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CN-122001121-A - Rotor structure, motor and design method

CN122001121ACN 122001121 ACN122001121 ACN 122001121ACN-122001121-A

Abstract

The invention provides a rotor structure, a motor and a design method, wherein the rotor structure comprises a rotor core, the outer wall of the rotor core is provided with a plurality of protrusions, the protrusions are arranged at intervals along the circumferential direction of the rotor core, a first magnetic steel and a second magnetic steel are arranged between two adjacent protrusions, the first magnetic steel adopts neodymium-iron-boron magnetic steel, and the second magnetic steel adopts neodymium-iron-boron magnetic steel. According to the invention, the technical problems of high cost caused by the adoption of the rare earth permanent magnet in the surface-mounted synchronous motor in the prior art can be solved.

Inventors

  • WANG SHUO
  • XIE FANG
  • YANG YI
  • JIA XIAOLU

Assignees

  • 珠海格力电器股份有限公司

Dates

Publication Date
20260508
Application Date
20251231

Claims (10)

  1. 1. The rotor structure is characterized by comprising a rotor core, wherein a plurality of protrusions (1) are arranged on the outer wall of the rotor core, the protrusions (1) are arranged at intervals along the circumferential direction of the rotor core, a first magnetic steel (2) and a second magnetic steel (3) are arranged between two adjacent protrusions (1), the first magnetic steel (2) is neodymium-iron-boron magnetic steel or ferrite, and the second magnetic steel (3) is neodymium-iron-boron magnetic steel.
  2. 2. The rotor structure according to claim 1, wherein the thickness of the first magnetic steel (2) is greater than the thickness of the second magnetic steel (3) in the radial direction of the rotor core.
  3. 3. The rotor structure according to claim 1, wherein the first magnetic steel (2) and the second magnetic steel (3) are sequentially arranged along the circumferential direction of the rotor core, the cross section of the rotor core is taken as a projection surface, and the outer circumferential walls of the first magnetic steel (2) and the second magnetic steel (3) are overlapped with a circle formed by the outer circumferential walls of the protrusions (1).
  4. 4. The rotor structure according to claim 1, wherein the rotor core is provided with a slot (4), and the slot (4) is located on the d-axis.
  5. 5. An electric machine comprising a rotor structure according to any one of claims 1 to 4.
  6. 6. The method of designing a rotor structure according to any one of claims 1 to 4, characterized in that it is carried out in particular according to the following steps: step 1, calculating a relation between a magnetic flux density fundamental wave component B and permanent magnet angle parameters, wherein the magnetic flux density fundamental wave component B of an empty air gap on a rotor core is B; step 2, obtaining structural parameters and performance parameter expressions of the magnetic density B and the permanent magnet; And step 3, combining the relation in the step 1 and the relation in the step 2 to obtain a constraint expression meeting the requirement that the permanent magnet torque and the reluctance torque reach a peak value under the same current angle.
  7. 7. The method according to claim 6, wherein step 1 is specifically that an air-gap flux density fundamental wave expression is calculated by fourier transformation, and the flux density fundamental wave is composed of sine component and cosine component due to non-odd-even magnetic density fundamental wave Writable do When the fundamental wave coefficient of Fourier The fundamental component can be written further , Is the current angle.
  8. 8. The method according to claim 7, wherein the step 1 further comprises establishing a coordinate system with the center of the rotor core as the origin of coordinates, wherein the Y-axis passes through the center of one of the protrusions (1), and the angle between the Y-axis and one side of the protrusion (1) along the axial direction of the rotor core is The angle between the 1, d axis and the Y axis is 2, The angle between the side of the second magnetic steel facing away from the Y axis and the Y axis is 3; From the following components Obtaining the relation between B and the angle parameter of the permanent magnet ; ; Wherein p is the pole pair number, B1, B2 is the air gap flux density in ideal state The method can obtain the following steps: ; Further, it is possible to obtain: 。
  9. 9. the method according to claim 6, wherein the step 2 is specifically that the magnetic flux density B, the permanent magnet structural parameters and the performance parameter expression are obtained by a magnetic circuit model.
  10. 10. The method according to claim 6, wherein step 2 is specifically performed by combining the relation of step 1 and the relation of step 2, and eliminating B, so as to obtain a constraint expression satisfying the peak value of the permanent magnet torque and the reluctance torque at the same current angle.

Description

Rotor structure, motor and design method Technical Field The invention belongs to the technical field of motors, and particularly relates to a rotor structure, a motor and a design method. Background For the surface-mounted rare earth permanent magnet synchronous motor, the motor has a series of advantages of high power density, high torque density, good speed regulation performance and the like. The electromagnetic torque of the surface-mounted rare earth permanent magnet synchronous motor is only composed of one component of permanent magnet torque, the performance of the surface-mounted rare earth permanent magnet synchronous motor is limited by the performance of rare earth permanent magnets, and the price of the rare earth permanent magnets is high. Two common ways to increase the maximum output torque are to increase the amount of permanent magnets or increase the volume of the motor, and in some occasions, such as a robot joint motor, it is not preferable to increase the volume and increase the amount of permanent magnets. The salient pole-containing surface-mounted permanent magnet synchronous motor has the advantages that the d-q axis inductance is unequal, the torque component of the salient pole-containing surface-mounted permanent magnet synchronous motor consists of a permanent magnet torque component and a reluctance torque component, and the utilization rate of a permanent magnet material is improved. However, the reluctance torque and the permanent magnet torque have a phase difference, and cannot form the maximum electromagnetic torque under the same current angle, so that certain performance waste is caused. Because the surface-mounted synchronous motor in the prior art adopts rare earth permanent magnets and has high cost and other technical problems, the invention designs a rotor structure, a motor and a design method. Disclosure of Invention Therefore, the invention provides a rotor structure, a motor and a design method, which can solve the technical problems of rare earth permanent magnets and high cost of the surface-mounted synchronous motor in the prior art. In order to solve the problems, the invention provides a rotor structure, which comprises a rotor core, wherein a plurality of bulges are arranged on the outer wall of the rotor core, the bulges are arranged at intervals along the circumferential direction of the rotor core, a first magnetic steel and a second magnetic steel are arranged between two adjacent bulges, the first magnetic steel adopts neodymium-iron-boron magnetic steel or ferrite, and the second magnetic steel adopts neodymium-iron-boron magnetic steel. In some embodiments, the thickness of the first magnetic steel is greater than the thickness of the second magnetic steel in the radial direction of the rotor core. In some embodiments, the first magnetic steel and the second magnetic steel are sequentially arranged along the circumferential direction of the rotor core, the cross section of the rotor core is taken as a projection surface, and the peripheral walls of the first magnetic steel and the second magnetic steel are overlapped with a circle formed by the raised peripheral walls. In some embodiments, the rotor core is provided with slots, the slots being located on the d-axis. The invention also provides a motor which comprises the rotor structure. The invention also provides a design method of the rotor structure, which is implemented according to the following steps: step 1, calculating a relation between a magnetic flux density fundamental wave component B and permanent magnet angle parameters, wherein the magnetic flux density fundamental wave component B of an empty air gap on a rotor core is B; step 2, obtaining structural parameters and performance parameter expressions of the magnetic density B and the permanent magnet; And step 3, combining the relation in the step 1 and the relation in the step 2 to obtain a constraint expression meeting the requirement that the permanent magnet torque and the reluctance torque reach a peak value under the same current angle. In some embodiments, the step 1 is specifically that the air-gap flux density fundamental wave expression is calculated through fourier transformation, and the flux density fundamental wave is composed of sine component and cosine component due to non-odd-even magnetic density fundamental waveWritable doWhen the fundamental wave coefficient of FourierThe fundamental component can be written further,Is the current angle. In some embodiments, the step 1 further includes establishing a coordinate system with the center of the rotor core as a coordinate origin, wherein the Y axis passes through the center of one of the protrusions, and an angle between the Y axis and one side of the protrusion isThe angle between the 1, d axis and the Y axis is2, The angle between the side of the second magnetic steel facing away from the Y axis and the Y axis is3; From the following componentsAnd obtaining a rela