Wind power gear arc fuse additive manufacturing auxiliary device and repairing method

Abstract

A wind power gear electric arc fuse additive manufacturing auxiliary device comprises an electric arc fuse robot, a workbench, a gear fixing mechanism, an ultrasonic vibration generating mechanism and an electromagnetic field generating mechanism. The arc fuse robot is arranged on one side of the workbench; the gear fixing mechanism comprises a spindle box and a tailstock which are installed on the workbench and used for clamping and fixing a gear. The ultrasonic vibration generating mechanism is mounted at the end part of a welding gun of the arc fuse robot, so that the ultrasonic vibration generating mechanism can synchronously move along with the arc fuse robot; the electromagnetic field generating mechanism comprises a clamping and fixing part and an electromagnet installed at the upper end of the clamping and fixing part. The clamping and fixing part is installed on the workbench, and the electromagnet can be adjusted to the position matched with the gear to be repaired by adjusting the clamping and fixing part. According to the method, one-time clamping and multiple welding procedures are achieved, and through ultrasonic and electromagnetic auxiliary cladding, the defect problems of air holes, cracks, thick columnar grains and the like in a cladding layer in wind power gear electric arc fuse additive manufacturing can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power equipment, and in particular to an additive manufacturing auxiliary device and a repair method for arc fuses of wind power gears. Background Art

[0002] Large-capacity wind turbines are usually installed in areas rich in wind energy resources, such as mountains, wilderness, beaches, and islands. Affected by irregular phase-changing and load-changing wind forces, strong gusts of wind, extreme heat and cold, and extreme temperature differences, the operating environment of the units is relatively harsh. The design requirement for wind turbines is a 20-year service life, but wind turbines at home and abroad enter a period of frequent failures after 10 or even 5 years of operation. Gear failure is one of the main causes of wind turbine failures, accounting for about 20% of the total number of failures. Common forms of gear failure include gear wear, gear fracture, tooth surface pitting, tooth surface bonding, and plastic deformation.

[0003] Traditional methods for remanufacturing failed wind turbine gears include adjustment and transposition, displacement processing, surfacing, thermal spraying, etc. Arc additive manufacturing directly forms components by depositing melted welding wire layer by layer. It is insensitive to the environment and metal materials, has high deposition efficiency, high wire utilization rate, short overall manufacturing cycle and low production cost. It is widely used in the rapid prototyping of complex and large metal components.

[0004] However, the arc fuse additive manufacturing process involves many complex physical phenomena such as welding wire melting, droplet transition, convection flow of high-temperature liquid metal in the molten pool, deformation of the free surface of the molten pool, and solidification of liquid metal.

[0005] The reverse flow of the molten pool fluid and the expansion of the metal will cause differences in the geometry of the weld. Metal over-deposition is prone to occur at special features in the structure, such as intersections or inflection points, which can easily cause defects such as pores, cracks, and coarse columnar grains in the coating. Summary of the invention

[0006] In order to solve the technical problems existing in the above-mentioned technologies, it is necessary to provide an auxiliary device for additive manufacturing of arc fuses for wind power gears.

[0007] An auxiliary device for additive manufacturing of arc fuses for wind power gears, comprising an arc fuse robot, a workbench, a gear fixing mechanism, an ultrasonic vibration generating mechanism, and an electromagnetic field generating mechanism;

[0008] The arc fuse robot is arranged on one side of the workbench;

[0009] The gear fixing mechanism comprises a spindle box and a tailstock mounted on the workbench; the spindle box and the tailstock can clamp and fix the gear to be repaired between the two, and can drive the gear to rotate under the rotation of the spindle box main shaft;

[0010] The ultrasonic vibration generating mechanism is installed at the end of the welding gun of the arc fuse robot, so that when the arc fuse robot is welding, the ultrasonic vibration generating mechanism can move synchronously with the arc fuse robot, and the relative position of the ultrasonic vibration and the heat source is kept unchanged;

[0011] The electromagnetic field generating mechanism includes a clamping and fixing component, and an electromagnet installed on the upper end of the clamping and fixing component; the clamping and fixing component is installed on a workbench, and by adjusting the clamping and fixing component, the electromagnet can be adjusted to a position that matches the gear to be repaired, so that the magnetic field generated by the electromagnet can change the molten pool flow, heat transfer and mass transfer behavior during the arc fuse additive manufacturing process.

[0012] Preferably, the ultrasonic vibration generating mechanism includes a fixed connection component, a clamping component, and an ultrasonic vibration generator mounted on the clamping component; the fixed connection component is installed at the end of the welding gun of the arc fuse robot, and the clamping component is installed on the fixed connection component, and the lateral distance between the clamping component and the fixed connection component can be adjusted to achieve the distance adjustment between the ultrasonic vibration generator and the welding gun.

[0013] Preferably, the clamping assembly is rotatably connected to the fixed connection assembly, so that the angle between the clamping assembly and the fixed connection assembly in the vertical direction can be adjusted to achieve angle adjustment between the ultrasonic vibration generator and the welding gun.

[0014] Preferably, the fixed connection assembly includes a first arc-shaped clamp and a second arc-shaped clamp; the first arc-shaped clamp is rotatably connected to one end of the second arc-shaped clamp, and the other ends of the first arc-shaped clamp and the second arc-shaped clamp are fastened by bolts, so that the first arc-shaped clamp and the second arc-shaped clamp are docked and clamped and fixed on the end of the welding gun of the arc fuse robot; a connecting clamp is provided on the side of the first arc-shaped clamp.

[0015] Preferably, the clamping assembly includes a first semicircular clamping ring and a second semicircular clamping ring; the first semicircular clamping ring and the second semicircular clamping ring are fixed together by bolts to achieve clamping and fixation of the ultrasonic vibration generator, a connecting rod is fixed on the first circular clamp, and the connecting clamp is fastened by bolts to achieve clamping and fixation of the connecting rod.

[0016] Preferably, a guide groove is provided in the first arc-shaped clamping ring, a sliding block is installed in the guide groove, and a screw connected to the sliding block is threadedly installed along the radial direction of the first arc-shaped clamping ring.

[0017] Preferably, the clamping and fixing component includes a support column and a clamping assembly; the lower end of the support column is provided with a base plate for mounting on a workbench, the upper end of the support column is provided with a fixing block, the lower end of the fixing block and the upper end of the base plate are both provided with a threaded rod threadedly connected to the support column, and the clamping assembly is rotatably mounted on the fixing block to adjust the angle between the clamping assembly and the support column.

[0018] Preferably, the clamping assembly includes a mounting groove and a pressure plate; one end of the mounting groove is rotatably connected to the fixed block, and one end of the pressure plate is hinged to the upper end of the mounting groove, so that the pressure plate can be freely opened and closed along the top of the mounting groove with this end, and the other end of the pressure plate is fastened to the mounting groove by screws to clamp the electromagnet and fix it in the mounting groove.

[0019] Preferably, a first clamping rod is threadedly installed at one end of the installation groove, and a second clamping rod perpendicular to the first clamping rod is threadedly installed on the pressure plate. The first clamping rod and the second clamping rod cooperate with each other to clamp and fix the electromagnet in the installation groove.

[0020] It is also necessary to provide an additive manufacturing repair method for arc fuses in wind turbine gears.

[0021] A wind turbine gear arc fuse additive manufacturing repair method, using the wind turbine gear arc fuse additive manufacturing auxiliary device described above for cladding repair, comprising the following steps:

[0022] Step S1: Grind the damaged gear, remove the surface oxide layer and clean it, and use the spindle box and tailstock to clamp and position the gear to be repaired;

[0023] Step S2: using forward and reverse technology and Boolean operations to obtain a three-dimensional model of the defective part, and combining it with robot simulation programming software to generate a welding trajectory of the defective part;

[0024] Step S3: After adjusting the ultrasonic vibration generator to a suitable height, the first semicircular clamp and the second semicircular clamp are fixed by bolts; the distance of the connecting rod inserted into the connecting clamp is adjusted to be suitable, the spacing between the ultrasonic vibration generator and the welding gun is adjusted to be suitable, the connecting rod is rotated, the angle between the ultrasonic vibration generator and the welding gun is adjusted to be suitable, and the connecting clamp is tightened by bolts to clamp the connecting rod;

[0025] Step S4: adjust the bottom plate so that the electromagnet is aligned with the area to be welded, and adjust the height of the electromagnet to a suitable position by rotating the support column; rotate the mounting slot to adjust the relative angle between the electromagnet and the gear to be repaired to a suitable position;

[0026] Step S5: According to the obtained welding trajectory, the gear is repaired by using an arc fuse robot.

[0027] Compared with the prior art, the wind turbine gear arc fuse additive manufacturing auxiliary device and repair method provided by the present invention adopts a spindle box and a tailstock to clamp the workpiece, and is driven by a servo motor to rotate the spindle through a synchronous pulley, so as to realize one-time clamping and multiple welding processes. Since the arc fuse additive manufacturing process involves complex physical processes such as multiple thermal cycles, stress reconstruction and strain inheritance, in order to reduce the defects such as pores, cracks, and coarse columnar grains in the coating during the wind turbine gear arc fuse additive manufacturing, an ultrasonic vibration generating mechanism and an electromagnetic field generating mechanism are introduced. During the cladding process, the ultrasonic vibration moves synchronously with the arc fuse robot to keep the relative position of the ultrasonic vibration and the heat source unchanged, so as to avoid the ultrasonic vibration from having an insignificant effect due to the increase in the distance between the ultrasonic vibration and the molten pool. The magnetic field generated by the electromagnetic field generating mechanism can change the flow, heat transfer and mass transfer behavior of the molten pool during the arc fuse additive manufacturing process to ensure the quality of the cladding repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0029] Figure 1 It is a front view structural schematic diagram of the present invention.

[0030] Figure 2 For the present invention Figure 1 Schematic diagram of the structure from another angle.

[0031] Figure 3 For the present invention Figure 1 Schematic diagram of the side structure.

[0032] Figure 4 For the present invention Figure 3 Schematic diagram of the structure from another angle.

[0033] Figure 5 It is a structural schematic diagram of the connection of the gear fixing mechanism, the ultrasonic vibration generating mechanism, and the electromagnetic field generating mechanism of the present invention.

[0034] Figure 6 For the present invention Figure 5 A partial enlarged view of point A in the middle.

[0035] Figure 7 It is a structural schematic diagram of the ultrasonic vibration generating mechanism of the present invention.

[0036] Figure 8 It is a structural schematic diagram of the electromagnetic field generating mechanism of the present invention.

[0037] Fig. 9 For the present invention Figure 8 Schematic diagram of the side structure.

[0038] Fig.10 For the present invention Figure 8 Schematic diagram of the structure from another angle.

[0039] In the figure: arc fuse robot 01, workbench 02, gear fixing mechanism 03, spindle box 31, tailstock 32, ultrasonic vibration generating mechanism 04, fixed connection assembly 41, first arc-shaped snap ring 411, second arc-shaped snap ring 412, connecting clamp 413, guide groove 414, sliding block 415, clamping assembly 42, first semicircular snap ring 421, second semicircular snap ring 422, connecting rod 423, ultrasonic vibration generator 43, electromagnetic field generating mechanism 05, electromagnet 51, clamping and fixing component 52, support column 521, bottom plate 5211, fixing block 5212, threaded rod 5213, clamping assembly 522, mounting groove 5221, pressure plate 5222, first tightening rod 5223, second tightening rod 5224, gear 06. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 are within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be understood that the terms "upper", "middle", "outer", "inner", "lower" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0042] Please see Figures 1 to 10The present invention provides an auxiliary device for additive manufacturing of arc fuses for wind power gears, comprising an arc fuse robot 01, a workbench 02, a gear fixing mechanism 03, an ultrasonic vibration generating mechanism 04, and an electromagnetic field generating mechanism 05; the arc fuse robot 01 is arranged on one side of the workbench 02; the gear fixing mechanism 03 comprises a spindle box 31 and a tailstock 32 oppositely mounted on the workbench 02; the spindle box 31 and the tailstock 32 can clamp and fix the gear to be repaired between the two, and can rotate circumferentially along the axis of the gear under the drive of the spindle box 31; wherein the spindle box 31 is driven by a servo motor and a synchronous pulley to realize the rotation of the spindle on the spindle box 31. The spindle box 31 is connected to a three-jaw chuck, and the three-jaw chuck and the tailstock 32 restrict the movement of the workpiece in the three directions of XYZ and the rotation in the two directions of YZ, a total of 5 degrees of freedom, to realize the clamping of the workpiece. The ultrasonic vibration generating mechanism 04 is installed at the end of the welding gun of the arc fuse robot 01, so that the ultrasonic vibration generating mechanism 04 can move synchronously with the arc fuse robot 01 when the arc fuse robot 01 is welding, and keep the relative position of the ultrasonic vibration and the heat source unchanged. The electromagnetic field generating mechanism 05 includes a clamping and fixing component 52, and an electromagnet 51 installed at the upper end of the clamping and fixing component 52; the clamping and fixing component 52 is installed on the workbench 02, and the electromagnet 51 can be adjusted to a position that matches the gear to be repaired by adjusting the clamping and fixing component 52, so that the magnetic field generated by the electromagnet 51 can change the flow, heat transfer and mass transfer behavior of the molten pool during the arc fuse additive manufacturing process.

[0043] In one embodiment, the ultrasonic vibration generating mechanism 04 includes a fixed connection component 41, a clamping component 42, and an ultrasonic vibration generator 43 installed on the clamping component 42; the fixed connection component 41 is installed at the end of the welding gun of the arc fuse robot 01, and the clamping component 42 is installed on the fixed connection component 41. The lateral distance between the clamping component 42 and the fixed connection component 41 can be adjusted to achieve the distance adjustment between the ultrasonic vibration generator 43 and the welding gun.

[0044] The clamping assembly 42 is rotatably connected to the fixed connection assembly 41, so that the angle between the clamping assembly 42 and the fixed connection assembly 41 in the vertical direction can be adjusted to achieve angle adjustment between the ultrasonic vibration generator 43 and the welding gun.

[0045] To be more specific, the fixed connection assembly 41 includes a first arc-shaped snap ring 411 and a second arc-shaped snap ring 412; the first arc-shaped snap ring 411 is rotatably connected to one end of the second arc-shaped snap ring 412, and the other ends of the first arc-shaped snap ring 411 and the second arc-shaped snap ring 412 are fastened by bolts, so that the first arc-shaped snap ring 411 and the second arc-shaped snap ring 412 are docked and clamped and fixed to the end of the welding gun of the arc fuse robot 01; the side of the first arc-shaped snap ring 411 is provided with a connecting clamp 413. Among them, a guide groove 414 is provided in the first arc-shaped snap ring 411, and a sliding block 415 is installed in the guide groove 414. A screw connected to the sliding block 415 is threadedly installed along the radial direction of the first arc-shaped snap ring 411. When the screw is turned, the sliding block 415 can be urged to move along the guide groove 414, so that the end of the welding gun of the arc fuse robot 01 is clamped by the sliding block 415, which can adapt to different types of welding robots. Of course, the sliding block 415 can be made of an elastic material, such as rubber.

[0046] To be more specific, the clamping assembly 42 includes a first semicircular snap ring 421 and a second semicircular snap ring 422; the first semicircular snap ring 421 and the second semicircular snap ring 422 are fixed by bolts to achieve clamping and fixing of the ultrasonic vibration generator 43. A connecting rod 423 is fixedly arranged on the first circular snap ring, and the connecting clamp 413 is fastened by bolts to achieve clamping and fixing of the connecting rod 423. When the distance between the ultrasonic vibration generator 43 and the welding gun needs to be adjusted, the length of the connecting rod 423 inserted into the connecting clamp 413 can be controlled to achieve it; when the angle between the ultrasonic vibration generator 43 and the welding gun needs to be adjusted, it is only necessary to rotate the connecting rod 423; after completing the above two adjustment actions, the connecting clamp 413 is tightened and pressed by bolts, so that the connecting rod 423 can be fixed to the connecting clamp 413. The angle between the ultrasonic vibration generator 43 and the welding gun is preferably 30°, at which the cladding effect is best.

[0047] In one embodiment, the clamping and fixing component 52 includes a support column 521 and a clamping assembly 522; the lower end of the support column 521 is provided with a base plate 5211 for installation on the workbench 02, and the upper end of the support column 521 is provided with a fixing block 5212, and the lower end of the fixing block 5212 and the upper end of the base plate 5211 are both provided with a threaded rod 5213 threadedly connected to the support column 521. By rotating the support column 521, the height of the support column 521 can be adjusted. When the height is adjusted to a suitable position, tightening the nut can prevent relative sliding during the processing. The clamping assembly 522 is rotatably installed on the fixing block 5212 to adjust the angle between the clamping assembly 522 and the support column 521.

[0048] To explain in more detail, the clamping assembly 522 includes a mounting groove 5221 and a pressure plate 5222; one end of the mounting groove 5221 is rotatably connected to the fixed block 5212, and one end of the pressure plate 5222 is hinged to the upper end of the mounting groove 5221, so that the pressure plate 5222 can be freely opened and closed along the top of the mounting groove 5221 with this end, and the other end of the pressure plate 5222 is fastened to the mounting groove 5221 by screws to clamp and fix the electromagnet 51 in the mounting groove 5221.

[0049] To explain more specifically, a first pressing rod 5223 is threadedly installed at one end of the installation groove 5221, and a second pressing rod 5224 perpendicular to the first pressing rod 5223 is threadedly installed on the pressure plate 5222. The first pressing rod 5223 and the second pressing rod 5224 cooperate with each other to clamp and fix the electromagnet 51 in the installation groove 5221. The ends of the first pressing rod 5223 and the second pressing rod 5224 are both provided with soft pads, which can increase the contact area when the first pressing rod 5223 and the second pressing rod 5224 are used to press the electromagnet 51, thereby preventing the electromagnet 51 from moving.

[0050] Of course, in order to facilitate the adjustment of the angle of the mounting groove 5221, an arc-shaped rotation groove is opened on the mounting groove 5221, and the rotation groove is connected by bolts. After the mounting groove 5221 is adjusted to a suitable angle, the bolts can be used to achieve tightening and positioning.

[0051] In one embodiment, the present invention provides a wind turbine gear arc fuse additive manufacturing repair method, using the wind turbine gear arc fuse additive manufacturing auxiliary device for cladding repair, including the following steps:

[0052] Step S1: Grind the damaged gear, remove the surface oxide layer and clean it, and use the spindle box 31 and the tailstock 32 to clamp and position the gear to be repaired to ensure the correct position of the workpiece during the welding process;

[0053] Step S2: using forward and reverse technology and Boolean operations to obtain a three-dimensional model of the defective part, and combining it with robot simulation programming software to generate a welding trajectory of the defective part;

[0054] Step S3: After adjusting the ultrasonic vibration generator 43 to a suitable height, the first semicircular clamp 421 and the second semicircular clamp 422 are fixed by bolts; the distance between the connecting rod 423 and the connecting clamp 413 is adjusted to be suitable, the distance between the ultrasonic vibration generator 43 and the welding gun is adjusted to be suitable, the connecting rod 423 is rotated, the angle between the ultrasonic vibration generator 43 and the welding gun is adjusted to be suitable, and the connecting clamp 413 is tightened by bolts to clamp the connecting rod 423;

[0055] Step S4: adjust the bottom plate 5211 so that the electromagnet 51 is aligned with the area to be welded, and adjust the height of the electromagnet 51 to a suitable position by rotating the support column 521; rotate the mounting slot 5221 to adjust the relative angle between the electromagnet 51 and the gear to be repaired to a suitable position;

[0056] Step S5: The arc fuse welding system is controlled by a computer, and the welding trajectory of the defective part generated by the robot simulation programming software is imported into the computer. The welding gun moves according to the corresponding path, and under the control of the control system, the wire feeder continuously provides molten wire at a certain wire feeding speed, and the arc fuse robot 01 is used to perform cladding repair on the gear.

[0057] The key to ultrasonic treatment of metal materials is to convert the sound energy into the propagation medium, so that the molten pool will produce nonlinear effects (cavitation effect and acoustic streaming effect). The sound pressure of ultrasound in the molten pool can be expressed as:

[0058]

[0059] Where P is the ultrasonic power, ρ s is the density of liquid metal in the molten pool, s is the effect of ultrasonic horn, and c is the speed of sound in the propagation medium.

[0060] When sufficiently strong ultrasonic waves act on the solution medium, if the amplitude of the exchange sound pressure P m If the pressure is greater than the static pressure P0 in the solution, then in the negative pressure phase of the acoustic pressure, the peak of the negative pressure can not only offset the static pressure, but also form a local negative pressure action area in the solution. When this negative pressure area is sufficient to overcome the binding force between the molecules of the solution, the solution will be broken to form a cavity, that is, a cavitation effect will occur. Then, when the positive pressure of the acoustic pressure arrives, the air bubbles close and collapse, producing a series of acoustic cavitation effects.

[0061] According to the alternating changes of positive and negative pressures during ultrasonic propagation in the molten pool, the sound pressure threshold for the cavitation effect in the molten pool is:

[0062]

[0063] Where P b is the cavitation acoustic pressure threshold, P0 is the static pressure of the liquid metal in the molten pool, P v is the saturated vapor pressure in the cavitation bubble, δ is the surface tension of the molten pool, and R0 is the nucleation radius of the cavitation bubble. When the surface tension decreases, the threshold of the cavitation effect in the molten pool decreases, and it is easier for cavitation bubbles to nucleate in the molten pool, resulting in cavitation effect.

[0064] In addition, when the cavitation bubble closes / collapses, a high-pressure shock wave and acoustic jet will be generated, thereby generating a higher pressure near the air bubble. The effect of the change in the acoustic pressure of the cavitation bubble in the molten pool on the melting point of the metal can be expressed as:

[0065]

[0066] Where, T m is the theoretical crystallization temperature, p is the pressure, ΔH m is the latent heat of solidification, V L is the liquid phase volume, V S is the solid phase to volume.

[0067] When the pressure of the melt changes, its solidification temperature will also change. The cavitation effect increases the pressure of the local melt around the cavitation bubble, so the solidification temperature of the melt around the cavitation bubble also increases. When ultrasonic cavitation occurs, the theoretical crystallization temperature of the local melt rises, resulting in an increase in the crystallization supercooling, an increase in the difference in Gibbs free energy between the liquid and solid phases, an increase in the nucleation driving force, and the nucleation of grains is promoted locally.

[0068] After the embryo is produced, when the embryo radius is smaller than the critical nucleus radius, the solidification resistance must be overcome, and the magnitude of this resistance is the critical nucleation work, which is expressed as:

[0069]

[0070] Where ΔG is the nucleation work, θ is the wetting angle, and T m is the theoretical crystallization temperature, and ΔT is the supercooling degree.

[0071] When ultrasonic cavitation occurs, the shock waves and acoustic jets generated by cavitation will improve the wettability of the surface of the nucleation point and reduce the wetting angle, so that the critical nucleation radius can be reached at a smaller supercooling degree, thereby promoting nucleation.

[0072] Because ultrasound produces cavitation effect in the molten pool, cavitation bubbles will undergo dynamic process changes in the molten pool under the influence of external forces. Under the synergistic effect of ultrasound and magnetic field, cavitation bubbles in the molten pool are mainly affected by Lorentz force, gravity, buoyancy, and viscous resistance, and the combined force is:

[0073] F=F L +F G +F B +F D

[0074] Among them, the Lorentz force F exerted on the cavitation bubble in the molten pool is L It can be expressed as:

[0075]

[0076] Where V b =4πR 3 / 3 is the volume of cavitation bubbles.

[0077] The electromagnet 51 is composed of an iron core and an excitation coil. The excitation coil is wound around the outer periphery of the iron core. When a current I is passed through it, a magnetic field with a strength of B is generated. The magnitude of the magnetic field can be changed by changing the current strength. Under the action of a stable magnetic field, the melt cuts off the magnetic induction line and generates a current j m , the expression is as follows:

[0078]

[0079] Where v is the fluid velocity, δ is the melt conductivity, and B is the magnetic induction intensity.

[0080] The gravity acting on the cavitation bubble can be expressed as:

[0081]

[0082] In the formula, ρ b is the gas density in the cavitation bubble, and g is the gravitational acceleration.

[0083] The buoyancy force on the cavitation bubble is:

[0084]

[0085] In the formula, ρ m Density of liquid metal in the molten pool.

[0086] The viscous force on cavitation bubbles in the molten pool includes friction resistance and shape resistance. When the Rayleigh coefficient is greater than 1, the viscous resistance can be expressed as:

[0087]

[0088] In the formula, u b is the velocity vector of the cavitation bubble, u m is the melt pool flow velocity vector, C D is the viscous drag coefficient:

[0089]

[0090] Where, u is the dynamic viscosity of the melt, Re is the Reynolds coefficient;

[0091] According to Newton's second law, under the combined action of ultrasound and magnetic field, the acceleration of cavitation bubbles can be expressed as:

[0092]

[0093] From the above formula, we can see that the Lorentz force increases the upward acceleration of the cavitation bubble in the molten pool, and the additional acceleration generated by the Lorentz force is Its value is proportional to the induced current and the magnetic field strength. It can be seen that the cavitation bubbles in the bottom area of ​​the molten pool can move to the upper area of ​​the molten pool under the acceleration of the Lorentz force, which means that the magnetic field expands the role of cavitation bubbles in the molten pool and directly enhances the cavitation effect.

[0094] What is disclosed above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A wind turbine gear arc fuse additive manufacturing auxiliary device, characterized in that: It includes an arc fuse robot, a workbench, a gear fixing mechanism, an ultrasonic vibration generating mechanism, and an electromagnetic field generating mechanism; The arc fuse robot is arranged on one side of the workbench; The gear fixing mechanism comprises a spindle box and a tailstock mounted on the workbench; the spindle box and the tailstock can clamp and fix the gear to be repaired between the two, and can drive the gear to rotate under the rotation of the spindle box main shaft; The ultrasonic vibration generating mechanism is installed at the end of the welding gun of the arc fuse robot, so that when the arc fuse robot is welding, the ultrasonic vibration generating mechanism can move synchronously with the arc fuse robot, and the relative position of the ultrasonic vibration and the heat source is kept unchanged; The electromagnetic field generating mechanism includes a clamping and fixing component, and an electromagnet installed on the upper end of the clamping and fixing component; the clamping and fixing component is installed on a workbench, and by adjusting the clamping and fixing component, the electromagnet can be adjusted to a position that matches the gear to be repaired, so that the magnetic field generated by the electromagnet can change the molten pool flow, heat transfer and mass transfer behavior during the arc fuse additive manufacturing process.

2. The wind turbine gear arc fuse additive manufacturing auxiliary device according to claim 1, characterized in that: The ultrasonic vibration generating mechanism includes a fixed connection component, a clamping component, and an ultrasonic vibration generator installed on the clamping component; the fixed connection component is installed at the end of the welding gun of the arc fuse robot, and the clamping component is installed on the fixed connection component. The lateral distance between the clamping component and the fixed connection component can be adjusted to achieve the distance adjustment between the ultrasonic vibration generator and the welding gun.

3. The wind turbine gear arc fuse additive manufacturing auxiliary device according to claim 2, characterized in that: The clamping assembly is rotatably connected to the fixed connection assembly, so that the angle between the clamping assembly and the fixed connection assembly in the vertical direction can be adjusted to achieve angle adjustment between the ultrasonic vibration generator and the welding gun.

4. The wind turbine gear arc fuse additive manufacturing auxiliary device according to claim 3, characterized in that: The fixed connection assembly includes a first arc-shaped clamp and a second arc-shaped clamp; the first arc-shaped clamp is rotatably connected to one end of the second arc-shaped clamp, and the other ends of the first arc-shaped clamp and the second arc-shaped clamp are fastened by bolts, so that the first arc-shaped clamp and the second arc-shaped clamp are docked and clamped and fixed on the end of the welding gun of the arc fuse robot; a connecting clamp is provided on the side of the first arc-shaped clamp.

5. The wind turbine gear arc fuse additive manufacturing auxiliary device according to claim 4, characterized in that: The clamping assembly includes a first semicircular clamping ring and a second semicircular clamping ring; the first semicircular clamping ring and the second semicircular clamping ring are fixed together by bolts to achieve clamping and fixing of the ultrasonic vibration generator, a connecting rod is fixedly provided on the first circular clamping ring, and the connecting clamp is fastened by bolts to achieve clamping and fixing of the connecting rod.

6. The wind turbine gear arc fuse additive manufacturing auxiliary device according to claim 4, characterized in that: A guide groove is arranged in the first arc-shaped clamping ring, a sliding block is installed in the guide groove, and a screw connected to the sliding block is threadedly installed along the radial direction of the first arc-shaped clamping ring.

7. The wind turbine gear arc fuse additive manufacturing auxiliary device according to claim 1 or 2, characterized in that: The clamping and fixing component includes a support column and a clamping assembly; the lower end of the support column is provided with a base plate for installation on a workbench, the upper end of the support column is provided with a fixing block, the lower end of the fixing block and the upper end of the base plate are both provided with a threaded rod threadedly connected to the support column, and the clamping assembly is rotatably installed on the fixing block to adjust the angle between the clamping assembly and the support column.

8. The wind turbine gear arc fuse additive manufacturing auxiliary device according to claim 7, characterized in that: The clamping assembly includes a mounting groove and a pressure plate; one end of the mounting groove is rotatably connected to a fixed block, and one end of the pressure plate is hinged to the upper end of the mounting groove, so that the pressure plate can be freely opened and closed along the top of the mounting groove with this end, and the other end of the pressure plate is fastened to the mounting groove by screws to clamp the electromagnet and fix it in the mounting groove.

9. The wind turbine gear arc fuse additive manufacturing auxiliary device according to claim 8, characterized in that: A first pressing rod is threadedly installed at one end of the installation groove, and a second pressing rod perpendicular to the first pressing rod is threadedly installed on the pressure plate. The first pressing rod and the second pressing rod cooperate with each other to clamp and fix the electromagnet in the installation groove.

10. A method for repairing wind turbine gear arc fuse by additive manufacturing, using the wind turbine gear arc fuse additive manufacturing auxiliary device according to any one of claims 1 to 9 for cladding repair, characterized in that: The following steps are included: Step S1: Grind the damaged gear, remove the surface oxide layer and clean it, and use the spindle box and tailstock to clamp and position the gear to be repaired; Step S2: using forward and reverse technology and Boolean operations to obtain a three-dimensional model of the defective part, and combining it with robot simulation programming software to generate a welding trajectory of the defective part; Step S3: After adjusting the ultrasonic vibration generator to a suitable height, the first semicircular clamp and the second semicircular clamp are fixed by bolts; the distance of the connecting rod inserted into the connecting clamp is adjusted to be suitable, the spacing between the ultrasonic vibration generator and the welding gun is adjusted to be suitable, the connecting rod is rotated, the angle between the ultrasonic vibration generator and the welding gun is adjusted to be suitable, and the connecting clamp is tightened by bolts to clamp the connecting rod; Step S4: adjust the bottom plate so that the electromagnet is aligned with the area to be welded, and adjust the height of the electromagnet to a suitable position by rotating the support column; rotate the mounting slot to adjust the relative angle between the electromagnet and the gear to be repaired to a suitable position; Step S5: According to the obtained welding trajectory, the gear is repaired by using an arc fuse robot.

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