Motor rotor metal plate processing apparatus, device, production line, strengthening method, and motor

Abstract

The present application relates to the technical field of motors, and discloses a motor rotor metal plate processing apparatus, a device, a production line, a strengthening method, and a motor. The motor rotor metal plate processing apparatus comprises at least one heat transfer member and a heating assembly. The heat transfer member is configured to perform heat treatment on a magnetic isolation bridge of the rotor metal plate and synchronously penetrate at least part of constituent elements of the heat transfer member to a surface layer of the magnetic isolation bridge. The processing apparatus of the present application can improve the strength of the magnetic isolation bridge by simply performing heat treatment on the position of the magnetic isolation bridge using the heat transfer member, so that the processing efficiency of rotor punching can be greatly improved compared with existing surface processing methods. Therefore, the present application can solve the problem of a low processing efficiency in the existing technology.

Description

Processing equipment, production lines, and strengthening methods for motor rotor metal plates; motors

[0001] This application claims priority to Chinese Patent Application No. 202411916538.7, filed on December 24, 2024, entitled “Apparatus, Equipment, Production Line and Strengthening Method for Motor Rotor Metal Plate, Motor”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of motor technology, and more specifically, to a processing apparatus, equipment, production line and strengthening method for motor rotor metal plates, and a motor. Background Technology

[0003] As the power density of motors increases, both frequency and speed also tend to increase, which places higher demands on the strength of the motor rotor. The magnetic bridge is the area where the entire motor rotor experiences the most concentrated stress and is the weakest point in the overall motor structure; it can break under high-speed conditions.

[0004] Conventional techniques include local surface treatment of the rotor magnetic bridge area, but this method suffers from complex processes and low processing efficiency. Summary of the Invention

[0005] The main purpose of this application is to propose a processing device, equipment, production line, and strengthening method for motor rotor metal plates, as well as a motor, in order to solve the problem of low processing efficiency in the prior art.

[0006] To achieve the above objectives, in a first aspect, this application proposes a processing apparatus for a motor rotor metal plate. The rotor metal plate includes a body, on which magnetic slots and magnetic isolation bridges are provided; wherein, the processing apparatus includes:

[0007] At least one heat transfer element is used to heat treat the magnetic bridge of the rotor metal plate and simultaneously penetrate at least a portion of the constituent elements of the heat transfer element into the surface layer of the magnetic bridge.

[0008] A heating element, which comes into contact with a heat transfer element, is used to provide energy to the heat transfer element.

[0009] In one embodiment, the heat transfer element comprises at least one of carbon, silicon, manganese, nickel, and chromium.

[0010] In one embodiment, the heat transfer element includes a rod having a tapered end; the rod is connected to the heating assembly.

[0011] In one embodiment, the heating assembly includes electrodes and a power source, and the heat transfer element is connected in series with the electrodes and the power source to form a circuit.

[0012] Secondly, this application provides a processing apparatus for a motor rotor metal plate, comprising any of the above-mentioned processing apparatuses for motor rotor metal plates, and further comprising:

[0013] Mounting plate, used to fix heat transfer components;

[0014] The pressurization mechanism, connected to the mounting plate, is used to drive the heat transfer components to move and apply pressure to the magnetic bridge.

[0015] In one embodiment, the mounting plate is provided with multiple fixing positions, and the heat transfer element cooperates with the fixing positions.

[0016] In one embodiment, the pressurizing mechanism includes at least one telescopic body, the telescopic end of which is fixed to the mounting plate.

[0017] In one embodiment, the telescopic body includes one of a hydraulic rod, a pneumatic rod, and an electric push rod.

[0018] Thirdly, this application proposes a method for strengthening a metal plate of an electric motor rotor, comprising:

[0019] The rotor metal plate is heat-treated by heat transfer components at the magnetic bridge, and at least some of the constituent elements of the heat transfer components are simultaneously penetrated into the surface layer of the magnetic bridge. The temperature of the heat transfer components is greater than or equal to 750°C.

[0020] The rotor metal plate, after heat transfer treatment, is subjected to a cooling process.

[0021] In one embodiment, the heat transfer time of the heat transfer element does not exceed 60 seconds.

[0022] In one embodiment, pressure is applied to the heat transfer element while heat treatment is performed on the magnetic bridge of the rotor metal plate through the heat transfer element. The applied pressure of the heat transfer element is 0.1MPa-10MPa.

[0023] In one embodiment, the cooling process includes:

[0024] The rotor metal plate, after heat transfer treatment of the heat transfer components, is immersed in a cooling medium to cool to room temperature; or...

[0025] The rotor metal plate, after heat transfer treatment, is placed in cooling gas to cool to room temperature.

[0026] Fourthly, this application provides a production line for an electric motor rotor metal plate, including any of the above-mentioned processing equipment for electric motor rotor metal plates.

[0027] Fifthly, this application provides an electric motor, including an electric motor rotor, the electric motor rotor including a rotor core formed by stacking rotor metal plates, the motor rotor metal plates being obtained by any of the above-mentioned strengthening methods or by any of the above-mentioned production lines.

[0028] The processing apparatus of this application performs heat treatment on the magnetic bridge using a heat transfer component. During the heat treatment process, the constituent elements of the heat transfer component can penetrate into the surface layer of the magnetic bridge, thereby improving the strength of the magnetic bridge. In other words, the processing apparatus of this application only needs to perform heat treatment on the magnetic bridge using a heat transfer component to improve the strength of the magnetic bridge. Compared with existing surface treatment methods, this can significantly improve the processing efficiency of the rotor metal plate. Therefore, this application can solve the problem of low processing efficiency in the prior art. Attached Figure Description

[0029] Figure 1 is a schematic diagram of the structure of a processing equipment for a motor rotor metal plate according to an embodiment of this application;

[0030] Figure 2 is a schematic diagram of the rotor metal plate in one embodiment of this application;

[0031] Figure 3 is a metallographic image of the magnetic bridge on the rotor metal plate in one embodiment of this application;

[0032] Figure 4 is a metallographic image of the magnetic bridge on the rotor metal plate in one embodiment of this application;

[0033] Figure 5 is a hysteresis loop diagram of the rotor metal plate in one embodiment of this application;

[0034] Figure 6 shows the hysteresis loop diagram of the rotor metal plate in the comparative example.

[0035] The reference numerals in the attached figures are explained as follows: 100, processing device for motor rotor metal plate; 11, heat transfer component; 111, rod body; 112, conical part; 200, rotor metal plate; 21, magnet slot; 22, magnetic isolation bridge; 300, mounting plate; 400, pressurizing mechanism; 41, telescopic body; 500, bracket; 600, operating table. Detailed Implementation

[0036] It should be noted that if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the use of "and / or" or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied. In the embodiments of this application, "at least one" refers to one or more, and "more" refers to two or more.

[0037] In the description of the embodiments of this application, if technical terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the embodiments of this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments of this application.

[0038] In the description of the embodiments of this application, unless otherwise explicitly specified and limited, the technical terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0039] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0040] Ideally, the magnetic flux in a motor should pass entirely through the air gap between the stator and rotor. However, in reality, some flux always leaks into the external structure or windings of the motor, resulting in leakage flux. In this case, a magnetic isolation bridge is needed to reduce or block leakage flux between the rotor and stator, thereby improving the motor's efficiency and power density. The working principle of a magnetic isolation bridge is as follows: When the motor is running, the rotating magnetic field generated by the stator induces current in the rotor. These currents form a closed magnetic circuit in the rotor core. By providing a low-resistivity path, the magnetic flux lines can pass smoothly through the rotor instead of leaking out from the rotor slots. In this way, most of the magnetic flux is confined within the main magnetic circuit of the motor, reducing leakage flux and related losses.

[0041] Based on the above design, the magnetic isolation bridge is usually made of a material with high magnetic permeability, such as silicon steel or soft iron. This material can effectively guide the magnetic field and reduce the amount of magnetic field passing through. Furthermore, the magnetic isolation bridge should be as narrow as possible. If the bridge is too wide, it will occupy more space, allowing magnetic flux lines more opportunities to bypass it, thus generating leakage flux. This makes the magnetic isolation bridge the area where the motor rotor experiences the most concentrated stress, making it prone to breakage under high-speed conditions.

[0042] To improve the strength of the magnetic bridge of the motor rotor, the current conventional treatment methods are: (1) the rotor is made of high-strength silicon steel; (2) the rotor is fitted with a carbon fiber sheath; and (3) the magnetic bridge of the rotor is enlarged.

[0043] The first method uses high-strength silicon steel, which has the disadvantages of difficulty in increasing yield strength and high loss; the second method can protect the rotor to operate safely, but it also brings problems such as increased loss and reduced motor efficiency; the third method can prevent stress concentration, but increasing the magnetic bridge will increase leakage flux, thereby reducing the motor's output torque capability.

[0044] Given the problems inherent in the aforementioned processing methods, a conventional technique has emerged involving localized surface treatment of the motor rotor's magnetic isolation bridge. This involves coating the non-carburized areas of the rotor laminations with a special low-pressure vacuum carburizing coating, followed by localized carburizing in a low-pressure vacuum carburizing heat treatment apparatus. However, since carburizing the entire rotor lamination increases overall rotor leakage flux and raises production costs, this localized treatment method—pre-coating the non-carburized areas with a special coating before processing the entire rotor lamination in the carburizing heat treatment apparatus—is complex and results in low processing efficiency.

[0045] Based on this, this application proposes a method of heat treatment and carburizing of heat transfer components. The heat transfer components are only pressurized at the magnetic bridge, and other areas of the rotor laminations are not treated. Therefore, there is no need to apply paint to the non-carburized areas, saving the paint application step and simplifying the process. Compared with existing surface treatment methods, this method can significantly improve the processing efficiency of rotor laminations.

[0046] According to some embodiments of this application, referring to FIG1, this application proposes a processing device 100 for a motor rotor metal plate. The rotor metal plate 200 is usually made of silicon steel material, and its structural schematic diagram is shown in FIG2. It includes a body, on which a magnetic steel groove 21 and a magnetic isolation bridge 22 are provided.

[0047] The processing apparatus 100 includes at least one heat transfer element 11 and a heating assembly. The heat transfer element 11 is used to perform heat treatment on the magnetic bridge 22 of the rotor metal plate 200 and simultaneously infiltrate at least some of the constituent elements of the heat transfer element 11 into the surface layer of the magnetic bridge 22. The heating assembly is in contact with the heat transfer element 11 and is used to provide energy to the heat transfer element.

[0048] The heat transfer element 11 refers to a permeation source capable of maintaining a certain temperature. It can be composed entirely of the elements to be permeated, or only at the contact points with the magnetic bridge 22 can the elements to be permeated be present. The number of heat transfer elements 11 can correspond to the number of magnetic bridges 22 on the rotor metal plate 200, allowing multiple magnetic bridges 22 on the rotor laminations to be heated and permeated simultaneously for enhanced processing, further improving processing efficiency. The heating assembly is used to heat the heat transfer element 11 to bring it to the required temperature.

[0049] The processing apparatus of this application embodiment can simultaneously perform heat penetration enhancement treatment on multiple magnetic isolation bridges 22 on the rotor metal plate, thereby further improving processing efficiency.

[0050] According to some embodiments of this application, the heat transfer element 11 comprises at least one of carbon, silicon, manganese, nickel, and chromium.

[0051] When the heat transfer element 11 is composed of carbon, it can be made of carbon powder. At this time, the magnetic bridge 22 is carburized, and the carbon element penetrates into the surface layer of the magnetic bridge 22. The microstructure of the silicon steel at the magnetic bridge 22 changes from ferrite to austenite. After subsequent cooling treatment, the austenite further changes into martensite, which improves the strength of the magnetic bridge 22.

[0052] When the constituent element of the heat transfer element 11 is silicon, the heat transfer element 11 can be formed by pressing silicon powder. In this case, the heat transfer element 11 is separated from the silicon powder.

[0053] The magnetic bridge 22 undergoes silicon infiltration, where silicon permeates into the surface layer of the magnetic bridge 22. During subsequent cooling, the silicon is fixed to the surface layer. Silicon infiltration increases the surface hardness and strength of the magnetic bridge 22. The same principle applies to other elements.

[0054] When the heat transfer element 11 comprises multiple elements, the powders of the multiple elements can be mixed evenly and then pressed into the heat transfer element 11 to achieve multi-element penetration enhancement treatment.

[0055] According to some embodiments of this application, referring to FIG1, the heat transfer element 11 includes a rod 111, the end of the rod 111 having a tapered portion 112, the size of the tapered portion 112 matching the width of the magnetic bridge 22, and the rod 111 being connected to the heating assembly.

[0056] According to some embodiments of this application, the heating assembly includes electrodes and a power source, and the heat transfer element 11 is connected in series with the electrodes and the power source to form a circuit.

[0057] In this embodiment, the heat transfer element 11 is heated by the thermal effect generated when the current passes through the electrode. At this time, the electrode should be made of a high resistivity material to generate more heat. For example, the electrode can be made of tungsten, copper, molybdenum, etc.

[0058] In some other embodiments, the heating assembly may also include a coil and a power source, which are connected in series to form a circuit. The coil is wound around the outer circumference of the rod 111. That is, the heat transfer element 11 can be heated by the induced current generated by electromagnetic induction. In this case, the heat transfer element 11 should be a conductor, and the power source is an alternating power source to change the magnetic field generated by the coil, thereby generating an induced current at the heat transfer element 11, and thus heating the heat transfer element 11.

[0059] According to some embodiments of this application, this application also provides a processing equipment for a motor rotor metal plate. The processing equipment includes the processing device 100 described above. The processing equipment also includes a mounting plate 300 and a pressurizing mechanism 400. The mounting plate 300 is used to fix the heat transfer element 11. The pressurizing mechanism 400 is connected to the mounting plate 300 and is used to drive the heat transfer element 11 to move and apply pressure to the magnetic isolation bridge 22.

[0060] The mounting plate 300 can be circular, in which case multiple heat transfer elements 11 are evenly distributed in a ring on the lower surface of the mounting plate 300, and the distribution positions of the heat transfer elements 11 correspond one-to-one with the magnetic isolation bridges 22 on the rotor metal plate 200. The shape of the mounting plate 300 is not limited to this.

[0061] The pressurizing mechanism 400 is connected to the upper surface of the mounting plate 300 so as to drive the heat transfer element 11 to move up and down and apply pressure through the mounting plate 300. In order to support and fix the pressurizing mechanism 400, as shown in Figure 1, a bracket 500 can be added. The bracket 500 consists of a bracket vertical rod and a bracket horizontal rod, and the top of the pressurizing mechanism 400 is fixed to the bracket horizontal rod of the bracket 500.

[0062] For ease of operation, the processing equipment also includes an operating table 600, which is used to place the rotor metal plate 200. At this time, the support vertical rod of the bracket 500 can be fixed to the operating table 600.

[0063] According to some embodiments of this application, the mounting plate 300 is provided with multiple fixing positions, and the heat transfer element 11 mates with the fixing positions. The fixing structure of the fixing positions is not specifically limited in this application. In some embodiments, the fixing position can be a threaded hole, and the end of the heat transfer element 11 is threaded into the threaded hole. In other embodiments, the fixing position can also be a clamp structure, and the end of the heat transfer element 11 is fixed by the clamp structure.

[0064] According to some embodiments of this application, the pressurizing mechanism 400 includes at least one telescopic body 41, the telescopic end of which is fixed to the mounting plate 300.

[0065] Referring to Figure 1, a telescopic body 41 is provided, with its top end fixed to the support crossbar of the bracket 500 and its bottom end fixed to the mounting plate 300. In other embodiments, multiple telescopic bodies 41 can also be provided, and controlling multiple telescopic bodies 41 to extend and retract synchronously can ensure the movement stability of the heat transfer element 11.

[0066] According to some embodiments of this application, the telescopic body 41 includes one of a hydraulic rod, a pneumatic rod, and an electric actuator. A hydraulic rod can provide a large thrust and relatively smooth movement, but its hydraulic system is relatively complex and maintenance costs are high. A pneumatic rod has a fast response speed and relatively simple manufacturing cost, but its thrust is small and its movement stability is poor. An electric actuator has high movement accuracy and a fast response speed, but its thrust is also relatively small and its cost is relatively high. Embodiments of this application can be selected as needed.

[0067] According to some embodiments of this application, this application also provides a method for strengthening a motor rotor metal plate, including: heat-treating the magnetic bridge of the rotor metal plate through a heat transfer element, and simultaneously penetrating at least some of the constituent elements of the heat transfer element into the surface layer of the magnetic bridge, wherein the temperature of the heat transfer element is greater than or equal to 750°C; and cooling the rotor metal plate after the heat transfer element has undergone heat transfer treatment.

[0068] The heat transfer element heat-treats the magnetic bridge, and the constituent elements of the heat transfer element penetrate into the surface layer of the magnetic bridge. Setting the temperature of the heat transfer element to be greater than or equal to 750℃ can promote the penetration of the constituent elements into the surface layer of the magnetic bridge. After subsequent cooling treatment, the penetrated elements are fixed in the surface layer, thereby improving the strength of the magnetic bridge.

[0069] According to some embodiments of this application, the heat transfer time of the heat transfer element does not exceed 60 seconds.

[0070] The heat transfer time of the heat transfer component not exceeding 60 seconds refers to the heating and penetration treatment time of the heat transfer component on the magnetic bridge not exceeding 60 seconds. The strengthening method of this application can significantly improve the strength of the magnetic bridge by only requiring the heat transfer component to be in contact with the magnetic bridge for no more than 60 seconds. Compared with the prior art method that requires carburizing treatment at high temperature for 30-50 minutes, this application can significantly shorten the strengthening process and further improve processing efficiency.

[0071] It should be noted that the heat treatment time for heat transfer components can certainly exceed 60 seconds, and extending the pressure application time can be expected to increase further strength. However, based on improving processing efficiency and short treatment time, significant improvements can be achieved.

[0072] To increase the strength, the pressure application time in this embodiment is selected to be within 60 seconds.

[0073] According to some embodiments of this application, pressure is applied to the heat transfer element while heat treatment is performed on the magnetic bridge of the rotor metal plate via the heat transfer element. The applied pressure to the heat transfer element is 0.1 MPa-10 MPa. This range of applied pressure can ensure the permeation rate of elements while preventing the heat transfer element from sticking to the rotor metal plate.

[0074] According to some embodiments of this application, the cooling process includes: immersing the rotor metal plate after heat transfer treatment in a cooling medium to cool to room temperature; or placing the rotor metal plate after heat transfer treatment in a cooling gas to cool to room temperature.

[0075] The cooling medium can be water or oil. For example, oil quenching can be kerosene, diesel, engine oil, silicone oil, polyester oil, soybean oil, rapeseed oil, etc.

[0076] Cooling gas refers to a gas with a low temperature, which can be nitrogen, air, or an inert gas. Placing the rotor metal plates in the cooling gas can be done by spraying the cooling gas onto the rotor metal plates, blowing the cooling gas onto the rotor metal plates using a fan or blower, or simply placing them directly in the cooling gas environment for natural cooling.

[0077] Taking carbon as the constituent element of the heat transfer component as an example, after the magnetic bridge is heated and carburized by the heat transfer component, the rotor metal plate is immersed in water at room temperature (20℃-25℃) for quenching. At this time, the microstructure of the carburized area changes from austenite to martensite, which significantly improves the strength and hardness of the magnetic bridge.

[0078] Taking silicon as an example, after the magnetic bridge is heated and infiltrated with silicon through the heat transfer component, the rotor metal plate is placed at room temperature to cool slowly and naturally. The silicon element is fixed in the surface layer, thereby increasing the hardness and strength of the magnetic bridge. The same principle applies to other elements.

[0079] According to some embodiments of this application, this application also provides a production line for motor rotor metal plates, including the above-described processing equipment for motor rotor metal plates. The specific structure of the processing equipment is as described in the above embodiments. Since the production line adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated upon here.

[0080] In some embodiments, the production line for the motor rotor may further include stamping fixtures and stacking fixtures. The stamping fixtures are used to stamp metal sheets to form rotor metal sheets; the stacking fixtures are used to stack the rotor metal sheets processed by the processing equipment to form rotor cores.

[0081] According to some embodiments of this application, this application provides an electric motor, including an electric motor rotor, the electric motor rotor including a rotor core formed by stacking rotor metal plates, the electric motor rotor metal plates being processed by any of the above-mentioned processing equipment or treated by any of the above-mentioned strengthening methods.

[0082] The content of this application will be described below through specific embodiments.

[0083] Example 1

[0084] A method for strengthening a metal plate for an electric motor rotor includes the following steps:

[0085] (1) Press graphite powder into graphite rods and heat the graphite rods to 850°C;

[0086] (2) The heated graphite rod is moved to the bottom end through the pressurizing mechanism and abuts against the magnetic bridge of the motor rotor metal plate. A pressure of 1MPa is applied to the graphite rod and held for 60s.

[0087] (3) Immerse the rotor laminations that have undergone heating and carburizing in step (2) into room temperature water for quenching.

[0088] Example 2

[0089] Unlike Example 1, the temperature of the graphite rod in this example is 750°C, and the remaining steps are the same as in Example 1.

[0090] Example 3

[0091] Unlike Example 1, the temperature of the graphite rod in this example is 800°C, and the remaining steps are the same as in Example 1.

[0092] Example 4

[0093] Unlike Example 1, the temperature of the graphite rod in this example is 900°C, and the remaining steps are the same as in Example 1.

[0094] Example 5

[0095] Unlike Example 1, the temperature of the graphite rod in this example is 950°C, and the remaining steps are the same as in Example 1.

[0096] Example 6

[0097] Unlike Example 1, the temperature of the graphite rod in this example is 1000°C, and the remaining steps are the same as in Example 1.

[0098] Example 7

[0099] Unlike Example 1, the carburizing time in this example is 45 seconds, while the remaining steps are the same as in Example 1.

[0100] Example 8

[0101] Unlike Example 1, the carburizing time in this example is 30 seconds, while the remaining steps are the same as in Example 1.

[0102] Example 9

[0103] Unlike Example 1, the carburizing time in this example is 15 seconds, while the remaining steps are the same as in Example 1.

[0104] Example 10

[0105] Unlike Example 1, the carburizing time in this example is 5 seconds, while the remaining steps are the same as in Example 1. The metallographic image of the magnetic bridge on the rotor metal plate after treatment in this example is shown in Figure 3. The testing instrument was an optical microscope, model KEYENCE VHX5000. As can be seen from Figure 3, martensite has formed on the surface layer of the magnetic bridge.

[0106] Example 11

[0107] Unlike Example 1, the pressure of the graphite rod in this example is 0.1 MPa, and the remaining steps are the same as in Example 1.

[0108] Example 12

[0109] Unlike Example 1, the pressure of the graphite rod in this example is 5 MPa, and the remaining steps are the same as in Example 1.

[0110] Example 13

[0111] Unlike Example 1, the temperature of the graphite rod in this example is 850°C, the carburizing time is 10 seconds, and the remaining steps are the same as in Example 1. The metallographic image of the magnetic bridge on the rotor metal plate after treatment in this example is shown in Figure 4. Similarly, martensite is formed on the surface layer of the magnetic bridge.

[0112] Comparative Example

[0113] The comparative example is a rotor metal plate that has not undergone any strengthening treatment.

[0114] Performance testing

[0115] Tensile strength: A diamond indenter in the shape of a square pyramid is pressed into the surface of the specimen with a test force of 0.3 kgf, held for 10 seconds, and then the test force is removed. The diagonal length of the indentation is measured. The Vickers hardness value is calculated based on the diagonal length of the indentation and the test force. The tensile strength value is obtained according to the conversion relationship between hardness and strength in GB / T 33362-2016.

[0116] Hysteresis loop and torque: The hysteresis loop was measured using a JDAW-2000C&D type vibrating sample magnetometer, and the torque was simulated using ANSYS MAXWELL software.

[0117] Test Results

[0118] Table 1 shows the tensile strength data of the rotor metal plate magnetic bridge in Examples 1-13 and the comparative examples.

[0119] Table 1 shows the tensile strength at the magnetic bridge in Examples 1-13 and Comparative Examples.

[0120] As can be seen from Table 1, the tensile strength of the magnetic bridge of the rotor metal plate in the embodiments of this application is higher than that in the comparative example, indicating that the strengthening method of this application can significantly improve the tensile strength of the magnetic bridge.

[0121] Comparative examples 1-6 show that when the temperature of the graphite rod increases from 750°C to 1000°C, the tensile strength at the magnetic bridge increases accordingly. This is because the increase in temperature facilitates the penetration of carbon elements, and the increase in the amount of penetrating carbon elements helps to improve the tensile strength at the magnetic bridge.

[0122] Comparing Examples 1 and 7-10, it can be seen that the tensile strength at the magnetic bridge increases with the extension of carburizing time. Comparing Examples 1 and 11-12, it can be seen that increased pressure helps to improve the infiltration efficiency, and therefore, the tensile strength also increases accordingly.

[0123] In Example 13 and the comparative example, the hardness HV0.3 at the magnetic bridge of the rotor metal plate were 458 and 223, respectively, indicating that the strengthening method of this application can significantly improve the hardness at the magnetic bridge. The torques of the rotor metal plates in Example 13 and the comparative example were 349.2 Nm and 328.8 Nm, respectively, representing a 6.2% increase in torque compared to the comparative example.

[0124] The hysteresis loop of the rotor metal plate after strengthening treatment in Example 13 is shown in Figure 5, and the hysteresis loop of the rotor metal plate without strengthening treatment in the comparative example is shown in Figure 6. It can be seen that compared to...

[0125] In comparison, the saturation magnetic moment of the rotor metal plate in Example 13 decreased from 201 emu / g to 123 emu / g, and the loop area decreased from 1.8 kOe·emu / g to 0.4 kOe·emu / g. This demonstrates that the strengthening treatment method of this application can reduce the saturation magnetic moment and magnetostrictive losses of the rotor metal plate, resulting in higher torque and lower losses in motor applications.

[0126] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A device for machining a metal plate of an electric machine rotor, wherein The rotor metal plate includes a body, on which magnetic slots and magnetic isolation bridges are provided; wherein, the processing device includes: At least one heat transfer element is used to heat treat the magnetic bridge of the rotor metal plate and simultaneously penetrate at least a portion of the constituent elements of the heat transfer element into the surface layer of the magnetic bridge. A heating component that is in contact with the heat transfer element and is used to provide energy to the heat transfer element.

2. The apparatus for processing a metal plate of an electric motor rotor as claimed in claim 1, wherein The heat transfer element comprises at least one of the following elements: carbon, silicon, manganese, nickel, and chromium.

3. The processing apparatus for the motor rotor metal plate as described in claim 1, wherein, The heat transfer element includes a rod with a tapered end; the rod is connected to the heating assembly.

4. The processing apparatus for the motor rotor metal plate as described in claim 1, wherein, The heating component includes electrodes and a power source, and the heat transfer element is connected in series with the electrodes and the power source to form a circuit.

5. A processing equipment for a motor rotor metal plate, wherein, The apparatus for processing the motor rotor metal plate as described in any one of claims 1 to 4 further includes: Mounting plate, used to fix the heat transfer element; A pressurizing mechanism, connected to the mounting plate, is used to drive the heat transfer element to move and apply pressure to the magnetic bridge.

6. The processing equipment for the motor rotor metal plate as described in claim 5, wherein, The mounting plate has multiple fixing positions, and the heat transfer element cooperates with the fixing positions.

7. The processing equipment for the motor rotor metal plate as described in claim 5, wherein, The pressurizing mechanism includes at least one telescopic body, the telescopic end of which is fixed to the mounting plate.

8. The processing equipment for the motor rotor metal plate as described in claim 7, wherein, The telescopic body includes one of a hydraulic rod, a pneumatic rod, or an electric push rod.

9. A method for strengthening a metal plate for an electric motor rotor, wherein, include: The rotor metal plate is heat-treated at the magnetic bridge by a heat transfer element, and at least some of the constituent elements of the heat transfer element are simultaneously permeated into the surface layer of the magnetic bridge. The temperature of the heat transfer element is greater than or equal to 750°C. The rotor metal plate, after heat transfer treatment, is subjected to a cooling process.

10. The method for strengthening the metal plate of the motor rotor as described in claim 9, wherein, The heat transfer time of the heat transfer element does not exceed 60 seconds.

11. The method for strengthening the metal plate of the motor rotor as described in claim 9, wherein, While heat-treating the magnetic bridge of the rotor metal plate through the heat transfer element, pressure is applied to the heat transfer element, and the applied pressure of the heat transfer element is 0.1MPa-10MPa.

12. The method for strengthening the metal plate of the motor rotor as described in any one of claims 9 to 11, wherein, The cooling process includes: The rotor metal plate, after heat transfer treatment of the heat transfer components, is immersed in a cooling medium to cool to room temperature; or... The rotor metal plate, after heat transfer treatment, is placed in cooling gas to cool to room temperature.

13. A production line for a motor rotor metal plate, wherein, The equipment includes the processing equipment for the motor rotor metal plate as described in any one of claims 5 to 8.

14. An electric motor, comprising a motor rotor, said motor rotor comprising a rotor core formed by stacking rotor metal plates, wherein, The motor rotor metal plate is obtained by the strengthening method described in any one of claims 9 to 12 or by the production line described in claim 13.

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