On-line repairing method for gear tooth surface damage in rolling mill production line motor coupling

Abstract

The application discloses an on-line repairing method for gear tooth surface damage in a rolling mill production line motor coupling, and specifically comprises the following steps: (1) closing relevant equipment power and lubricating system, disassembling equipment peripheral auxiliary facilities, removing equipment input end and output end power transmission and load load, dismounting target gear matched parts to expose the target gear, so that the target gear and matched shaft parts are in an open space; (2) cleaning the gear tooth surface to be treated to remove oil stains on the gear tooth surface; (3) detecting the gear to be treated; (4) determining a repairing scheme for the gear tooth surface according to the detection result: when the gear does not reach the scrap standard, using a subtractive scheme to repair, and when the gear reaches the scrap standard, using an additive scheme to repair. According to the detection result of the gear, the application adopts two different methods for targeted repairing, can control accurate size and tooth shape, and further completes repairing and machining of more gear teeth or even all gear teeth.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of repairing and reinforcing the tooth surface of a rolling mill production line motor coupling, and specifically relates to a method for repairing the tooth surface of a rolling mill production line motor coupling on line by using laser processing technology. BACKGROUND

[0002] Gears are common transmission elements, and have many machining procedures, complex processes, long production cycles and high unit prices. The tooth surface of a gear often appears serious wear, pitting and gluing in complex working conditions. The transmission gear of a large device is not only expensive to manufacture, but also has a long cycle and large waste after being scrapped. Therefore, timely repair and reinforcement of old parts can effectively ensure the normal operation of the equipment and prolong the service life of the parts.

[0003] After the tooth surface of the gear in the rolling mill production line motor coupling is damaged, the traditional repair method is to disassemble and then repair. However, due to the difficulty of long-term shutdown for maintenance, the actual production requirements cannot be met. In addition, the assembly method of the gear and the matching parts adopts interference fit, which is not convenient for disassembly and repair. If forcibly disassembled, the matching surface of the matching parts will be damaged. Therefore, how to repair the tooth surface of the gear in the coupling on line is one of the problems faced by gear users.

[0004] Patent CN 108555468 B (authorized on October 9, 2020) discloses a large straight gear on-line welding repair process. It is a welding repair after the gear produces broken teeth. Its shortcomings are: 1. Manual welding and manual grinding in the repair process rely on the tooth profile template as the only processing reference. The accurate size and tooth profile cannot be controlled during the processing, and the repair processing of the tooth surface of a large number of teeth or even all the teeth cannot be completed. 2. The heat input of the surfacing processing method is large, the heat affected zone is large, the material organization of the repaired part is coarse, and defects such as inclusion, hydrogen embrittlement and welding cracks are easy to occur. The processing quality is difficult to meet the harsh working condition requirements of heavy load equipment. 3. Oxygen bottles and acetylene bottles are used on the welding site, which increases the risk of explosion. 4. The gear is in the box. No protective measures are taken during welding. The heat will affect other parts, and the residue will also fall into other parts or the box, so it will inevitably affect the later use. 5. Manual repair relies heavily on the experience and state of skilled operators, and the processing efficiency is low and the processing quality is unstable. SUMMARY

[0005] The problem to be solved by the present application is to provide an on-line repair method for the tooth surface damage of the gear in the rolling mill production line motor coupling. According to the detection results of the gear, two different methods are used for targeted repair, which ensures the quality of on-line repair. The present application can control the accurate size and tooth profile, and further complete the repair processing of the tooth surface of a large number of teeth or even all the teeth.

[0006] The specific steps of the on-line repairing method for gear tooth surface damage in a rolling mill production line motor coupling are as follows: (1) closing the power and lubrication system of the related equipment, disassembling the peripheral auxiliary facilities of the equipment, removing the power transmission and load of the input and output ends of the equipment, and dismounting the parts matched with the target gear to expose the target gear, so that the target gear and the matched shaft parts are in an open space; (2) cleaning the tooth surface of the gear to be treated to remove oil stains on the tooth surface; (3) detecting the gear to be treated, and the detection items include size and tooth profile measurement, wear measurement, tooth surface flaw detection, and tooth surface hardness detection; (4) determining the repairing scheme for the tooth surface of the gear according to the detection results: when the gear does not reach the scrap standard, using a subtractive scheme for repairing, and when the gear reaches the scrap standard, using an additive scheme for repairing.

[0007] When the gear to be treated is repaired by using the subtractive scheme: (1) manually grinding or mechanically processing the damaged area of the tooth surface to remove defects in the area, so that the tooth surface is free of pores, interlayer, rust, cracks and the like; using a tooth profile template to check the processed tooth surface to ensure that the tooth surface can be smoothly engaged; and cleaning the tooth surface to remove oil stains on the tooth surface; (2) performing laser quenching strengthening treatment on the tooth surface: ① installing and debugging a movable modular laser processing equipment in the space outside the gear: fixing the laser processing equipment through a support base, confirming that the laser state is normal, and adjusting the pose of the industrial robot; ② using a height gauge as an observation and adjustment tool for the rotary positioning reference of the gear, and ensuring that the tooth surface processing references are consistent through tooth-by-tooth coincidence fixed positions; ③ performing laser quenching on one side of the tooth surface of the gear: I rotating to adjust the circumferential angle of the gear, so that the first tooth surface (any tooth, marked and identified) of any side of the gear to be processed is in a horizontal position, measuring the angle and distance between the tooth surface to be processed and the laser processing head, and ensuring that the laser beam incidence angle does not interfere with the adjacent tooth surface, and the laser beam spot size and focal length meet the process requirements; II setting light shields on both sides of the tooth surface to be processed, and ensuring that the laser beam scanning track extends beyond the edge of the tooth surface, and the starting and ending positions of the laser beam scanning are located on the light shields; III skipping tooth processing after the laser quenching of the first tooth surface is completed, and the processing of the tooth surface on the same side of the gear is completed; ④ performing laser quenching on the tooth surface on the other side of the gear: repeating steps I-III in step ③ until the tooth surface on the other side of the gear is completely processed; (3) cleaning the tooth surface, detecting the hardness and roughness of the tooth surface, and performing non-destructive flaw detection on the tooth surface; using a tooth profile template to check the processed tooth surface to ensure that the tooth surface can be smoothly engaged; and delivering the gear for use after the detection is qualified.

[0008] When the tooth to be processed is repaired by an additive scheme: (1) manually grinding or machining the damaged area of the tooth surface, removing defects in the area, so that the tooth surface is free of pores, delamination, rust, cracks, etc.; the gear tooth surface is cleaned to remove oil stains on the tooth surface; (2) laser cladding repair processing is performed on the tooth surface: ① A movable modular laser processing equipment is installed and adjusted outside the gear space: the laser processing equipment is fixed through a support base, the laser state is confirmed to be normal, and the pose of the industrial robot is adjusted; ② A horizontal numerical control rotary indexing table is used to clamp the gear to ensure that the tooth surface machining reference is consistent; ③ Laser cladding is performed on one side of the gear tooth surface: I. Local induction heating preheating is performed using a tooth-shaped induction heating head before cladding; II. A calibrated industrial camera is used to take multiple images of the part to be processed, the image set is input into the machine vision image processing software, and the node coordinate data is output to the robot control system after processing and operation by the image processing software. The robot control system automatically calculates and generates the processing program by running the pre-programmed program and checks and verifies it; III. Cladding layer extension plates are arranged on both sides of the tooth surface to be processed, the laser beam scanning tooth surface motion trajectory is extended beyond the tooth surface edge, and the starting and ending positions of the laser beam scanning are located on the cladding layer extension plates; IV. The robot executes the laser cladding processing program to perform laser cladding on the tooth surface. After the first tooth surface is completed, the gear is jumped to process until the tooth surface on one side of the gear is completely processed; V. Local induction heating post-treatment is performed using a tooth-shaped induction heating head after cladding; ④ Laser cladding is performed on the other side of the gear tooth surface: repeat steps I-V in step ③ above to complete the laser cladding of the other side of the tooth surface; ⑤ Vibration aging treatment is performed on the cladded tooth surface; (3) Install external shaft processing equipment to perform gear tooth surface milling: ① Calibrate the part coordinate system, calibrate the vision camera calibration tool coordinate system, take the initial image of the part, and output the actual coordinate values of the gear profile (relative to the tool coordinate system) to the industrial robot after the image processing software reads and processes the image. The robot compares it with the ideal coordinate values of the built-in gear profile to automatically generate an industrial robot processing program; ② The processing knife table of the external shaft processing equipment processes the gear tooth surface, and the tooth surface milling is completed tooth by tooth until the entire gear tooth surface is processed; ③ The tooth surface edge is manually ground with a tooth-shaped sample as a reference; ④ The gear tooth surface is cleaned, and the tooth profile and dimensional tolerance, tooth surface hardness, roughness, and non-destructive flaw detection of the tooth surface are detected; after passing the detection, it is delivered for use.

[0009] In step (1), the two ways of grinding the damaged area of the tooth surface are: one, manually grinding to remove defects in the area, grinding the concave pits to be open, and rounding the edges of the concave pits; two, mechanical machining to remove the defect material layer, and processing a smooth transition at the contact position between the removed area and the original tooth surface.

[0010] The movable modular laser processing equipment used in step (2) is integrated by multiple devices: a laser LDM 6000-100ER, a laser head SN02099805845, a laser head D2009763041800503215, a powder feeder RC-PGF-D (004#), a robot KR20R1810-2, a robot control cabinet KRC4, and a laser water cooler MCWL-120DTR-01AES7Z1-3385. The laser head SN02099805845 is used for quenching, and the laser head D2009763041800503215 is used for cladding.

[0011] In step (2), the composition of the iron-based self-fluxing alloy powder used for laser cladding is as follows (mass percentage): 0.15-0.2% C, 15-17% Cr, 2% Ni, 1% Si, 1% B, 0.5% Mo, 0.3% Mn, 0.15% Nb, 0.05 V, 0.05 Cu, Ti≤0.02, P≤0.02, S≤0.02, and the rest is Fe.

[0012] In step (2), in step ③ of laser cladding, the heating temperature in steps I and VI is calculated according to the carbon equivalent of the substrate material and the cladding material:

[0013] CE = W(c) + W(Mn) / 6 + [W(Cr) + W(Mo) + W(V)] / 5 + [W(Ni) + W(Cu)] / 15 (%);

[0014] When CE is less than 0.45%, no preheating is required; when CE is between 0.45% and 0.60%, preheating is required at 100-200°C; and when CE is greater than 0.60%, preheating is required at 200-370°C.

[0015] In step (2), during laser cladding, a copper nozzle is used to align the laser spot to irradiate the molten pool for axial powder feeding, and the light head is protected by an argon gas atmosphere.

[0016] In step (2), during laser cladding, multiple cladding layers are used to form a large-area planar cladding. When multiple layers are overlapped, each layer is cleaned and polished to remove surface oxides and slag before the next layer is cladded.

[0017] The extension plate is in the shape of "[", and its two ends are respectively clamped on both sides of the tooth surface that needs to be cladded.

[0018] The advantages of the online repair method of the present invention are as follows: 1. By first conducting relevant inspections on the gears, two different methods are used for targeted repair based on the inspection results, ensuring both repair quality and cost savings. 2. When the gears do not meet the scrap standard, a subtractive repair method using laser quenching and strengthening is used, ensuring repair quality and saving costs. When the gears meet the scrap standard, an additive repair method combining laser cladding and metallurgy is used, which has low heat input and low thermal impact, and is supplemented by machine vision to ensure the contour of the final machined gear, with high machining accuracy and full-tooth machining capability. This method provides high machining efficiency, good machining quality, and is energy-saving and environmentally friendly. 3. During the laser cladding process in the additive repair method, extension plates are provided on both sides of the tooth surface to be machined to ensure a full cladding layer at the edge of the tooth surface, thereby ensuring the cladding quality of the tooth surface. 4. The gears being repaired online are located in an open space and are protected to prevent heat and debris generated during the repair from affecting other parts, thus preventing safety accidents. Therefore, the method of the present invention can accurately control the size and tooth shape, completing online repair processing of tooth surfaces with a large number of teeth, or even the entire number of teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a flow chart of the online repair method of the present invention;

[0020] Figure 2 It is a flowchart of the repair of the subtractive solution;

[0021] Figure 3 It is a flowchart of the additive solution repair;

[0022] Figure 4 It is a schematic diagram of the extended plate in the additive repair scheme;

[0023] Figure 5 This is a schematic diagram of the installation of the extension plate;

[0024] Figure 6 yes Figure 5 The main view;

[0025] Figure 7 yes Figure 5 Right view of;

[0026] Figure 8 yes Figure 5 Top view of . DETAILED DESCRIPTION

[0027] Example 1

[0028] The online repair method for gear tooth surface damage in the motor coupling of the rolling mill production line of the present invention comprises the following specific steps:

[0029] (1) Close the power and lubrication system of the relevant equipment, remove the peripheral auxiliary facilities of the equipment, remove the power transmission and load of the input and output ends of the equipment, and remove the parts matched with the target gear to expose the target gear and the shaft parts matched with the target gear in an open space;

[0030] (2) Clean the gear tooth surface to be treated to remove oil stains on the tooth surface;

[0031] (3) Detect the gear to be treated, including size and tooth shape measurement, wear measurement, tooth surface flaw detection, and tooth surface hardness detection;

[0032] (4) Determine the repair scheme of the gear tooth surface according to the detection results: when the gear does not reach the scrap standard, use the subtractive scheme for repair, and when the gear reaches the scrap standard, use the additive scheme for repair.

[0033] Among them, the scrap standard of the gear is determined as follows: 1. The gear has cracks or tooth breakage; 2. The pitting damage of the tooth surface reaches 30% of the meshing tooth surface and the depth reaches 10% of the original tooth thickness, or the pitting area along the tooth width and tooth height exceeds 60%; 3. The tooth thickness of the gear wear is not less than 80% of the original tooth thickness; 4. The gear has obvious abnormal noise and vibration, and the load is obviously increased.

[0034] Example 2

[0035] When the gear to be treated is repaired by using the subtractive scheme:

[0036] (1) Artificially grind or machine the damaged area of the tooth surface to remove defects in the area, so that the tooth surface has no pores, inclusions, rust, cracks, etc.; use a tooth profile template to check the machined tooth surface to ensure smooth meshing; clean the gear tooth surface to remove oil stains on the tooth surface;

[0037] (2) Laser quenching treatment is performed on the tooth surface:

[0038] ① Install and debug the movable modular laser processing equipment outside the gear: fix the laser processing equipment through the support base, confirm that the laser state is normal, and adjust the pose of the industrial robot;

[0039] ② Use a height gauge as an observation and adjustment tool for the rotational positioning reference of the gear, and ensure the consistency of the tooth surface machining reference by tooth-by-tooth coincidence and fixed position;

[0040] ③ Laser quenching is performed on one side of the gear tooth surface:

[0041] ⅠRotating the circumferential rotation angle of the adjusting gear, the first tooth surface (any tooth, mark identification) on any side of the gear to be processed is in a horizontal position, the angle and distance between the tooth surface to be processed and the laser processing head are measured, to ensure that the laser beam incidence angle does not interfere with the adjacent tooth surface, and the laser beam spot size and focal length meet the process requirements;

[0042] ⅡSetting light shielding plates on both sides of the tooth surface to be processed, and the laser beam scanning trajectory extends beyond the edge of the tooth surface to ensure that the starting and ending positions of the laser beam scanning are located on the light shielding plates;

[0043] ⅢAfter the laser quenching of the first tooth surface is completed, the gear is processed by skipping teeth until the tooth surfaces on the same side of the gear are all processed;

[0044] ④Laser quenching of the tooth surface on the other side of the gear: repeating steps Ⅰ-Ⅲ in step ③ above until the tooth surfaces on the other side of the gear are all processed;

[0045] (3) Cleaning the tooth surface, detecting the hardness and roughness of the tooth surface, and performing non-destructive flaw detection on the tooth surface; using a tooth profile template to check the processed tooth surface to ensure smooth meshing; after detection, it is delivered for use.

[0046] In step (2)③Ⅱ: Because the spot size of the beam is different at different focal lengths, if the laser beam is irradiated to other positions during processing, it may cause melting and burning of other tooth surfaces, so protective measures are taken, i.e. setting light shielding plates on both sides of the tooth surface to be processed.

[0047] In step (2)④Ⅰ: After the tooth surface on one side of the gear is processed, the tooth surface on the other side of the gear is processed, and the starting position is determined according to the size of the working space: when the working space is limited and the robot can only work on one side of the workpiece, the circumferential rotation angle of the adjusting gear is rotated to make the first tooth surface (any tooth, mark identification) on the unprocessed side of the gear be in a vertical position; when the working space is large enough and the robot can work on the other side of the workpiece, the circumferential rotation angle of the adjusting gear is rotated to make the first tooth surface (any tooth, mark identification) on the unprocessed side of the gear be in a horizontal position. Processing on both sides of the gear is the preferred scheme.

[0048] Example 3

[0049] When the tooth to be treated is repaired by additive scheme:

[0050] (1) Artificially grinding or machining the damaged area of the tooth surface to remove defects in the area, so that the tooth surface is free of pores, inclusions, rust, cracks, etc.; the gear tooth surface is cleaned to remove oil stains on the tooth surface;

[0051] (2) Laser cladding repair treatment of the tooth surface:

[0052] ①Install and debug the movable modular laser processing equipment outside the gear space: fix the laser processing equipment through the support base, confirm the normal state of the laser, and adjust the pose of the industrial robot;

[0053] ②Clamp the gear using a horizontal numerical control rotary indexing table to ensure the consistency of the tooth surface processing reference;

[0054] ③Laser cladding is performed on one side of the gear tooth surface:

[0055] ⅠBefore cladding, use a tooth-shaped induction heating head for local induction heating preheating;

[0056] ⅡUse a calibrated industrial camera to take multiple images of the part to be processed, input the image set into the machine vision image processing software, process and calculate the image processing software, output the node coordinate data to the robot control system, and the robot control system automatically calculates and generates the processing program through the pre-programmed program, and checks and verifies it;

[0057] Ⅲ Set up a cladding layer extension plate on both sides of the tooth surface to be processed, and the laser beam scanning tooth surface motion trajectory is extended beyond the tooth surface edge to ensure that the laser beam scanning start and end positions are located on the cladding layer extension plate;

[0058] Ⅳ The robot executes the laser cladding processing program to perform laser cladding on the tooth surface, and after the first tooth surface is completed, it jumps to the next tooth to process until the entire tooth surface on one side of the gear is processed;

[0059] Ⅴ After cladding, use a tooth-shaped induction heating head for local induction heating post-treatment;

[0060] ④ Laser cladding is performed on the tooth surface of the other side of the gear: repeat steps Ⅰ-Ⅴ in step ③ above to complete the laser cladding of the tooth surface on the other side;

[0061] ⑤ Perform vibration aging treatment on the cladded tooth surface;

[0062] (3) Install external shaft processing equipment for gear tooth surface milling:

[0063] ①Calibrate the part coordinate system, calibrate the vision camera calibration tool coordinate system, take the initial image of the part, and process the image after the image processing software reads the image. Output the actual coordinate value of the gear profile (relative to the tool coordinate system) to the industrial robot, and the robot compares it with the ideal coordinate value of the built-in gear profile to automatically generate an industrial robot processing program;

[0064] ② The processing tool table of the external shaft processing equipment performs gear tooth surface processing, and each tooth is completed by milling until the entire gear tooth surface is processed;

[0065] ③ Use a tooth-shaped sample as a reference to manually grind the edge of the tooth surface;

[0066] (4) Gear tooth surface is cleaned, and the tooth profile and dimensional tolerance, tooth surface hardness, roughness, and non-destructive flaw detection of the tooth surface are detected; after the detection is qualified, the gear is delivered for use.

[0067] In step (2) of the method, I in (4) is: after the gear tooth surface on one side is machined, the machining of the gear tooth surface on the other side is started, and the starting position is determined according to the size of the working space: when the working space is limited and the robot can only work on one side of the workpiece, the circumferential rotation angle of the gear is adjusted so that the first tooth surface (arbitrary tooth, marked identification) on the unprocessed side of the gear is in a vertical position; when the working space is large enough and the robot can work on the other side of the workpiece, the circumferential rotation angle of the gear is adjusted so that the first tooth surface (arbitrary tooth, marked identification) on the unprocessed side of the gear is in a horizontal position. The machining of the gear on both sides in a horizontal manner is a preferred scheme.

[0068] Example 4

[0069] The two ways of step (1) of the two methods of subtractive repair and additive repair for grinding the damaged area of the tooth surface are: 1. manual grinding to remove defects in the area, and grinding the concave pit to be open, and smoothing the edge of the concave pit; 2. mechanical machining to remove the defect material layer and process a smooth transition at the contact position between the removed area and the original tooth surface.

[0070] The equipment used for mechanical machining can be an electric grinding head or an electric milling cutter, etc.; the electric milling cutter has a large cutting amount and high efficiency.

[0071] The specific way mainly depends on the size of the grinding amount: when the grinding amount is small, manual grinding is adopted, and when the grinding amount is large, mechanical machining is adopted.

[0072] Example 5

[0073] The movable modular laser processing equipment used in step (2) of the two methods of subtractive repair and additive repair is integrated by multiple devices: such as a laser LDM 6000-100ER, a laser head SN02099805845, a laser head D2009763041800503215, a powder feeder RC-PGF-D(004#), a robot KR20R1810-2, a robot control cabinet KRC4, and a laser water cooler

[0074] MCWL-120DTR-01AES7Z1-3385; wherein the laser head SN02099805845 is used for quenching, and the laser head D2009763041800503215 is used for cladding.

[0075] Example 6

[0076] The determination of the gear machining reference in step (2) in both the subtractive repair and the additive repair methods is divided into two modes: one is manual adjustment using a height gauge, and the other is mechanical adjustment using an indexing table.

[0077] The specific mode mainly depends on the positioning accuracy requirement: because the laser quenching has relatively low requirement on the machining reference, manual adjustment can be adopted; because the post-cladding machining has high requirement on the positioning accuracy of the gear, a numerical control indexing table is required for indexing machining. In addition, factors such as the gear size, structure, overall layout, and whether the load of the related matching parts is removed also need to be considered: if the gear is difficult to rotate manually, even laser quenching also needs to use an indexing table for mechanical adjustment.

[0078] Example 7

[0079] The third step in step (2) in both the subtractive repair and the additive repair methods is to skip teeth and add tool bodies: after the first tooth surface of the gear is machined, machining is continued at intervals of more than two tooth surfaces until the machining of all tooth surfaces on one side of the gear is completed.

[0080] The skip tooth machining is to consider heat dissipation to avoid heat accumulation causing thermal deformation and large changes in process conditions of the parts; on the other hand, through the skip tooth machining mode, the negative effects of heat deformation and heat accumulation are dispersed, and the possible negative effects are balanced and offset through symmetric configuration.

[0081] Example 8

[0082] In the additive repair method, when laser cladding is performed in step (2), the cladding alloy powder is selected according to the gear base material and the technical requirements of the working conditions: the composition of the iron-based self-fluxing alloy powder is as follows (mass percentage): 0.15-0.2% C, 15-17% Cr, 2% Ni, 1% Si, 1% B, 0.5% Mo, 0.3% Mn, 0.15% Nb, 0.05 V, 0.05 Cu, Ti≤0.02, P≤0.02, S≤0.02, and the rest is Fe.

[0083] Example 9

[0084] Step ③ in step (2) in the additive repair method: the heating temperature in steps I and VI is calculated according to the carbon equivalent of the base material and the cladding material.

[0085] CE = W(c) + W(Mn) / 6 + [W(Cr) + W(Mo) + W(V)] / 5 + [W(Ni) + W(Cu)] / 15 (%)

[0086] When CE < 0.45%, no preheating is required; when CE is between 0.45% and 0.60%, preheating is required at 100-200°C; when CE > 0.60%, preheating is required at 200-370°C.

[0087] Example 10

[0088] In step ③ of step (2) of the additive repair method: the copper tube nozzle is used to irradiate the laser spot on the molten pool to realize the shaft side powder feeding, and the light head is protected by argon gas atmosphere.

[0089] Since the cladding is carried out online, the tooth surface cladding space is narrow, and the powder feeding carrier gas is easy to form turbulence between the tooth surfaces, so the copper tube nozzle is preferred to realize accurate shaft side powder feeding; during laser cladding, coaxial powder feeding and shaft side powder feeding can be switched at any time as needed.

[0090] Example 11

[0091] In step ③ of step (2) of the additive repair method: step V uses slow heating and slow cooling to reduce the stress of the cladding part.

[0092] Example 12

[0093] In step ③ of step (2) of the additive repair method: large-area planar cladding uses multiple cladding layers to form a lap joint; when multiple layers are lapped, each layer is cleaned between layers to remove surface oxides and slag, and the lap joint is offset to form an overlap and is polished to a slope angle before cladding the next layer.

[0094] Example 13

[0095] In step ⑤ of step (2) of the additive repair method: the vibration head is magnetically attached to the surface of the part, and external stress is applied to the target site through mechanical vibration to cause changes in internal stress of the target site, thereby releasing stress and relieving local stress concentration, stabilizing performance, and reducing subsequent deformation.

[0096] Example 14

[0097] In the additive repair method: before milling the gear tooth surface, the mobile modular laser processing equipment can be removed, and the same equipment used for milling can be used when mechanical grinding is performed.

[0098] Example 15

[0099] In the additive repair method: when laser cladding and milling the tooth surface by the machining equipment, the industrial camera captures real-time images of the end surface and side surface of the gear at various angles, and compares them with the design model data to obtain the tooth surface machining allowance size, and automatically feeds back and corrects the processing program (coordinate system, node coordinate value, trajectory path, motion program, logic instruction).

[0100] Example 16

[0101] As Figure 4As shown in the additive repair method: in step (2) of ③ III, the extension plate 11 is in the shape of "[", and its two ends are respectively clamped on both sides of the tooth surface that needs to be cladded.

[0102] As shown in the additive repair method: in step (2) of ③ III, the extension plate 11 is in the shape of "[", and its two ends are respectively clamped on both sides of the tooth surface that needs to be cladded. Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 As shown in the additive repair method: in step (2) of ③ III, the extension plate 11 is in the shape of "[", and its two ends are respectively clamped on both sides of the tooth surface that needs to be cladded.

[0103] Before cladding, the positioning teeth of the fixed support 12 are clamped in the gear tooth gap, and the two vertical bars are located at both ends of the gear tooth surface, and then the extension plate 11 is placed on the tail of the two vertical bars of the fixed support and flush with the tooth surface, at this time the extension plate 11 tightly clamps the two sides of the tooth surface. The starting and ending positions of the laser beam scanning tooth surface movement during cladding are located on the extension plate, and the extension plate is integrated with the tooth surface after cladding is completed, and the fixed support can be removed for repeated use. In subsequent gear tooth surface milling processing, the excess part of the tooth is processed according to the final shape of the tooth surface.

[0104] When laser cladding is performed in the additive repair method: the function of setting the extension plate on both sides of the tooth surface to be processed is: first, if there is no extension plate, the cladding edge of the tooth surface will collapse, resulting in insufficient processing allowance; using the extension plate can ensure that the cladding layer of the tooth surface edge is full; second, it can protect other tooth surfaces. The extension plate has specific requirements for material and thickness: the material of the extension plate is consistent or close to that of the gear, and the thickness of the extension plate prevents it from being penetrated by laser.

[0105] The online repair method has the following advantages: 1. The gear is detected first, then two different repair methods are used according to the detection results, so that the repair quality is guaranteed and the cost is saved; 2. When the gear does not reach the scrap standard, the laser quenching strengthening subtractive repair method is used to guarantee the repair quality and save the cost; when the gear reaches the scrap standard, the laser cladding metallurgical combined additive repair method is used, the heat input is small, the heat influence is small, and the machine vision is used to ensure the profile of the finally processed gear, the machining precision is high, and the whole gear can be processed; the machining efficiency is high, the machining quality is good, energy saving and environmental protection are achieved; 3. In the additive repair method, when the laser cladding is carried out, the extension plates are arranged on both sides of the gear surface to be processed, so that the cladding layer of the gear surface edge is full, and the cladding quality of the gear surface is guaranteed; 4. The gear repaired online is in an open space, and protective measures are taken, so that the heat and residues generated during repair do not affect other parts, and safety accidents do not occur. Therefore, the method can accurately control the size and tooth shape, and complete the online repair processing of a large number of teeth or even all the teeth.

[0106] The online repair method of the application is not limited to the damage of the gear tooth surface in the rolling mill production line motor coupling, and can be applied to other gears that are not convenient to disassemble from the matched parts and heavy load gears.

Claims

1. The on-line repair method for gear tooth surface damage in rolling mill train motor coupling, which comprises the following specific steps: (1) Close the power and lubrication system of the related equipment, remove the auxiliary facilities around the equipment, remove the power transmission and load of the input and output ends of the equipment, and remove the parts matched with the target gear to expose the target gear, so that the target gear and the shaft parts matched therewith are in an open space; (2) Clean the tooth surface of the gear to be treated to remove oil stains on the tooth surface; (3) Detect the gear to be treated, and the detection items include size and tooth shape measurement, wear measurement, tooth surface flaw detection, tooth surface hardness detection, etc.; (4) Determine the repair scheme of the gear tooth surface according to the detection results: when the gear does not reach the scrap standard, use the subtractive scheme for repair, and when the gear reaches the scrap standard, use the additive scheme for repair; the scrap standard of the gear is determined as follows:

1. the gear has cracks or tooth breakage; 2. the pitting damage of the tooth surface reaches 30% of the meshing tooth surface and the depth reaches 10% of the original tooth thickness, or the pitting area of the tooth surface exceeds 60% along the tooth width and tooth height; 3. the tooth thickness of the gear wear is not less than 80% of the original tooth thickness; 4. the gear has obvious abnormal noise and vibration, and the load is obviously increased; wherein, when the gear to be treated is repaired by the additive scheme: (1) Artificially grind or machine the damaged area of the tooth surface to remove defects such as pores, laminations, rust, cracks, etc. in the area, and clean the tooth surface of the gear to remove oil stains on the tooth surface; (2) Perform laser cladding repair treatment on the tooth surface: ① Install and debug the movable modular laser processing equipment in the space outside the gear: fix the laser processing equipment through the supporting base, confirm that the laser state is normal, and adjust the pose of the industrial robot; ② Use a horizontal numerical control rotary indexing table to clamp the gear to ensure that the tooth surface processing reference is consistent; ③ Perform laser cladding on one side of the tooth surface of the gear: Ⅰ. Before cladding, use a tooth profile induction heating head to perform local induction heating preheating; Ⅱ. Use a calibrated industrial camera to shoot multiple images of the part to be processed, input the image set into a machine vision image processing software, process and calculate the image through the image processing software, output node coordinate data to a robot control system, and the robot control system automatically calculates and generates a processing program through a pre-programmed program and checks and verifies it; Ⅲ. Set a cladding layer extension plate on both sides of the tooth surface to be processed, and the laser beam scanning tooth surface motion track is extended beyond the tooth surface edge to ensure that the starting and ending positions of the laser beam scanning are located on the cladding layer extension plate; Ⅳ. The robot executes the laser cladding processing program to perform laser cladding on the tooth surface, and after the first tooth surface is completed, the gear is jumped to process until the tooth surface on one side of the gear is completely processed; Ⅴ. After cladding, use a tooth profile induction heating head to perform local induction heating post-treatment simultaneously; ④ Perform laser cladding on the other side of the tooth surface of the gear: repeat steps Ⅰ-Ⅴ in step ③ above to complete the laser cladding of the other side of the tooth surface; ⑤ Perform vibration aging treatment on the cladded tooth surface; (3) Install external shaft processing equipment to perform milling of the tooth surface of the gear: ①Calibrate the part coordinate system, calibrate the vision camera calibration tool coordinate system, take the initial image of the part, and process the image after the image processing software reads the image. The actual coordinate value of the gear profile relative to the tool coordinate system is output to the industrial robot. The robot compares it with the ideal coordinate value of the built-in gear profile, and automatically generates the industrial robot processing program; ②The machining tool table of the external shaft machining equipment performs gear tooth surface machining, and each tooth is completed by tooth surface milling until the entire gear tooth surface is machined; ③Take the tooth profile template as the reference, and manually grind the tooth surface edge roundness; ④Clean the gear tooth surface, detect the tooth profile and dimensional tolerance, tooth surface hardness, roughness, and perform non-destructive flaw detection on the tooth surface; after passing the detection, it is put into use.

2. The online repair method according to claim 1, characterized in that: When the gear to be processed adopts a subtractive scheme for repair: (1) Artificially grinding or mechanically processing the damaged area of the tooth surface to remove defects in the area, so that the tooth surface is free of pores, inclusions, rust, cracks, etc.; use a tooth profile template to check the machined tooth surface to ensure smooth meshing; clean the gear tooth surface to remove oil stains on the tooth surface; (2) Laser quenching and strengthening treatment is performed on the tooth surface: ①Install and debug the movable modular laser processing equipment in the space outside the gear: fix the laser processing equipment through the support base, confirm that the laser state is normal, and adjust the pose of the industrial robot; ②Use a height gauge as an observation and adjustment tool for the rotational positioning reference of the gear, and ensure that the tooth surface machining reference is consistent by overlapping the fixed position of each tooth; ③Laser quenching is performed on one side of the gear tooth surface: ⅠAdjust the circumferential rotation angle of the gear so that the first tooth surface (any tooth, marked and identified) of any side of the gear to be machined is in a horizontal position. Measure the angle and distance between the tooth surface to be machined and the laser processing head to ensure that the laser beam incidence angle does not interfere with the adjacent tooth surface, and the laser beam spot size and focal length meet the process requirements; ⅡSet up light shields on both sides of the tooth surface to be machined, and ensure that the laser beam scanning trajectory extends beyond the tooth surface edge to ensure that the starting and ending positions of the laser beam scanning are located on the light shields; ⅢAfter the laser quenching of the first tooth surface is completed, skip the tooth processing until the machining of the tooth surface on the same side of the gear is completed; ④Repeat steps Ⅰ-Ⅲ in step ③ to complete the machining of the tooth surface on the other side of the gear; (3) Clean the tooth surface, detect the tooth surface hardness and roughness, and perform non-destructive flaw detection on the tooth surface; use a tooth profile template to check the machined tooth surface to ensure smooth meshing; after passing the detection, it is put into use.

3. The online repair method according to claim 1 or 2, characterized in that: The two ways of grinding the damaged area of the tooth surface in step (1) are as follows: one is manual grinding to remove defects in the area, and the grinding pit is in an open state with a smooth edge; the other is mechanical processing to remove the defect material layer, and the processed area and the original tooth surface contact position are smoothly transitioned.

4. The online repair method of claim 1, wherein: The movable modular laser processing equipment used in step (2) of the repair by additive scheme is integrated by multiple devices: laser LDM 6000-100ER, laser head D2009763041800503215, powder feeder RC-PGF-D (004#), robot KR20R1810-2, robot control cabinet KRC4, and laser water cooler MCWL-120DTR-01AES7Z1-3385.

5. The online repair method of claim 2, wherein: The movable modular laser processing equipment used in step (2) of the repair by subtractive scheme is integrated by multiple devices: laser LDM 6000-100ER, laser head SN02099805845, powder feeder RC-PGF-D (004#), robot KR20R1810-2, robot control cabinet KRC4, and laser water cooler MCWL-120DTR-01AES7Z1-3385.

6. The online repair method of claim 1, wherein: The composition of the iron-based self-fluxing alloy powder used in step (2) of the repair by additive scheme is as follows (mass percentage): 0.15-0.2% C, 15-17% Cr, 2% Ni, 1% Si, 1% B, 0.5% Mo, 0.3% Mn, 0.15% Nb, 0.05 V, 0.05 Cu, Ti≤0.02, P≤0.02, S≤0.02, and the balance of Fe.

7. The online repair method of claim 1, wherein: In step ③ of the laser cladding in step (2) of the repair by additive scheme: the heating temperature in steps I and VI is calculated according to the carbon equivalent of the base material and the cladding material: CE = W(c) + W(Mn) / 6 + [W(Cr) + W(Mo) + W(V)] / 5 + [W(Ni) + W(Cu)] / 15 (%). When CE < 0.45%, no preheating is needed; when CE is between 0.45% and 0.60%, preheating is performed at 100-200°C; and when CE > 0.60%, preheating is performed at 200-370°C.

8. The online repair method of claim 1, wherein: When performing laser cladding in step (2) of the repair by additive scheme, a copper nozzle is used to align the laser spot to irradiate the molten pool to achieve axial powder feeding, and the light head is protected by an argon atmosphere.

9. The online repair method of claim 1, wherein: When performing laser cladding in step (2) of the repair by additive scheme, multiple cladding layers are used to form a large-area planar cladding; when multiple layers are overlapped, each layer is cleaned and polished to remove surface oxides and slag before the next layer is cladded.

10. The online repair method of claim 1, wherein: The extension plate is "[” shaped, and its two ends are respectively clamped on both sides of the tooth surface that needs to be cladded.

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