A kind of wind power gear remanufacturing-oriented additive and subtractive composite machining device and method

Abstract

This invention relates to a composite additive and subtractive machining apparatus and method for remanufacturing wind turbine gears. The apparatus includes a machine bed, an X-axis motion unit, a Y-axis motion unit, a Z-axis motion unit, a workpiece positioning and rotation unit, a laser additive machining unit, a grinding and subtractive machining unit, a worktable fixture, a spindle motor, a power supply, a motion control system, a multi-energy field auxiliary system, and an online monitoring system. The method includes steps such as defect assessment and benchmark establishment, surface cleaning and preheating, laser additive repair, in-situ subtractive finishing, and retesting. This invention employs a multi-energy field coupling and synergistic control strategy to precisely manage the evolution of the laser molten pool. It utilizes electromagnetic induction heating to achieve local preheating of the gear substrate, leverages ultrasonic cavitation effects to refine the cladding solidification structure, and utilizes the Lorentz force generated by an applied electromagnetic field to drive the directional transport of the molten metal in the pool. This improves the coating forming quality from multiple dimensions, including molten pool morphology control, grain refinement, and defect suppression, thereby enhancing the overall performance of wind turbine gear remanufacturing.

Description

Technical Field

[0001] This invention relates to the fields of laser additive manufacturing, subtractive precision shaping and remanufacturing, and particularly to an additive and subtractive composite processing apparatus and method for remanufacturing wind turbine gears. Background Technology

[0002] As a key load-bearing component in the transmission system of wind turbine generators, wind turbine gears are subjected to a combination of alternating loads, impact loads, fluctuating lubrication conditions, and environmental corrosion over long periods. This makes their tooth surfaces susceptible to damage such as pitting, spalling, scuffing, abrasive wear, tooth tip chipping, tooth root cracks, and axial wear. These damages not only alter the gear meshing state but also increase vibration and noise, concentrate contact stress, and reduce transmission efficiency, potentially leading to gearbox downtime for maintenance in severe cases.

[0003] Laser additive manufacturing can form a repair layer that is metallurgically bonded to the substrate in locally damaged areas. It offers advantages such as a relatively small heat-affected zone, high material utilization, and suitability for localized repair. However, wind turbine gears have extremely high requirements for tooth profile accuracy, tooth direction and profile errors, surface roughness, residual stress, and hardness gradient. Relying solely on additive manufacturing often fails to meet the final assembly and transmission performance requirements, resulting in significant surface machining errors. Therefore, it is necessary to integrate field-assisted additive manufacturing with subtractive manufacturing, and introduce online monitoring and real-time data feedback to ensure that the processing quality meets service requirements.

[0004] Existing research already includes application examples of additive-subtractive composite manufacturing technology, realizing the basic functions of the "defect identification - laser additive manufacturing - machining - in-situ detection" process flow. For example, the invention patent with publication number CN114473517B discloses "a device, system and method for additive-subtractive repair of shipborne wind turbine gears," whose main technical means is to combine laser additive manufacturing with machining, solving the problems of insufficient strength and numerous surface defects in traditional repair methods, and providing a feasible solution for on-site repair of wind turbine gears. However, this technology still has limitations in practical applications: First, the equipment integration is highly complex. The coordination of the rotating platform, multiple tool magazines, and robotic arms relies on high-precision control, resulting in high overall manufacturing and maintenance costs, and its reliability is easily affected by complex working conditions. Second, the adaptability of the gear fixing module is limited. Although the tightening range can be adjusted by telescopic push rods, the clamping stability and positioning accuracy of ultra-large or special-structure wind turbine gears are difficult to guarantee. Third, the closed-loop control of the processing flow is insufficient. Although it has basic processing and inspection links, it lacks a real-time monitoring and feedback mechanism, making it impossible to dynamically adjust the cladding and finishing parameters, and difficult to cope with sudden defects that occur during the repair process.

[0005] In summary, traditional additive and subtractive composite technologies lack multi-energy field-assisted synergistic control, relying solely on a simple combination of laser additive manufacturing and machining. This lack of proactive control over temperature gradients, molten pool flow, porosity migration, grain growth, and residual stress evolution during the cladding process leads to potential porosity, incomplete fusion, cracks, coarse microstructure, and localized segregation within the cladding layer. This results in limited bonding strength and a tendency for detachment under high-speed, heavy-load conditions in wind turbine gears. Furthermore, the finishing stage cannot compensate for internal defects in the cladding layer, impacting the service life of the repaired gear. Existing single-energy field-assisted technologies have limited control effects and struggle to address multiple control objectives simultaneously. Induction heating primarily improves substrate preheating and molten pool temperature gradients, ultrasonic vibration primarily improves molten pool disturbance, and magnetic field assistance primarily regulates conductive molten pool flow and solidification microstructure. When these three technologies independently assist the laser additive manufacturing stage, problems such as dispersed control targets and poor process stability arise, failing to meet the synergistic control requirements of the entire processing flow. The lack of closed-loop control in the processing process, the absence of a real-time monitoring and dynamic feedback mechanism for key parameters such as cladding layer quality and residual stress, and the difficulty in adjusting field parameters and processing parameters according to the evolution of defects during the processing process result in low product qualification rate, long process connection time, and repair efficiency needs to be improved. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide an additive-subtractive composite machining apparatus and method for remanufacturing wind turbine gears. By combining additive and subtractive machining, it improves the machining efficiency and precision of parts, incorporates multi-energy field assistance to regulate the dynamic process of the molten pool during additive machining, refines the microstructure, and improves overall performance. Simultaneously, it utilizes an online monitoring system to monitor the machining status and progress. This effectively solves the technical shortcomings of existing methods, such as limited control by a single physical field, poor synergy in traditional additive-subtractive composite machining processes, and the lack of real-time online monitoring and closed-loop parameter control during the machining process.

[0007] The technical solution adopted in this invention is as follows: This invention proposes a composite machining device for remanufacturing wind turbine gears, comprising a machine bed, an X-axis motion unit, a Y-axis motion unit, a Z-axis motion unit, a workpiece positioning and rotating unit, a laser additive machining unit, a grinding and reducing machining unit, a worktable fixture, a spindle motor, a power supply, a motion control system, a multi-energy field auxiliary system, and an online monitoring system. The machine bed has a composite machining area, and the workpiece positioning and rotating unit is located within this area. The worktable fixture is fixedly mounted on the rotary table working surface of the workpiece positioning and rotating unit for holding the gear to be repaired. The X-axis motion unit is positioned along the depth direction of the machine bed. The Y-axis motion unit is connected to the X-axis motion unit and arranged along the width direction of the machine bed. The Z-axis motion unit is connected to the Y-axis motion unit along the vertical direction of the machine tool. The spindle motor is fixedly connected to the bottom end of the Z-axis motion unit. The X-axis motion unit, Y-axis motion unit, and Z-axis motion unit are driven by lead screw transmission mechanisms to perform linear motion on their corresponding moving parts. The laser additive manufacturing unit is located below the Z-axis motion unit and connected to the output end of the spindle motor, with its processing end facing the workpiece processing area on the worktable fixture. The grinding and cutting unit is located on one side inside the machine bed, with its grinding end facing the workpiece processing area. The motion control system is located outside the machine bed and connected to the power supply. The multi-energy field auxiliary system is located inside the machine bed and arranged around the workpiece processing area. The online monitoring system is located on the Z-axis motion unit and is connected to the motion control system. The motion control system is connected to the X-axis motion unit, Y-axis motion unit, Z-axis motion unit, workpiece positioning and rotation unit, laser additive manufacturing unit, grinding and cutting unit, multi-energy field auxiliary system, and online monitoring system.

[0008] Furthermore, the multi-energy field auxiliary system includes an induction heating auxiliary system, an ultrasonic vibration system, and a magnetic field auxiliary system; the magnetic field auxiliary system includes electromagnetic field generating components disposed opposite to each other on both sides of the workpiece processing area; the induction heating auxiliary system is disposed between the magnetic field auxiliary system and the laser additive processing unit; the ultrasonic vibration system is disposed on the side away from the area to be repaired and corresponds to the area to be repaired.

[0009] Furthermore, the online monitoring system includes a three-dimensional morphology measurement unit, a temperature and melt pool monitoring unit, a visual recognition unit, a force / vibration monitoring unit, and a data acquisition unit; the three-dimensional morphology measurement unit, the temperature and melt pool monitoring unit, the visual recognition unit, and the force / vibration monitoring unit are respectively signal-connected to the data acquisition unit; the data acquisition unit is signal-connected to the motion control system; the three-dimensional morphology measurement unit is used to obtain the morphology of the defective area, the additive layer, and the tooth surface after grinding.

[0010] Furthermore, the motion control system incorporates an industrial computer, a motion controller, and a process parameter controller; the industrial computer is connected to the online monitoring system, the motion controller, and the process parameter controller respectively; the motion controller is connected to the X-axis motion unit, the Y-axis motion unit, the Z-axis motion unit, the workpiece positioning and rotation unit, the laser additive manufacturing unit, the grinding and cutting unit, the multi-energy field auxiliary system, and the online monitoring system respectively; the process parameter controller is connected to the laser additive manufacturing unit, the grinding and cutting unit, and the multi-energy field auxiliary system respectively.

[0011] A composite processing method for additive and subtractive manufacturing of wind turbine gears, the method comprising the following steps: Step S1, Defect Assessment and Benchmark Establishment: Perform a 3D scan on the gear to be repaired to obtain the morphological data of the damaged area, and establish benchmark points on the gear to ensure accurate positioning of the gear during the repair process; Step S2, Surface cleaning and preheating; Clean the surface of the defective area to remove impurities; Preheat the defective area using induction heating; Step S3: Laser additive repair; Start the laser additive processing unit, select appropriate additive powder, and repair the damaged area; During the additive repair process, activate the multi-energy field auxiliary system to adjust the molten pool state and reduce cladding defects; Step S4: In-situ subtractive finishing; The repair area is finely finished by the grinding and subtractive processing unit to restore the tooth profile and tooth direction of the gear; Feedback control is performed through the online monitoring system to ensure that the gear's accuracy and surface quality meet the design requirements; Step S5: Perform a three-dimensional re-measurement of the repaired gear to ensure that the gear accuracy meets the technical requirements; finally, perform heat treatment or shot peening on the repaired gear to eliminate residual stress and improve the gear's durability and hardness.

[0012] Furthermore, in step 2, the preheating temperature is 80~350℃.

[0013] Furthermore, in step 3, the parameters of laser additive manufacturing are as follows: laser power is 500~2000W; scanning speed is 3~20mm / s; powder feed rate is 3~30g / min; overlap rate is 30%~60%; single-layer additive thickness is 0.2~1.2mm; and protective gas flow rate is 5~25L / min.

[0014] Furthermore, in step 3, the parameters of the multi-energy field auxiliary system are as follows: ultrasonic frequency is 15~40kHz; ultrasonic amplitude is 5~40μm; magnetic field strength is 0.05~0.8T.

[0015] Furthermore, in step 4, the grinding parameters are as follows: grinding linear speed is 20~80m / s; grinding feed rate is 0.005~0.10mm / pass.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention effectively improves the precision and efficiency of wind turbine gear repair, reducing downtime and maintenance costs. Compared with existing technologies, this invention offers higher repair quality, precisely controls the gear tooth profile and direction, and ensures the stability and consistency of the repair process through field assistance technology and real-time feedback control, demonstrating promising application prospects.

[0017] This invention utilizes a multi-energy field assisted processing system to control the quality of the laser additive manufacturing process using multiple technologies such as induction heating, ultrasonic vibration, and magnetic field assistance. This improves the melt flow boundary, dilution rate, and interlayer bonding state, thereby enhancing the reliability of the bond between the repair layer and the gear substrate.

[0018] Since laser additive manufacturing and grinding cutting are completed on the same machine tool and under the same clamping conditions, errors caused by workpiece transfer, repeated positioning and secondary clamping can be reduced, thereby improving the accuracy of tooth profile and tooth direction restoration and repair efficiency.

[0019] This invention sets up multi-source online monitoring of three-dimensional morphology, temperature molten pool, vision, and force / vibration, which can identify anomalies during processing and correct process parameters in a timely manner, thereby improving the stability and quality consistency of the repair process. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of an additive and subtractive composite processing device for wind turbine gear remanufacturing proposed in this invention. Figure 2 This is a schematic diagram of the structure of the multi-energy field assisted laser cladding region of the present invention; Figure 3 This is a schematic diagram illustrating the principle of online monitoring and dynamic feedback control of the present invention; Figure 4 This is a schematic flowchart of an additive and subtractive composite processing method for remanufacturing wind turbine gears proposed in this invention. Figure 5 This is a schematic diagram showing the positioning relationship between the workbench fixture of this invention and the wind turbine gear to be repaired. Detailed Implementation

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] It should be noted that in the description of this invention, the terms "upper", "lower", "top", "bottom", "one side", "the other side", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not mean that the device or element must have a specific orientation, or be constructed and operated in a specific orientation.

[0023] See appendix Figure 1 The present invention proposes an additive and subtractive composite processing device for wind turbine gear remanufacturing, comprising a high-rigidity bed 1, an X-axis motion unit 2, a Y-axis motion unit 3, a Z-axis motion unit 4, a workpiece positioning and rotation unit 5, a laser additive processing unit 6, a grinding and subtractive processing unit 7, a worktable fixture 8, a spindle motor 9, a power supply 10, a motion control system 11, a multi-energy field auxiliary system 12, and an online monitoring system 13.

[0024] The grinding and reduction processing unit 7 can adopt existing mature technologies. It is located on one side inside the bed 1 and includes a processing spindle, a replaceable grinding head, a feed motor, a cooling and lubrication unit, a dust collection and waste treatment system, etc., to realize the subtractive shaping function after additive processing.

[0025] The machine bed 1 has a composite machining area inside, and the workpiece positioning and rotating unit 5 is set in the composite machining area. The worktable fixture 8 is fixedly set on the working surface of the workpiece positioning and rotating unit 5 and is used to clamp the gear 22 to be repaired. The X-axis motion unit 2 is set along the depth direction of the machine bed 1. The X-axis motion unit 2 is used to drive the Y-axis motion unit 3 to move along the depth direction of the machine bed 1, that is, the X-axis direction. The Y-axis motion unit 3 is connected to the X-axis motion unit 2 and is set along the width direction of the machine bed 1. The Y-axis motion unit 3 is used to drive the Z-axis motion unit 4 to move along the width direction of the machine bed 1, that is, the Y-axis direction. The Z-axis motion unit 4 is connected to the Y-axis motion unit 3 along the vertical direction of the machine tool 1. The spindle motor 9 is fixed to the bottom end of the Z-axis motion unit 4. The Z-axis motion unit 4 is used to drive the spindle motor 9 to perform vertical lifting and lowering movements in the Z-axis direction. The X-axis motion unit 2, Y-axis motion unit 3, and Z-axis motion unit 4 are driven by lead screw transmission mechanisms to perform linear motion on their corresponding moving parts. The laser additive manufacturing unit 6 is located below the Z-axis motion unit 4 and connected to the output end of the spindle motor 9. The processing end of the laser additive manufacturing unit 6 faces the workpiece processing area on the worktable fixture 8. The grinding and cutting unit 7 is located on the other side inside the bed 1. The grinding end of the grinding and cutting unit 7 faces the workpiece processing area and is used to perform in-situ grinding and finishing on the additive repair area while maintaining the same clamping reference for the workpiece. The motion control system 11 is located outside the bed 1 and connected to the power supply 10. The multi-energy field auxiliary system 12 is located inside the bed 1 and arranged around the workpiece processing area. The online monitoring system 13 is located on the Z-axis motion unit 4 and is signal-connected to the motion control system 11. The motion control system 11 is connected to the X-axis motion unit 2, Y-axis motion unit 3, Z-axis motion unit 4, workpiece positioning and rotation unit 5, laser additive processing unit 6, grinding and cutting processing unit 7, multi-energy field auxiliary system 12 and online monitoring system 13 respectively.

[0026] The laser additive manufacturing unit 6 can be made using existing mature technologies, including fiber lasers, lenses, nozzles and powder supply systems, to realize laser additive remanufacturing functions.

[0027] The workpiece positioning rotary unit 5 is located below the Z-axis motion unit 4 and is used to drive the gear 22 to be repaired to rotate; the worktable clamp 8 is fixed to the outside of the turntable of the workpiece positioning rotary unit 5 and is used to clamp and fix the gear 22 to be repaired on the workpiece positioning rotary unit 5, such as... Figure 5 As shown.

[0028] like Figure 2As shown, the multi-energy field auxiliary system 12 includes an induction heating auxiliary system 14, an ultrasonic vibration system 15, and a magnetic field auxiliary system 21. The magnetic field auxiliary system 21 includes electromagnetic field generating components positioned opposite each other on both sides of the workpiece processing area to generate an external electromagnetic field in the area to be repaired, thereby controlling the flow of liquid metal in the laser molten pool. The induction heating auxiliary system 14 is positioned between the magnetic field auxiliary system 21 and the laser additive manufacturing unit 6. It uses induction coil heating, with the induction coil positioned adjacent to the area to be repaired, for local induction preheating of the area to be repaired. The ultrasonic vibration system 15 is positioned on the side away from the area to be repaired and corresponds to the area to be repaired. The ultrasonic vibration system 15 is coupled to the base of the gear 22 to be repaired and is used to apply ultrasonic vibration to the area to be repaired. The induction heating auxiliary system 14 preheats the cladding area using the principle of electromagnetic induction to control heat input, improve the thermal gradient during the cladding process, and prevent overheating or cracking of the material. The ultrasonic vibration system 15 breaks bubbles during the cladding process through cavitation effect, promotes the flow of molten metal in the molten pool, and thus reduces the generation of pores. The magnetic field auxiliary system 21 optimizes the flow behavior of the molten pool, reduces the generation of defects, and improves the bonding strength of the cladding layer through the action of the electromagnetic field.

[0029] like Figure 3 As shown, the online monitoring system includes a three-dimensional morphology measurement unit 16, a temperature and molten pool monitoring unit 17, a vision recognition unit 18, a force / vibration monitoring unit 19, and a data acquisition unit 20. The three-dimensional morphology measurement unit 16, temperature and molten pool monitoring unit 17, vision recognition unit 18, and force / vibration monitoring unit 19 are all signal-connected to the data acquisition unit 20. The data acquisition unit 20 is signal-connected to the motion control system 11. The three-dimensional morphology measurement unit 16 is used to obtain the morphology of the defective area, the additive layer, and the ground tooth surface. The temperature and molten pool monitoring unit 17 is used to collect information on the temperature of the area to be repaired, the molten pool temperature, the molten pool width, the molten pool length, and the molten pool brightness. The vision recognition unit 18 is used to identify powder beams, cladding boundary lines, spatter, and surface anomalies. The force / vibration monitoring unit 19 is used to monitor grinding force, spindle vibration, and clamping status, and to determine the workpiece clamping status based on the collected force and vibration information. The data acquisition unit 20 is used to collect and transmit the monitoring data collected by each monitoring unit.

[0030] The motion control system 11 integrates an industrial computer, a motion controller, and a process parameter controller. The industrial computer is connected to the online monitoring system 13, the motion controller, and the process parameter controller. The motion controller is connected to the X-axis motion unit 2, Y-axis motion unit 3, Z-axis motion unit 4, workpiece positioning and rotation unit 5, laser additive processing unit 6, grinding and cutting unit 7, multi-energy field auxiliary system 12, and online monitoring system 13, and is used to control the motion trajectory of the laser additive processing unit 6 and the grinding and cutting unit 7 relative to the gear 22 to be repaired. The process parameter controller is connected to the laser additive processing unit 6, the grinding unit 7, the grinding unit 8, the process parameter controller 9, the grinding unit 10, the grinding unit 11, and the process parameter controller 11. The subtractive processing unit 7 is connected to the multi-energy field auxiliary system 12; the industrial computer is used to receive monitoring data collected by the online monitoring system 13, compare the monitoring data with preset processing target parameters, and generate parameter adjustment instructions based on the comparison results; the motion controller and process parameter controller dynamically adjust the laser power, scanning speed, powder feed, preheating temperature, ultrasonic amplitude, magnetic field strength, and grinding feed based on the monitoring data according to the parameter adjustment instructions; the online monitoring system 13 is used to continuously monitor the processing status after parameter adjustment and feed the updated monitoring data back to the industrial computer, forming a closed-loop control for wind turbine gear remanufacturing.

[0031] like Figure 4 As shown, the online monitoring and closed-loop control are integrated throughout the surface preheating, laser additive repair, in-situ grinding finishing, and repair quality retesting processes, using defect morphology data, tooth surface reference, and target tooth profile data as the benchmarks for subsequent processing parameter adjustments and quality judgment. During the surface preheating stage, the temperature and molten pool monitoring unit 17 collects real-time temperature information of the area to be repaired, and the motion control system 11 adjusts the induction heating power according to the deviation between the actual temperature and the preset temperature. During the laser additive repair stage, the temperature and molten pool monitoring unit 17 and the vision recognition unit 18 acquire real-time information such as molten pool temperature, molten pool size, molten pool brightness, powder beam morphology, cladding boundary, spatter, and surface anomalies. The motion control system 11 compares the monitoring results with preset target parameters and dynamically adjusts the laser power, scanning speed, powder feed rate, ultrasonic amplitude, and excitation current of the electromagnetic field auxiliary system accordingly to maintain the molten pool state and cladding formation quality. During the in-situ grinding finishing stage, the three-dimensional morphology measurement unit 16 and the force / vibration monitoring unit 19 collect information on tooth surface morphology, machining allowance, grinding force, and spindle vibration in real time. The motion control system 11 adjusts the grinding trajectory, grinding speed, feed rate, and depth of cut according to the tooth profile deviation and machining status. After machining, the repaired tooth surface is re-measured in three dimensions and its quality is evaluated. When the test results do not meet the preset requirements, the laser additive repair step or the in-situ grinding finishing step is returned to perform local compensation according to the deviation type until the repair quality meets the technical requirements. This forms a closed-loop control process of "data acquisition - status identification - parameter comparison - control adjustment - re-monitoring - re-measurement and evaluation".

[0032] When the device of this invention is in operation, the gear 22 to be repaired is first installed on the worktable fixture 8, and the worktable fixture 8 positions and clamps the gear 22 to be repaired, so that the gear 22 to be repaired maintains the same clamping reference during defect detection, laser additive repair, in-situ grinding and finishing, and post-repair retesting. The workpiece positioning rotary unit 5 drives the gear 22 to be repaired to rotate around its rotation axis, so that different teeth and different tooth surfaces of the same tooth rotate sequentially into the composite processing area, thereby adjusting the spatial position and processing posture of the area to be repaired relative to the laser additive processing unit 6, the grinding and cutting processing unit 7, the multi-energy field auxiliary system 12, and the online monitoring system 13. During defect detection and laser additive processing, the motion control system 11 controls the actions of the X-axis motion unit 2, the Y-axis motion unit 3, and the Z-axis motion unit 4 respectively according to the preset processing trajectory. The X-axis motion unit 2 drives the Y-axis motion unit 3 and its mounted components to perform linear X-axis motion along the depth direction of the bed 1; the Y-axis motion unit 3 drives the Z-axis motion unit 4 and its mounted components to perform linear Y-axis motion along the width direction of the bed 1; and the Z-axis motion unit 4 drives the spindle motor 9 and the laser additive processing unit 6 to perform vertical Z-axis lifting motion. Through the three-axis linkage of the X-axis motion unit 2, Y-axis motion unit 3, and Z-axis motion unit 4, and in conjunction with the rotational motion of the workpiece positioning rotary unit 5, the laser additive processing unit 6 and the online monitoring system 13 achieve spatial positioning, trajectory following, and processing distance adjustment relative to the gear 22 to be repaired, enabling the laser additive processing unit 6 to perform point-by-point, line-by-line, and layer-by-layer additive repair along the defective area.

[0033] Before the additive manufacturing process begins, the motion control system 11 controls the workpiece positioning and rotation unit 5 to rotate the area to be repaired to the preset processing position, and controls the laser additive manufacturing unit 6 to adjust to the corresponding working position. The induction coil of the induction heating auxiliary system 14 is set near the area to be repaired to perform local induction preheating on the gear substrate; the ultrasonic vibration system 15 is coupled to the side of the gear substrate away from the area to be repaired to transmit ultrasonic vibration to the area to be repaired; the electromagnetic field auxiliary system 21, which is set on both sides of the workpiece processing area, forms an external electromagnetic field after being energized. The laser additive manufacturing unit 6 feeds powder and performs laser cladding according to the preset trajectory. The induction preheating, ultrasonic vibration and external electromagnetic field act synchronously or in a set sequence on the laser molten pool. By reducing the temperature gradient between the substrate and the cladding layer, promoting the escape of bubbles and grain refinement in the molten pool, and using the Lorentz force generated by the electromagnetic field to regulate the flow of liquid metal, the molten pool morphology, cladding channel uniformity and interlayer bonding state are improved, and defects such as porosity, cracks, lack of fusion and coarsening are suppressed.

[0034] During the laser additive repair process, the online monitoring system 13 continuously monitors the area to be repaired throughout the processing. The temperature and molten pool monitoring unit 17 collects information on the substrate temperature, molten pool temperature, molten pool width, molten pool length, and molten pool brightness; the visual recognition unit 18 collects information on the powder beam morphology, cladding boundary, spatter, and surface condition of the repair layer; and the three-dimensional morphology measurement unit 16 collects information on the morphology of the additive layer and the processing allowance. The above monitoring data are transmitted to the motion control system 11 via the data acquisition unit 20. The motion control system 11 compares the actual processing state with the preset target parameters and adjusts the laser power, scanning speed, powder feed rate, induction preheating parameters, ultrasonic amplitude, excitation current of the electromagnetic field auxiliary system 21, and three-axis motion trajectory according to the comparison results to keep the molten pool state and the cladding layer forming size within the set range.

[0035] After the additive manufacturing repair is completed, the laser additive manufacturing unit 6 exits the processing position, and the workpiece positioning and rotation unit 5 rotates the additive manufacturing repair area to the corresponding processing position of the grinding and reduction processing unit 7 according to the grinding trajectory. The feed motor of the grinding and reduction processing unit 7 drives the grinding head to approach the additive manufacturing repair area and performs in-situ grinding and finishing of the additive layer according to the set grinding speed, feed rate, and depth of cut. The workpiece positioning and rotation unit 5 cooperates with the grinding and reduction processing unit 7 to perform indexing and continuous rotation, so that the grinding head can process different gear teeth and different tooth surfaces in sequence. Since the laser additive manufacturing repair and the grinding and reduction processing are both completed on the same bed 1, in the same machine tool coordinate system, and under the same clamping condition, the reference error caused by the transfer of the gear 22 to be repaired between different devices and the repeated positioning and secondary clamping is avoided.

[0036] During the grinding process, the force / vibration monitoring unit 19 collects the grinding force, spindle vibration, and workpiece clamping status in real time, while the three-dimensional morphology measurement unit 16 collects the tooth surface morphology, remaining machining allowance, and tooth profile deviation after grinding. The motion control system 11 adjusts the grinding feed, grinding speed, depth of cut, and machining trajectory of the grinding and cutting unit 7 based on the monitoring results. When the grinding force or spindle vibration exceeds the preset threshold, or when an abnormal clamping status is detected, the motion control system 11 reduces the grinding load, pauses processing, or issues an abnormality warning. After grinding is completed, the workpiece positioning and rotation unit 5 drives the gear 22 to be repaired to rotate sequentially to the retest position, where the three-dimensional morphology measurement unit 16 retests the repaired tooth surface. When the test results do not meet the preset requirements, the motion control system 11 controls the device to perform local laser additive repair or local grinding compensation according to the deviation type until the tooth profile, tooth direction, and surface quality of the gear meet the set requirements.

[0037] This invention integrates three-axis linear motion, workpiece rotation positioning, laser additive manufacturing, in-situ grinding and reduction, multi-energy field assistance, and multi-source online monitoring into a single machine bed and unified coordinate system, forming an integrated working mode of "workpiece clamping—defect location—cooperative positioning—multi-energy field assisted additive manufacturing—in-situ grinding and finishing—online retesting and feedback compensation." This structure not only improves the machining accessibility of different gear teeth and complex tooth surfaces in large wind turbine gears, but also reduces positioning errors caused by process transitions. Furthermore, through multi-energy field collaborative control and online closed-loop feedback, it improves the forming quality of the repair layer, the accuracy of tooth surface restoration, and the consistency of the remanufacturing process.

[0038] like Figure 5 As shown, the additive and subtractive composite processing method for wind turbine gear remanufacturing proposed in this invention includes the following steps: Step S1, Defect Assessment and Benchmark Establishment: Perform a three-dimensional scan of the gear 22 to be repaired to obtain the morphological data of the damaged area, and establish benchmark points on the gear to ensure the accurate positioning of the gear 22 to be repaired during the repair process; Step S2, Surface cleaning and preheating; Clean the surface of the damaged area to remove impurities such as oil and oxide layer; Preheat the damaged area using induction heating or other methods at a temperature of 80~350℃ to reduce thermal gradient and crack tendency, and avoid deformation caused by excessive heat input; Step S3: Laser Additive Repair; Start the laser additive processing unit 6, select suitable additive powder, and repair the damaged area; The parameters of laser additive processing are as follows: Laser power is 500~2000W, used to control melt height, melt depth, melt width, and dilution rate; Scanning speed is 3~20mm / s, used to control line energy and single-pass forming; Powder feed rate is 3~30g / min, used to control layer height and material utilization rate; Overlap rate is 30%~60%, used to ensure the flatness of multi-pass cladding; Single-layer additive thickness is 0.2~1.2mm, used for layer-by-layer shaping and allowance control; Protective gas flow rate is 5~25L / min, used to suppress oxidation and stabilize the powder beam.

[0039] During the additive repair process, a multi-energy field auxiliary system 12 is activated to adjust the state of the molten pool and reduce cladding defects. The parameters of the multi-energy field auxiliary system 12 are as follows: the ultrasonic frequency is 15~40kHz, used for molten pool disturbance and tissue refinement; the ultrasonic amplitude is 5~40μm, used to adjust the vibration energy input; and the magnetic field strength is 0.05~0.8T, used for molten pool flow control.

[0040] Step S4: In-situ subtractive finishing; the repair area is finely finished by grinding in the grinding subtractive processing unit 7 to restore the tooth profile and direction of the gear; the grinding parameters are as follows: grinding linear speed is 20~80m / s for tooth surface finishing; grinding feed rate is 0.005~0.10mm / pass for shaping accuracy and surface quality control. Feedback control is performed through the online monitoring system 13 to ensure that the gear's accuracy and surface quality meet the design requirements; Step S5: Perform a three-dimensional re-measurement of the repaired gear to ensure that the gear accuracy meets the technical requirements; finally, perform heat treatment or shot peening on the repaired gear to eliminate residual stress and improve the gear's durability and hardness.

[0041] This invention integrates a laser additive manufacturing unit 6, a grinding and subtractive processing unit 7, a multi-energy field auxiliary system 12, and an online monitoring system 13 within the same machine tool coordinate system. It sequentially completes digital defect identification of the damaged area of ​​the wind turbine gear, quantitative laser additive manufacturing, multi-energy field synergistic modification, in-situ grinding precision shaping, and integrated geometric-performance re-inspection after repair, achieving a closed-loop integrated operation for the entire gear remanufacturing process. It enables defect identification, additive shaping, subtractive shaping, and re-evaluation of wind turbine gears in a single setup.

[0042] The multi-energy field auxiliary system 12 includes an induction heating auxiliary system, an ultrasonic vibration system, and a magnetic field auxiliary system. The three systems are arranged around the cladding area and are linked with the laser cladding parameters to reduce crack tendency, promote bubble escape, regulate melt pool flow, and refine the cladding layer structure.

[0043] The worktable fixture 8 is combined with the workpiece positioning and rotation unit 5, enabling large wind turbine gears to complete laser cladding, grinding and monitoring under different tooth surface postures, thereby improving tooth surface accessibility and positioning stability.

[0044] The online monitoring system 13 simultaneously collects three-dimensional morphology, molten pool temperature, molten pool size, visual images, grinding force, and vibration signals, and feeds the detection results back to the computer.

[0045] The computer dynamically adjusts laser power, scanning speed, powder feed rate, preheating temperature, ultrasonic amplitude, magnetic field strength, and grinding feed rate based on monitoring data, forming a closed-loop control system for wind turbine gear remanufacturing. The processing is monitored online and receives real-time data feedback, measuring various parameters and dynamically adjusting the process to ensure repair quality.

[0046] Matters not covered in this invention are common knowledge.

[0047] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A composite processing device for additive and subtractive manufacturing of wind turbine gears, characterized in that: The device includes a machine bed, an X-axis motion unit, a Y-axis motion unit, a Z-axis motion unit, a workpiece positioning and rotating unit, a laser additive manufacturing unit, a grinding and cutting unit, a worktable fixture, a spindle motor, a power supply, a motion control system, a multi-energy field auxiliary system, and an online monitoring system. The machine bed has a composite machining area, and the workpiece positioning and rotating unit is located within this area. The worktable fixture is fixedly mounted on the rotary table surface of the workpiece positioning and rotating unit and is used to clamp the gear to be repaired. The X-axis motion unit is positioned along the depth direction of the machine bed. The Y-axis motion unit is connected to the X-axis motion unit and arranged along the width direction of the machine bed. The Z-axis motion unit is connected to the Y-axis motion unit along the vertical direction of the machine tool. The spindle motor is fixedly connected to the bottom end of the Z-axis motion unit. The X-axis motion unit, Y-axis motion unit, and... The Z-axis motion units drive their corresponding moving parts to perform linear motion via lead screw transmission mechanisms. The laser additive manufacturing unit is located below the Z-axis motion units and connected to the output end of the spindle motor, with its processing end facing the workpiece processing area on the worktable fixture. The grinding and cutting unit is located on one side inside the machine bed, with its grinding end facing the workpiece processing area. The motion control system is located outside the machine bed and connected to the power supply. The multi-energy field auxiliary system is located inside the machine bed and arranged around the workpiece processing area. The online monitoring system is located on the Z-axis motion units and is connected to the motion control system. The motion control system is connected to the X-axis motion units, Y-axis motion units, Z-axis motion units, workpiece positioning and rotation units, laser additive manufacturing units, grinding and cutting units, multi-energy field auxiliary systems, and online monitoring systems.

2. The additive and subtractive composite processing device for wind turbine gear remanufacturing according to claim 1, characterized in that: The multi-energy field auxiliary system includes an induction heating auxiliary system, an ultrasonic vibration system, and a magnetic field auxiliary system; the magnetic field auxiliary system includes electromagnetic field generating components that are disposed opposite to each other on both sides of the workpiece processing area; the induction heating auxiliary system is disposed between the magnetic field auxiliary system and the laser additive processing unit; the ultrasonic vibration system is disposed on the side away from the area to be repaired and corresponds to the area to be repaired.

3. The additive and subtractive composite processing device for wind turbine gear remanufacturing according to claim 1, characterized in that: The online monitoring system includes a three-dimensional morphology measurement unit, a temperature and melt pool monitoring unit, a visual recognition unit, a force / vibration monitoring unit, and a data acquisition unit. The three-dimensional morphology measurement unit, temperature and melt pool monitoring unit, visual recognition unit, and force / vibration monitoring unit are respectively connected to the data acquisition unit. The data acquisition unit is connected to the motion control system. The three-dimensional morphology measurement unit is used to obtain the morphology of the defective area, the additive layer, and the tooth surface after grinding.

4. The additive and subtractive composite processing device for wind turbine gear remanufacturing according to claim 1, characterized in that: The motion control system integrates an industrial computer, a motion controller, and a process parameter controller. The industrial computer is connected to the online monitoring system, the motion controller, and the process parameter controller. The motion controller is connected to the X-axis motion unit, the Y-axis motion unit, the Z-axis motion unit, the workpiece positioning and rotation unit, the laser additive manufacturing unit, the grinding and cutting unit, the multi-energy field auxiliary system, and the online monitoring system. The process parameter controller is connected to the laser additive manufacturing unit, the grinding and cutting unit, and the multi-energy field auxiliary system.

5. A composite processing method for additive and subtractive manufacturing of wind turbine gears, implemented based on the apparatus described in claim 2, characterized in that, The method includes the following steps: Step S1, Defect Assessment and Benchmark Establishment: Perform a 3D scan on the gear to be repaired to obtain the morphological data of the damaged area, and establish benchmark points on the gear to ensure accurate positioning of the gear during the repair process; Step S2, Surface cleaning and preheating; Clean the surface of the defective area to remove impurities; Preheat the defective area using induction heating; Step S3: Laser additive repair; Start the laser additive processing unit, select appropriate additive powder, and repair the damaged area; During the additive repair process, activate the multi-energy field auxiliary system to adjust the molten pool state and reduce cladding defects; Step S4: In-situ subtractive finishing; The repair area is finely finished by the grinding and subtractive processing unit to restore the tooth profile and tooth direction of the gear; Feedback control is performed through the online monitoring system to ensure that the gear's accuracy and surface quality meet the design requirements; Step S5: Perform a three-dimensional re-measurement of the repaired gear to ensure that the gear accuracy meets the technical requirements; finally, perform heat treatment or shot peening on the repaired gear to eliminate residual stress and improve the gear's durability and hardness.

6. The additive and subtractive composite processing method for remanufacturing wind turbine gears according to claim 5, characterized in that: In step 2, the preheating temperature is 80~350℃.

7. The additive and subtractive composite processing method for remanufacturing wind turbine gears according to claim 5, characterized in that: In step 3, the parameters of laser additive manufacturing are as follows: laser power is 500~2000W; scanning speed is 3~20mm / s; powder feed rate is 3~30g / min; overlap rate is 30%~60%; single-layer additive thickness is 0.2~1.2mm; protective gas flow rate is 5~25L / min.

8. The additive and subtractive composite processing method for remanufacturing wind turbine gears according to claim 5, characterized in that: In step 3, the parameters of the multi-energy field auxiliary system are as follows: ultrasonic frequency is 15~40kHz; ultrasonic amplitude is 5~40μm; magnetic field strength is 0.05~0.8T.

9. A composite processing method for additive and subtractive manufacturing of wind turbine gears according to claim 5, characterized in that: In step 4, the grinding parameters are as follows: grinding linear speed is 20~80m / s; grinding feed rate is 0.005~0.10mm / pass.

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