Surface roller coating device and method for Halbach sintered neodymium iron boron multi-pole magnetic ring

Abstract

The invention discloses a surface roller coating device and method for a Halbach sintered NdFeB multi-pole magnetic ring, and relates to the technical field of Halbach sintered NdFeB multi-pole magnetic ring machining. A coating hopper bin is fixedly arranged on a support, a control roller and a coating roller are arranged below the support, the rotating direction is downward between the control roller and the coating roller, the distance between the control roller and the coating roller is adjustable, discharged materials of the coating hopper bin make contact with any position from the position between the control roller and the coating roller to the upper end of the roller face of the control roller at first, and a collecting tray is arranged below the control roller and the coating roller; a mechanical arm is fixedly arranged on one side of the support, the end of the mechanical arm is connected with an inner supporting clamp used for taking and placing a magnetic ring, the mechanical arm can drive the magnetic ring to rotate, and the movement range of the inner supporting clamp driven by the mechanical arm comprises a material taking area and a discharging area and further comprises linear movement from one end to the other end of the coating roller in the axial direction of the coating roller along the roller face of the coating roller. The scheme is simple and reasonable, the use amount of rare earth is reduced, higher-precision and more uniform coating of the magnetic ring can be achieved, and performance improvement is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of Halbach sintered NdFeB multi-pole magnetic ring processing, in particular to a Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device and method. Background Art

[0002] With the development of automation, intelligence, and smart technology, the application scenarios of motors are becoming more and more abundant. They are indispensable from land, sea, sky to the household appliances around us. The application of motors is so wide that the technology of motors is also developing towards miniaturization, lightness, and high energy, and the requirements are getting higher and higher. Permanent magnet motors are the first choice under the current circumstances. The permanent magnet materials in permanent magnet motors are key materials for manufacturing high-performance motors. Among them, Halbach sintered NdFeB multi-pole magnetic rings have an increasing proportion in the field of micro permanent magnet motor application technology, and the development trend is obvious. This is mainly due to the fact that Halbach is an ideal magnetic circuit structure that uses the least amount of magnets to generate the strongest magnetic field strength in a specific direction, so that it can generate the strongest possible magnetic field. Under the same volume, it significantly improves the power density and other performance of the motor without increasing the use of permanent magnets.

[0003] With the continuous iteration and innovation of motors, requirements have been put forward in the application environment, which also puts higher requirements on permanent magnet materials. In the application of NdFeB multi-pole magnetic rings, in order to adapt to the requirements of higher occasions, it is necessary to improve the high temperature resistance. The use of magnetic ring surface coating technology is the best choice. The coating can increase the coercive force of the magnetic ring and improve the performance at high temperature to meet the requirements of high cost performance and motor application scenarios.

[0004] At present, the main way to improve the coercivity of sintered NdFeB is to add more rare earths during the manufacturing process. In addition, there are spraying technology and screen printing technology. The former two are costly, waste a lot of rare earth materials, are not economical, and are not environmentally friendly; the latter is only suitable for planar magnetic tiles, and cannot achieve coating on the outer surface of cylindrical magnetic rings. The invention patent with the announcement number CN117000545B and the name of the automatic conveying coating equipment for magnetic ring production discloses that by setting the magnetic ring on the rotating rod, the rotating rod is rotated during powder dipping to drive the magnetic ring body to roll through the powder dipping chamber in a vertical state, ensuring full powder dipping and improving the quality and uniformity of the coating; however, this powder dipping equipment can only be used for the coating of the insulating outer layer with lower technical requirements, and cannot be used for the coating of rare earth slurry. It not only cannot meet the requirements of uniform coating for coercivity, but also the coating thickness is difficult to control at a relatively thin level. Therefore, a Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device and method are urgently needed to solve this problem. Summary of the invention

[0005] The object of the present invention is to provide a device and method for roller coating the surface of a Halbach sintered NdFeB multi-pole magnetic ring, so as to meet the coating requirements of the Halbach magnetic ring.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device, comprising a bracket, on which a paint funnel bin is fixedly arranged, the bracket is also provided with a parallel control roller and a paint roller below the paint funnel bin, the two are transmission-connected, and the rotation direction is downward between the two, the two ends of the rotating shaft of the control roller and the paint roller are respectively connected to the bracket through bearings, wherein a positioning displacement mechanism is also connected between the bearing of the control roller and the bracket, and the displacement direction is close to and away from the paint roller for adjusting the roller surface distance between the two; the discharge of the paint funnel bin first contacts between the control roller and the paint roller to any position on the upper end of the roller surface of the control roller, and a collecting material tray is provided below the control roller and the paint roller;

[0007] A manipulator is fixedly provided on one side of the bracket, and an inner support clamp is connected to its end. The clamping part of the manipulator can extend and retract along the radial direction of the magnetic ring, and is used to penetrate into the hole of the magnetic ring and then extend to support the inner wall of the magnetic ring to achieve material picking and contraction to achieve material discharge. The manipulator can drive the inner support clamp to rotate along the axial direction of the clamped magnetic ring, or the inner support clamp can drive the magnetic ring to rotate along its axial direction; the movement range of the magnetic ring driven by the manipulator includes not only the material picking area and the material discharge area, but also includes the linear movement from one end of the paint roller to the other end along the roller surface of the paint roller in the axial direction of the paint roller.

[0008] Preferably, it also includes a loading tray and a unloading tray, and a magnetic ring positioning structure is provided in the material storage space of the two trays for robot programming to record the material picking and unloading positions, and the loading tray is connected to a vibrating feeder or a magnetic ring conveyor belt.

[0009] Preferably, the paint funnel bin and the control roller surface are made of wear-resistant and corrosion-resistant materials, the paint roller surface is made of rubber or polyurethane material, the lower part of the paint funnel bin is funnel-shaped, and the lower end of the paint funnel bin is rotatably connected to a bottom roller shaft parallel to the control roller, and a displacement mechanism identical to that connected to the bearing of the control roller is connected between the paint funnel bin and the bracket, and the displacement mechanism is a screw nut mechanism or a hydraulic adjustment device, and when the distance between the control roller and the paint roller is adjusted, the paint funnel bin and the control roller move synchronously; the control roller and the bottom roller shaft are connected by a chain or gear transmission, and the control roller and the paint roller are driven to rotate by motors respectively.

[0010] Preferably, the clamping portion of the inner support clamp is a claw or an airbag structure, which has two air holes for connecting to the pneumatic system. The clamping portion includes two working states. When air is taken in by the first air hole, the outer end of the claw or the airbag structure stretches or expands from the center axis of the magnetic ring to the inner wall of the magnetic ring until it is in close contact with the inner wall of the magnetic ring. When the first air hole is deflated or the second air hole is let in air, the outer end of the claw or the airbag structure contracts from the inner wall of the magnetic ring to the center axis of the magnetic ring.

[0011] Preferably, the paint roller is hollow inside and is equipped with a temperature regulating device for heating to maintain the fluidity of the paint on the roller surface in a low temperature environment and cooling in a high temperature environment to prevent the paint from deteriorating or drying out too quickly.

[0012] Another technical solution provided by the present invention is a method for roller coating the surface of a Halbach sintered NdFeB multi-pole magnetic ring, using the above-mentioned device, comprising the following specific steps:

[0013] Coating preparation: Mix rare earth, dispersant and binder to prepare slurry and put it into the coating hopper, stir evenly, and control the ambient humidity and temperature;

[0014] Magnetic ring loading: Place the magnetic ring within the grasping range of the robot manually or through an automatic loading device, and the robot grabs the magnetic ring;

[0015] Magnetic ring roller coating: control the rotation of the roller and the paint roller, adjust the spacing so that the paint roller carries the required thickness of paint, and the manipulator moves the magnetic ring to one side of the paint roller. When the magnetic ring contacts the paint roller, the manipulator or the inner support fixture drives the magnetic ring to rotate and move at a uniform speed in the axial direction of the paint roller, along the surface of the paint roller, from one end of the paint roller to the other end to complete the roller coating;

[0016] Magnetic ring unloading: After roller coating is completed, the robot moves the magnetic ring to the unloading area for placement;

[0017] Subsequent processing: heat treatment of the magnetic ring after roller coating, and then quality inspection, and adjustment of process parameters according to the inspection results.

[0018] Preferably, in the above coating preparation step, the ratio of rare earth, dispersant and binder is adjusted according to the performance requirements of the magnetic ring, the stirring time is 5 to 15 minutes, the ambient humidity is controlled at 40 to 60%, and the temperature is controlled at 20 to 30°C.

[0019] Preferably, the above-mentioned adjustment process parameters include: the distance between the control roller and the coating roller, the control roller rotation speed, the rotation speed of the magnetic ring, the linear movement speed of the magnetic ring, the coating formula and / or the contact pressure between the coating roller and the magnetic ring.

[0020] Preferably, in the above magnetic ring roller coating step, the roller speed is controlled to be 10 to 30 revolutions per minute, the distance from the coating roller is adjusted to 0.1 to 1 mm, the magnetic ring rotation speed is 5 to 20 revolutions per minute, and the forward speed of the linear movement is 5 to 15 cm per minute.

[0021] Preferably, in the above-mentioned subsequent processing steps, the heat treatment is carried out in a protective gas atmosphere, the gas flow rate is 5 to 15 liters per minute, the temperature is 600 to 1000°C, and the time is 1 to 20 hours. The quality inspection includes coating thickness inspection, magnetic property inspection and appearance inspection, wherein the coating thickness error is controlled within ±10μm.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device and method has a simple structure and reasonable design. The coating control part can stably provide uniform coating, and the roller coating can accurately form a coating on the outer surface of the magnetic ring. Compared with the method of adding more rare earth to increase the coercive force in the traditional manufacturing process, it effectively reduces the use of heavy rare earth. Heavy rare earth resources are relatively scarce and expensive. Reducing their use not only reduces the cost of raw materials, but also reduces the waste of rare earth resources, which is in line with the development trend of sustainable resource utilization. At the same time, it also reduces the environmental pressure caused by the large-scale use of rare earths, which has positive significance in both economic and environmental protection.

[0024] 2. The Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device and method, the magnetic ring coating working part can realize the automated operation of the magnetic ring roller coating operation through the coordinated work of the manipulator, the internal support clamp, etc., the loading plate automatically loads, the manipulator accurately grabs and positions, the coating roller continuously coats, and the unloading plate unloads in an orderly manner. Each link is closely connected, so that the magnetic ring can be continuously roller coated, which greatly improves the production efficiency, shortens the production cycle, helps to meet the market's growing demand for magnetic ring products, and improves the company's production efficiency and market competitiveness.

[0025] 3. The Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device and method, the coating control part can accurately adjust the thickness and uniformity of the coating through the precise matching of the control roller and the coating roller, laying the foundation for high-quality coating. During the roller coating process, the manipulator accurately controls the movement of the magnetic ring, including the rotation speed, forward speed and contact pressure with the coating roller, so that the outer surface of the magnetic ring can be evenly coated with paint to form a coating with uniform thickness and stable quality. The uniform coating not only ensures the consistency of the magnetic ring performance, but also improves the appearance quality of the magnetic ring, reduces local performance differences or defects that may be caused by uneven coating, and improves the overall quality of the product.

[0026] 4. The Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device and method forms a heavy rare earth coating on the outer surface of the magnetic ring through a roller coating process, and significantly improves the coercivity of the magnetic ring after heat treatment. The increase in intrinsic coercivity enhances the performance of the magnetic ring in a high temperature environment, allowing the magnetic ring to resist a larger reverse magnetic field during operation and reduce the risk of demagnetization, thereby improving the stability and reliability of the magnetic ring in a high temperature environment, enabling it to adapt to a wider range of application scenarios, such as high-temperature industrial motors, electric vehicle drive motors, and other fields that have high requirements for magnetic properties and temperature stability.

[0027] 5. The Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device and method provide a new technical means and process method for the outer surface treatment of the sintered NdFeB multi-pole magnetic ring of permanent magnetic material, solving the problems of high cost and inability to achieve outer surface coating of cylindrical magnetic rings in the prior art. Its successful application and promotion can provide motor and other related industries with better performance and lower cost permanent magnetic materials, promote the further development of motors in the direction of miniaturization, lightweight and high energy, and promote the technological progress and industrial upgrading of the entire permanent magnetic material and motor industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the working state of the present invention. For the convenience of observation, the bracket part and the magnetic ring being coated in the figure are the main viewing angle, and the manipulator, the upper material tray and the lower material tray are the top viewing angle;

[0029] Figure 2 It is a structural schematic diagram of an implementation mode of the internal support clamp of the present invention;

[0030] Figure 3 It is a three-dimensional schematic diagram of the surface of the magnetic ring after roller coating using the method of the present invention.

[0031] In the figure: 1. Paint hopper; 2. Control roller; 3. Paint roller; 4. Collection tray; 5. Bracket; 6. Loading tray; 7. Magnetic ring to be coated; 8. Magnetic ring being coated; 9. Unloading tray; 10. Robot; 11. Internal support fixture. DETAILED DESCRIPTION

[0032] See also Figure 1A Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device comprises a bracket 5, on which a paint funnel bin 1 is fixedly arranged, and the bracket 5 is also provided with a parallel control roller 2 and a paint roller 3 below the paint funnel bin 1, the two are transmission-connected, and the rotation direction is downward between the two, and the two ends of the rotating shafts of the control roller 2 and the paint roller 3 are respectively rotatably connected to the bracket 5 through bearings, wherein a positioning displacement mechanism is also connected between the bearing of the control roller 2 and the bracket 5, and the displacement direction is close to and away from the paint roller 3 for adjusting the roller surface distance between the two; the discharge of the paint funnel bin 1 first contacts between the control roller 2 and the paint roller 3 to any position on the upper end of the roller surface of the control roller 2, and a collecting tray 4 is arranged below the control roller 2 and the paint roller 3;

[0033] A manipulator 10 is fixedly provided on one side of the bracket 5, and an inner support clamp 11 is connected to its end. The clamping part thereof can extend and retract along the radial direction of the magnetic ring, and is used to penetrate into the hole of the magnetic ring and then extend to support the inner wall of the magnetic ring to achieve material picking and contraction to achieve material discharge. The manipulator 10 can drive the inner support clamp 11 to rotate along the axial direction of the clamped magnetic ring, or the inner support clamp 11 can drive the magnetic ring to rotate along its axial direction (among which the rotation of the manipulator is preferred, and even if the inner support clamp rotates, it is best to use a method in which the front end of the manipulator drives the inner support clamp to rotate, because the magnetic ring may have multiple sizes, and the inner support clamp may also need to be replaced with multiple sizes for matching. Therefore, if the inner support clamp itself has a rotation function, the cost will be doubled); the movement range of the magnetic ring driven by the manipulator 10 includes not only the material picking area and the material discharge area, but also includes the linear movement from one end of the coating roller 3 to the other end along the roller surface of the coating roller 3 in the axial direction of the coating roller 3.

[0034] In an optional embodiment, the upper part of the paint hopper can be a rectangular structure, which can provide a larger slurry storage space, so that the slurry can be temporarily stored and buffered in the hopper. The lower part can be a funnel-shaped structure, such as an inverted triangle structure, which can use gravity to make the slurry flow naturally to the bottom. Its material should have a certain wear resistance and corrosion resistance to prevent the components in the slurry from damaging the hopper. Of course, inside the hopper, it is also possible to consider setting a stirring device to prevent the slurry from settling or stratifying after being left still for a long time, to ensure the uniformity of the slurry components, and to ensure the stability of the slurry quality brought out each time.

[0035] In an optional embodiment, the control roller is driven to rotate by a motor, and the rotation speed of the control roller can be accurately controlled by adjusting the speed of the motor. In terms of adjusting the spacing with the coating roller, a high-precision screw nut mechanism or a hydraulic adjustment device can be used, which can achieve micron-level spacing adjustment, thereby accurately controlling the thickness of the coating; further optionally, the lower end of the coating funnel bin can be rotatably connected to a bottom roller shaft parallel to the control roller, and the transmission connection between the bottom roller shaft and the control roller can be a chain drive or a gear drive to ensure that the roller shaft can stably follow the rotation of the control roller to bring out the slurry. Specifically, the bottom roller shaft can be kept obliquely above the control roller, and the distance between the two roller surfaces can be fixed at 0.1 to 1 mm; the coating funnel bin and the bracket are connected with the same displacement mechanism as the bearing of the control roller, and the displacement mechanism is a screw nut mechanism or a hydraulic adjustment device. When adjusting the distance between the control roller and the coating roller, the coating funnel bin and the control roller move synchronously. The surface material of the control roller should have certain wear resistance and corrosion resistance to ensure that the flatness and performance of the roller surface are not affected during long-term contact and extrusion with the slurry. At the same time, the diameter and length of the control roller can be reasonably designed according to the size of the paint hopper and the size of the paint roller, ensuring that the control roller and the paint roller are coordinated and consistent throughout the entire working process.

[0036] In an optional embodiment, the paint roller is made of a material with good elasticity and adsorption, such as rubber or polyurethane, so that the paint can be better adsorbed and evenly applied when in contact with the outer surface of the magnetic ring. The internal structure of the paint roller can be designed as a hollow structure, which can not only reduce the overall weight, but also a temperature regulating device can be installed in the hollow part. In a low temperature environment, the paint can be heated to maintain a certain fluidity to prevent the paint from solidifying; in a high temperature environment, it can be cooled to prevent the paint from deteriorating or drying too quickly due to excessive temperature. The bearings at both ends of the paint roller should be high-precision bearings to ensure that it is stable and smooth during rotation, reduce jumping and shaking, and thus ensure the uniformity of paint application.

[0037] In an optional embodiment, the collecting tray can be rectangular or circular, and its depth should be moderate, which can effectively collect the fallen paint without affecting the normal rotation of the roller. The material of the collecting tray should have good corrosion resistance and easy cleaning, such as stainless steel or plastic. At the bottom of the collecting tray, an inclined angle can be designed to facilitate the pouring of the paint and the recycling of the collected paint. At the same time, a protective baffle can be installed around the collecting tray to prevent the paint from splashing out of the collection area and keep the working environment clean.

[0038] In an optional embodiment, each joint of the manipulator can be equipped with a high-precision servo motor or pneumatic device to achieve precise motion control. When grabbing the magnetic ring, the end inner support clamp of the manipulator can be customized according to the size and shape of the magnetic ring to ensure a firm grasp without damaging the magnetic ring. The motion trajectory and action sequence of the manipulator are generally controlled by a preset program, which can be flexibly adjusted according to the requirements of magnetic rings of different specifications and roller coating processes. When it is necessary to locate the roller surface, the manipulator generally uses a high-precision positioning sensor, such as a visual sensor or a laser ranging sensor, to monitor the relative position between the magnetic ring and the paint roller in real time to ensure that the contact position is accurate. It can also be used for positioning when taking and placing the magnetic ring, but this sensor is a conventional configuration in the field of manipulators, so it will not be repeated here. During the extension and rotation of the magnetic ring, the joint movement of the manipulator must cooperate to ensure that the magnetic ring can move along the surface of the paint roller at a stable speed and posture to achieve uniform coating.

[0039] See also Figure 2 In an optional embodiment, the design principle of the internal support clamp is based on the pneumatic transmission principle. The air inlet and the air outlet are connected to the external air source, and the internal support and contraction actions are achieved by controlling the inlet and outlet of the gas. The clamping part of the internal support clamp can adopt a plurality of retractable claws or airbag structures, which are provided with two air holes for connecting to the pneumatic system. The clamping part includes two working states. When the first air hole is inlet, the outer end of the claw or airbag structure stretches or expands from the center axis of the magnetic ring to the inner wall of the magnetic ring until it is in close contact with the inner wall of the magnetic ring. When the first air hole is deflated or the second air hole is inlet, the outer end of the claw or airbag structure shrinks from the inner wall of the magnetic ring to the center axis of the magnetic ring. The material of the internal support clamp should have a certain strength and wear resistance to ensure that it will not be damaged during frequent material removal and discharge operations. At the same time, the size of the internal support clamp can be quickly replaced or adjusted according to the size of the inner ring of magnetic rings of different specifications to meet the production needs of various models of magnetic rings.

[0040] In a preferred embodiment, the device of the present invention also includes a loading tray 6 and a discharging tray 9, and a magnetic ring positioning structure can be provided in the material storage space of the two. The loading tray can be equipped with an automatic loading device, such as a vibrating feeder or a conveyor belt, to transport the magnetic rings one by one to the grabbing position of the manipulator to improve the loading efficiency. For reference, the loading tray and the discharging tray have similar structures, generally in the shape of a circular disc or a square disc, and the magnetic ring positioning structure can be a positioning groove or a positioning pin, which is used to accurately place the magnetic ring to ensure that the position of the magnetic ring is stable while waiting for loading and completing the coating and discharging process, and at the same time facilitates the programming of the manipulator to record the material position. The discharging tray can be connected to subsequent processing equipment or a transmission device to realize the automatic transfer of the coated magnetic ring to the next process. The material of the loading tray and the discharging tray can be selected from lightweight materials such as aluminum alloy or plastic, which is easy to operate and move, and at the same time, a certain strength and stability must be guaranteed to prevent deformation or displacement during the placement and retrieval of the magnetic ring.

[0041] In the above device description, the contact between the coating roller surface carrying the coating and the outer cylindrical surface of the magnetic ring is the core link of the roller coating of the present invention. During the rotation of the coating roller, due to the viscosity of the coating on its surface, the coating will maintain a certain distribution state as the roller surface rotates. The following is an example of the magnetic ring being driven to rotate by a manipulator. When the magnetic ring contacts the coating roller under the precise control of the manipulator, a relative motion occurs between the outer cylindrical surface of the magnetic ring and the coating roller. The magnetic ring is controlled by the manipulator, and the rotation of the manipulator enables the magnetic ring to rotate clockwise at a certain angular velocity (at a speed of 1 / 400) when it contacts the coating roller. Figure 1 ), and at the same time, the uniform forward movement of the manipulator drives the magnetic ring to move uniformly along the axial direction of the coating roller. This composite movement of rotation and advancement enables the outer cylindrical surface of the magnetic ring to contact the coating on the coating roller comprehensively and uniformly, and the coating gradually adheres to the outer surface of the magnetic ring and forms a uniform coating. In the whole process, the parameters such as the gripping force of the manipulator on the magnetic ring, the contact pressure between the magnetic ring and the coating roller, and the movement speed of the magnetic ring need to be precisely controlled. The gripping force must ensure that the magnetic ring does not fall during the movement, and the contact pressure must be moderate. Too large a contact pressure may cause uneven coating or deformation of the magnetic ring, and too small a contact pressure may cause the coating to be loose (the present invention focuses on providing the device and its use method, and the specific pressure value can be adjusted according to the actual equipment size, process requirements, test results and experience). The movement speed of the magnetic ring should be comprehensively adjusted according to factors such as the viscosity of the coating, the rotation speed of the coating roller, and the required coating thickness. The optimal movement parameters are determined through a large number of experiments and process optimization to achieve a high-quality roller coating effect.

[0042] The above-mentioned device is used to roll-coat the surface of Halbach sintered NdFeB multi-pole magnetic ring, which may include the following specific steps:

[0043] Coating preparation: Mix rare earth, dispersant and binder to prepare slurry and put it into the coating funnel, stir evenly, and control the ambient humidity and temperature; the proportion of rare earth, dispersant and binder is adjusted according to the performance requirements of the magnetic ring. For reference, the stirring time can be 5 to 15 minutes, the ambient humidity can be controlled at 40 to 60%, and the temperature can be controlled at 20 to 30°C;

[0044] In addition, before loading, it is necessary to check whether the device is normal at intervals during production, for example: ensure that the roller shaft at the bottom of the funnel bin, the control roller, the paint roller and other components are installed correctly and can operate normally. Check whether the collection tray is placed in the right position and there are no foreign objects blocking the collection of paint. Initialize and debug the manipulator, including calibration of parameters such as the range of motion of each joint, movement speed and positioning accuracy, to ensure that the manipulator can accurately grasp and place the magnetic ring. Test the air intake and exhaust systems of the internal support fixture to ensure that it can normally realize the internal support and contraction actions to firmly grasp magnetic rings of different specifications. At the same time, check whether the positioning devices of the upper and lower material trays are normal, and ensure that the magnetic rings can be stably placed in the trays.

[0045] Magnetic ring loading: Place the magnetic ring within the grasping range of the robot manually or through an automatic loading device, and the robot grabs the magnetic ring;

[0046] Specifically, in the above optional implementation, the Halbach sintered NdFeB multi-pole magnetic ring to be roller-coated is placed on the positioning groove or positioning pin of the loading tray, so that the position of the magnetic ring is fixed and convenient for the robot to grab. The magnetic rings can be delivered one by one to the grabbing range of the robot through the automatic loading device of the loading tray (such as a vibrating feeder or a conveyor belt). Under the control of a preset program, the robot moves to the top of the loading tray and grabs the magnetic ring with an internal support clamp. At this time, the internal support clamp takes in air through the air inlet, so that the internal support part (such as a claw or an airbag) stretches, tightly clamps the inner ring of the magnetic ring, and then lifts the magnetic ring away from the loading tray.

[0047] Magnetic ring roller coating: control the rotation of the roller and the paint roller, adjust the spacing so that the paint roller carries the required thickness of paint, and the manipulator moves the magnetic ring to one side of the paint roller. When the magnetic ring contacts the paint roller, the manipulator or the inner support fixture drives the magnetic ring to rotate and move at a uniform speed in the axial direction of the paint roller, along the surface of the paint roller, from one end of the paint roller to the other end to complete the roller coating;

[0048] For reference, after the manipulator grabs the magnetic ring, it can move the magnetic ring to the top of the paint roller according to the preset positioning program, and adjust the relative position of the magnetic ring and the paint roller so that the outer surface of the magnetic ring is accurately aligned with the surface of the paint roller. The control roller and the paint roller start to rotate, the control roller rotates clockwise at the set speed, and the paint roller rotates counterclockwise at the corresponding speed (with Figure 1 Direction instructions shown). By adjusting the distance between the control roller and the coating roller, the coating is squeezed to a suitable thickness and uniformity, and the coating roller surface carries the coating. When the magnetic ring contacts the coating roller, the manipulator rotates and moves forward at a uniform speed at the same time. Driven by the manipulator, the magnetic ring rotates clockwise and moves forward at a uniform speed along the axis of the coating roller, so that the coating is evenly coated on the outer surface of the magnetic ring. During the entire roller coating process, closely monitor the thickness and uniformity of the coating on the coating roller, as well as the contact pressure between the magnetic ring and the coating roller and the movement state of the magnetic ring. If there is any abnormality, make timely adjustments;

[0049] Magnetic ring unloading: After roller coating is completed, the robot moves the magnetic ring to the unloading area for placement;

[0050] In the above optional implementation mode for reference, the manipulator moves the coated magnetic ring to the top of the unloading tray, the inner support fixture exhausts air through the air outlet, the inner support part shrinks, the magnetic ring is released, and the magnetic ring is placed at the designated position of the unloading tray. The positioning device of the unloading tray ensures that the magnetic ring stands stably in the tray for subsequent processing;

[0051] Subsequent treatment: heat treatment of the magnetic ring after roller coating, and then quality inspection, and adjustment of process parameters according to the inspection results, which may include the distance between the control roller and the coating roller, the rotation speed of the control roller, the rotation speed of the magnetic ring, the linear moving speed of the magnetic ring, the coating formula and / or the contact pressure between the coating roller and the magnetic ring, etc.;

[0052] The heat treatment is to heat treat the magnetic ring according to the established process to improve the coercive force of the magnetic ring. During the heat treatment process, parameters such as temperature, time and atmosphere should be strictly controlled to ensure the best heat treatment effect. The heat-treated magnetic ring is subjected to quality inspection, including coating thickness inspection, coating uniformity inspection, magnetic properties (such as intrinsic coercive force, remanence, etc.) inspection and appearance inspection. According to the test results, the roller coating process parameters (such as coating formula, roller coating speed, contact pressure between the coating roller and the magnetic ring, etc.) are adjusted and optimized to ensure that the product quality is stable and meets the requirements. For example, if the coating thickness is uneven, it may be necessary to check the surface state of the coating roller, whether the control roller and the coating roller spacing adjustment mechanism is normal, or adjust the movement speed and rotation speed of the magnetic ring during roller coating; if the magnetic properties are not up to standard, it may be necessary to optimize the heat treatment process parameters or adjust the content of rare earth and other components in the coating formula.

[0053] In the above magnetic ring roller coating step, the roller speed is further optionally controlled to be 10 to 30 revolutions per minute, the distance from the coating roller is adjusted to 0.1 to 1 mm, the magnetic ring rotation speed is 5 to 20 revolutions per minute, and the linear forward speed is 5 to 15 cm per minute.

[0054] Further optionally, in the above-mentioned subsequent processing steps, the heat treatment is carried out in a protective gas atmosphere with a gas flow rate of 5 to 15 liters per minute, a temperature of 600 to 1000°C, and a time of 1 to 20 hours. The quality inspection includes coating thickness inspection, magnetic property inspection and appearance inspection, wherein the coating thickness error is controlled within ±10μm.

[0055] The roller coating device and method of the present invention have significant advantages in reducing the use of heavy rare earths. Traditional methods may require the addition of a large amount of heavy rare earths to increase the coercive force of the magnetic ring, while the solution of the present invention can utilize heavy rare earth resources in a more accurate and efficient manner by forming a layer of heavy rare earth coating on the outer surface of the magnetic ring. Compared with the overall addition of heavy rare earths, this local coating method not only reduces the use of heavy rare earths, reduces costs, but also reduces potential impacts on the environment. The coercive force of the magnetic ring surface can be improved after heat treatment. This is because the roller-coated heavy rare earth coating undergoes physical and chemical reactions with the surface of the magnetic ring during the heat treatment process, optimizing the microstructure of the magnetic ring. The increase in intrinsic coercive force enables the magnetic ring to maintain better magnetic properties in a high temperature environment, and the temperature stability is significantly enhanced.

[0056] The following examples use the device and method in the above-mentioned embodiment to roller-coat Halbach sintered NdFeB multi-pole magnetic rings. The magnetic ring specifications include two types of 8-level magnetic rings with specifications of D22.5d12.5H20 and D25.5d15.5H25, and corresponding tests are performed.

[0057] Example:

[0058] according to Figure 1 As shown in the structure, first assemble the paint control part. Fix the paint funnel bin on the bracket to ensure that it is firmly installed and in a stable position. Install the roller at the bottom of the paint funnel bin and connect it to the control roller through a suitable transmission method (such as chain drive or gear drive) to ensure that the roller can rotate smoothly with the control roller. Install the control roller and the paint roller, and adjust the position of the control roller so that it can accurately adjust the distance between it and the paint roller through the screw nut mechanism or hydraulic adjustment device. Connect the power device (such as a motor) of the control roller and debug it to ensure that the control roller can rotate stably at the set speed and the speed adjustment range meets the process requirements. Install the collection tray at a suitable position below the roller to ensure that it can effectively collect the fallen paint without affecting the normal operation of the roller.

[0059] Assemble the working part of the magnetic ring coating. Install the manipulator on a suitable working platform, connect its power source (such as a servo motor or pneumatic device) and control system, perform initialization debugging, and calibrate the motion parameters of each joint, including the range of motion, speed, and positioning accuracy. Install the internal support fixture at the end of the manipulator, connect the air inlet and outlet to the external air source, and test the internal support and contraction functions of the internal support fixture to ensure that it can firmly grasp magnetic rings of different specifications. Place the upper and lower material trays at appropriate positions within the working range of the manipulator, check whether its positioning devices (such as positioning grooves or positioning pins) are working properly, and ensure that the magnetic rings can be stably placed in the tray.

[0060] According to the predetermined formula, accurately weigh the raw materials such as rare earth, dispersant and binder, mix them in the paint funnel, and use the stirring device (if any) to fully stir the slurry to ensure that the slurry composition is uniform and there is no precipitation or stratification. During the slurry preparation process, pay attention to controlling the ambient humidity and temperature to avoid the slurry from deteriorating or affecting its fluidity due to environmental factors. At the same time, according to actual production needs, slurries of different formulas or concentrations can be prepared to meet the requirements of magnetic roller coating of different types or specifications.

[0061] Place the Halbach sintered NdFeB multi-pole magnetic ring to be roller coated on the loading tray, start the automatic loading device of the loading tray (such as a vibrating feeder or a conveyor belt), and transport the magnetic rings one by one to the grabbing position of the robot. Under the control of the preset program, the robot moves to the top of the loading tray, the internal support fixture is air-filled, grabs the magnetic ring and lifts it off the loading tray;

[0062] The manipulator moves the magnetic ring to the top of the coating roller, and according to the pre-set positioning program, accurately adjusts the relative position of the magnetic ring and the coating roller, so that the outer cylindrical surface of the magnetic ring is parallel to the roller surface of the coating roller and the spacing is appropriate. Start the control roller and the coating roller, the control roller rotates clockwise, and the coating roller rotates counterclockwise. By adjusting the spacing between the control roller and the coating roller, the coating is squeezed to the required thickness (such as the thickness suitable for the current magnetic ring specifications and process requirements determined by experiments, generally in the range of 50 to 500 μm). When the magnetic ring contacts the coating roller, the manipulator rotates and extends forward at a uniform speed at the same time. The clockwise rotation speed of the magnetic ring and the forward speed along the axial direction of the coating roller are determined according to factors such as the viscosity of the coating and the thickness requirements of the roller coating (for example, through multiple tests, the rotation speed of the magnetic ring is determined to be 5 to 20 revolutions per minute, and the forward speed is 5 to 15 cm per minute, etc.). During the roller coating process, sensors (such as visual sensors or laser ranging sensors) are used to monitor in real time the thickness and uniformity of the paint on the paint roller, as well as the contact pressure between the magnetic ring and the paint roller and the movement state of the magnetic ring. If any abnormality is found (such as uneven paint thickness, stuck magnetic ring movement, etc.), the control roller speed, spacing or robot movement parameters are adjusted in time.

[0063] After the magnetic ring is roller coated, as the robot continues to move, the magnetic ring is separated from the coating roller. The robot moves the coated magnetic ring to the top of the unloading tray, the inner support clamp contracts to release the magnetic ring, and the magnetic ring is placed at the designated position of the unloading tray to ensure that the magnetic ring stands stably on the unloading tray.

[0064] Heat treat the magnetic ring after roller coating on the unloading plate according to the process requirements. Place the magnetic ring in the heat treatment furnace, set the appropriate heat treatment temperature (determined according to the material of the magnetic ring and the coating composition, such as 600-1000°C), time (such as 1-20 hours) and atmosphere (such as inert gas protective atmosphere) and other parameters, and start the heat treatment process. After the heat treatment is completed, the magnetic ring is quality inspected. Use a coating thickness measuring instrument to detect whether the coating thickness is within the specified range (generally 50-500μm) and has good uniformity; use magnetic performance testing equipment (such as vibrating sample magnetometer, etc.) to detect whether the magnetic performance indicators such as intrinsic coercive force and remanence of the magnetic ring meet the expected improvement requirements; perform an appearance inspection to check whether the surface coating of the magnetic ring has defects such as cracks and peeling. According to the test results, adjust and optimize the roller coating process parameters (such as coating formula, roller coating speed, contact pressure between the coating roller and the magnetic ring, etc.) and heat treatment process parameters to ensure that the product quality is stable and meets the requirements. For example, if the detection finds that the coating thickness is uneven, it may be necessary to check whether the surface condition of the coating roller is worn, whether the control roller and the coating roller spacing adjustment mechanism is loose, or further optimize the movement speed and rotation speed of the magnetic ring during roller coating; if the magnetic properties do not meet the standards, it may be necessary to adjust the heat treatment temperature, time or atmosphere, or optimize the content of rare earth and other ingredients in the coating formula.

[0065] The above device and method were used to carry out magnetic ring roller coating of two specifications, and the test results are as follows:

[0066] The intrinsic coercivity of the magnetic ring with specification of D22.5d12.5H20 is 14.04kOe before roller coating. After roller coating with 0.2mm thick coating and heat treatment, the intrinsic coercivity is increased to 19.85kOe, and the maximum operating temperature is increased from ≤100℃ to ≤140℃;

[0067] The 8-level magnetic ring with specification of D25.5d15.5H25 has an intrinsic coercivity of 16.87kOe before roller coating. After roller coating with 0.4mm thick coating and heat treatment, the intrinsic coercivity is increased to 25.62kOe, and the maximum operating temperature is increased from ≤110℃ to ≤180℃.

[0068] The above are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined by the claims.

[0069] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

Claims

1. A Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device, characterized in that: The invention comprises a support (5) on which a paint funnel bin (1) is fixedly arranged. The support (5) is also provided with a parallel control roller (2) and a paint roller (3) below the paint funnel bin (1). The two are connected in a transmission manner, and the rotation direction is downward between the two. The two ends of the rotating shafts of the control roller (2) and the paint roller (3) are respectively connected in rotation with the support (5) through bearings. A positioning displacement mechanism is also connected between the bearing of the control roller (2) and the support (5). The displacement direction is close to and away from the paint roller (3) for adjusting the distance between the roller surfaces of the two. The discharge of the paint funnel bin (1) first contacts between the control roller (2) and the paint roller (3) to any position on the upper end of the roller surface of the control roller (2). A collecting tray (4) is provided below the control roller (2) and the paint roller (3). A manipulator (10) is fixedly provided on one side of the bracket (5), and an inner support clamp (11) is connected to the end of the manipulator (10). The clamping portion of the manipulator (10) can be extended and retracted along the radial direction of the magnetic ring, and is used to penetrate into the hole of the magnetic ring and then extend to support the inner wall of the magnetic ring to achieve material collection and contraction to achieve material discharge. The manipulator (10) can drive the inner support clamp (11) to rotate along the axial direction of the clamped magnetic ring, or the inner support clamp (11) can drive the magnetic ring to rotate along its axial direction. The range of motion of the manipulator (10) driving the magnetic ring includes not only a material collection area and a material discharge area, but also a linear motion from one end of the coating roller (3) to the other end along the roller surface of the coating roller (3) in the axial direction of the coating roller (3).

2. The Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device according to claim 1, characterized in that: It also includes a loading tray (6) and a unloading tray (9), wherein the material storage spaces of the two trays are provided with magnetic ring positioning structures for programming a manipulator (10) to record material taking and unloading positions, and the loading tray (6) is connected to a vibrating feeder or a magnetic ring conveyor belt.

3. The Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device according to claim 1, characterized in that: The surfaces of the paint funnel bin (1) and the control roller (2) are made of wear-resistant and corrosion-resistant materials, and the surface of the paint roller (3) is made of rubber or polyurethane material. The lower part of the paint funnel bin (1) is funnel-shaped, and the lower end of the paint funnel bin (1) is rotatably connected to a bottom roller shaft parallel to the control roller (2). A displacement mechanism similar to that connected to the bearing of the control roller (2) is connected between the paint funnel bin (1) and the bracket (5). The displacement mechanism is a screw nut mechanism or a hydraulic adjustment device. When the distance between the control roller (2) and the paint roller (3) is adjusted, the paint funnel bin (1) and the control roller (2) move synchronously. The control roller (2) and the bottom roller shaft are connected by a chain or gear transmission, and the control roller (2) and the paint roller (3) are driven to rotate by motors respectively.

4. The Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device according to claim 1, characterized in that: The clamping part of the inner support clamp (11) is a claw or an airbag structure, which has two air holes for connecting to the pneumatic system. The clamping part includes two working states. When air is admitted to the first air hole, the outer end of the claw or the airbag structure stretches or expands from the central axis of the magnetic ring to the inner wall of the magnetic ring until it is in close contact with the inner wall of the magnetic ring. When the first air hole is deflated or the second air hole is admitted, the outer end of the claw or the airbag structure shrinks from the inner wall of the magnetic ring to the central axis of the magnetic ring.

5. The Halbach sintered NdFeB multi-pole magnetic ring surface roller coating device according to claim 1, characterized in that: The coating roller (3) is hollow inside and is equipped with a temperature regulating device, which is used for heating to maintain the fluidity of the coating on the roller surface in a low-temperature environment, and cooling in a high-temperature environment to prevent the coating from deteriorating or drying out too quickly.

6. A method for roller coating the surface of a Halbach sintered NdFeB multi-pole magnetic ring, using the device according to any one of claims 1 to 5, characterized in that: The specific steps include: Coating preparation: Mix rare earth, dispersant and binder to prepare slurry and put it into the coating hopper, stir evenly, and control the ambient humidity and temperature; Magnetic ring loading: Place the magnetic ring within the grasping range of the robot manually or through an automatic loading device, and the robot grabs the magnetic ring; Magnetic ring roller coating: control the rotation of the roller and the paint roller, adjust the spacing so that the paint roller carries the required thickness of paint, and the manipulator moves the magnetic ring to one side of the paint roller. When the magnetic ring contacts the paint roller, the manipulator or the inner support fixture drives the magnetic ring to rotate and move at a uniform speed in the axial direction of the paint roller, along the surface of the paint roller, from one end of the paint roller to the other end to complete the roller coating; Magnetic ring unloading: After roller coating is completed, the robot moves the magnetic ring to the unloading area for placement; Subsequent processing: heat treatment of the magnetic ring after roller coating, and then quality inspection, and adjustment of process parameters according to the inspection results.

7. The method according to claim 6, characterized in that: In the coating preparation step, the ratio of rare earth, dispersant and binder is adjusted according to the performance requirements of the magnetic ring, the stirring time is 5 to 15 minutes, the environmental humidity is controlled at 40 to 60%, and the temperature is controlled at 20 to 30°C.

8. The method according to claim 6, characterized in that The adjustment process parameters include: the distance between the control roller and the coating roller, the rotation speed of the control roller, the rotation speed of the magnetic ring, the linear moving speed of the magnetic ring, the coating formula and / or the contact pressure between the coating roller and the magnetic ring.

9. The method according to claim 6 or 8, characterized in that: In the magnetic ring roller coating step, the roller speed is controlled to be 10 to 30 revolutions per minute, the distance from the coating roller is adjusted to 0.1 to 1 mm, the magnetic ring rotation speed is 5 to 20 revolutions per minute, and the forward speed of the linear movement is 5 to 15 cm per minute.

10. The method according to claim 6 or 8, characterized in that: In the subsequent processing steps, the heat treatment is carried out in a protective gas atmosphere, the gas flow rate is 5 to 15 liters per minute, the temperature is 600 to 1000°C, and the time is 1 to 20 hours. The quality inspection includes coating thickness inspection, magnetic property inspection and appearance inspection, and the coating thickness error is controlled within ±10μm.

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