Clutch driving shaft platform additive repairing method based on laser cladding technology

Abstract

The invention discloses a clutch driving shaft platform additive repairing method based on a laser cladding technology. The clutch driving shaft platform additive repairing method comprises the steps that a clutch driving shaft and Fe-5 iron-based powder are preheated before welding; fe-5 iron-based powder is used for carrying out laser melting material adding on the abraded position, without machining allowance, of the clutch driving shaft; and after-welding slow cooling and supplementary machining are conducted on the clutch driving shaft obtained after laser melting additive manufacturing, and the clutch driving shaft is repaired. According to the method, material reduction repair is changed into material increase repair, Fe-5 iron-based powder is selected as material increase repair powder, after laser cladding, the surface hardness of the Fe-5 iron-based powder reaches or is superior to that of an original matrix carburizing surface, cladding can be directly carried out on an original clutch driving shaft platform, and the clutch driving shaft which cannot be ground and repaired is recovered to the original technological level; and meanwhile, the wear resistance of the repaired platform is verified through a fretting wear test.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive repair of aviation transmission equipment remanufacturing. More specifically, the present invention relates to an additive repair method for the clutch drive shaft platform based on laser cladding technology. Background Art

[0002] The M17 series helicopter engine is connected to the main reducer by a roller type free-travel clutch. This type of clutch is a relatively common one-way power transmission mechanism in applications. Its function is to enable the engine to drive the rotor, rather than allowing the rotor to drive the engine. When the engine is stopped or the helicopter is in autorotation flight, it ensures that the rotor is disengaged from the engine, and the rotor can rotate freely; for helicopters equipped with multiple engines, the shutdown of any one engine will not affect the operation of other engines and the rotor. As Figure 1 shown, due to the impact during startup and fretting wear during use, indentations and wear occur at the contact position between the clutch roller and the clutch drive shaft. When the wear exceeds the process regulations, it will lead to a decrease in the transmission performance of the clutch, thereby affecting flight safety.

[0003] For the clutch drive shaft platform with excessive wear, the method of grinding the platform has been used for a long time during the repair process. For the main reducer that has been overhauled many times, the size of its drive shaft platform has approached the lower limit and cannot be ground for repair again. Therefore, it is urgent to explore a reasonable additive method to perform additive repair on the platform that has no grinding allowance after being repaired many times. Summary of the Invention

[0004] An object of the present invention is to solve at least the above problems and / or defects and provide at least the advantages described hereinafter.

[0005] To achieve these objects and other advantages of the present invention, an additive repair method for the clutch drive shaft platform based on laser cladding technology is provided, including the following steps: Step 1: Preheat the clutch drive shaft and Fe-5 iron-based powder before welding; Step 2: Use Fe-5 iron-based powder to perform laser melting additive on the worn part of the clutch drive shaft without machining allowance; Step 3: Slowly cool the clutch drive shaft after laser melting additive, and perform supplementary machining to complete the repair of the clutch drive shaft.

[0006] Preferably, in the step 1, the specific method for preheating the clutch drive shaft includes: heating the clutch drive shaft in the furnace to 100°C to 150°C and holding for 30 minutes; The specific method for preheating the Fe-5 iron-based powder before welding includes: placing the Fe-5 iron-based powder in a powder feeding tank, heating the tank to 100°C - 150°C, and holding for 30 minutes.

[0007] Preferably, in step two, the Fe-5 iron-based powder by mass percentage includes: 0.40 - 0.45% C powder, 13 - 15% Cr powder, 0.3 - 0.6% Si powder, 0.15 - 0.30% Mn powder, and the balance is Fe powder.

[0008] Preferably, in step two, the hardness of the Fe-5 iron-based powder is 62HRC - 67HRC.

[0009] Preferably, in step two, when performing laser melting additive manufacturing on the worn part of the clutch driving shaft without machining allowance, set the laser power to 300 - 400W, the scanning speed to 6 - 8mm / s, the powder trough width to 6mm, the powder feeding rate to 0.20 - 0.40 revolutions / min, the track spacing to 0.35 - 0.5mm, the single layer height to 0.4mm, and the single track width to 0.7 - 1mm.

[0010] Preferably, in step two, when performing laser melting additive manufacturing on the worn part of the clutch driving shaft, the effective additive depth is not more than 0.15mm, and the single layer thickness of laser cladding is 0.3 - 0.5mm.

[0011] Preferably, in step three, the specific method for slow cooling of the clutch driving shaft after welding includes: after welding, place the clutch driving shaft in an electric oven at a temperature of 130°C - 150°C, hold for 2 hours, turn off the oven power, and cool with the furnace.

[0012] Preferably, in step three, after slow cooling of the clutch driving shaft after laser melting additive manufacturing, it also includes performing machining and shaping.

[0013] Preferably, in step three, after the repair of the clutch driving shaft is completed, it also includes performing a compressive calculation on the un-repaired clutch driving shaft and the repaired clutch driving shaft to determine whether the surface strength of the additive position of the repaired clutch driving shaft meets the usage requirements.

[0014] Preferably, the specific method for performing a compressive calculation on the un-repaired clutch driving shaft includes: S1. Calculate the acting load F of the single-engine on the clutch driving shaft: F = P / v Wherein, P is the power of the single-engine,P = W / t , t For time, W To do work for the engine; v is the engine linear speed, v = πDn , n is the engine speed, D is the circumference of the contact position between the engine and the clutch driving shaft; Among them, the clutch active shaft includes 16 platforms, and the load acting on each platform is F 1= F / 16; S2. Calculate the clutch driving shaft pressure p 1: p 1= F 1 / S in, p 1 is the pressure of a single engine acting on the clutch driving shaft, S is the contact area between the engine and the clutch driving shaft, S= l × b , l is the contact length between the engine and the clutch driving shaft, b is the contact width between the engine and the clutch driving shaft, where , R represents the equivalent radius of curvature, i.e. the roller radius, l Indicates the effective length of the roller, E * represents the comprehensive elastic modulus of the contact between the cylindrical roller and the clutch platform, where , E 1. E 2 are the elastic moduli of the roller and clutch driving shaft platform, v 1. v 2 are the Poisson's ratios of the roller and clutch driving shaft respectively; The specific method for calculating the pressure on the repaired clutch drive shaft includes: setting a test load F 2. Load the repaired cladding layer according to the pit area. S 2. Calculation F 2 Pressure failure test pressure under test load p 2, namely p 2= F 2 / S 2; like p 2≥ p 1, the surface strength of the repaired clutch driving shaft at the material-adding position meets the use requirements.

[0015] The present invention has at least the following beneficial effects: The present invention proposes an additive repair method based on laser cladding technology, which restores the platform that cannot be repaired by grinding to the original process level, achieves the goal of cost reduction and efficiency improvement, and at the same time verifies the wear resistance of the repaired platform through fretting wear tests.

[0016] The present invention improves the repair process of the clutch driving shaft platform, changes the subtractive repair to additive repair, conforms to the repair concept of remanufacturing, and repairs the scrapped parts without machining repair allowance to the original technical level by additive method, reducing costs and increasing efficiency, and achieving sustainable development.

[0017] Based on the material and working conditions of the driving shaft, the present invention selects Fe-5 iron-based powder as the additive repair powder, so that after laser cladding, the surface hardness reaches or is better than the original matrix carburized surface, and it can be directly clad on the original clutch driving shaft platform, simplifying the process flow.

[0018] Due to the small amount of additive and the use of a symmetric and alternating cladding method, it is easier to control deformation, and after machining to remove the allowance after cladding, there is no need to consider supplementary chemical treatment and heat treatment, which will not affect the original infiltration layer, and at the same time its fretting wear resistance meets the usage requirements.

[0019] Other advantages, objectives and features of the present invention will be partially reflected by the following description, and partially will also be understood by those skilled in the art through the research and practice of the present invention. Brief Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the wear of the clutch driving shaft platform; Figure 2 It is a schematic flow diagram of the additive repair method of the clutch driving shaft platform based on laser cladding technology of the present invention; Figure 3 It is a schematic diagram of the fabricated cladding test piece; Figure 4 It is a 200X metallographic micrograph after laser cladding at a certain place on the cladding test piece according to the method of Example 1; Figure 5 It is a 200X metallographic micrograph after laser cladding at a certain place on the cladding test piece according to the method of Example 1; Figure 6 It is a 200X metallographic micrograph after laser cladding at a certain place on the cladding test piece according to the method of Example 1; Figure 7 It is a 200X microscopic magnification effect diagram of the 5 kg load destructive test of the cladding test piece; Figure 8 It is a 200X microscopic magnification effect diagram of the 10 kg load destructive test of the cladding test piece; Figure 9 It is a 200X microscopic magnification effect diagram for the destructive force test of the cladding specimen under a 20 kg load; Figure 10 It is a 200X microscopic magnification effect diagram for the destructive force test of the cladding specimen under a 60 kg load; Figure 11 It is a 1000X microscopic magnification effect diagram for the destructive force test of the central area of the cladding specimen under a 60 kg load; Figure 12 It is a 1000X microscopic magnification effect diagram for the destructive force test of the edge area of the cladding specimen under a 60 kg load. Specific implementation mode

[0021] The following further elaborates on the present invention in conjunction with the attached drawings, so that those skilled in the art can implement it with reference to the text of the specification.

[0022] It should be understood that terms such as "having", "comprising", and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations. Example 1 As Figure 2 shown, this example provides a method for additive repair of the clutch driving shaft platform based on laser cladding technology, including the following steps: Step 1: Heat the clutch driving shaft in the furnace to 150 °C and keep it warm for 30 min; place the Fe-5 iron-based powder in the powder feeding tank and heat it in the tank to 150 °C and keep it warm for 30 min; among them, the Fe-5 iron-based powder includes by mass percentage: 0.45% C powder, 15% Cr powder, 0.6% Si powder, 0.3% Mn powder, and the balance is Fe powder; Step 2: Set the laser power to 400 W, the scanning speed to 6 mm / s, the powder trough width to 6 mm, the powder feeding rate to 0.40 revolutions / min, the track spacing to 0.5 mm, the single layer height to 0.4 mm, and the single track width to 1 mm, and perform laser melting additive manufacturing on the clutch driving shaft platform without machining allowance; Step 3: After laser cladding is completed, place the clutch driving shaft in an electric oven at a temperature of 150 °C, keep it warm for 2 hours, turn off the oven power supply, and cool it with the furnace. The repair of the clutch driving shaft platform is completed.

[0023] The single layer thickness of laser cladding in this example is about 0.5 mm, and the required effective additive depth is not greater than 0.15 mm. This example has sufficient machining allowance to meet the production and processing requirements. Therefore, performing single layer cladding can fully meet the repair requirements.

[0024] Example 2 A method for additive repair of the clutch driving shaft platform based on laser cladding technology, including the following steps: Step 1: Heat the clutch driving shaft in the furnace to 150°C and hold for 30 min; place the Fe-5 iron-based powder in the powder feeding tank and heat it in the tank to 150°C and hold for 30 min. The Fe-5 iron-based powder contains, by mass percentage: 0.45% C powder, 15% Cr powder, 0.6% Si powder, 0.3% Mn powder, and the balance is Fe powder. Step 2: Set the laser power to 300 W, the scanning speed to 8 mm / s, the powder trough width to 6 mm, the powder feeding rate to 0.20 revolutions / min, the track pitch to 0.35 mm, the single-layer height to 0.3 mm, and the single-track width to 0.7 mm, and perform laser melting additive manufacturing on the clutch driving shaft platform without machining allowance. Step 3: After laser cladding is completed, place the clutch driving shaft in an electric oven at a temperature of 150°C, hold for 2 hours, turn off the oven power supply, and cool it in the furnace. The repair of the clutch driving shaft platform is completed.

[0025] Example 3 An additive repair method for the clutch driving shaft platform based on laser cladding technology includes the following steps: Step 1: Heat the clutch driving shaft in the furnace to 150°C and hold for 30 min; place the Fe-5 iron-based powder in the powder feeding tank and heat it in the tank to 150°C and hold for 30 min. The Fe-5 iron-based powder contains, by mass percentage: 0.45% C powder, 15% Cr powder, 0.6% Si powder, 0.3% Mn powder, and the balance is Fe powder. Step 2: Set the laser power to 350 W, the scanning speed to 8 mm / s, the powder trough width to 6 mm, the powder feeding rate to 0.20 revolutions / min, the track pitch to 0.35 mm, the single-layer height to 0.3 mm, and the single-track width to 0.7 mm, and perform laser melting additive manufacturing on the clutch driving shaft platform without machining allowance. Step 3: After laser cladding is completed, place the clutch driving shaft in an electric oven at a temperature of 150°C, hold for 2 hours, turn off the oven power supply, and cool it in the furnace. The repair of the clutch driving shaft platform is completed.

[0026] Example 4 An additive repair method for the clutch driving shaft platform based on laser cladding technology includes the following steps: Step 1: Heat the clutch driving shaft in the furnace to 150°C and hold for 30 min; place the Fe-5 iron-based powder in the powder feeding tank and heat it in the tank to 150°C and hold for 30 min. The Fe-5 iron-based powder contains, by mass percentage: 0.45% C powder, 15% Cr powder, 0.6% Si powder, 0.3% Mn powder, and the balance is Fe powder. Step 2: Set the laser power to 350 W, the scanning speed to 8 mm / s, the powder trough width to 6 mm, the powder feeding rate to 0.30 revolutions per minute, the track spacing to 0.35 mm, the single-layer height to 0.3 mm, and the single-track width to 0.7 mm. Perform laser melting and additive manufacturing on the worn part of the clutch driving shaft platform without machining allowance; Step 3: After laser cladding is completed, place the clutch driving shaft in an electric oven at a temperature of 150 °C, keep it warm for 2 hours, turn off the oven power, and cool it with the furnace. The repair of the clutch driving shaft platform is completed.

[0027] For the laser cladding parameters of Example 2, due to the small power, the powder was not fully melted, and there was a situation where the powder was not completely melted locally. The surface after cladding was significantly rougher, with a high porosity and low bonding strength; after the laser cladding power was increased in Example 3 and Example 4, the situation of locally unmelted powder was basically eliminated, but the local thickness after cladding was insufficient, resulting in the edge not being polished during supplementary processing; in Example 1, in order to increase the thickness of the cladding layer, the powder feeding speed was increased and the scanning speed was reduced. In order to ensure complete melting of the powder, the power was appropriately increased.

[0028] Use a cladding test piece to conduct relevant hardness tests on the method of Example 1. After the cladding test piece was grooved in the middle (depth: 0.2 mm, width: 5 mm) and then single-layer stacked, it was made as Figure 3 shown. After X-ray inspection, no cracks were found. The laser cladding method was the same as that of Example 1. Randomly select 2 test pieces for microhardness inspection. The inspection data shows that the microhardness of the base material is 340.667 HV1 and 359.667 HV1 (corresponding to Rockwell hardness of about 37 HRC and 39 HRC), and the microhardness of the heat-affected zone is 300 HV1 and 301 HV1 (corresponding to Rockwell hardness of about 31.5 HRC). The heat-affected zone is reduced by 11.9% and 16.3% respectively compared with the base material. The microhardness of the additive zone is 815 HV1 and 829 HV1, corresponding to Rockwell hardness of about 65 HRC, meeting the technical requirements of the specified surface hardness of the clutch driving shaft ≥ HRC61 or HV721. The specific test data is shown in Table 1.

[0029] Table Microhardness Test Results of 12Cr2Ni4A (Fe-5) Process Test Pieces (HV1) According to Figure 3The prepared mechanical property test specimens have a test piece thickness of 2.5 mm, with a groove in the middle, a depth of 0.5 mm, and a width of 5 mm. The tensile strength is the average value of the tensile strengths of three specimens under the same test conditions. Tensile tests were carried out on the non-welded and welded specimens, and the test data are shown in Table 2; the test data show that the tensile strength of the original non-welded specimen is 1004.3 MPa, and the tensile strength after surfacing welding is 909.3 MPa.

[0030] Table 2 Strength test results of 12Cr2Ni4A (Fe-5) process test pieces Metallographic inspection was carried out on the prepared test pieces, as Figures 4 - 6 shown. It can be seen from the metallographic micrograph that no defects such as pores, inclusions, and cracks were found on the test pieces, indicating that the test pieces after Fe-5 powder cladding meet the usage process requirements.

[0031] The clutch driving shaft platform is used to transmit the rotational speed and power input by the engine. During the working process, this surface is mainly under pressure. The method of gradually increasing the test load of metallographic microhardness testing was used to carry out the pressure failure test. The measurement of the pit diameters in the 5 kg, 10 kg, 20 kg, and 60 kg pressure failure tests is shown in Figures 7 - 10 . The partial enlarged view of the measurement of the pit diameter in the 60 kg pressure failure test is as Figures 11 - 12 shown. The center and the rounded corners around of the 60 kg test piece were inspected under a 1000X microscope, and no microcracks were found. This indicates that the pressure resistance failure performance of the test piece meets the standards.

[0032] By calculating the pressure on the clutch driving shaft platform and comparing it with the pressure test of the Fe-5 test piece, it is judged whether the specimen prepared by the process method of the present invention meets the actual pressure-bearing requirements. According to the relationship between parameters such as power and speed, the load transmitted by the clutch driving shaft platform is calculated, and the pressure on each platform is calculated. Among them, the engine is calculated according to the maximum emergency power of 2400 hp, which is converted into a power of 1764 kW. The relevant calculation process is as follows: S1. Calculate the acting load of a single engine on the clutch driving shaft F : F = P / v Among them, P is the power of a single engine, P = W / t , t is the time, W is the work done by the engine, the calculated result of the power is 1764 kW, and the acting load F is 24955.49471 N; v is the linear velocity of the engine, v = πDn, the calculation result is 70.68583575 m / s, n is the engine speed, with a value of 15000 rpm / min, D is the perimeter at the contact position between the engine and the clutch driving shaft, with a value of 90 mm, and π is taken as 3.1415927; Among them, the clutch driving shaft includes 16 platforms, then the applied load on each platform F 1 = F / 16, and the calculation result is 1559.718419 N; S2. Calculate the applied pressure on the clutch driving shaft platform p 1: p 1 = F 1 / S Among them, p 1 is the applied pressure of a single engine on the clutch driving shaft, and the calculation result is 530.4 MPa, S is the contact area between the engine and the clutch driving shaft, S = l × b , l is the contact length between the engine and the clutch driving shaft, b is the contact width between the engine and the clutch driving shaft, among which , R represents the equivalent radius of curvature, that is, the roller radius, with a value of 0.00625 m, l represents the effective length of the roller, with a value of 0.0195 m, E * represents the comprehensive elastic modulus of the cylindrical roller in contact with the clutch platform. Among them, , E 1, E 2 are the elastic moduli of the roller and the clutch driving shaft platform respectively, v 1, v 2 are the Poisson's ratios of the roller and the clutch driving shaft platform respectively. The elastic modulus of 12Cr2Ni4A is 190 GPa - 210 GPa, taking 200 GPa, the elastic modulus of GCr15A is 206 GPa - 212 GPa, taking 209 GPa, the Poisson's ratio of 12Cr2Ni4A is 0.28 - 0.30, taking 0.29, and the Poisson's ratio of GCr15A is 0.30 - 0.31, taking 0.30.

[0033] The calculation results show that under a working load of 60 kg, the pressure borne by the Fe-5 specimen is approximately 8065.8 MPa. The pressure in the pressure failure test is approximately 15.21 times the maximum pressure when a single platform is working. The results of the pressure failure test indicate that the surface strength meets the usage requirements after laser cladding with Fe-5 iron-based alloy powder.

[0034] Table 3 Pressure in the pressure failure test of the Fe5 specimen Wear resistance verification tests were respectively carried out on the laser-cladded specimen and the non-cladded substrate specimen on a fretting wear testing machine. In the test design, the upper specimen is a cylindrical roller, and the lower specimen is a square specimen block. The contact stress between the friction pairs is controlled by adjusting the loading pressure and the effective length of the cylindrical roller to keep it consistent with the working pressure of the clutch driving shaft platform. The fretting frequency is set at 20 Hz, the displacement amplitude is 200 μm, and the number of fretting cycles is 5×10 4 times. The fretting wear resistance test is carried out in the ambient atmosphere at room temperature. An optical 3D surface profiler (SuperView W1-Pro) is used to measure the three-dimensional topography of the wear scar, and multi-faceted data such as the three-dimensional profile of the wear scar, the wear scar depth, and the wear volume are obtained. By comparing the wear results, it is found that the wear scar depth and the wear amount of the cladded specimen are slightly smaller than those of the substrate specimen, indicating that the wear resistance is basically the same as or even improved compared with the original substrate after cladding additive manufacturing, meeting the usage standards.

[0035] The equipment quantity and processing scale described here are used to simplify the description of the present invention. The applications, modifications, and variations of the present invention are obvious to those skilled in the art.

[0036] Although the embodiments of the present invention have been disclosed as above, it is not limited to only the applications listed in the description and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the examples shown and described here.

Claims

1. An additive repair method for the clutch driving shaft platform based on laser cladding technology, characterized in that, It includes the following steps: Step 1: Preheat the clutch driving shaft and Fe-5 iron-based powder before welding; Step 2: Use Fe-5 iron-based powder to perform laser melting additive manufacturing on the worn part of the clutch driving shaft without machining allowance; Step 3: Slowly cool the clutch driving shaft after laser melting additive manufacturing, and perform supplementary machining to complete the repair of the clutch driving shaft.

2. The additive repair method for the clutch driving shaft platform based on laser cladding technology according to claim 1, characterized in that In the above Step 1, the specific method for preheating the clutch driving shaft before welding includes: heating the clutch driving shaft in the furnace to 100°C to 150°C and holding for 30 minutes; The specific method for preheating the Fe-5 iron-based powder before welding includes: placing the Fe-5 iron-based powder in the powder feeding tank and heating it in the tank to 100°C to 150°C and holding for 30 minutes.

3. The additive repair method for the clutch driving shaft platform based on laser cladding technology according to claim 1, characterized in that In the above Step 2, the Fe-5 iron-based powder by mass percentage includes: 0.40 - 0.45% C powder, 13 - 15% Cr powder, 0.3 - 0.6% Si powder, 0.15 - 0.30% Mn powder, and the balance is Fe powder.

4. The additive repair method for the clutch driving shaft platform based on the laser cladding technology according to claim 1, characterized in that, In the above Step 2, the hardness of the Fe-5 iron-based powder is 62HRC - 67HRC.

5. The additive repair method for the clutch driving shaft platform based on the laser cladding technology according to claim 1, wherein, In the above Step 2, when performing laser melting additive manufacturing on the worn part of the clutch driving shaft without machining allowance, set the laser power to 300 - 400W, the scanning speed to 6 - 8mm / s, the powder trough width to 6mm, the powder feeding rate to 0.20 - 0.40 revolutions / min, the track spacing to 0.35 - 0.5mm, the single layer height to 0.4mm, and the single track width to 0.7 - 1mm.

6. The additive repair method for the clutch driving shaft platform based on the laser cladding technology according to claim 1, wherein In the above Step 2, when performing laser melting additive manufacturing on the worn part of the clutch driving shaft, the effective additive depth is not more than 0.15mm, and the single layer thickness of laser cladding is 0.3 - 0.5mm.

7. The additive repair method for the clutch driving shaft platform based on the laser cladding technology according to claim 1, characterized in that In the above Step 3, the specific method for slowly cooling the clutch driving shaft after welding includes: after welding, place the clutch driving shaft in an electric oven at a temperature of 130°C to 150°C, hold for 2 hours, turn off the oven power, and cool it in the furnace.

8. The additive repair method for the clutch driving shaft platform based on the laser cladding technology according to claim 1, wherein In the above Step 3, after slowly cooling the clutch driving shaft after laser melting additive manufacturing, it also includes performing machining and shaping.

9. The additive repair method for the clutch driving shaft platform based on the laser cladding technology according to claim 1, wherein After the repair of the clutch driving shaft is completed in the above Step 3, it also includes performing a compression calculation on the un-repaired clutch driving shaft and the repaired clutch driving shaft to determine whether the surface strength of the additive position of the repaired clutch driving shaft meets the usage requirements.

10. The additive repair method for the clutch driving shaft platform based on the laser cladding technology according to claim 9, characterized in that, The specific method for performing a compression calculation on the un-repaired clutch driving shaft includes: S1. Calculate the acting load of a single engine on the clutch driving shaft F : F = P / v Among them, P is the single-engine power, P = W / t , t is the time, W is the work done by the engine; v is the linear velocity of the engine, v = πDn , n is the engine speed, D is the circumference of the contact position between the engine and the clutch main shaft; Among them, the clutch drive shaft includes 16 platforms, and the applied load of each platform F 1 = F / 16; S2. Calculate the acting pressure on the clutch driving shaft p 1: p 1= F 1 / S Among them, p 1 is the acting pressure of a single engine on the clutch driving shaft, S is the contact area between the engine and the clutch driving shaft, S = l × b , l is the contact length between the engine and the clutch driving shaft, b is the contact width between the engine and the clutch driving shaft, where , R represents the equivalent curvature radius, i.e., the roller radius, l represents the effective length of the roller, E * represents the comprehensive elastic modulus of the cylindrical roller in contact with the clutch platform. Among them, , E 1, E 2 are the elastic moduli of the roller and the clutch driving shaft platform respectively, v 1, v 2 are the Poisson's ratios of the roller and the clutch driving shaft respectively; The specific method for performing a compressive calculation on the repaired clutch driving shaft includes: setting a test load F 2, loading the repaired cladding layer, and calculating the pressure failure test pressure S 2 under the test load according to the indentation area F 2, that is p 2 = p 2 = F 2 / S 2; If p 2 ≥ p 1, the surface strength of the additive manufacturing position of the clutch driving shaft after repair meets the usage requirements.

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