WO2022016437A1 - 电机转子和电机 - Google Patents

电机转子和电机 Download PDF

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Publication number
WO2022016437A1
WO2022016437A1 PCT/CN2020/103671 CN2020103671W WO2022016437A1 WO 2022016437 A1 WO2022016437 A1 WO 2022016437A1 CN 2020103671 W CN2020103671 W CN 2020103671W WO 2022016437 A1 WO2022016437 A1 WO 2022016437A1
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WO
WIPO (PCT)
Prior art keywords
coercive force
permanent magnet
motor rotor
segment
rotor according
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PCT/CN2020/103671
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English (en)
French (fr)
Inventor
赖彬
兰华
李孟德
王子京
Original Assignee
华为数字能源技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 华为数字能源技术有限公司 filed Critical 华为数字能源技术有限公司
Priority to CN202080079869.3A priority Critical patent/CN114731075A/zh
Priority to EP20945794.4A priority patent/EP4178081A4/en
Priority to PCT/CN2020/103671 priority patent/WO2022016437A1/zh
Publication of WO2022016437A1 publication Critical patent/WO2022016437A1/zh
Priority to US18/157,712 priority patent/US20230163647A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22—Rotating parts of the magnetic circuit
    • H02K1/27—Rotor cores with permanent magnets
    • H02K1/2706—Inner rotors
    • H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
    • H02K1/274—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets
    • H02K1/2753—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets the rotor consisting of magnets or groups of magnets arranged with alternating polarity
    • H02K1/276—Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM]
    • H02K1/2766—Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] having a flux concentration effect
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22—Rotating parts of the magnetic circuit
    • H02K1/27—Rotor cores with permanent magnets
    • H02K1/2706—Inner rotors
    • H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
    • H02K1/274—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets
    • H02K1/2753—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets the rotor consisting of magnets or groups of magnets arranged with alternating polarity
    • H02K1/276—Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM]
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/02—Details of the magnetic circuit characterised by the magnetic material
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
    • H02K21/12—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
    • H02K21/14—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating within the armatures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
    • H01F41/0273—Imparting anisotropy
    • H01F41/028—Radial anisotropy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
    • H01F41/0293—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K2213/00—Specific aspects, not otherwise provided for and not covered by codes H02K2201/00 - H02K2211/00
    • H02K2213/03—Machines characterised by numerical values, ranges, mathematical expressions or similar information

Definitions

  • the present application relates to the technical field of permanent magnet motors, and in particular, to a motor rotor and a motor.
  • a conventional permanent magnet synchronous motor is generally composed of a stator and a rotor, wherein the rotor includes a rotor iron core and a permanent magnet installed on the rotor iron core; the stator includes a stator iron core and a stator winding. After the motor is powered on, the rotating magnetic field generated by the stator winding drives the rotor to rotate and output torque.
  • NdFeB permanent magnets usually need to add heavy rare earth elements such as dysprosium Dy and terbium Tb to improve their anti-demagnetization ability.
  • these heavy rare earths are expensive, which greatly increases the cost of the motor. Therefore, it is necessary to develop a motor with high reliability and low cost.
  • the embodiments of the present application provide a motor rotor and a motor.
  • the motor rotor adopts a permanent magnet with a coercive force gradient design, so that the motor can obtain excellent stability and reliability, while reducing the amount of heavy rare earth elements and reducing the cost of the motor.
  • a first aspect of the embodiments of the present application provides a motor rotor, including a rotor iron core and a plurality of permanent magnets disposed on the rotor iron core, at least a part of the permanent magnets along at least one of the permanent magnets perpendicular to the magnetization direction direction, the coercive force from the middle to both ends showed a continuous gradient distribution or a multi-level gradient gradient distribution.
  • the rotor of the motor in the embodiment of the present application adopts a permanent magnet with a coercive force gradient design.
  • the permanent magnet has a high anti-demagnetization area to ensure the reliability of the motor, and the low anti-demagnetization area reduces the content of heavy rare earth elements and minimizes the cost.
  • each permanent magnet may be designed to be along at least one direction perpendicular to the magnetization direction, and the coercive force is continuously and gradually distributed from the middle to the two ends or a multi-level gradient. Gradient distribution.
  • the magnetization direction of the permanent magnet is generally the direction with the shortest distance between the two opposite faces of the permanent magnet.
  • the magnetization direction is generally the height direction, and the direction perpendicular to the magnetization direction can be the length direction, or is the width direction.
  • the at least part of the permanent magnets are along at least one direction perpendicular to the magnetization direction, and the coercive force changes from the middle to both ends in a continuous gradual increase or a multi-level gradient gradual increase.
  • the anti-demagnetization requirement at both ends of the permanent magnet is greater than that of the middle part.
  • the coercive force is designed to gradually increase from the middle to the two ends, so that the permanent magnet has both high anti-demagnetization areas at the ends to ensure the motor Reliability, yet a low anti-demagnetization region with low heavy rare earth element content in the middle section reduces cost.
  • the coercive force can also be designed to gradually decrease from the middle to both ends according to actual needs.
  • the coercive force is greater than 0.
  • the concentration of heavy rare earth metal elements in at least part of the permanent magnets is distributed in a continuous gradient or a multi-level gradient along the gradient direction of the coercive force from the middle to both ends.
  • the concentration of heavy rare earth metal elements in the permanent magnet directly determines its coercive force.
  • the change trend of the concentration of heavy rare earth metal elements corresponds to the change trend of the coercive force. The greater the concentration of heavy rare earth metal elements, the greater the coercivity.
  • the at least part of the permanent magnet is an integrally formed structure, that is, a continuous integral structure.
  • the coercive force gradient design can be realized by diffusing different concentrations of heavy rare earth metal elements at different positions along at least one direction perpendicular to the magnetization direction of the permanent magnet having an integral structure.
  • the permanent magnet of the integrally formed structure with the coercivity gradient design can be prepared in one step, and does not need to be bonded by a relatively expensive adhesive, and the structure is stable, which can improve the reliability of the motor.
  • the concentration of the heavy rare earth metal elements in the permanent magnet can be continuously increased or decreased from the middle to the two ends, or it can be a multi-level gradient. Increase or decrease distribution.
  • the at least part of the permanent magnets are formed by splicing multiple segments of magnets with different coercive forces.
  • the permanent magnet is formed by bonding a plurality of segments of magnets with different coercive forces by adhesive bonding or by welding.
  • the horizontal distribution of the coercive force of each segment of magnets used for splicing is generally uniform, that is, the coercive force at any position is generally the same, the permanent magnet formed by splicing multiple segments of magnets is from the middle to the two ends.
  • the coercivity generally increases or decreases gradually in a gradient.
  • the coercive force may also be continuously and gradually distributed from the middle to the two ends.
  • the at least part of the permanent magnets may include a center segment and end segments located at both ends of the center segment along the coercive force gradient direction, and at least one further between the center segment and the end segments Transition.
  • the end sections have relatively higher coercive force, which can ensure the reliability of the motor, while the central section has relatively smaller coercive force and low content of heavy rare earth elements, which can minimize the cost, There is a transition section between the high anti-demagnetization area and the low anti-demagnetization area.
  • the arrangement of the transition section makes the coercive force distribution of the permanent magnet more uniform, the change is more uniform, and the center section and the end section can be better enlarged
  • the difference in coercivity can better ensure the stability and reliability of the motor, avoid excess anti-demagnetization performance, and take into account the low cost.
  • the coercive force of the end section is greater than that of the transition section, and the coercive force of the transition section is greater than that of the center section.
  • the coercive force of the end section constitutes a multi-level gradient. If the coercive force of each section is continuously gradient, the coercive force from the center section to the end section can also constitute a continuous gradient.
  • the width of the central segment is more than 30% of the total width of the permanent magnet.
  • the central section has low coercivity, that is, has a low concentration of heavy rare earth elements, and controlling the central section to a certain width ratio is beneficial to reducing the amount of heavy rare earth elements used in the entire permanent magnet.
  • the width of the end section is less than 10% of the total width of the permanent magnet.
  • the end section has the highest coercivity, that is, the highest concentration of heavy rare earth elements, and controlling the width of the end section to a smaller width is beneficial to reduce the amount of heavy rare earth elements used.
  • the minimum coercive force of the end section is higher than the minimum coercive force of the center section by more than 30%.
  • the anti-demagnetization ability of the end section is higher, while the anti-demagnetization ability of the center section is lower. Designing the coercive force of the end section at a higher level can improve the anti-demagnetization ability of the end of the permanent magnet and improve the reliability of the motor. Therefore, designing the coercive force of the center section at a lower level can reduce the amount of rare earth and reduce the cost of the motor.
  • the difference between the maximum coercive force and the minimum coercive force of the end section is 5%-30%. Controlling the suitable coercivity change degree of the end section can better take into account the reliability of the motor and the amount of heavy rare earth.
  • the difference between the minimum coercive force of the end section and the adjacent transition section is greater than 12%.
  • the difference between the minimum coercive force of the central segment and the adjacent transition segment is 3%-10%.
  • the coercive force gradation degree at both ends of the permanent magnet is greater than the coercive force gradation degree at the middle part. Specifically, in some embodiments, from the middle to the two ends, the coercive force gradually increases in degree of gradation.
  • the coercive force of the opposite ends of the permanent magnet that is, the outermost adjacent segment, is designed to change relatively quickly, which can more fully meet the higher anti-demagnetization requirements of the end of the permanent magnet of the motor and improve the reliability of the motor.
  • the coercivity of the middle part of the permanent magnet that is, the inner adjacent segment, is designed to change relatively slowly, which can meet the actual anti-demagnetization requirements, reduce the redundancy of the coercive force of the permanent magnet, and save heavy rare earths more effectively. Element usage.
  • the difference in remanence of two adjacent segments of the permanent magnet is less than or equal to 3%. Since the remanence of the permanent magnet generally fluctuates to a certain extent, the difference of remanence ⁇ 3% can be considered to be consistent.
  • one or more transition sections may be provided between the central section and the end section.
  • the change of coercive force from the center section to the end section will be more gradual, which can further reduce the redundancy of the coercive force of the permanent magnet, ensure the reliability of the permanent magnet, and save the use of heavy rare earth elements. quantity.
  • a transition segment is included between the central segment and the end segment, and the permanent magnet is a five-segment structure.
  • two transition segments are included between the central segment and the end segment, and the permanent magnet is a seven-segment structure.
  • three transition segments are included between the central segment and the end segment, and the permanent magnet is a nine-segment structure.
  • the coercive force of the permanent magnet may be distributed symmetrically or asymmetrically from the middle to both ends along the width direction.
  • the permanent magnets are sintered NdFeB magnets.
  • the arrangement of the plurality of permanent magnets on the rotor core may be a built-in type or a surface-mounted type.
  • the arrangement of a plurality of permanent magnets on the rotor iron core is a built-in type
  • the rotor iron core is provided with a plurality of magnetic steel slots
  • the plurality of permanent magnets are arranged in a one-to-one correspondence with the rotor iron core. in multiple magnet slots.
  • the plurality of magnetic steel grooves may be formed on the axial end surface of the rotor iron core at intervals along the circumferential direction of the rotor iron core.
  • the two ends of the magnetic steel slot are provided with positioning protrusions for fixing the permanent magnets on one side away from the rotating shaft of the rotor iron core. Since the demagnetizing field received by the permanent magnet mainly acts on the outer edge area of the magnet. Introducing a positioning protrusion structure in the outer edge area of the magnetic steel groove can reduce the coercive force requirements at both ends of the magnet, reduce the possibility of demagnetization of the permanent magnet in actual use, improve the overall anti-demagnetization ability of the motor, and ensure its reliability. Further effectively reduce the use of heavy rare earths and save resources.
  • the outer peripheral surface of the positioning protrusion is an arc-shaped curved surface.
  • the curved surface avoids the formation of stress concentrations at the corners.
  • the protruding size of the positioning protrusion is less than or equal to 1/3 of the size of the permanent magnet in the protruding direction of the positioning protrusion.
  • the rotor iron core is further provided with a groove connected with the positioning protrusion, and the groove is located on the side of the positioning protrusion close to the middle of the magnetic steel groove.
  • the design of the groove is conducive to the assembly of the permanent magnet and avoids the permanent magnet being damaged during the assembly process.
  • the size of the opening width of the groove is less than or equal to 1/5 of the size of the permanent magnet in the extending direction of the opening of the groove.
  • the arrangement of the plurality of permanent magnets is not limited, and may be any existing form, for example, a straight-line, V-shaped, double-V-shaped, shape, U shape or double U shape.
  • the arrangement of the plurality of permanent magnets on the rotor iron core is surface-mounted, and the plurality of permanent magnets are attached to the outer peripheral surface of the rotor iron core.
  • a second aspect of the embodiments of the present application provides a motor including a rotor of the motor and a stator, and the rotor of the motor includes the rotor of the motor described in the first aspect of the embodiments of the present application.
  • the stator is fixedly arranged around the rotor of the motor, and the stator includes a stator iron core and a stator winding.
  • the motor can be a radial flux motor or an axial flux motor.
  • An embodiment of the present application further provides a vehicle, including the motor described in the second aspect of the embodiment of the present application, and the motor provides a driving force for the vehicle.
  • An embodiment of the present application further provides an electrical appliance, including the motor described in the second aspect of the embodiment of the present application, where the motor provides a driving force for the electrical appliance.
  • the motor rotor adopts the permanent magnet with the coercive force gradient design, which can improve the reliability of the motor and reduce the cost to the greatest extent.
  • the overall change trend is relatively gentle, not a sudden change, so it can better increase the difference between the coercive force between the center and the end of the permanent magnet, so as to better ensure the stability and reliability of the motor, and can also better avoid the anti-demagnetization performance.
  • Oversupply reduce the amount of heavy rare earths, and take into account the low cost.
  • the requirement for the coercive force at both ends of the magnet can be further reduced, the demagnetization possibility of the permanent magnet in actual use can be reduced, and the The overall anti-demagnetization ability of the motor ensures the reliability of the motor, and can further effectively reduce the use of heavy rare earths and reduce the cost of the motor.
  • the design of the groove can further reduce the anti-demagnetization requirement, which is also conducive to the assembly of the permanent magnet and avoids the damage of the permanent magnet.
  • FIG. 1 is a schematic three-dimensional structure diagram of a motor provided by an embodiment of the present application.
  • FIG. 2 is a schematic diagram of a shaft cross-sectional structure of a motor provided by an embodiment of the present application
  • FIG. 3 is a schematic structural diagram of a rectangular parallelepiped-structured permanent magnet in an embodiment of the present application
  • Fig. 4 is the structural representation of the permanent magnet in Fig. 2;
  • Fig. 5 is the coercive force design and actual coercive force distribution schematic diagram of the permanent magnet of Fig. 4;
  • FIG. 6 is a schematic structural diagram of a motor rotor provided by an embodiment of the present application.
  • Fig. 7 is the structural representation of the permanent magnet in Fig. 6;
  • Fig. 8 is the coercive force design and actual coercive force distribution schematic diagram of the permanent magnet of Fig. 7;
  • FIG. 9 is a schematic diagram of the arrangement of positioning protrusions and grooves in an embodiment of the present application.
  • an embodiment of the present application provides a motor 100 , including a motor rotor 10 and a stator 20 fixedly disposed around the motor rotor 10 .
  • the motor rotor 10 is inserted through the center of the stator 20 .
  • a gap is left between the stator 20 and the motor rotor 10 .
  • Permanent magnets are arranged in the motor rotor 10 to form a permanent magnet motor.
  • the stator 20 includes a stator core and stator windings. Wherein, the stator iron core may be formed by stacking a plurality of silicon steel sheets.
  • the motor 100 may be a radial flux motor as shown in FIG. 1 and FIG. 2 , or an axial flux motor.
  • the motor rotor 10 includes a rotor iron core 101 and a plurality of permanent magnets 102 arranged on the rotor iron core 101 .
  • the rotating shaft 30 passes through the center of the rotor iron core 101 .
  • the permanent magnet 102 is along at least one direction perpendicular to the magnetization direction, and the coercive force is distributed in a multi-level gradient gradient or a continuous gradient distribution.
  • the coercive force of only part of the permanent magnets in at least one direction perpendicular to the magnetization direction may be distributed in a gradient from the middle to the two ends or in a continuous gradient.
  • the motor rotor 10 adopts a permanent magnet 102 with a coercive force gradient design.
  • the coercive force of the permanent magnet 102 is continuously gradient or multi-level gradient gradient from the middle to both ends, so that the coercive force of the entire permanent magnet changes uniformly and can be improved to the greatest extent.
  • the stability and reliability of the motor can also avoid excess anti-demagnetization performance, reduce the amount of heavy rare earth elements, and minimize the cost of the motor.
  • the coercive force is an index used to evaluate the quality of the permanent magnet.
  • the coercive force refers to the magnetic induction intensity B of the magnetic material after the saturation magnetization, when the external magnetic field returns to zero, does not return to zero.
  • the magnetic induction intensity can be returned to zero by adding a certain size of magnetic field in the opposite direction of the field. This magnetic field is called the coercive magnetic field, also known as the coercive force.
  • the coercive magnetic field also known as the coercive force.
  • For NdFeB permanent magnets by introducing heavy rare earth elements such as Dy and Tb into the magnet, the coercivity can be enhanced. The higher the heavy rare earth content, the higher the coercivity.
  • the change trend of the concentration of heavy rare earth metal elements corresponds to the change trend of the coercive force, and the concentration of heavy rare earth metal elements in the permanent magnet 102 along the coercivity
  • the force gradient direction is continuous gradient distribution or multi-level gradient gradient distribution from the middle to both ends.
  • the multi-levels in the multi-level gradient may be two or more levels.
  • the permanent magnet 102 is along at least one direction perpendicular to the magnetization direction, and the coercive force changes from the middle to the two ends in a continuous gradual increase or a multi-level gradient gradual increase. In most cases, the anti-demagnetization requirement at both ends of the permanent magnet is greater than that of the middle part.
  • the coercive force is designed to gradually increase from the middle to the two ends, so that the permanent magnet has both high anti-demagnetization areas at the ends to ensure the motor Reliability, yet a low anti-demagnetization region with low heavy rare earth element content in the middle section reduces cost.
  • the coercive force can also be designed to gradually decrease from the middle to both ends according to actual needs. In the embodiments of the present application, in order to ensure that any position of the permanent magnet has a certain anti-demagnetization performance, the coercive force is greater than 0 at any position along the gradient direction of the coercive force.
  • the specific shape of the permanent magnet 102 is not limited, and may be designed into different shapes according to actual application requirements.
  • the axial cross-sectional shape of the permanent magnets 102 in the direction perpendicular to the rotation axis of the rotor core may be rectangular, tile-shaped, bread-shaped, crescent-shaped, or the like.
  • the cylindrical cross-sectional shape of the permanent magnet 102 in the radial direction may be rectangular, tile-shaped, bread-shaped, crescent-shaped, or the like.
  • the permanent magnet 102 may be a rectangular parallelepiped structure as shown in FIG. 3 . As shown in FIG.
  • the length direction of the cuboid permanent magnet is consistent with the axial direction of the rotor core
  • the width direction of the permanent magnet is The extension direction on the axial end face of the rotor core (vertical to the end face of the rotating shaft 30 of the rotor core, that is, the axial cross section), that is, the width direction of the magnetic steel slot
  • the magnetization direction of the cuboid permanent magnet is generally the height direction, that is The thickness direction, so the direction perpendicular to the magnetization direction may be the length direction or the width direction.
  • the rectangular parallelepiped permanent magnet 102 may have the above-mentioned gradual change in coercive force along the length direction, or the above-mentioned gradual design in the coercive force along the width direction, or the above-mentioned gradual design in both the length and width directions.
  • the permanent magnet 102 may be a sintered NdFeB magnet.
  • the permanent magnet 102 is an integrally formed permanent magnet, that is, a continuous overall structure, and along the direction of the coercivity gradient, the concentration of heavy rare earth metal elements in the permanent magnet is continuously gradient from the center to both ends distribution or multi-level gradient gradient distribution, so that the coercive force is continuously or multi-level gradient gradient distribution from the center to both ends.
  • the permanent magnet 102 with a coercive force gradient design is formed by an integral structure permanent magnet through heavy rare earth grain boundary diffusion technology, and specifically, an integral structure permanent magnet in at least one direction perpendicular to the magnetization direction.
  • the permanent magnet 102 may be formed by the diffusion of different concentrations of heavy rare earth metal elements in segments of a permanent magnet of a certain brand. Specifically, it can be formed by coating layers containing heavy rare earth elements with different concentrations or thicknesses on the surface of a permanent magnet of a certain brand to perform element diffusion. In this embodiment, the permanent magnet 102 is obtained by integral molding and does not need to be bonded and fixed by an adhesive. It can be realized by means of existing diffusion equipment without increasing the number of processes.
  • the efficiency is high, and the material utilization rate is higher, which is beneficial to mass production.
  • the integrally formed permanent magnet has a stable structure and higher mechanical reliability, and there is no permanent magnet failure problem caused by the aging and shedding of the glue.
  • This embodiment can better realize the continuous and gradual distribution of the coercive force from the center to the two ends, so that the coercive force of the permanent magnet can be distributed more uniformly and change more gently, so as to better ensure the stability and reliability of the motor, and at the same time can The redundancy of the design to reduce the coercive force of the permanent magnet more accurately, reduce the usage of heavy rare earth, and reduce the cost of the permanent magnet.
  • the permanent magnet 102 is formed by splicing multiple segments of magnets with different coercive forces.
  • the permanent magnet 102 is formed by bonding or welding a plurality of segments of magnets with different coercive forces through adhesive bonding.
  • the coercive force distribution of each segment of the magnet is generally uniform, that is, the coercive force at any position is the same, so the permanent magnet 102 formed by splicing multiple segments of magnets is from the middle to both ends.
  • the coercive force is distributed in a multi-level gradient.
  • the coercive force of each segment of magnets can also be gradually distributed, so that the coercive force of the permanent magnets 102 formed by splicing forms a continuous change, or a change with a small gradient.
  • the permanent magnet 102 may include a center segment 1021 and end segments 1022 located at both ends of the center segment 1021 along the width direction perpendicular to the magnetization direction.
  • the center segment 1021 and the end segments 1022 At least one transition section 1023 is included in between, and the coercive force of the permanent magnet 102 from the central section 1021 to the end sections 1022 at both ends is distributed in a multi-level gradient or in a continuous gradient.
  • the width of each segment may be more than 1 mm.
  • the motor rotor 10 generally requires strong anti-demagnetization capability at both ends of the permanent magnet 102 , while the requirement for the anti-demagnetization capability at the center is relatively low.
  • the following will be described in detail by taking as an example that the coercive force of the permanent magnet 102 increases continuously and gradually from the middle to both ends along the width direction, or increases gradually with a multi-level gradient.
  • the rotor 10 of the motor in the embodiment of the present application adopts the permanent magnet 102 with a coercive force gradient design, wherein the end section 1022 has a high coercive force, so as to have high anti-demagnetization performance, which can ensure the reliability of the motor; the center section 1021 has a relatively high coercivity. Low coercivity, so that it has a lower content of heavy rare earth elements, which can reduce the amount of rare earth and reduce costs; and the setting of the transition section 1023 can make the coercive force distribution of the permanent magnet more uniform, and the coercive force from the center to both ends changes more.
  • the width of the center section 1021 accounts for more than 30% of the total width of the permanent magnet 102 .
  • the proportion of the width of the central segment may be 35%-50%.
  • the width of the central segment 1021 accounts for more than 50% of the total width of the permanent magnet 102 .
  • the proportion of the width of the central segment may be 55%-65%.
  • the central segment 1021 has low coercivity, and thus has a lower concentration of heavy rare earth elements. Controlling the central segment to a certain width ratio is beneficial to reducing the amount of heavy rare earth elements used in the entire permanent magnet.
  • the width of the end segment 1022 (referring to each end segment) is less than 10% of the total width of the permanent magnet 102 . In some embodiments of the present application, the width of the end section 1022 is 5%-9% of the total width of the permanent magnet 102 .
  • the end section 1022 has the highest coercivity and has the highest concentration of heavy rare earth elements. Controlling the end section to a smaller width is beneficial to reduce the proportion of the end section with the highest concentration of heavy rare earth elements and reduce the concentration of heavy rare earth elements. Usage amount.
  • the minimum coercivity of the end segment 1022 is higher than that of the center segment 1021 by more than 30%. In some embodiments of the present application, the minimum coercivity of the end section 1022 may be more than 50% higher than the minimum coercivity of the center section 1021 .
  • the anti-demagnetization ability of the end section is higher, while the anti-demagnetization ability of the center section is lower. Designing the coercive force of the end section at a higher level can improve the anti-demagnetization ability of the end of the permanent magnet and improve the reliability of the motor. Therefore, designing the coercive force of the center section at a lower level can reduce the amount of rare earth and reduce the cost of the motor.
  • the difference between the maximum coercive force and the minimum coercive force of the end section is 5%-30%. Specifically, it can be 10%-25%, 15%-20%.
  • the difference between the minimum coercive force of the end section 1022 and the minimum coercive force of the adjacent transition section is greater than 12%. In the embodiment of the present application, the difference between the minimum coercive force of the central segment 1021 and the adjacent transition segment is 3%-10%.
  • the coercive force gradation degree at both ends of the permanent magnet is greater than the coercive force gradation degree at the middle part. Specifically, in some embodiments, from the middle to the two ends, the coercive force gradually increases in degree of gradation.
  • the coercive force of the opposite ends of the permanent magnet that is, the outermost adjacent segment, is designed to change relatively quickly, which can more fully meet the higher anti-demagnetization requirements of the end of the permanent magnet of the motor and improve the reliability of the motor.
  • the coercivity of the middle part of the permanent magnet that is, the inner adjacent segment, is designed to change relatively slowly, which can meet the actual anti-demagnetization requirements, reduce the redundancy of the coercive force of the permanent magnet, and save heavy rare earths more effectively. Element usage.
  • the coercive force of the permanent magnet may be distributed symmetrically or asymmetrically from the center to both ends along the width direction.
  • the difference in remanence of two adjacent segments of the permanent magnet is the same or substantially the same. In some embodiments, the difference in remanence of two adjacent segments of the permanent magnet 102 is less than or equal to 3%. In other embodiments, the difference in remanence of two adjacent segments of the permanent magnet 102 is less than or equal to 2%. In other embodiments, the difference in remanence of two adjacent segments of the permanent magnet is less than or equal to 1%.
  • Residual magnetism that is, residual magnetic induction intensity, refers to the surface field retained after the permanent magnet is magnetized to technical saturation and the external magnetic field is removed, and is represented by Br.
  • one or more transition sections 1023 may be provided between the central section 1021 and the end section 1022 .
  • the coercive force changes more gently from the center section to the end section, which is beneficial to the improvement of the overall performance of the permanent magnet.
  • a transition section 1023 is included between the center section 1021 and the end section 1022 , and the permanent magnet 102 has a five-section structure, which are ab section, bc section, cd section respectively. segment, de segment, ef segment.
  • the permanent magnets 102 are distributed on the rotor core 101 at inline intervals.
  • the permanent magnet 102 can be formed by splicing permanent magnets with different coercive forces in ab segment, bc segment, cd segment, de segment, and ef segment along a certain direction to form a coercive force along the direction. Gradient distribution. Among them, the coercive force ab segment>bc segment>cd segment, the coercive force ef segment>de segment>cd segment, that is, the coercive force of the permanent magnet 102 increases in a gradient from the center to both ends.
  • Curve 1 in FIG. 5 is a coercive force design curve of the permanent magnet 102 with a five-segment structure in an embodiment of the present application.
  • the coercive force of each segment of the magnet is generally a single value, the overall coercive force of the permanent magnet 102 increases and distributes gradually from the center to the two ends.
  • the actual coercivity distribution curve of the permanent magnet 102 along the width direction is basically consistent with the coercivity design curve 1 .
  • the actual coercivity of each segment may also be slightly higher than the coercivity design value of curve 1 .
  • the coercive force of the permanent magnet 102 may be symmetrically distributed, that is, the coercive force of the ab segment and the ef segment is the same, and the coercive force of the bc segment and the de segment is the same;
  • the anti-demagnetization performance requirements of different positions are designed to have an asymmetric distribution of coercive force, that is, the coercive forces of the ab segment and the ef segment are different and/or the coercive force of the bc segment and the de segment are different.
  • the widths of the segments on both sides of the central segment can also be symmetrical, that is, the widths of the ab segment and the ef segment are the same, and the width of the bc segment and the de segment are the same, or the widths of the segments on both sides of the central segment can be different. symmetry.
  • the permanent magnet 102 is an integrally formed structure, that is, the ab segment, the bc segment, the cd segment, the de segment, and the ef segment are a continuous overall structure, and the organization structure of each segment of the permanent magnet 102 is continuous.
  • the permanent magnet 102 is formed by diffusing heavy rare earth metal elements with different concentrations in sections along the width direction to form a continuous and gradual increase in coercive force from the center to both ends. >de segment >cd segment.
  • Curve 2 in FIG. 5 is an actual coercive force distribution curve along the width direction of the permanent magnet 102 prepared according to the coercive force customization requirement of Curve 1 in an embodiment of the present application.
  • the coercive force of the permanent magnet 102 increases continuously and gradually increases along the width direction from the center to both ends.
  • the actual coercivity values of the magnets all reach the design coercivity values of the corresponding segments in Curve 1.
  • the actual coercivity value of each segment of the magnet must reach the coercivity design value of the corresponding segment, that is, the coercivity design value of curve 1 is the minimum coercivity of the actual product.
  • the limitation is that the coercivity value at any position needs to reach the design value of the coercivity, which can be higher than the design value.
  • the coercive force of the permanent magnet 102 may be symmetrically distributed as shown in FIG. 5 , that is, the coercive force of the ab segment and the ef segment is the same, and the coercive force of the bc segment and the de segment is the same;
  • the anti-demagnetization performance requirements of the motor for different positions of the permanent magnet 102 are designed so that the coercive force is distributed asymmetrically, that is, the coercive forces of the ab segment and the ef segment are different and/or the coercive force of the bc segment and the de segment are different.
  • the widths of the segments on both sides of the central segment can also be symmetrical, that is, the widths of the ab segment and the ef segment are the same, and the width of the bc segment and the de segment are the same, or the widths of the segments on both sides of the central segment can be different. symmetry.
  • the permanent magnet 102 is a seven-section structure, which are a section ab, section bc, cd segment, de segment, ef segment, fg segment, gh segment.
  • the permanent magnets 102 are distributed on the rotor core at V-shaped intervals.
  • the curve 3 in FIG. 8 is the coercive force design curve of the permanent magnet 102 of the seven-segment structure in an embodiment of the present application.
  • the permanent magnet 102 has an integrally formed structure, that is, the ab segment, the bc segment, the cd segment, the de segment, the ef segment, the fg segment, and the gh segment are a continuous integral structure.
  • the structure is continuous.
  • the permanent magnet 102 is formed by the diffusion of different concentrations of heavy rare-earth metal elements along the width direction to form a continuous and gradual increase in the coercive force from the center to the two ends.
  • the curve 4 in FIG. 8 is the actual coercive force distribution curve of the permanent magnet 102 along the width direction prepared according to the coercive force customization requirement of the curve 3 in an embodiment of the application. It can be seen from curve 4 that the coercive force of the permanent magnet 102 increases continuously and gradually increases along the width direction from the center to both ends.
  • the coercivity of the permanent magnet 102 may be asymmetrically distributed as shown in FIG. 8 , that is, the coercivity of the ab segment and the gh segment are different, and/or the coercivity of the bc segment and the fg segment are different , cd segment and ef segment have different coercivity.
  • the coercive force may be designed to be symmetrically distributed according to the anti-demagnetization performance requirements of the motor for different positions of the permanent magnet 102 , that is, the coercive force of the ab segment and the gh segment are the same, and the bc segment and the fg segment have the same coercivity.
  • the coercivity is the same, and the coercivity of the cd segment and the ef segment is the same.
  • the widths of the segments on both sides of the central segment can also be symmetrical, that is, the widths of the ab segment and the gh segment are the same, the width of the bc segment and the fg segment are the same, the width of the cd segment and the ef segment are the same, or the center
  • the widths of the segments on either side of the segment are asymmetrical.
  • the coercive force of the adjacent segments at opposite ends of the permanent magnet 102 changes rapidly, and the coercive force of the adjacent segments in the middle part changes slowly, for example, the coercive force changes from the ab segment to the cd segment, wherein From the ab segment to the bc segment, the coercive force changes rapidly and the gradient is large, while from the bc segment to the cd segment, the coercive force changes slowly and the gradient is small.
  • Another example is the change of coercivity from the ab segment to the de segment.
  • the coercive force changes rapidly and the gradient is large, while from the bc segment to the cd segment, and from the cd segment to the de segment, the coercivity changes slowly. , the gradient is small.
  • the center segment 1021 and the end segment 1022 may include three transition segments, and the permanent magnet 102 is a nine-segment structure. In other embodiments, the center section 1021 and the end section 1022 may include more transition sections.
  • the arrangement of the plurality of permanent magnets on the rotor core may be a built-in type or a surface-mounted type.
  • the arrangement of the plurality of permanent magnets on the rotor iron core is a built-in type.
  • the rotor iron core is provided with a plurality of magnetic steel slots 103 .
  • 103 is provided on the axial end face of the rotor iron core at intervals along the circumferential direction of the rotor iron core.
  • the plurality of permanent magnets are arranged in the plurality of magnetic steel slots in a one-to-one correspondence.
  • the two ends of the magnetic steel slot 103 are provided with positioning protrusions 3 for fixing the permanent magnets on the side away from the rotation axis of the rotor iron core 101 .
  • the shape of the positioning protrusion 3 is not limited, and it can form abutting or clamping on the permanent magnet, so that the permanent magnet can be fixed. Since the demagnetizing field received by the permanent magnet mainly acts on the outer edge area of the magnet.
  • Introducing a positioning protrusion structure in the outer edge area of the magnetic steel groove can reduce the coercive force requirements at both ends of the magnet, reduce the possibility of demagnetization of the permanent magnet in actual use, improve the overall anti-demagnetization ability of the motor, and ensure its reliability. Further effectively reduce the use of heavy rare earths and save resources.
  • the shape of the positioning protrusion 3 may specifically be various shapes.
  • the outer peripheral surface of the positioning protrusion 3 is in the shape of a smooth curved surface, specifically an arc curved surface.
  • the curved curved surface can avoid stress concentration at angular positions, reduce local stress, prolong the service life of the rotor, and improve the motor. work reliability.
  • the cross-sectional shape of the positioning protrusion 3 on the axial end face of the rotor core may be an arc segment, specifically, a semi-elliptical shape.
  • the protruding dimension of the positioning protrusion 3 is less than or equal to 1/3 of the size of the permanent magnet in the protruding direction of the positioning protrusion 3 .
  • the protruding size of the positioning protrusion 3 may be 1/10-1/4 or 1/8-1/6 of the size of the permanent magnet in the protruding direction of the positioning protrusion 3 .
  • the protruding direction is generally the height direction of the permanent magnet.
  • the dimension of the permanent magnet in the protruding direction of the positioning protrusion is usually the largest dimension in that direction.
  • a suitable size of the positioning protrusion can not only ensure a better fixation of the permanent magnet, but also better avoid stress concentration.
  • the rotor core 101 is further provided with a groove 4 connected with the positioning protrusion 3 , and the groove 4 is located on the side of the positioning protrusion 3 close to the middle of the magnetic steel groove 103 .
  • the setting of the groove 4 can further reduce the anti-demagnetization requirement for the end of the permanent magnet and reduce the amount of heavy rare earth elements; The problem that the permanent magnets are damaged during the assembly process or the working process can improve the service life of the motor rotor.
  • the inner concave surface of the groove 4 can also be in the shape of an arc curved surface.
  • the size of the opening width of the groove 4 may be less than or equal to 1/5 of the size of the permanent magnet in the extending direction of the opening of the groove 4 .
  • the size of the opening width of the groove 4 is 1/10-1/6 or 1/9-1/7 of the size of the permanent magnet in the extending direction of the opening of the groove 4 .
  • the dimension of the permanent magnet in the extending direction of the opening of the groove 4 is generally the width direction of the permanent magnet.
  • the dimension of the permanent magnet in the extending direction of the opening of the groove 4 is usually the largest dimension in this direction.
  • the suitable groove size can not only ensure smooth assembly, but also prevent the problem that the permanent magnet assembly is unstable due to excessive clearance, and can also prevent the electromagnetic function from being affected by the excessive groove size.
  • the arrangement of the plurality of permanent magnets 102 on the rotor core 101 is not limited, and may be any existing form, for example, the in-line shape as shown in FIG.
  • the V type shown it can also be a double V type, It can be arranged according to the actual design requirements of the motor.
  • the arrangement of the plurality of permanent magnets 102 on the rotor core 101 is surface-mounted, and the plurality of permanent magnets 102 are attached to the outer peripheral surface of the rotor core 101 .
  • the plurality of permanent magnets 102 are distributed at intervals along the circumferential direction of the rotor core 101 .
  • the embodiment of the present application further provides a vehicle, the vehicle adopts the motor described above in the embodiment of the present application, and the motor provides a driving force for the vehicle.
  • the specific type of the vehicle is not limited.
  • the embodiment of the present application also provides an electrical appliance, the electrical appliance adopts the above-mentioned motor in the embodiment of the present application, and the motor provides the driving force for the electrical appliance.
  • the specific type of the electrical appliance is not limited, and can be various household appliances, industrial appliances, and the like.

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Abstract

本申请提供一种电机转子，包括转子铁芯和设置在所述转子铁芯上的多个永磁体，至少部分所述永磁体沿垂直于磁化方向的至少一个方向，矫顽力由中间向两端呈连续渐变分布或呈多级梯度渐变分布。该电机转子采用矫顽力渐变设计的永磁体，永磁体由中间到两端矫顽力呈连续渐变或多级梯度渐变，整个永磁体的矫顽力变化较均匀，能最大程度提升电机的稳定可靠性，同时可避免抗退磁性能过剩，减少重稀土元素的用量，最大限度降低电机成本。本申请实施例还提供了采用该电机转子的电机，兼具高可靠性和低成本。

Description

电机转子和电机 技术领域
本申请涉及永磁电机技术领域，尤其涉及一种电机转子和电机。
背景技术
永磁电机以其体积小、效率高、功率密度高等优点广泛应用于航空航天、家电、工业制造、计算机、新能源汽车等领域。常规的永磁同步电机一般由定子和转子两部分组成，其中转子包括转子铁芯和安装在转子铁芯上的永磁体；定子包括定子铁芯、定子绕组。电机通电后，定子绕组产生的旋转磁场带动转子进行旋转，输出转矩。
由于永磁体的抗退磁能力有限，当电机工作温度高出永磁体允许的最高工作温度或定子绕组对永磁体施加的反向磁场超过永磁体本身的抗退磁能力时，永磁体就会发生退磁，电机因此发生失效。为避免永磁体发生退磁，钕铁硼永磁通常需要加入镝Dy、铽Tb等重稀土元素来提高其抗退磁能力，然而这些重稀土价格高昂，导致电机成本大大增加。因此，有必要开发一种具有高可靠性，同时兼具低成本的电机。
发明内容
本申请实施例提供了一种电机转子和电机，电机转子采用矫顽力渐变设计的永磁体，使电机获得优异稳定可靠性的同时，减少了重稀土元素的用量，降低了电机成本。
具体地，本申请实施例第一方面提供了一种电机转子，包括转子铁芯和设置在所述转子铁芯上的多个永磁体，至少部分所述永磁体沿垂直于磁化方向的至少一个方向，矫顽力由中间向两端呈连续渐变分布或呈多级梯度渐变分布。本申请实施例电机转子采用矫顽力渐变设计的永磁体，永磁体兼具高抗退磁区域保证电机的可靠性，低抗退磁区域减少重稀土元素含量，最大限度降低成本，且由中间到两端矫顽力是连续渐变或多级梯度渐变，从而使得整个永磁体的矫顽力变化较均匀，也能更好地加大中间部分与端部的矫顽力差异，更好地保证电机的稳定可靠性，避免抗退磁性能过剩，兼顾低成本。为了获得更好的效果，本申请实施方式中，可以是将每一永磁体都设计为沿垂直于磁化方向的至少一个方向，矫顽力由中间向两端呈连续渐变分布或呈多级梯度渐变分布。
永磁体的磁化方向一般是永磁体中两个相对面中距离最短的方向，以长方体结构的永磁体为例，磁化方向一般为高度方向，而与磁化方向垂直的方向可以是长度方向，也可以是宽度方向。
本申请一些实施方式中，所述至少部分永磁体沿垂直于磁化方向的至少一个方向，矫顽力由中间向两端的变化趋势为连续渐变增大或多级梯度渐变增大。大多数情况下，永磁体两端的抗退磁需求大于中间部分的抗退磁需求，将矫顽力设计为由中间向两端渐变增大，可使永磁体既具有端部的高抗退磁区域保证电机的可靠性，又具有中间部分的低重稀土元素含量的低抗退磁区域降低成本。当然在其他一些实施方式中，也可以根据实际需要将矫顽力设计为由中间向两端渐变减小。
本申请实施方式中，为保证永磁体任意位置均具有一定的抗退磁性能，沿矫顽力渐变 方向的任意位置处，矫顽力都大于0。
本申请实施方式中，所述至少部分永磁体中的重稀土金属元素浓度，沿矫顽力渐变方向由中间向两端呈连续渐变分布或呈多级梯度渐变分布。永磁体中重稀土金属元素的浓度直接决定了其矫顽力的大小，沿矫顽力渐变方向，重稀土金属元素的浓度变化趋势与矫顽力变化趋势是相对应的。重稀土金属元素浓度越大，矫顽力越大。
本申请实施方式中，所述至少部分永磁体为一体成型结构，即为一连续的整体结构。该实施方式中，矫顽力渐变设计可通过将具有一整体结构的永磁体在沿垂直于磁化方向的至少一个方向的不同位置进行不同浓度重稀土金属元素扩散实现。该实施方式中，矫顽力渐变设计的一体成型结构的永磁体可一步制备获得，不需要通过价格较高的粘结剂进行粘结，结构稳定，可提升电机使用可靠性。该一体成型结构的永磁体，沿矫顽力渐变方向，重稀土金属元素在永磁体中的浓度可以是由中间向两端呈连续渐变增大或减小分布，也可以是呈多级梯度渐变增大或减小分布。
本申请实施方式中，所述至少部分永磁体由多段具有不同矫顽力的磁体拼接形成。具体地，永磁体由多段具有不同矫顽力的磁体通过粘结剂粘结形成或通过焊接形成。该实施方式中，由于用于拼接的每一段磁体本身的矫顽力水平分布一般是均一的，即任意位置的矫顽力一般是相同的，因此多段磁体拼接形成的永磁体由中间向两端，矫顽力一般呈梯度渐变增大或减小分布。当然在一些实施方式中，也可以是矫顽力由中间向两端呈连续渐变分布。
本申请实施方式中，所述至少部分永磁体沿矫顽力渐变方向可包括中心段和位于所述中心段两端的端部段，所述中心段与所述端部段之间还包括至少一个过渡段。在本申请一些实施方式中，端部段相对具有更高的矫顽力，可保证电机的可靠性，而中心段的矫顽力相对更小，重稀土元素含量低，可最大限度降低成本，而在高抗退磁区域与低抗退磁区域之间具有过渡段，该过渡段的设置使得永磁体的矫顽力分布更均匀，变化更均匀，而且能更好地加大中心段与端部段的矫顽力差异，从而更好地保证电机的稳定可靠性，避免抗退磁性能过剩，兼顾低成本。该实施方式中，端部段的矫顽力大于过渡段的矫顽力，过渡段的矫顽力大于中心段的矫顽力，每一段的矫顽力若为均一值，则由中心段向端部段矫顽力构成多级梯度渐变，每一段的矫顽力若为连续渐变，则由中心段向端部段矫顽力也可构成连续渐变。
本申请实施方式中，沿矫顽力渐变方向，所述中心段的宽度为所述永磁体总宽度的30％以上。中心段具有低矫顽力，即具有较低的重稀土元素浓度，将中心段控制达到一定的宽度比例有利于降低永磁体整体的重稀土元素的使用量。
本申请实施方式中，沿矫顽力渐变方向，所述端部段的宽度为所述永磁体总宽度的10％以下。端部段具有最高矫顽力，即具有最高的重稀土元素浓度，将端部段控制在较小的宽度有利于降低重稀土元素的使用量。
本申请实施方式中，所述端部段的最小矫顽力比所述中心段的最小矫顽力高30％以上。端部段的抗退磁能力要求较高，而中心段的抗退磁能力要求较低，将端部段的矫顽力设计在较高水平可以提高永磁体端部的抗退磁能力，提高电机的可靠性，将中心段的矫顽力设计在较低水平可以减少稀土用量，降低电机成本。
本申请实施方式中，当所述端部段的矫顽力为连续渐变分布时，所述端部段的最大矫顽力和最小矫顽力之间的差异为5％-30％。控制端部段的适合矫顽力变化程度，可以较好兼顾电机可靠性和重稀土用量。
本申请实施方式中，所述端部段与相邻的所述过渡段的最小矫顽力的差异大于12％。
本申请实施方式中，所述中心段与相邻的所述过渡段的最小矫顽力的差异为3％-10％。
本申请实施方式中，所述永磁体两端的矫顽力渐变程度大于中间部分的矫顽力渐变程度。具体地，在一些实施方式中，由中间向两端，矫顽力渐变程度逐渐增大。将永磁体相对两端即最外侧的相邻段的矫顽力设计成相对较快的变化，可以更充分的满足电机永磁体端部更高的抗退磁要求，提升电机的可靠性。将永磁体中间部分，即内侧的相邻段的矫顽力设计成相对较慢的变化，可以在满足实际抗退磁要求的同时，减少永磁体矫顽力的冗余，更有效的节约重稀土元素的使用量。
本申请实施方式中，所述永磁体的相邻两段的剩磁差异小于或等于3％。由于永磁体的剩磁一般是有一定波动的，剩磁差异≤3％即可以认为是一致。
本申请实施方式中，中心段与端部段之间可以是设置一个或多个过渡段。当为多个过渡段时，矫顽力由中心段变化到端部段将更加平缓，可在进一步降低永磁体矫顽力的冗余，保证永磁体可靠性的同时，节约重稀土元素的使用量。
本申请一实施方式中，所述中心段与所述端部段之间包括一个过渡段，所述永磁体为五段式结构。
本申请另一实施方式中，所述中心段与所述端部段之间包括两个过渡段，所述永磁体为七段式结构。
本申请另一实施方式中，所述中心段与所述端部段之间包括三个过渡段，所述永磁体为九段式结构。
本申请实施方式中，所述永磁体沿宽度方向由中间向两端矫顽力可以是对称分布，也可以是非对称分布。
本申请实施方式中，所述永磁体为烧结钕铁硼磁体。
本申请实施方式中，多个永磁体在转子铁芯上的布置方式可以是内置式，也可以是表贴式。
本申请一些实施方式中，多个永磁体在转子铁芯上的布置方式为内置式，所述转子铁芯上设置有多个磁钢槽，所述多个永磁体一一对应设置于所述多个磁钢槽中。所述多个磁钢槽可以是沿转子铁芯的周向间隔开设于转子铁芯的轴向端面上。
本申请实施方式中，所述转子铁芯上，所述磁钢槽的两端远离所述转子铁芯的转轴的一侧设有用于固定所述永磁体的定位突起。由于永磁体受到的退磁场主要作用在磁体的外缘区域。在磁钢槽外缘区域引入定位突起结构，可降低对磁体两端的矫顽力需求，减少永磁体在实际使用中的退磁可能性，提高电机的整体抗退磁能力，保证其可靠性，也可以进一步有效减少重稀土使用量，节约资源。
本申请实施方式中，所述定位突起的外周面为弧形曲面。弧形曲面能够避免在角位置形成应力集中。
本申请实施方式中，所述定位突起的突出尺寸小于或等于所述永磁体在所述定位突起 突出方向上的尺寸的1/3。
本申请一些实施方式中，所述转子铁芯上，还设置与所述定位突起相连的凹槽，所述凹槽位于所述定位突起靠近所述磁钢槽中部的一侧。凹槽的设计有利于永磁体装配，避免永磁体在装配过程中遭到破坏。
本申请实施方式中，所述凹槽的开口宽度尺寸小于或等于所述永磁体在所述凹槽的开口延伸方向上的尺寸的1/5。
本申请实施方式中，所述多个永磁体的布置方式不限，可以是现有的任意形式，具体例如可以是一字型、V型、双V型、
Figure PCTCN2020103671-appb-000001
型、U型或双U型。
本申请另一些实施方式中，多个永磁体在转子铁芯上的布置方式为表贴式，多个永磁体贴合在所述转子铁芯的外周面上。
本申请实施例第二方面提供了一种电机，包括电机转子和定子，所述电机转子包括本申请实施例第一方面所述的电机转子。定子固定设置在电机转子周围，定子包括定子铁芯和定子绕组。该电机可以是径向磁通电机，也可以是轴向磁通电机。
本申请实施例还提供了一种车辆，包括本申请实施例第二方面所述的电机，电机为所述车辆提供驱动力。
本申请实施例还提供了一种电器，包括本申请实施例第二方面所述的电机，电机为所述电器提供驱动力。
本申请实施例提供的电机转子和永磁电机，电机转子采用矫顽力渐变设计的永磁体，可以在提升电机可靠性的同时，最大限度降低成本，而且永磁体由中心向两端矫顽力整体的变化趋势较和缓，不是骤变，因而能更好地加大永磁体中心与端部的矫顽力差异，从而更好地保证电机的稳定可靠性，也能更好地避免抗退磁性能过剩，降低重稀土用量，兼顾低成本。另外，本申请实施例通过将磁钢槽两端远离转子铁芯转轴的一侧设置定位突起，可以进一步降低对磁体两端的矫顽力需求，减少永磁体在实际使用中的退磁可能性，提高电机的整体抗退磁能力，保证电机可靠性，也可以进一步有效的减少重稀土使用量，降低电机成本。而凹槽的设计可以进一步降低抗退磁需求，也有利于永磁体装配，避免永磁体破坏。
附图说明
图1是本申请一实施例提供的电机的立体结构示意图；
图2是本申请一实施例提供的电机的轴截面结构示意图；
图3是本申请实施方式中的长方体结构永磁体的结构示意图；
图4是图2中永磁体的结构示意图；
图5是图4的永磁体的矫顽力设计和实际矫顽力分布示意图；
图6是本申请一实施例提供的电机转子的结构示意图；
图7是图6中永磁体的结构示意图；
图8是图7的永磁体的矫顽力设计和实际矫顽力分布示意图；
图9是本申请实施例中定位突起和凹槽的设置示意图。
具体实施方式
下面结合本申请实施例中的附图对本申请实施例进行描述。
参见图1和图2，本申请实施例提供一种电机100，包括电机转子10和固定设置在电机转子10周围的定子20。电机转子10穿设于定子20的中心位置。在定子20和电机转子10之间留有间隙。电机转子10中设置永磁体，形成永磁电机。定子20包括定子铁芯和定子绕组。其中，定子铁芯可以是由多个硅钢片堆叠形成。电机100可以是如图1和图2所示的径向磁通电机，也可以是轴向磁通电机。
如图1和图2所示，本申请实施例电机转子10包括转子铁芯101和设置在转子铁芯101上的多个永磁体102，转轴30穿设于转子铁芯101中心位置，每一永磁体102沿垂直于磁化方向的至少一个方向，矫顽力呈多级梯度渐变分布或呈连续渐变分布。在本申请一些实施方式中，多个永磁体102中，也可以是只有部分永磁体沿垂直于磁化方向的至少一个方向的矫顽力由中间向两端呈梯度渐变分布或呈连续渐变分布。电机转子10采用矫顽力渐变设计的永磁体102，永磁体102由中间到两端矫顽力呈连续渐变或多级梯度渐变，这样整个永磁体的矫顽力变化较均匀，能最大程度提升电机的稳定可靠性，同时可避免抗退磁性能过剩，减少重稀土元素的用量，最大限度降低电机成本。
矫顽力(coercive force)是用来评价永磁体质量的一个指标，矫顽力是指磁性材料在饱和磁化后，当外磁场退回到零时其磁感应强度B并不退到零，只有在原磁化场相反方向加上一定大小的磁场才能使磁感应强度退回到零，该磁场称为矫顽磁场，又称矫顽力。对于钕铁硼永磁体，通过向磁体中引入Dy、Tb等重稀土元素，可使得矫顽力得到增强，重稀土含量越大，矫顽力越高。本申请实施方式中，永磁体102中沿矫顽力渐变方向，重稀土金属元素的浓度变化趋势与矫顽力变化趋势是相对应的，永磁体102中的重稀土金属元素浓度，沿矫顽力渐变方向由中间向两端呈连续渐变分布或呈多级梯度渐变分布。本申请实施方式中，多级梯度渐变中的多级可以是两级或两级以上。
本申请一些实施方式中，永磁体102沿垂直于磁化方向的至少一个方向，矫顽力由中间向两端的变化趋势为连续渐变增大或多级梯度渐变增大。大多数情况下，永磁体两端的抗退磁需求大于中间部分的抗退磁需求，将矫顽力设计为由中间向两端渐变增大，可使永磁体既具有端部的高抗退磁区域保证电机的可靠性，又具有中间部分的低重稀土元素含量的低抗退磁区域降低成本。在其他一些实施方式中，也可以根据实际需要将矫顽力设计为由中间向两端渐变减小。本申请实施方式中，为保证永磁体任意位置均具有一定的抗退磁性能，沿矫顽力渐变方向的任意位置处，矫顽力都大于0。
本申请实施方式中，永磁体102的具体形状不限，可以是根据实际应用需求设计成不同形状。对于径向磁通电机而言，永磁体102在垂直于转子铁芯转轴方向的轴截面形状可以是矩形、瓦形、面包形、月牙形等。对于轴向磁通电机而言，永磁体102在径向上的圆柱截面形状可以是矩形、瓦形、面包形、月牙形等。本申请一些实施方式中，永磁体102可以是如图3所示的长方体结构。如图2所示，对于长方体永磁体，永磁体102配置于转子铁芯101上的磁钢槽103中时，长方体永磁体的长度方向与转子铁芯的轴向一致，宽度方向为永磁体在转子铁芯的轴向端面(垂直于转子铁芯的转轴30的端面，即轴截面)上的延伸方向，也即磁钢槽的宽度方向，而长方体永磁体的磁化方向一般为高度方向，即厚度 方向，因此垂直于磁化方向的方向可以是长度方向，也可以是宽度方向。即长方体永磁体102可以是沿长度方向矫顽力呈上述渐变设计，也可以是沿宽度方向矫顽力呈上述渐变设计，还可以是长度方向和宽度方向同时满足上述渐变设计。
本申请实施方式中，永磁体102可以是烧结钕铁硼磁体。
本申请一些实施方式中，永磁体102为一体成型的永磁体，即为一连续的整体结构，沿矫顽力渐变方向，重稀土金属元素在永磁体中的浓度由中心向两端呈连续渐变分布或多级梯度渐变分布，从而使得矫顽力由中心向两端呈连续渐变分布或多级梯度渐变分布。该实施方式中，具有矫顽力渐变设计的永磁体102是由一整体结构永磁体经重稀土晶界扩散技术形成，具体地由一整体结构永磁体在沿垂直于磁化方向的至少一个方向的不同位置进行不同浓度重稀土金属元素扩散形成，其中重稀土金属元素可以包括镝Dy、铽Tb等元素。本申请实施方式中，永磁体102可以是由某一牌号的永磁体分段进行不同浓度重稀土金属元素扩散形成。具体地，可以是由某一牌号永磁体在不同的位置表面涂覆不同浓度或厚度的含重稀土元素的涂覆层进行元素扩散形成。该实施方式中，永磁体102为一体成型获得，不需要通过粘结剂粘结固定，可借助现有的扩散设备实现，不增加工序，效率高，材料利用率更高，有利于大批量生产；且一体成型永磁体结构稳定，力学可靠性更高，不会出现因胶水的老化和脱落导致的永磁体失效问题。该实施方式可以较好地实现矫顽力由中心向两端连续渐变分布，从而可以使得永磁体的矫顽力分布更均匀，变化更平缓，从而更好地保证电机的稳定可靠性，同时能更准确的降低永磁体矫顽力的设计的冗余，减少重稀土的使用量，降低永磁体成本。
本申请另一些实施方式中，永磁体102由多段具有不同矫顽力的磁体拼接形成。具体地，永磁体102由多段具有不同矫顽力的磁体通过粘结剂粘结形成或焊接形成。该实施方式中，为降低制备难度，每一段磁体的矫顽力分布一般是均一的，即任意位置的矫顽力是相同的，因此多段磁体拼接形成的永磁体102由中间向两端，矫顽力呈多级梯度渐变分布。当然在一些实施方式中，每一段磁体的矫顽力也可以是渐变分布，从而使得拼接形成的永磁体102的矫顽力形成连续变化，或形成梯度很小的变化。
如图4所示，本申请一些实施方式中，永磁体102沿垂直于磁化方向的宽度方向，可包括中心段1021和位于中心段1021两端的端部段1022，中心段1021与端部段1022之间包括至少一个过渡段1023，永磁体102由中心段1021向两端的端部段1022矫顽力呈多级梯度渐变分布或呈连续渐变分布。本申请实施方式中，每段的宽度可以是1mm以上。
电机转子10一般要求永磁体102两端具有较强抗退磁能力，而中心部位的抗退磁能力要求相对较低。下面以永磁体102沿宽度方向，矫顽力由中间向两端呈连续渐变增大或多级梯度渐变增大为例进行具体介绍。
本申请实施例电机转子10采用矫顽力渐变设计的永磁体102，其中，端部段1022具有较高矫顽力，从而具有高抗退磁性能，能够保证电机的可靠性；中心段1021具有较低矫顽力，从而具有较低重稀土元素含量，可以减少稀土用量，降低成本；而过渡段1023的设置可使得永磁体的矫顽力分布更均匀，由中心向两端的矫顽力变化更平缓，而且能更好地加大中心段1021与端部段1023的矫顽力差异，从而更好地保证电机的稳定可靠性，并避免抗退磁性能过剩，降低稀土用量，兼顾低成本。
本申请实施方式中，沿矫顽力渐变方向即宽度方向，中心段1021的宽度占永磁体102总宽度的占比大于30％。具体地，中心段宽度占比可以是为35％-50％。本申请一些实施方式中，中心段1021的宽度占永磁体102总宽度的占比大于50％。具体地，中心段宽度占比可以是为55％-65％。中心段1021具有低矫顽力，则具有较低的重稀土元素浓度，将中心段控制达到一定的宽度比例有利于降低永磁体整体的重稀土元素的使用量。
本申请实施方式中，沿矫顽力渐变方向，端部段1022(指每一个端部段)的宽度为永磁体102总宽度的10％以下。本申请一些实施方式中，端部段1022的宽度为永磁体102总宽度的5％-9％。端部段1022具有最高矫顽力，则具有最高的重稀土元素浓度，将端部段控制在较小的宽度有利于降低具有最高重稀土元素浓度的端部段的比例，降低重稀土元素的使用量。
本申请实施方式中，端部段1022的最小矫顽力比中心段1021的最小矫顽力高30％以上。本申请一些实施方式中，端部段1022的最小矫顽力可以是比中心段1021的最小矫顽力高50％以上。端部段的抗退磁能力要求较高，而中心段的抗退磁能力要求较低，将端部段的矫顽力设计在较高水平可以提高永磁体端部的抗退磁能力，提高电机的可靠性，将中心段的矫顽力设计在较低水平可以减少稀土用量，降低电机成本。
本申请实施方式中，当端部段的矫顽力为连续渐变分布时，端部段的最大矫顽力和最小矫顽力之间的差异为5％-30％。具体地，可以是10％-25％、15％-20％。
本申请实施方式中，端部段1022的最小矫顽力与相邻的过渡段的最小矫顽力的差异大于12％。本申请实施方式中，中心段1021与相邻的过渡段的最小矫顽力的差异为3％-10％。
本申请实施方式中，永磁体两端的矫顽力渐变程度大于中间部分的矫顽力渐变程度。具体地，在一些实施方式中，由中间向两端，矫顽力渐变程度逐渐增大。将永磁体相对两端即最外侧的相邻段的矫顽力设计成相对较快的变化，可以更充分的满足电机永磁体端部更高的抗退磁要求，提升电机的可靠性。将永磁体中间部分，即内侧的相邻段的矫顽力设计成相对较慢的变化，可以在满足实际抗退磁要求的同时，减少永磁体矫顽力的冗余，更有效的节约重稀土元素的使用量。
本申请实施方式中，永磁体沿宽度方向由中心向两端矫顽力可以是对称分布，也可以是非对称分布。
本申请实施方式中，永磁体的相邻两段的剩磁差异相同或基本相同。一些实施方式中，永磁体102的相邻两段的剩磁差异小于或等于3％。另一些实施方式中，永磁体102的相邻两段的剩磁差异小于或等于2％。其他一些实施方式中，永磁体的相邻两段的剩磁差异小于或等于1％。剩磁，即剩余磁感感应强度，是指永磁体经磁化至技术饱和，并去掉外磁场后所保留的表面场，用Br表示。
本申请实施方式中，中心段1021与端部段1022之间可以是设置一个或多个过渡段1023。当为多个过渡段时，矫顽力由中心段变化到端部段将更加平缓，有利于永磁体整体性能的提升。
本申请一实施方式中，如图2和图4所示，中心段1021与端部段1022之间包括一个过渡段1023，永磁体102为五段式结构，分别为ab段、bc段、cd段、de段、ef段。永磁体102呈一字型间隔分布在转子铁芯101上。
本申请一些实施方式中，永磁体102可由ab段、bc段、cd段、de段、ef段五段具有不同矫顽力的永磁体沿一定方向拼接形成，形成沿该方向上的矫顽力渐变分布。其中，矫顽力ab段>bc段>cd段，矫顽力ef段>de段>cd段，即永磁体102的矫顽力由中心向两端呈梯度渐变增大分布。图5中曲线1为本申请一实施方式中，五段式结构的永磁体102的矫顽力设计曲线。对于拼接方式形成的永磁体102，由于每一段磁体的矫顽力一般为单一值，永磁体102整体的矫顽力由中心向两端呈梯度渐变增大分布，因此根据曲线1进行生产制备得到的永磁体102沿宽度方向的实际的矫顽力分布曲线与矫顽力设计曲线1基本一致。当然，在一些实施例中，每段的实际矫顽力也可能稍高于曲线1的矫顽力设计值。本申请实施方式中，永磁体102的矫顽力可以是对称分布，即ab段和ef段的矫顽力相同，bc段和de段的矫顽力相同；也可以是根据电机对永磁体102不同位置的抗退磁性能需求，设计成矫顽力非对称分布，即ab段和ef段的矫顽力不同和/或bc段和de段的矫顽力不同。另外，位于中心段两侧的各段的宽度也可以是对称的，即ab段和ef段的宽度相同，bc段和de段的宽度相同，也可以是中心段两侧的各段的宽度非对称。
本申请另一些实施方式中，永磁体102为一体成型结构，即ab段、bc段、cd段、de段、ef段为一连续的整体结构，永磁体102各段的组织结构是连续的，永磁体102通过沿宽度方向分段进行不同浓度重稀土金属元素扩散形成由中心向两端矫顽力呈连续渐变增大分布，矫顽力ab段>bc段>cd段，矫顽力ef段>de段>cd段。图5中曲线2为本申请一实施方式中根据曲线1的矫顽力定制要求制备得到的永磁体102沿宽度方向的实际的矫顽力分布曲线。从曲线2可知，永磁体102沿宽度方向由中心向两端矫顽力呈连续渐变增大分布，相邻段磁体沿宽度方向的矫顽力是连续变化的，没有明显的梯度界限，每段磁体的实际矫顽力值均达到曲线1中相应段的矫顽力设计值。根据曲线1定制要求生产的永磁体，每段磁体的实际矫顽力值均要达到相应段的矫顽力设计值，即曲线1的矫顽力设计值是对实际产品的最小矫顽力的限定，即任意位置处的矫顽力值需要达到矫顽力设计值，可以是高于该设计值。本申请实施方式中，永磁体102的矫顽力可以是如图5所示对称分布，即ab段和ef段的矫顽力相同，bc段和de段的矫顽力相同；也可以是根据电机对永磁体102不同位置的抗退磁性能需求，设计成矫顽力非对称分布，即ab段和ef段的矫顽力不同和/或bc段和de段的矫顽力不同。另外，位于中心段两侧的各段的宽度也可以是对称的，即ab段和ef段的宽度相同，bc段和de段的宽度相同，也可以是中心段两侧的各段的宽度非对称。
本申请另一实施方式中，如图6和图7所示，中心段1021与端部段1022之间包括两个过渡段，永磁体102为七段式结构，分别为ab段、bc段、cd段、de段、ef段、fg段、gh段。永磁体102呈V字型间隔分布在转子铁芯上。图8中曲线3为本申请一实施方式中七段式结构的永磁体102的矫顽力设计曲线。与上述五段式结构一样，若本申请实施例的七段磁体是采用拼接方式形成永磁体102，则根据曲线3进行生产制备得到的永磁体102沿宽度方向的实际的矫顽力分布曲线与矫顽力设计曲线3基本一致。本申请另一实施方式中，永磁体102为一体成型结构，即ab段、bc段、cd段、de段、ef段、fg段、gh段为一连续的整体结构，永磁体102各段的组织结构是连续的，永磁体102通过沿宽度方向分段进行不同浓度重稀土金属元素扩散形成由中心向两端矫顽力呈连续渐变增大分布，矫顽力 ab段>bc段>cd段>de段，矫顽力gh段>fg段>ef段>de段。图8中曲线4为本申请一实施方式中根据曲线3的矫顽力定制要求制备得到的永磁体102沿宽度方向的实际的矫顽力分布曲线。从曲线4可知，永磁体102沿宽度方向由中心向两端矫顽力呈连续渐变增大分布，相邻段磁体沿宽度方向的矫顽力是连续变化的，没有明显的梯度界限，每段磁体的实际矫顽力值均达到曲线3中相应段的矫顽力设计值。本申请一些实施方式中，永磁体102的矫顽力可以是如图8所示非对称分布，即ab段和gh段的矫顽力不同，和/或bc段和fg段的矫顽力不同、cd段和ef段的矫顽力不同。本申请另一些实施方式中，也可以是根据电机对永磁体102不同位置的抗退磁性能需求，设计成矫顽力对称分布，即ab段和gh段的矫顽力相同，bc段和fg段的矫顽力相同，cd段和ef段的矫顽力相同。另外，位于中心段两侧的各段的宽度也可以是对称的，即ab段和gh段的宽度相同，bc段和fg段的宽度相同，cd段和ef段的宽度相同，也可以是中心段两侧的各段的宽度非对称。
另外，本申请实施方式中，永磁体102相对两端相邻段的矫顽力变化快，中间部分相邻段的矫顽力变化慢，例如由ab段到cd段的矫顽力变化，其中由ab段到bc段，矫顽力变化快，梯度大，而由bc段到cd段，矫顽力变化慢，梯度小。又例如ab段到de段的矫顽力变化，其中由ab段到bc段，矫顽力变化快，梯度大，而由bc段到cd段，以及cd段到de段，矫顽力变化慢，梯度小。
本申请其他实施方式中，中心段1021与端部段1022之间可包括三个过渡段，永磁体102为九段式结构。在其他一些实施方式中，中心段1021与端部段1022之间可以是包括更多个过渡段。
本申请实施方式中，多个永磁体在转子铁芯上的布置方式可以是内置式，也可以是表贴式。
本申请一些实施方式中，多个永磁体在转子铁芯上的布置方式为内置式，如图2和图6所示，转子铁芯上设置有多个磁钢槽103，多个磁钢槽103沿转子铁芯的周向间隔开设于转子铁芯的轴向端面上。多个永磁体一一对应设置于多个磁钢槽中。
参见图9，本申请实施方式中，转子铁芯101上，磁钢槽103的两端远离转子铁芯101转轴的一侧设有用于固定永磁体的定位突起3。定位突起3的形状不限，能够对永磁体形成抵持或卡持，使永磁体固定即可。由于永磁体受到的退磁场主要作用在磁体的外缘区域。在磁钢槽外缘区域引入定位突起结构，可降低对磁体两端的矫顽力需求，减少永磁体在实际使用中的退磁可能性，提高电机的整体抗退磁能力，保证其可靠性，也可以进一步有效的减少重稀土使用量，节约资源。
本申请实施方式中，定位突起3的形状具体可以是各种不同形状。本申请一些实施方式中，定位突起3的外周面为光滑曲面形状，具体可以是弧形曲面形状，弧形曲面能够避免在角位置形成应力集中，减小局部应力，延长转子使用寿命，提升电机的工作可靠性。定位突起3在转子铁芯的轴向端面上的截面形状可以是弧形段，具体例如为半椭圆形。
本申请实施方式中，定位突起3的突出尺寸小于或等于永磁体在定位突起3突出方向上的尺寸的1/3。具体地，定位突起3的突出尺寸可以是永磁体在定位突起3突出方向上的尺寸的1/10-1/4、或1/8-1/6。该突出方向一般为永磁体的高度方向。对于在突出方向上尺寸不均一的永磁体，永磁体在定位突起突出方向上的尺寸通常为该方向上的最大尺寸。适 合的定位突起尺寸，既能够保证永磁体较好地固定，又能够较好地避免应力集中。
本申请一些实施方式中，转子铁芯101上，还设置与定位突起3相连的凹槽4，凹槽4位于定位突起3靠近磁钢槽103中部的一侧。凹槽4的设置一方面可以进一步降低对永磁体端部的抗退磁需求，减少重稀土元素的用量；另一方面有利于进行永磁体装配，可避免因转子铁芯及永磁体的加工误差导致的永磁体在装配过程中或工作过程中遭到破坏的问题，从而可提升电机转子的使用寿命。凹槽4的内凹面也可以弧形曲面形状。
本申请实施方式中，凹槽4的开口宽度尺寸可以是小于或等于永磁体在凹槽4的开口延伸方向上的尺寸的1/5。具体地，凹槽4的开口宽度尺寸为永磁体在凹槽4的开口延伸方向上的尺寸的1/10-1/6、或1/9-1/7。永磁体在凹槽4的开口延伸方向上的尺寸一般为永磁体的宽度方向。对于在开口延伸方向上尺寸不均一的永磁体，永磁体在凹槽4的开口延伸方向上的尺寸通常为该方向上的最大尺寸。适合的凹槽尺寸，既能保证顺利装配，又可防止间隙过大导致永磁体装配不稳固的问题，也能防止凹槽尺寸过大影响电磁功能。
本申请实施方式中，多个永磁体102在转子铁芯101的布置方式不限，可以是现有的任意形式，例如可以是如图2所示的一字型、如图1和图6所示的V型，也可以是双V型、
Figure PCTCN2020103671-appb-000002
型、U型或双U型等，具体可根据电机的实际设计需求进行布置。
本申请一些实施方式中，多个永磁体102在转子铁芯101上的布置方式为表贴式，多个永磁体102贴合在转子铁芯101的外周面上。多个永磁体102沿转子铁芯101的周向间隔分布。
本申请实施例还提供了一种车辆，该车辆采用本申请实施例上述的电机，电机为车辆提供驱动力。该车辆的具体类型不限。
本申请实施例还提供了一种电器，该电器采用本申请实施例上述的电机，电机为电器提供驱动力。该电器的具体种类不限，可以是各种家用电器、工业电器等。

Claims (30)

  1. 一种电机转子，其特征在于，包括转子铁芯和设置在所述转子铁芯上的多个永磁体，至少部分所述永磁体沿垂直于磁化方向的至少一个方向，矫顽力由中间向两端呈连续渐变分布或呈多级梯度渐变分布。
  2. 如权利要求1所述的电机转子，其特征在于，所述至少部分永磁体沿垂直于磁化方向的至少一个方向，矫顽力由中间向两端的变化趋势为连续渐变增大或多级梯度渐变增大。
  3. 如权利要求1或2所述的电机转子，其特征在于，所述至少部分永磁体中的重稀土金属元素浓度，沿矫顽力渐变方向由中间向两端呈连续渐变分布或呈多级梯度渐变分布。
  4. 如权利要求1-3任一项所述的电机转子，其特征在于，所述至少部分永磁体为一体成型结构。
  5. 如权利要求1-3任一项所述的电机转子，其特征在于，所述永磁体由多段具有不同矫顽力的磁体拼接形成。
  6. 如权利要求1-5任一项所述的电机转子，其特征在于，所述永磁体两端的矫顽力渐变程度大于中间部分的矫顽力渐变程度。
  7. 如权利要求1-6任一项所述的电机转子，其特征在于，所述至少部分永磁体沿矫顽力渐变方向包括中心段和位于所述中心段两端的端部段，所述中心段与所述端部段之间还包括至少一个过渡段。
  8. 如权利要求7所述的电机转子，其特征在于，沿矫顽力渐变方向，所述中心段的宽度为所述永磁体总宽度的30％以上。
  9. 如权利要求7或8所述的电机转子，其特征在于，沿矫顽力渐变方向，所述端部段的宽度为所述永磁体总宽度的10％以下。
  10. 如权利要求7-9任一项所述的电机转子，其特征在于，所述端部段的最小矫顽力比所述中心段的最小矫顽力高30％以上。
  11. 如权利要求7-10任一项所述的电机转子，其特征在于，当所述端部段的矫顽力为连续渐变分布时，所述端部段的最大矫顽力和最小矫顽力之间的差异为5％-30％。
  12. 如权利要求7-11任一项所述的电机转子，其特征在于，所述端部段与相邻的所述过渡段的最小矫顽力的差异大于12％。
  13. 如权利要求7-12任一项所述的电机转子，其特征在于，所述中心段与相邻的所述过渡段的最小矫顽力的差异为3％-10％。
  14. 如权利要求7-13任一项所述的电机转子，其特征在于，所述永磁体的相邻两段的剩磁差异小于或等于3％。
  15. 如权利要求7-14任一项所述的电机转子，其特征在于，所述中心段与所述端部段之间包括一个过渡段，所述永磁体为五段式结构。
  16. 如权利要求7-14任一项所述的电机转子，其特征在于，所述中心段与所述端部段之间包括两个过渡段，所述永磁体为七段式结构。
  17. 如权利要求7-14任一项所述的电机转子，其特征在于，所述中心段与所述端部段之间包括三个过渡段，所述永磁体为九段式结构。
  18. 如权利要求1-17任一项所述的电机转子，其特征在于，沿矫顽力渐变方向，所述永磁体由中间向两端矫顽力为对称分布或非对称分布。
  19. 如权利要求1-18任一项所述的电机转子，其特征在于，所述转子铁芯上设置有多个磁钢槽，所述多个永磁体一一对应设置于所述多个磁钢槽中。
  20. 如权利要求19所述的电机转子，其特征在于，所述转子铁芯上，所述磁钢槽的两端远离所述转子铁芯的转轴的一侧设有用于固定所述永磁体的定位突起。
  21. 如权利要求20所述的电机转子，其特征在于，所述定位突起的外周面为弧形曲面。
  22. 如权利要求20或21所述的电机转子，其特征在于，所述定位突起的突出尺寸小于或等于所述永磁体在所述定位突起突出方向上的尺寸的1/3。
  23. 如权利要求20-22任一项所述的电机转子，其特征在于，所述转子铁芯上，还设置与所述定位突起相连的凹槽，所述凹槽位于所述定位突起靠近所述磁钢槽中部的一侧。
  24. 如权利要求23所述的电机转子，其特征在于，所述凹槽的开口宽度尺寸小于或等于所述永磁体在所述凹槽的开口延伸方向上的尺寸的1/5。
  25. 如权利要求1-24任一项所述的电机转子，其特征在于，所述多个永磁体的布置方式为一字型、V型、双V型、
    Figure PCTCN2020103671-appb-100001
    型、U型或双U型。
  26. 如权利要求1-25任一项所述的电机转子，其特征在于，所述永磁体为烧结钕铁硼磁体。
  27. 如权利要求1所述的电机转子，其特征在于，所述多个永磁体贴合在所述转子铁芯的外周面上。
  28. 一种电机，其特征在于，包括电机转子和定子，所述电机转子包括权利要求1-27任一项所述的电机转子。
  29. 一种车辆，其特征在于，包括权利要求28所述的电机，所述电机为所述车辆提供驱动力。
  30. 一种电器，其特征在于，包括权利要求28所述的电机，所述电机为所述电器提供驱动力。
PCT/CN2020/103671 2020-07-23 2020-07-23 电机转子和电机 WO2022016437A1 (zh)

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PCT/CN2020/103671 WO2022016437A1 (zh) 2020-07-23 2020-07-23 电机转子和电机
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