Magnetizing system and magnetizing method for electric motor rotor

Abstract

The present disclosure relates to the technical field of electric motor magnetizing. Disclosed are a magnetizing system and magnetizing method for an electric motor rotor. The magnetizing system comprises a magnetizing apparatus and a shielding block, wherein the magnetizing apparatus is configured to magnetize an electric motor rotor in a state where a first permanent magnet is fixed in a first mounting groove and the shielding block is fixed in a second mounting groove; and the shielding block is configured to shield a magnetizing magnetic field of the magnetizing apparatus in the second mounting groove, and re-magnetize the electric motor rotor in a state where the first permanent magnet is fixed in the first mounting groove and a second permanent magnet is fixed in the second mounting groove. An electric motor rotor has two types of permanent magnets; compared with a second permanent magnet, it is more difficult for a first permanent magnet to reach a magnetic saturation state; a shielding block is used to restrict a magnetizing magnetic circuit of the electric motor rotor, such that the first permanent magnet that is difficult to magnetize is first individually magnetized to the magnetic saturation state; and the first permanent magnet and the second permanent magnet are then jointly magnetized, such that the two permanent magnets both reach the magnetic saturation state, thereby improving the performance of the electric motor rotor.

Description

Magnetizing system and method for motor rotor

[0001] This application claims priority to Chinese Patent Application No. 202411988407.X, filed on December 30, 2024, entitled “Magnetic System and Magnetizing Method for Motor Rotor”, which is incorporated herein by reference in its entirety.

[0002] [Technical Field]

[0003] This disclosure relates to the field of motor magnetization technology, and in particular to a magnetization system and magnetization method for a motor rotor.

[0004] [Background Technology]

[0005] Permanent magnet motors are widely used in the industrial field due to their high performance. In order to save costs while achieving high power density, permanent magnet motors usually adopt a hybrid permanent magnet rotor structure with rare earth permanent magnet materials and ferrite permanent magnet materials in parallel. The total thickness of rare earth permanent magnets along the magnetic circuit direction is usually significantly thinner than that of ferrite permanent magnets.

[0006] In related technologies, an integrated magnetization method is usually used for motor rotors with parallel magnetic circuits. This involves assembling both types of permanent magnets with the rotor core and then magnetizing both types of permanent magnets simultaneously.

[0007] During the magnetization process described above, due to differences in thickness and material parameters, the magnetization magnetic field strength of the first type of permanent magnet will be significantly higher than that of the second type of permanent magnet. Further increasing the total magnetization amount will lead to saturation of the rotor core magnetic flux, making it difficult for the second type of permanent magnet to reach magnetic saturation, which in turn leads to poor performance of the motor rotor.

[0008] [Summary of the Invention]

[0009] This disclosure provides a magnetization system and method for an electric motor rotor, which can solve the aforementioned technical problems existing in related technologies. The technical solution is as follows:

[0010] In a first aspect, a magnetization system for an electric motor rotor is provided. The electric motor rotor includes a rotor core, a plurality of first permanent magnets and a plurality of second permanent magnets. The rotor core has a plurality of first mounting slots and a plurality of second mounting slots arranged alternately in a circumferential direction. The first permanent magnets and the second permanent magnets are used to form a parallel magnetic field loop.

[0011] The magnetization system includes a magnetization device and a shielding block;

[0012] The magnetizing device is used for:

[0013] With the first permanent magnet fixed in the first mounting slot and the shielding block fixed in the second mounting slot, the motor rotor is magnetized, wherein the shielding block is used to shield the magnetizing magnetic field of the magnetizing device in the second mounting slot.

[0014] With the first permanent magnet fixed in the first mounting slot and the second permanent magnet fixed in the second mounting slot, the motor rotor is magnetized again.

[0015] In some possible implementations, the shielding block is made of a non-ferromagnetic conductive material.

[0016] In some possible implementations, the shielding block includes at least one of copper, aluminum, and silver blocks.

[0017] In some possible implementations, the length of the shielding block in the direction of the motor rotor axis is greater than the length of the rotor core in the direction of the motor rotor axis.

[0018] In some possible implementations, when the shielding block is fixed in the second mounting groove, both ends of the shielding block protrude from the second mounting groove in the direction of the motor rotor axis.

[0019] In some possible implementations, the second mounting slot includes an interconnected receiving area and a magnetic barrier area, the receiving area for receiving the second permanent magnet and the magnetic barrier area for receiving air;

[0020] The shielding block fills the receiving area and the magnetic barrier area.

[0021] In some possible implementations, the first permanent magnet is a ferrite permanent magnet, and the second permanent magnet is a rare earth permanent magnet.

[0022] In some possible implementations, the magnetizing device includes an annular support and a plurality of magnetizing coils. The annular support is used to be fitted over the outside of the motor rotor when in a magnetized state. The plurality of magnetizing coils are wound around the annular support, wherein the number of magnetizing coils is equal to the number of magnetic poles of the motor rotor.

[0023] In a second aspect, a magnetization method is provided, wherein the magnetization method is applied to a magnetization system described in any one of the first aspects to magnetize a motor rotor, wherein the motor rotor includes a rotor core, a first permanent magnet and a second permanent magnet, wherein the first permanent magnet is used to form a first magnetic field loop and the second permanent magnet is used to form a second magnetic field loop;

[0024] The magnetization method includes:

[0025] The first permanent magnet is fixed in the first mounting slot, and the shielding block is fixed in the second mounting slot; the magnetizing device is controlled to magnetize the motor rotor.

[0026] The first permanent magnet is fixed in the first mounting slot, and the second permanent magnet is fixed in the second mounting slot;

[0027] The magnetizing device is controlled to remagnetize the motor rotor.

[0028] In some possible implementations, before fixing the first permanent magnet in the first mounting slot and the shielding block in the second mounting slot, the magnetization method further includes:

[0029] A third permanent magnet is fixed in the first mounting slot, and a fourth permanent magnet is fixed in the second mounting slot, wherein the third permanent magnet is the same permanent magnet as the first permanent magnet, and the fourth permanent magnet is the same permanent magnet as the second permanent magnet;

[0030] The magnetizing device is controlled to magnetize the motor rotor;

[0031] The first magnetization ratio of the third permanent magnet is determined to be less than the second magnetization ratio of the fourth permanent magnet. The first magnetization ratio is the ratio of the magnetization amount of the third permanent magnet to the saturation magnetization amount of the third permanent magnet under the above conditions. The second magnetization ratio is the ratio of the magnetization amount of the fourth permanent magnet to the saturation magnetization amount of the fourth permanent magnet under the above conditions.

[0032] The beneficial effects of the technical solution provided in this disclosure include at least the following:

[0033] In this disclosure, the motor rotor has two types of permanent magnets. Compared with the second permanent magnet, the first permanent magnet is more difficult to reach magnetic saturation. The magnetic circuit of the motor rotor is restricted by the shielding block, so that the first permanent magnet, which is difficult to magnetize, is first magnetized to magnetic saturation alone. Then, the first permanent magnet and the second permanent magnet are magnetized together, so that both permanent magnets reach magnetic saturation, thereby improving the performance of the motor rotor.

[0034] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure.

[0035] [Attached Image Description]

[0036] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 is an exploded schematic diagram of an electric motor rotor provided in an embodiment of this disclosure;

[0038] Figure 2 is a schematic diagram of magnetization of a motor rotor provided in an embodiment of this disclosure;

[0039] Figure 3 is a cross-sectional schematic diagram of a motor rotor and a shielding block provided in an embodiment of this disclosure;

[0040] Figure 4 is a partial schematic diagram of a motor rotor and a shielding block provided in an embodiment of this disclosure;

[0041] Figure 5 is an assembly schematic diagram of a motor rotor and a magnetization system provided in an embodiment of this disclosure;

[0042] Figure 6 is a schematic flowchart of a motor rotor magnetization method provided in an embodiment of this disclosure;

[0043] Figure 7 is a schematic flowchart of a motor rotor magnetization method provided in an embodiment of this disclosure.

[0044] Figure label:

[0045] 1. Magnetization system;

[0046] 11. Magnetizing device; 111. Magnetizing core; 112. Magnetizing coil;

[0047] 12. Shielding block;

[0048] 2. Motor rotor;

[0049] 21. Rotor core; 211. First mounting slot; 212. Second mounting slot; 212a. Receiving area; 212b.

[0050] Magnetic barrier zone;

[0051] 22. The first permanent magnet;

[0052] 23. Second permanent magnet.

[0053] The accompanying drawings have illustrated specific embodiments of this disclosure, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this disclosure to those skilled in the art through reference to particular embodiments.

[0054]

Detailed Implementation Methods

[0055] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0056] The following explains the terminology that may appear in the embodiments of this disclosure.

[0057] Magnetic saturation: Ferromagnetic materials contain many tiny, spontaneously magnetized regions called magnetic domains. Before magnetization, these domains are arranged randomly, and therefore the material as a whole does not exhibit magnetism. When an external magnetic field acts on a ferromagnetic material, the domains rotate and rearrange, aligning their magnetic moments with the direction of the external magnetic field, thus exhibiting magnetism. However, once the arrangement of the domains reaches a certain point, due to the limitations of the physical structure, the domains cannot rearrange further, causing the magnetization intensity to stop increasing, reaching a state of magnetic saturation.

[0058] Eddy currents: These are generally eddy currents generated in conductors (such as shielding blocks, permanent magnets, etc.) in electromagnetic equipment (such as motors, transformers, etc.) due to changes in the electromagnetic field.

[0059] Ferrite permanent magnets: a type of ferromagnetic metal oxide, mainly made from strontium oxide (SrO) or barium oxide (BaO) and ferric oxide (Fe2O3) through ceramic processes.

[0060] Rare earth permanent magnets: permanent magnet materials made from alloys of rare earth metals and transition metals through specific processes. Rare earth elements mainly include the lanthanides and closely related elements such as scandium (Sc) and yttrium (Y), totaling 17 elements. The two types of rare earth permanent magnets with the strongest magnetic properties are samarium-cobalt permanent magnets and neodymium-iron-boron permanent magnets.

[0061] In related technologies, an integrated magnetization method is typically used for motor rotors with parallel magnetic circuits. This involves assembling both types of permanent magnets with the rotor core and then simultaneously magnetizing both types of permanent magnets. Taking the rotor structure shown in Figure 1 as an example, the motor rotor includes a rotor core, rare-earth permanent magnets, and ferrite permanent magnets. The magnetic circuit direction of the rare-earth permanent magnets is perpendicular to its radial direction, while the magnetic circuit direction of the ferrite permanent magnets is parallel to its radial direction. Furthermore, the rare-earth permanent magnet circuit between adjacent poles passes through only one permanent magnet, while the ferrite permanent magnet circuit passes through two permanent magnets. Therefore, the thickness of the rare-earth permanent magnet along the magnetic circuit direction (one times the thickness of the rare-earth permanent magnet) is thinner than the thickness of the ferrite permanent magnet along the magnetic circuit direction (twice the thickness of the ferrite permanent magnet).

[0062] The magnetizing device is fitted around the outside of the motor rotor. A rare earth permanent magnet and the magnetizing device form a magnetic field circuit, while two ferrite permanent magnets located on both sides of the rare earth permanent magnet and the magnetizing device form another magnetic field circuit.

[0063] After the rotor core, rare earth permanent magnets, and ferrite permanent magnets are assembled, a magnetizing device is used to magnetize both the rare earth permanent magnets and the ferrite permanent magnets simultaneously. Due to the difference in the thickness of the permanent magnets, the magnetizing magnetic field strength of the rare earth permanent magnets will be significantly higher than that of the ferrite permanent magnets during the magnetizing process. At this time, if the magnetizing amount of the magnetizing device is increased, it will cause the rotor core to experience magnetic saturation. The magnetic induction intensity of the rotor core will reach a limit value and can no longer increase with the increase of the magnetic field strength.

[0064] Thus, ferrite permanent magnets are difficult to saturate. Therefore, the integrated magnetization method cannot saturate each permanent magnet in the motor rotor that uses hybrid permanent magnets, thereby hindering the improvement of motor rotor performance.

[0065] In a first aspect, embodiments of this disclosure provide a motor rotor 2. Referring to FIG1, the motor rotor 2 includes a rotor core 21, a plurality of first permanent magnets 22, and a plurality of second permanent magnets 23. The rotor core 21 has a plurality of circumferentially alternating first mounting slots 211 and a plurality of second mounting slots 212. When the motor rotor 2 is operating, the plurality of first permanent magnets 22 correspond one-to-one with the plurality of first mounting slots 211, and the plurality of second permanent magnets 23 correspond one-to-one with the plurality of second mounting slots 212. The first permanent magnets 22 and the second permanent magnets 23 are used to form parallel magnetic field loops. A parallel magnetic field loop means that a portion of the magnetic lines of force generated by the same magnetizing coil 112 passes through the first permanent magnets 22 to form a closed loop, and another portion passes through the second permanent magnets 23 to form a closed loop.

[0066] The magnetization ratio of the first permanent magnet 22 is less than that of the second permanent magnet 23. The magnetization ratio refers to the amount of magnetization of the permanent magnet under specified conditions / the amount of magnetization of the permanent magnet when it reaches magnetic saturation. The specified conditions are that the first permanent magnet 22 and the second permanent magnet 23 are magnetized at the same time, that is, the first permanent magnet 22 without magnetization is fixed in the first mounting groove 211, the second permanent magnet 23 without magnetization is fixed in the second mounting groove 212, and the motor rotor 2 is magnetized until the rotor core 21 reaches magnetic saturation.

[0067] The magnetization system 1 includes a magnetization device 11 and a shielding block 12. Referring to FIG2, the magnetization device 11 is used for:

[0068] With the first permanent magnet 22 fixed in the first mounting slot 211 and the shielding block 12 fixed in the second mounting slot 212, the motor rotor 2 is magnetized, wherein the shielding block 12 is used to shield the magnetizing magnetic field of the magnetizing device 11 in the second mounting slot; with the first permanent magnet 22 fixed in the first mounting slot 211 and the second permanent magnet 23 fixed in the second mounting slot 212, the motor rotor 2 is magnetized again.

[0069] During the first magnetization process of the magnetization system 1, the shielding block 12 located in the second mounting groove 212 is placed as a conductor in the magnetization magnetic field applied by the magnetization device 11. Due to the change in the magnetization magnetic field, eddy currents are induced inside the shielding block 12. The magnetic field generated by the eddy currents is opposite in direction to the external magnetization magnetic field, thereby resisting the penetration of the external magnetic field. This resistance allows the shielding block 12 to effectively reduce or eliminate the influence of the external magnetization magnetic field on the internal area, thereby causing the magnetic lines of force in the magnetization magnetic field applied by the magnetization device 11 to pass through the first permanent magnet 22 located in the first mounting groove 211, increasing the magnetization amount of the first permanent magnet 22.

[0070] In this disclosure, the motor rotor 2 has two types of permanent magnets. Compared with the second permanent magnet 23, the first permanent magnet 22 is more difficult to reach magnetic saturation. The magnetic circuit of the motor rotor 2 is restricted by the shielding block 12, so that the first permanent magnet 22, which is difficult to magnetize, is first magnetized to magnetic saturation alone. Then, the first permanent magnet 22 and the second permanent magnet 23 are magnetized together, so that both permanent magnets reach magnetic saturation, thereby improving the performance of the motor rotor 2.

[0071] In some embodiments, the shielding block 12 is made of a non-ferromagnetic conductive material. Ferromagnetic materials (such as iron, nickel, cobalt, etc.) are easily magnetized and exhibit magnetic permeability, which would greatly reduce the shielding effect of the shielding block 12 under a strong magnetic field. Non-ferromagnetic conductive materials, on the other hand, can maintain a stable shielding effect.

[0072] In some embodiments, the shielding block 12 includes at least one of copper, aluminum, and silver. Copper, aluminum, and silver all possess non-ferromagnetic properties and electrical conductivity. This disclosure does not limit the specific material used for the shielding block 12; it can be matched and set according to parameters such as the magnetizing magnetic field strength and usage cost. Multiple shielding blocks 12 in a magnetizing system 1 can use the same material or different materials.

[0073] For example, the shielding block 12 is a copper block. First, copper is an excellent conductive material, with a conductivity far exceeding that of aluminum and second only to silver. Therefore, a copper block as the shielding block 12 can more effectively block the propagation of electromagnetic waves and improve the shielding effect.

[0074] Secondly, copper blocks possess excellent corrosion resistance, maintaining stable performance under various environmental conditions. This allows copper blocks, as shielding blocks 12, to maintain good shielding effectiveness in harsh environments such as humidity and corrosion, extending their service life. In contrast, aluminum blocks may experience performance degradation in certain corrosive environments.

[0075] Thirdly, while silver has better conductivity than copper, its manufacturing and usage costs are significantly higher, limiting its widespread application as shielding block 12. Copper, on the other hand, is relatively inexpensive and easy to process and manufacture, meeting the needs of large-scale production. This makes copper a significantly more cost-effective option as shielding block 12.

[0076] Therefore, the copper block as shielding block 12 achieves a good balance between conductivity, corrosion resistance and cost.

[0077] Referring to FIG3, in some embodiments, the length L1 of the shielding block 12 in the direction of the motor rotor 2 axis is greater than the length L2 of the rotor core 21 in the direction of the motor rotor 2 axis.

[0078] During magnetization, the magnetic flux in the rotor core 21 changes, thereby generating induced electromotive force and eddy currents in the shielding block 12. These eddy currents form closed loops inside the shielding block 12. If the length of the shielding block 12 is slightly longer than that of the rotor core 21, then the shielding block 12 can provide a more complete loop for these end eddy currents, thereby enhancing the shielding effect of the shielding block 12.

[0079] End eddy currents typically refer to eddy currents generated at the ends of conductors in electromagnetic devices (such as motors and transformers) due to changes in the electromagnetic field. When a conductor has ends or edges, these areas are prone to forming concentrated eddy current regions.

[0080] In some embodiments, when a shielding block 12 is fixed in the second mounting groove 212, both ends of the shielding block 12 protrude from the second mounting groove 212 in the axial direction of the motor rotor 2. In this way, the shielding block 12 can simultaneously provide a more complete loop for the end eddy currents at both ends of the motor rotor 2, thereby enhancing the shielding effect of the shielding block 12 on the entire second mounting groove 212.

[0081] Referring to FIG4, in some embodiments, the second mounting groove 212 includes an accommodating region 212a and a magnetic barrier region 212b that are interconnected. The accommodating region 212a is used to accommodate the second permanent magnet 23, and the magnetic barrier region 212b is used to accommodate air. The shielding block 12 is filled in the accommodating region 212a and the magnetic barrier region 212b.

[0082] When the motor rotor 2 is operating after magnetization, the second permanent magnet 23 is located in the receiving area 212a, and the magnetic barrier area 212b is not filled with permanent magnets. That is, an air magnetic barrier is formed inside the magnetic barrier area 212b. The air magnetic barrier can restrict the flow path of magnetic flux, so that the magnetic flux is mainly concentrated in the permanent magnets, thereby improving the efficiency of the magnetic circuit. Setting an air magnetic barrier can also reduce the leakage magnetic phenomenon between permanent magnets, reduce the loss of permanent magnet magnetic flux, and improve the performance and power density of the motor.

[0083] This disclosure does not specifically limit the shape and size of the air magnetic barrier formed in the magnetic barrier zone 212b, but can be matched and set according to the size, performance requirements and other parameters of different motors.

[0084] In some embodiments, the first permanent magnet 22 is a ferrite permanent magnet, and the second permanent magnet 23 is a rare earth permanent magnet.

[0085] Ferrite permanent magnets are non-metallic permanent magnet materials with a wide range of raw material sources and relatively low manufacturing costs, which helps to reduce the overall cost of motors. Ferrite permanent magnets also have good oxidation and corrosion resistance, and can maintain stable magnetic properties in a variety of harsh environments.

[0086] Rare earth permanent magnets have a higher magnetic energy product, meaning that they can store more magnetic energy in the same volume, which is beneficial for increasing the power density of motors.

[0087] The motor rotor 2 uses both ferrite permanent magnets and rare earth permanent magnets. On the one hand, ferrite permanent magnets can provide a stable magnetization state, while rare earth permanent magnets can provide a strong magnetic field, thereby improving the overall performance of the motor. On the other hand, by designing and controlling the amount used, the manufacturing cost can be reduced while ensuring the performance of the motor.

[0088] Combining two permanent magnet materials allows the motor to perform exceptionally well in a wider range of applications. Whether the application requires high performance or low cost, the needs can be met by adjusting the ratio of the two permanent magnets used.

[0089] Referring to FIG5, in some embodiments, the magnetizing device 11 includes a magnetizing core 111 and a plurality of magnetizing coils 112. The magnetizing core 111 is used to be sleeved on the outside of the motor rotor 2 when in the magnetizing state, and the plurality of magnetizing coils 112 are wound on the magnetizing core 111. The number of magnetizing coils 112 is equal to the number of magnetic poles 2a of the motor rotor 2.

[0090] The number of magnetizing coils 112 is equal to the number of magnetic poles 2a of the motor rotor 2. Each magnetic pole 2a can correspond to one magnetizing coil 112. This ensures that each magnetic pole 2a is subjected to a uniform and sufficient magnetic field, thereby achieving full magnetization of the magnetic pole 2a. The uniform magnetic field distribution helps to improve the operating efficiency and stability of the motor.

[0091] The number of magnetizing coils 112 is equal to the number of magnetic poles 2a of the motor rotor 2. This design avoids the complexity and increased manufacturing cost caused by too many magnetizing coils 112. This design helps to simplify the manufacturing process and improve production efficiency.

[0092] Secondly, this disclosure provides a magnetization method, which is applied to a magnetization system 1 of the first aspect to magnetize a motor rotor 2. The motor rotor 2 includes a rotor core 21, a first permanent magnet 22, and a second permanent magnet 23. The first permanent magnet 22 is used to form a first magnetic field loop, and the second permanent magnet 23 is used to form a second magnetic field loop.

[0093] Referring to Figure 6, the magnetization method includes:

[0094] Step 100: Fix the first permanent magnet 22 in the first mounting slot 211 and fix the shielding block 12 in the second mounting slot 212.

[0095] Step 200: Control the magnetizing device 11 to magnetize the motor rotor 2.

[0096] According to Lenz's law, when a magnetizing current pulse arrives, eddy currents will be induced in the shielding block 12 to resist the external magnetizing magnetic field, thus achieving the effect of magnetic shielding. This forces the magnetic lines of force to pass through the area where the first permanent magnet 22 is located, thereby increasing the magnetization of the first permanent magnet 22.

[0097] Step 300: Fix the first permanent magnet 22 in the first mounting slot 211 and fix the second permanent magnet 23 in the second mounting slot 212.

[0098] Step 400: Control the magnetizing device 11 to magnetize the motor rotor 2 again.

[0099] At this point, the first permanent magnet 22 is already in a magnetically saturated state, and the amount of magnetization will no longer increase with the increase of the magnetizing magnetic field strength. Thus, the second permanent magnet 23 is more likely to reach a magnetically saturated state during the second magnetization.

[0100] In some embodiments, before fixing the first permanent magnet 22 in the first mounting slot 211 and the shielding block 12 in the second mounting slot 212, as shown in FIG7, the magnetization method further includes:

[0101] Step 501: Fix the third permanent magnet in the first mounting slot 211 and fix the fourth permanent magnet in the second mounting slot 212, wherein the third permanent magnet is the same permanent magnet as the first permanent magnet 22 and the fourth permanent magnet is the same permanent magnet as the second permanent magnet 23.

[0102] Step 502: Control the magnetizing device 11 to magnetize the motor rotor 2.

[0103] Step 503: Determine that the first magnetization ratio of the third permanent magnet is less than the second magnetization ratio of the fourth permanent magnet. The first magnetization ratio is the ratio of the magnetization amount of the third permanent magnet to the saturation magnetization amount of the third permanent magnet under the above conditions. The second magnetization ratio is the ratio of the magnetization amount of the fourth permanent magnet to the saturation magnetization amount of the fourth permanent magnet under the above conditions.

[0104] Thus, through steps 501 to 503, it can be concluded that the magnetization ratio of the first permanent magnet 22 is less than that of the second permanent magnet 23.

[0105] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0106] It is understood that in this disclosure, "multiple" refers to two or more, and other quantifiers are similar. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. The singular forms "a," "the," and "the" are also intended to include the plural forms unless the context clearly indicates otherwise.

[0107] It is further understood that the terms "first," "second," etc., are used to describe various types of information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another, and do not indicate a specific order or degree of importance. In fact, the expressions "first," "second," etc., are completely interchangeable. For example, without departing from the scope of this disclosure, first information can also be referred to as second information, and similarly, second information can also be referred to as first information.

[0108] It is further understood that the terms “center,” “longitudinal,” “lateral,” “front,” “rear,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do 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.

[0109] It is further understood that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral molding; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the two components; they can refer to a direct connection between two components without the presence of other components, or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0110] It is further understood that although operations are described in a specific order in the accompanying drawings in the embodiments of this disclosure, this should not be construed as requiring these operations to be performed in the specific order or serial order shown, or requiring all of the shown operations to be performed to obtain the desired result. In certain environments, multitasking and parallel processing may be advantageous.

[0111] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the solutions disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the scope of the claims.

[0112] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A magnetization system for an electric motor rotor, wherein, The motor rotor includes a rotor core, a plurality of first permanent magnets and a plurality of second permanent magnets. The rotor core has a plurality of first mounting slots and a plurality of second mounting slots arranged alternately in the circumferential direction. The first permanent magnets and the second permanent magnets are used to form a parallel magnetic field loop. The magnetization system includes a magnetization device and a shielding block; The magnetizing device is used for: With the first permanent magnet fixed in the first mounting slot and the shielding block fixed in the second mounting slot, the motor rotor is magnetized, wherein the shielding block is used to shield the magnetizing magnetic field of the magnetizing device in the second mounting slot. With the first permanent magnet fixed in the first mounting slot and the second permanent magnet fixed in the second mounting slot, the motor rotor is magnetized again.

2. The magnetization system according to claim 1, wherein, The shielding block is made of a non-ferromagnetic conductive material.

3. The magnetization system according to claim 2, wherein, The shielding block includes at least one of copper, aluminum, and silver blocks.

4. The magnetization system according to claim 1, wherein, The length of the shielding block in the direction of the motor rotor axis is greater than the length of the rotor core in the direction of the motor rotor axis.

5. The magnetization system according to claim 4, wherein, When the shielding block is fixed in the second mounting groove, both ends of the shielding block protrude out of the second mounting groove in the direction of the motor rotor axis.

6. The magnetization system according to claim 1, wherein, The second mounting slot includes an accommodating area and a magnetic barrier area that are interconnected. The accommodating area is used to accommodate the second permanent magnet, and the magnetic barrier area is used to accommodate air. The shielding block fills the receiving area and the magnetic barrier area.

7. The magnetization system according to claim 1, wherein, The first permanent magnet is a ferrite permanent magnet, and the second permanent magnet is a rare earth permanent magnet.

8. The magnetization system according to claim 1, wherein, The magnetizing device includes an annular support and multiple magnetizing coils. The annular support is used to be sleeved on the outside of the motor rotor when in the magnetizing state. The multiple magnetizing coils are wound around the annular support, wherein the number of magnetizing coils is equal to the number of magnetic poles of the motor rotor.

9. A magnetization method, wherein, The magnetization method is applied to the magnetization system as described in any one of claims 1-8 to magnetize the motor rotor, wherein the motor rotor includes a rotor core, a first permanent magnet and a second permanent magnet, the first permanent magnet being used to form a first magnetic field loop and the second permanent magnet being used to form a second magnetic field loop; The magnetization method includes: The first permanent magnet is fixed in the first mounting slot, and the shielding block is fixed in the second mounting slot; The magnetizing device is controlled to magnetize the motor rotor; The first permanent magnet is fixed in the first mounting slot, and the second permanent magnet is fixed in the second mounting slot; The magnetizing device is controlled to remagnetize the motor rotor.

10. The magnetization method according to claim 9, wherein, Before fixing the first permanent magnet in the first mounting slot and the shielding block in the second mounting slot, the magnetization method further includes: A third permanent magnet is fixed in the first mounting slot, and a fourth permanent magnet is fixed in the second mounting slot, wherein the third permanent magnet is the same permanent magnet as the first permanent magnet, and the fourth permanent magnet is the same permanent magnet as the second permanent magnet; The magnetizing device is controlled to magnetize the motor rotor; The first magnetization ratio of the third permanent magnet is determined to be less than the second magnetization ratio of the fourth permanent magnet. The first magnetization ratio is the ratio of the magnetization amount of the third permanent magnet to the saturation magnetization amount of the third permanent magnet under the above conditions. The second magnetization ratio is the ratio of the magnetization amount of the fourth permanent magnet to the saturation magnetization amount of the fourth permanent magnet under the above conditions.

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