testing are carried out to ensure product quality and meet use requirements.

[0010] Preferably, the step S4 specifically includes the following contents: using turning or grinding to remove uneven parts of the shaft surface; performing ultrasonic testing on the wear-resistant layer on the shaft surface to ensure that there are no stratification, voids or cracks inside the wear-resistant layer; using a surface roughness meter to check the surface quality of the wear-resistant layer to ensure that it meets the designed roughness requirements.

[0011] Furthermore, in the above-mentioned process for preparing an integrated shaft by cold metal transfer cladding, in step S2, the processing parameters of the thermal spraying process are: flame speed of 1500~3000m / s, particle speed of 300~800m / s, flame temperature of 2000-3500℃, compressed air inlet pressure of 100~130 psi, air intake pressure of 110~140 psi, spray gun spacing of 100~200mm, moving speed of 10~11mm / s, workpiece temperature of <200℃, and spraying thickness of 0.1~1mm; the transition layer alloy is selected from chromium-based alloy, nickel-based alloy or one of other non-ferrous metal alloys.

[0012] Preferably, the flame temperature is 3200°C.

[0013] Furthermore, in the above-mentioned process for preparing an integrated shaft by cold metal transfer cladding, in step S2, the transition layer alloy includes the following components in percentage by mass: Co: 50~60%; Cr: 20~30%; W: 10~20%; C: 0.5~1.5%; Other elements: less than 2%.

[0014] Furthermore, in the above-mentioned process of preparing an integrated shaft by cold metal transfer cladding, in step S3, the processing parameters of the cold metal transfer cladding process are: current of 220~260A, voltage of 22~26V, cladding speed of 15~25mm / s, and flow rate of protective gas of 5~20L / min; the wear-resistant layer alloy is selected from one of copper-based alloy, aluminum-based alloy or other non-ferrous metal alloy.

[0015] Preferably, the shielding gas is He or other single or mixed shielding gases with equal flow rates.

[0016] The present invention ensures the uniformity and density of the alloy layer and reduces defects such as cracks, unfused or holes by finely controlling processing parameters such as current, voltage, surfacing speed and protective gas.

[0017] Furthermore, in the above-mentioned process of preparing an integrated shaft by cold metal transfer cladding, the step S3, before the cold metal transfer cladding process, preheat the shaft to 100-150°C, and control the temperature of the cladding area not to exceed 400°C during the cold metal transfer cladding process, and perform forced air cooling after cladding.

[0018] The influence of thermal stress is reduced by effective control of preheating and cooling processes.

[0019] Furthermore, in the above-mentioned process for preparing an integrated shaft by cold metal transfer cladding, in step S3, the wear-resistant layer alloy includes the following components in percentage by mass: Cu: 80~85% Sn: 10~13% Ni: 0.1~3% Other elements: less than 2%.

[0020] Furthermore, in the above-mentioned process for preparing an integrated shaft by cold metal transfer cladding, the material of the shaft is selected from steel or cast iron.

[0021] The material of the shaft is selected from steel or cast iron, such as 42CrMo, 40Cr, No. 20 steel, etc.

[0022] Furthermore, in the above-mentioned process for preparing an integrated shaft by cold metal transfer cladding, the total thickness of the transition layer and the wear-resistant layer is less than 1.5 mm.

[0023] Preferably, the thickness of the transition layer is less than 0.5 mm, and the thickness of the wear-resistant layer is less than 1 mm.

[0024] The present invention also relates to an integrated shaft, which is prepared by using the above-mentioned process for preparing the integrated shaft by cold metal transfer cladding.

[0025] The present invention also relates to the application of the above-mentioned integrated shaft, which is used for a planetary shaft of a wind power gearbox, in which a planetary shaft is rotatably mounted.

[0026] Furthermore, the above-mentioned cold metal transfer cladding process for preparing an integrated shaft, Compared with the prior art, the present invention has the following beneficial effects: the process for preparing an integrated shaft by cold metal transfer cladding described in the present invention not only significantly improves the performance of the shaft, but also effectively reduces the cost. Through the refined selection of the transition layer alloy and the wear-resistant layer alloy, the comprehensive performance of the integrated shaft can be significantly improved, and excellent ductility, thermal stability, corrosion resistance and high hardness are provided, and the ability of the shaft to resist thermal expansion, mechanical stress and wear resistance is enhanced. Through the fine control of processing parameters such as current, voltage, speed and gas protection, the uniformity and density of the alloy layer are ensured, and defects such as cracks, unfusion or holes are reduced, and the overall performance and reliability of the shaft are further improved; through the effective control of the preheating and cooling processes, the influence of thermal stress is reduced; the integrated shaft prepared by the process for preparing an integrated shaft by cold metal transfer cladding described in the present invention is applied to the planetary shaft of a wind power gearbox. Compared with traditional sliding bearings and shafts, this integrated shaft reduces the wall thickness of the alloy sleeve and reduces the material cost. At the same time, it also simplifies the assembly process, reduces the manufacturing and maintenance costs, enhances the environmental adaptability and operating efficiency, and plays an important role in promoting the sustainable development of the wind power industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of a traditional planetary shaft; Figure 2 It is a schematic diagram of the structure of a traditional alloy bushing; Figure 3 It is a schematic diagram of the structure of the integrated shaft of the present invention. DETAILED DESCRIPTION

[0028] The following will be attached Figure 3 In combination with Comparative Example 1 and Example 1, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention. The following comparative example 1 and embodiment 1 both provide a manufacturing process for an integrated shaft.

[0029] Comparative Example 1 Comparative Example 1 provides a manufacturing process for an integrated shaft, in which 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 (transition layer plus wear-resistant layer) in the radial direction is less than 3 mm.

[0030] As described above, in Comparative Example 1, a transition layer alloy and a wear-resistant layer alloy are clad on the shaft surface by a cold metal transfer cladding process. In a specific embodiment, the planetary shaft is clamped on a cladding device, and the material of the planetary shaft can be steel or cast iron, and cold metal transfer cladding is performed according to set parameters. After the first transition layer is clad, processing and testing are performed, and after ensuring the quality, the second wear-resistant layer is clad, and then processing and testing are performed. The details are as follows: Step S1: Preprocessing of the axis Clean the surface of the shaft by grinding and chemically cleaning to remove any remaining oxides and oils.

[0031] Step S2: Preparation of transition layer.

[0032] (1) Selection of transition layer alloy materials The transition layer alloy material can be chromium-based alloy, nickel-based alloy or other non-ferrous metal alloy.

[0033] Preferably, the transition layer alloy comprises the following components in percentage by mass: Co: 50~60%; Cr: 20~30%; W: 10~20%; C: 0.5~1.5%; Other elements are less than 2%.

[0034] The transition layer 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.

[0035] (2) Transition layer cladding parameter setting Current: 180-220A.

[0036] Speed: 15-25mm / s.

[0037] Gas protection: Use He gas (or other single or mixed protective gases with equivalent flow rate), and the flow rate is controlled at 15-20L / min.

[0038] Before surfacing the transition layer, preheat the planetary shaft to 100-150℃.

[0039] During the surfacing process, the temperature of the surfacing area is controlled not to exceed 400℃ to avoid degradation of material properties. After surfacing, insulation is performed and then forced air cooling is performed.

[0040] Transition layer processing and testing Rough machining: Mechanical machining using turning or grinding to remove uneven parts of the transition layer surface.

[0041] Non-destructive testing: Magnetic particle testing (MT) or penetrant testing (PT) is used to ensure that the transition layer has no cracks, unfused or hole defects.

[0042] Step S3: Preparation of wear-resistant layer.

[0043] (1) Selection of wear-resistant layer alloy material The wear-resistant layer alloy can be copper-based alloy, aluminum-based alloy or other non-ferrous metal alloy.

[0044] Preferably, the wear-resistant layer alloy comprises the following components in percentage by mass: Cu: 80~85% Sn: 10~13% Ni: 0.1~3% Other elements are less than 2%.

[0045] The wear-resistant layer alloy has extremely high hardness and wear resistance and can significantly increase the service life of the bearing.

[0046] (2) Wear-resistant layer cladding parameter setting Current: 220~260A, suitable for wear-resistant layer alloy.

[0047] Voltage: 22~26V, keep the arc stable.

[0048] Speed: 15~25mm / s, to ensure the uniformity and density of the alloy layer.

[0049] Shielding gas: Use He gas (or other single or mixed shielding gases with equal flow rate) as shielding gas, and control the flow rate at 15~20L / min.

[0050] Before surfacing the wear-resistant layer, preheat the shaft to 100~150℃.

[0051] During the cladding process, the temperature of the cladding area is controlled not to exceed 400°C.

[0052] Step S4: wear-resistant layer processing and testing.

[0053] Finishing: After the wear-resistant layer is clad, use turning or grinding to remove the uneven surface.

[0054] Ultrasonic Testing (UT): Ultrasonic testing of the wear-resistant layer ensures that there are no obvious internal defects such as delamination, voids or cracks.

[0055] Surface roughness detection: 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.

[0056] The integrated shaft is prepared by the manufacturing process of the comparative example.

[0057] Example 1 Example 1 provides a manufacturing process for an integrated shaft, in which a transition layer alloy is sprayed on the surface of the shaft by thermal spraying, and then a wear-resistant layer alloy is clad on the surface of the shaft by cold metal transfer welding. The total thickness of the alloy layer (transition layer plus wear-resistant layer) in the radial direction is less than 1.5 mm.

[0058] As described above, in Example 1, a transition layer alloy is sprayed on the shaft surface by cold metal transfer cladding process and then a wear-resistant layer alloy is clad. In the specific implementation, the shaft is clamped on the thermal spraying equipment, the material of the shaft can be steel or cast iron, and the transition layer is thermally sprayed according to the set parameters. Then the shaft is clamped on the cladding equipment, and cold metal transfer cladding is performed according to the set parameters. Finally, processing and testing are performed.

[0059] The details are as follows: Step S1: Axis preprocessing Clean the surface of the shaft by grinding and chemically cleaning to remove any remaining oxides and oils.

[0060] Step S2: Preparation of transition layer.

[0061] (1) Selection of transition layer alloy materials The transition layer alloy material can be chromium-based alloy, nickel-based alloy or other non-ferrous metal alloy.

[0062] Preferably, the transition layer alloy comprises the following components in percentage by mass: Co: 50~60%; Cr: 20~30%; W: 10~20%; C: 0.5~1.5%; Other elements are less than 2%.

[0063] The transition layer 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.

[0064] (2) Thermal spraying parameter setting of transition layer Flame speed: 1500~3000m / s ‌.

[0065] ‌Particle speed‌: The speed of sprayed particles is 300~800m / s ‌.

[0066] Temperature: The flame temperature is 3200℃.

[0067] ‌‌Compressed air inlet pressure‌: 84~87 pounds per square inch (100~130 psi)‌.

[0068] ‌‌Intake pressure‌: 110~140 psi‌.

[0069] ‌‌Spray gun spacing‌: 100~200mm‌.

[0070] Movement speed: 10~11 mm / s.

[0071] Workpiece temperature: below 200℃.

[0072] ‌‌Spraying thickness‌: 0.1~1mm‌.

[0073] Step S3: Preparation of wear-resistant layer.

[0074] (1) Selection of wear-resistant layer alloy material The wear-resistant layer alloy can be copper-based alloy, aluminum-based alloy or other non-ferrous metal alloy.

[0075] Preferably, the wear-resistant layer alloy comprises the following components in percentage by mass: Cu: 80~85% Sn: 10~13% Ni: 0.1~3% Other elements are less than 2%.

[0076] The wear-resistant layer alloy has extremely high hardness and wear resistance and can significantly increase the service life of the bearing.

[0077] (2) Wear-resistant layer cladding parameter setting Current: 220~260A, suitable for wear-resistant layer alloy.

[0078] Voltage: 22~26V, keep the arc stable.

[0079] Speed: 15~25mm / s, to ensure the uniformity and density of the alloy layer.

[0080] Shielding gas: Use He gas (or other single or mixed shielding gases with equal flow rate) as shielding gas, and control the flow rate at 15~20L / min to prevent oxidation and splashing.

[0081] Before surfacing the wear-resistant layer, the shaft is preheated to 100~150℃ to reduce thermal stress.

[0082] During the surfacing process, the temperature of the surfacing area is controlled not to exceed 400℃ to avoid degradation of material properties. After surfacing, insulation is performed and then forced air cooling is performed.

[0083] Step S4: wear-resistant layer processing and testing.

[0084] Finishing: After the wear-resistant layer is clad, use turning or grinding to remove the uneven surface.

[0085] Ultrasonic Testing (UT): Ultrasonic testing of the wear-resistant layer ensures that there are no obvious internal defects such as delamination, voids or cracks.

[0086] Surface roughness detection: 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.

[0087] The integrated shaft prepared by the manufacturing process of Example 1 is as follows Figure 3 As shown, the shaft 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, effectively solving the failure problem of the traditional sliding bearing and improving the reliability and cost-effectiveness of the bearing. The integrated shaft of Example 1 is ensured to be firm and reliable on the surface alloy layer through fine process parameter control and quality inspection. When it is applied to the planetary shaft of the wind power gearbox, it can meet the long-term operation requirements of the wind power gearbox.

[0088] Effect verification: Various technical performances of the integrated shafts of Comparative Example 1 and Example 1 were tested.

[0089] The testing standards for various technical performances are: Mechanical properties Reference standards hardness EN 1982 Yield Strength GB / T 7314 tensile strength GB / T 228.1 Dry friction coefficient GB / T 35083.1 Oil friction coefficient GB / T 35083.1 The technical performance test results are: Mechanical properties Comparative Example 1 Example 1 hardness >95HB >95HB Yield Strength >200Mpa >200Mpa tensile strength >200Mpa >200Mpa Dry friction coefficient <0.5 <0.5 Oil friction coefficient <0.2 <0.2 Although the technical performance test results of Example 1 are basically consistent with those of the comparative example, compared with Comparative Example 1, after the transition layer of Example 1 is changed from surfacing to thermal spraying, the thickness of the alloy layer in the radial direction of the finished product can be controlled to be <1.5mm, compared with the original <3mm, which significantly saves materials and improves efficiency.

[0090] The present invention has many specific application paths, and the above is only a preferred embodiment of the present invention. It should be pointed out that the above embodiments are only used to illustrate the present invention, and are not used to limit the protection scope of the present invention. For those of ordinary skill in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A process for preparing an integrated shaft by cold metal transfer cladding, characterized in that: The steps include: Step S1: Clean the surface of the shaft to remove oxides and oil stains; Step S2: using a thermal spraying process to spray a transition layer alloy onto the shaft surface to form a transition layer; Step S3: using a cold metal transfer cladding process to melt the wear-resistant layer alloy onto the transition layer on the shaft surface to form a wear-resistant layer; Step S4: Process and inspect the wear-resistant layer on the shaft surface to ensure that the surface has no cracks, unfused or hole defects and meets the designed roughness requirements, thereby preparing an integrated shaft.

2. The process for preparing an integrated shaft by cold metal transfer cladding according to claim 1, characterized in that: In step S2, the processing parameters of the thermal spraying process are: flame speed of 1500~3000m / s, particle speed of 300~800m / s, flame temperature of 2000-3500℃, compressed air inlet pressure of 100~130psi, air intake pressure of 110~140psi, spray gun spacing of 100~200mm, moving speed of 10~11 mm / s, workpiece temperature of <200℃, and spraying thickness of 0.1~1mm; the transition layer alloy is selected from chromium-based alloy, nickel-based alloy or one of other non-ferrous metal alloys.

3. The process for preparing an integrated shaft by cold metal transfer cladding according to claim 1, characterized in that: In step S2, the transition layer alloy includes the following components in percentage by mass: Co: 50~60%; Cr：20~30%； W：10~20%； C：0.5~1.5%； Other elements: less than 2%.

4. The process for preparing an integrated shaft by cold metal transfer cladding according to claim 1, characterized in that: In step S3, the processing parameters of the cold metal transfer cladding process are: current of 220-260A, voltage of 22-26V, cladding speed of 15-25mm / s, and flow rate of shielding gas of 5-20L / min; the wear-resistant layer alloy is selected from one of copper-based alloy, aluminum-based alloy or other non-ferrous metal alloy.

5. The process for preparing an integrated shaft by cold metal transfer cladding according to claim 1, characterized in that: In step S3, before the cold metal transfer cladding process, the shaft is preheated to 100-150° C., and during the cold metal transfer cladding process, the temperature of the cladding area is controlled not to exceed 400° C., and forced air cooling is performed after cladding.

6. The process for preparing an integrated shaft by cold metal transfer cladding according to claim 1, characterized in that: In step S3, the wear-resistant layer alloy includes the following components in percentage by mass: Cu: 80~85% Sn: 10~13% Ni: 0.1~3% Other elements: less than 2%.

7. 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.

8. The process for preparing an integrated shaft by cold metal transfer cladding according to claim 1, characterized in that: The total thickness of the transition layer and the wear-resistant layer is less than 1.5 mm.

9. An integrated shaft, characterized in that: The method is prepared by the process described in any one of claims 1 to 8.

10. The integrated shaft according to claim 9 is used as a planetary shaft of a wind power gearbox, wherein the planetary shaft is rotatably mounted in the wind power gearbox.

Images