Asymmetric rotor structure and permanent magnet motor thereof

Abstract

The invention discloses an asymmetric rotor structure and a permanent magnet motor thereof. The asymmetric rotor structure comprises a first iron core, a second iron core, a rotating shaft and magnetic steel. The first iron core comprises a plurality of preset areas, each preset area is provided with a first installation groove, a first magnetic barrier and a second magnetic barrier, and the first magnetic barrier and the second magnetic barrier communicate with the two ends of the first installation groove correspondingly. The second iron cores and the first iron cores are of a mirror symmetry structure, and the number of the second iron cores is consistent with that of the first iron cores. The magnetic steel is installed in one first installation groove of each first iron core, and the magnetic steel penetrates through all the second iron cores and is fixed to the second iron cores. The first iron cores located on the two sides of the symmetry plane are symmetrically arranged about the symmetry plane, and the second iron cores located on the two sides of the symmetry plane are symmetrically arranged about the symmetry plane. The permanent magnet motor comprises the asymmetric rotor structure. Through the arrangement, the torque pulsation, the vibration noise and the axial unbalanced force generated by the permanent magnet motor can be reduced, and the operation reliability of the permanent magnet motor is improved.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to an asymmetric rotor structure and a permanent magnet motor thereof. Background Art

[0002] Permanent magnet motor is a motor that uses magnetic steel to generate excitation magnetic field. It has many advantages such as high power density, high efficiency, wide speed regulation range, etc. It is widely used in many fields such as industrial servo, electrified transportation, aerospace, etc. Vibration noise, as an important performance indicator, will significantly affect the operating reliability of permanent magnet synchronous motor. Therefore, suppressing the vibration noise of permanent magnet synchronous motor is conducive to further improving its operating efficiency and service life, and can effectively improve the stability, reliability and performance level of the motor system.

[0003] At present, in order to suppress the vibration noise of permanent magnet synchronous motors, common motor topologies include: skew slot and skew pole structure, asymmetric motor structure, etc. However, all existing topologies have certain limitations due to their own structural characteristics. For example, in addition to significantly increasing the process complexity and motor production cost, the skew slot and skew pole structure may also cause additional axial unbalanced magnetic pull, thereby aggravating motor bearing damage and shortening the service life, which in turn leads to increased motor vibration noise; the asymmetric motor structure may destroy the symmetry and periodicity of the motor magnetic circuit, generate additional spatial order air gap magnetic field harmonics and electromagnetic force harmonics, and even cause radial or axial unbalanced magnetic pull, thereby increasing the vibration noise of the motor.

[0004] Therefore, how to reduce the vibration noise of the permanent magnet motor to improve the operating reliability of the permanent magnet motor is a technical problem that technicians in this field urgently need to solve. Summary of the invention

[0005] In order to solve the deficiencies of the prior art, the purpose of the present application is to provide an asymmetric rotor structure and a permanent magnet motor thereof, which have lower vibration noise and higher operating reliability.

[0006] To achieve the above objectives, this application adopts the following technical solutions: An asymmetric rotor structure includes a first iron core, a second iron core, a rotating shaft and a magnetic steel, wherein the first iron core, the second iron core and the magnetic steel are provided in plurality. Each first iron core is cylindrical, each first iron core includes a plurality of preset areas, the plurality of preset areas are arranged around the axis of the first iron core, each preset area is provided with a first mounting groove, a first magnetic barrier and a second magnetic barrier, the first mounting groove, the first magnetic barrier and the second magnetic barrier are all arranged to penetrate the first iron core along the axis of the first iron core, the first magnetic barrier and the second magnetic barrier are respectively connected to the two ends of the first mounting groove, the first mounting groove extends along the direction of a preset straight line, the first magnetic barrier extends along the direction of the first straight line, the second magnetic barrier extends along the direction of the second straight line, and a projection plane perpendicular to the axis of the first iron core is defined, the orthographic projection of the first straight line on the projection plane is the first projection line, the orthographic projection of the second straight line on the projection plane is the second projection line, the orthographic projection of the preset straight line on the projection plane is the preset projection line, and the angle between the first projection line and the preset projection line is different from the angle between the second projection line and the preset projection line. The second core and the first core are mirror-symmetrical structures, and the number of the second cores is the same as that of the first cores. Each magnet is installed in a first installation slot of each first core, and each magnet is passed through all second cores and fixed to the second cores. A symmetry plane perpendicular to the axial direction of the first core is defined, the symmetry plane bisects the asymmetric rotor structure, at least one first core and at least one second core are arranged on both sides of the symmetry plane, the first cores on both sides of the symmetry plane are arranged symmetrically about the symmetry plane, and the second cores on both sides of the symmetry plane are arranged symmetrically about the symmetry plane.

[0007] Furthermore, the second iron core is provided with a plurality of second mounting grooves, each second mounting groove corresponds to a first mounting groove, and each magnetic steel is installed in a first mounting groove of each first iron core and a second mounting groove of each second iron core corresponding to the first mounting groove.

[0008] Furthermore, the asymmetric rotor structure also includes a magnetic isolation plate, a plurality of magnetic isolation plates are provided, and the magnetic isolation plates are made of non-magnetic conductive material. If the first iron core and the second iron core are arranged adjacent to each other, a magnetic isolation plate is provided between the adjacent first iron core and the second iron core, and the magnetic isolation plate is fixed to the adjacent first iron core and the second iron core.

[0009] Furthermore, each magnetic isolation plate is provided with a plurality of third mounting grooves, each third mounting groove corresponds to a first mounting groove, each magnetic steel is installed in a first mounting groove of each first iron core and a third mounting groove of each magnetic isolation plate corresponding to the first mounting groove. The rotating shaft is provided through the plurality of first iron cores, the plurality of second iron cores and the plurality of magnetic isolation plates, and is fixed to the plurality of first iron cores, the plurality of second iron cores and the plurality of magnetic isolation plates.

[0010] Furthermore, the number of the second iron cores and the number of the first iron cores are both multiples of 2.

[0011] Furthermore, the total length of all the first cores along the axial direction of the first cores is equal to the total length of all the second cores along the axial direction of the first cores.

[0012] Further, the diameter of the first iron core perpendicular to the preset straight line is defined as the bisect diameter, the bisect diameter bisects the first installation slot, and the first magnetic barrier and the second magnetic barrier are located on both sides of the bisect diameter; the end face of the first magnetic barrier away from the first installation slot is defined as the first end face, the end face of the second magnetic barrier away from the first installation slot is defined as the second end face, the orthographic projection of the first end face on the projection plane is the first end face projection, the orthographic projection of the second end face on the projection plane is the second end face projection, the orthographic projection of the axis of the first iron core on the projection plane is the axis projection point, the line connecting the midpoint of the first end face projection and the axis projection point is the first line, the line connecting the midpoint of the second end face projection and the axis projection point is the second line, the orthographic projection of the bisect diameter on the projection plane is the diameter projection line, the acute angle between the first line and the diameter projection line is the first angle, the acute angle between the second line and the diameter projection line is the second angle, and the angle of the first angle is different from the angle of the second angle. When the first angle is greater than the second angle, if the first connecting line rotates around the axis projection point toward the straight line projection line at a preset angle, and the second connecting line rotates around the axis projection point away from the straight line projection line at a preset angle, the diameter projection line bisects the angle formed by the first connecting line and the second connecting line.

[0013] Furthermore, the asymmetric rotor structure also includes a fastener and two end pressure plates made of non-magnetic conductive materials, all the first iron cores and all the second iron cores are located between the two end pressure plates, the end pressure plates are provided with fixing holes, the fasteners are passed through the fixing holes and fixedly connected to the first iron core or the second iron core adjacent to the end pressure plates. The rotating shaft passes through the plurality of first iron cores, the plurality of second iron cores and the two end pressure plates, and is fixed to the plurality of first iron cores, the plurality of second iron cores and the two end pressure plates.

[0014] Furthermore, a plurality of preset areas are uniformly arranged around the axis of the first core along the circumference of the first core. The extension direction of the first installation slots of the plurality of preset areas is perpendicular to the extension direction of a diameter of the first core, and the angles between the two diameters corresponding to each two adjacent first installation slots are consistent.

[0015] To achieve the above objectives, this application adopts the following technical solutions: A permanent magnet motor comprises the above-mentioned asymmetric rotor structure.

[0016] The above-mentioned asymmetric rotor structure and permanent magnet motor thereof improve the electromagnetic force harmonics of the permanent magnet motor through the asymmetrically arranged first and second magnetic barriers and the mirror-symmetrically arranged first iron core and second iron core, so that the torque pulsation and electromagnetic vibration generated by the first iron core and the torque pulsation and electromagnetic vibration generated by the second iron core offset each other, thereby reducing the vibration noise generated during the operation of the permanent magnet motor; at the same time, the axial unbalanced magnetic pull of the motor is eliminated by the first iron core symmetrically arranged along the symmetric plane and the second iron core symmetrically arranged along the symmetric plane, thereby improving the operation reliability of the permanent magnet motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of the asymmetric rotor provided in an embodiment of the present application.

[0018] Figure 2 An exploded view of an asymmetric rotor structure provided in an embodiment of the present application.

[0019] Figure 3 A schematic structural diagram of the first iron core of the asymmetric rotor structure provided in an embodiment of the present application.

[0020] Figure 4 The cogging torque time domain waveform diagram of the asymmetric rotor structure and the symmetric rotor structure provided in the embodiments of the present application.

[0021] Figure 5 A diagram of the cogging torque harmonic amplitude of an asymmetric rotor structure and a symmetric rotor structure provided in an embodiment of the present application.

[0022] Figure 6 Time domain waveform diagram of load torque of the asymmetric rotor structure and the symmetric rotor structure provided in the embodiments of the present application.

[0023] Figure 7 A load torque harmonic amplitude diagram of an asymmetric rotor structure and a symmetric rotor structure provided in an embodiment of the present application.

[0024] Figure 8 The electromagnetic vibration amplitude diagram of the asymmetric rotor structure and the symmetric rotor structure provided in the embodiments of the present application.

[0025] Fig. 9 A schematic diagram of a preset angle of a first iron core of an asymmetric rotor structure provided in an embodiment of the present application.

[0026] Fig.10 The time domain waveform diagram of the line back electromotive force of the asymmetric rotor structure and the symmetric rotor structure provided in the embodiments of the present application.

[0027] Fig.11 Line back electromotive force harmonic amplitude diagram of the asymmetric rotor structure and the symmetric rotor structure provided in the embodiments of the present application.

[0028] Fig.12 A schematic structural diagram of the second core of the asymmetric rotor structure provided in an embodiment of the present application.

[0029] Fig.13 A schematic structural diagram of a magnetic isolation plate of an asymmetric rotor structure provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the specific implementation manner of the present application will be clearly and completely described below in conjunction with the drawings in the implementation manner of the present application.

[0031] It should be noted that the words "first", "second" and similar words used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "an" do not indicate a quantity limitation, but indicate the existence of at least one. "Multiple" or "several" means at least two. Words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprises" include the elements or objects listed after "include" or "comprises" and their equivalents, and do not exclude other elements or objects. Words such as "connected" or "connected" and similar words are not limited to physical or mechanical connections, and may include electrical connections, whether direct or indirect.

[0032] The singular forms "a", "said" and "the" used in this specification and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0033] like Figure 1 and Figure 2 As shown, the present application provides an asymmetric rotor structure 100, which can improve the electromagnetic force harmonics of the permanent magnet motor using the asymmetric rotor structure 100, and can suppress the torque pulsation, electromagnetic vibration and axial unbalanced magnetic pull of the permanent magnet motor, thereby reducing the vibration noise generated during the operation of the permanent magnet motor and improving the operation reliability of the permanent magnet motor.

[0034] Specifically, the asymmetric rotor structure 100 includes a plurality of first iron cores 11 , a plurality of second iron cores 12 , a rotating shaft 13 and a plurality of magnetic steels 14 .

[0035] The rotating shaft 13 is passed through the plurality of first cores 11 and the plurality of second cores 12, and is fixed to the plurality of first cores 11 and the plurality of second cores 12, thereby forming the basic framework of the asymmetric rotor structure 100. It should be noted that the rotating shaft 13, the plurality of first cores 11, and the plurality of second cores 12 rotate synchronously. The plurality of magnetic steels 14 are passed through the plurality of first cores 11 and the plurality of second cores 12, and are fixed to the plurality of first cores 11 and the plurality of second cores 12. The magnetic steels 14 can be made of permanent magnetic materials (such as neodymium iron boron, samarium cobalt, ferrite, etc.), and are arranged alternately in the order of N pole and S pole along the circumference of the rotating shaft 13.

[0036] Exemplarily, the rotating shaft 13 and the plurality of first cores 11 and the plurality of second cores 12 can be connected by interference fit; or, the rotating shaft 13 and the plurality of first cores 11 and the plurality of second cores 12 can be connected by key slots or key fit, which is not limited in this application. Specifically, the plurality of first cores 11 and the plurality of second cores 12 are each provided with an axial hole, and the rotating shaft 13 can be passed through the axial holes of the plurality of first cores 11 and the plurality of second cores 12.

[0037] Exemplarily, the first core 11 and the second core 12 are mirror-symmetrical structures, that is, the second core 12 can be considered to be formed by the mirror symmetry of the first core 11, so the structures of the first core 11 and the second core 12 are consistent. In the present application, the first core 11 and the second core 12 can be processed by the same set of stamping dies, and the second core 12 can be obtained by rotating the first core 11 180° around a straight line where a certain diameter of the first core 11 is located. Through the above arrangement, the processing efficiency of the first core 11 and the second core 12 can be improved, and the processing cost of the first core 11 and the second core 12 can be reduced.

[0038] It should be noted that the first core 11 and the second core 12 can be formed by stacking silicon steel sheets; or, the first core 11 and the second core 12 can be made by processing soft magnetic composite materials; or, the first core 11 and the second core 12 can be made by processing amorphous alloys, and this application does not impose any restrictions.

[0039] This application takes the structure of the first iron core 11 as an example for explanation, and the structure of the second iron core 12 is not described in detail.

[0040] like Figure 2 and Figure 3As shown, as an implementation method, each first iron core 11 is cylindrical, and each first iron core 11 includes a plurality of preset areas 111, and the plurality of preset areas 111 are arranged around the axis of the first iron core 11, and each preset area 111 is provided with a first mounting groove 112, a first magnetic barrier 113 and a second magnetic barrier 114, and the first mounting groove 112, the first magnetic barrier 113 and the second magnetic barrier 114 are all arranged along the axis of the first iron core 11, and the first magnetic barrier 113 and the second magnetic barrier 114 are respectively connected to the two ends of the first mounting groove 112.

[0041] The first magnetic barrier 113 and the second magnetic barrier 114 are used to optimize the magnetic circuit design and improve the performance of the permanent magnet motor using the asymmetric rotor structure 100. By designing a multi-layer magnetic barrier structure, the magnetic resistance torque can be fully utilized, thereby improving the torque density and power density of the permanent magnet motor using the asymmetric rotor structure 100.

[0042] Specifically, each magnetic steel 14 is installed in a first installation slot 112 of each first iron core 11 , and each magnetic steel 14 passes through all the second iron cores 12 and is fixed to the second iron cores 12 .

[0043] More specifically, the first mounting groove 112 extends in the direction of the preset straight line 101, the first magnetic barrier 113 extends in the direction of the first straight line 102, and the second magnetic barrier 114 extends in the direction of the second straight line 103, defining a projection plane 104 perpendicular to the axial direction of the first core 11, the orthographic projection of the first straight line 102 on the projection plane 104 is the first projection line, the orthographic projection of the second straight line 103 on the projection plane 104 is the second projection line, the orthographic projection of the preset straight line 101 on the projection plane 104 is the preset projection line, and the angle between the first projection line and the preset projection line is different from the angle between the second projection line and the preset projection line. Through the above arrangement, the first magnetic barrier 113 and the second magnetic barrier 114 can be relatively offset to realize the asymmetric rotor structure 100 of the present application.

[0044] like Figures 4 to 9As shown, compared with the traditional symmetrical rotor structure, in the asymmetric rotor structure 100 involved in the present application, the ends of the first magnetic barrier 113 and the second magnetic barrier 114 of the first core 11 are centered on the axis of the rotating shaft 13, and are offset by a preset angle in the counterclockwise direction; the ends of the two magnetic barriers of the second core 12 are centered on the axis of the rotating shaft 13, and are offset by a preset angle in the clockwise direction, so that the phase difference of the cogging torque, torque pulsation and electromagnetic vibration generated by the first core 11 and the second core 12 can be effectively adjusted, so that the cogging torque, torque pulsation and electromagnetic vibration generated by the first core 11 and the second core 12 offset each other, thereby reducing the overall cogging torque, torque pulsation and electromagnetic vibration of the permanent magnet motor using the asymmetric rotor structure 100, and then improving the NVH (noise, vibration and harshness) performance of the permanent magnet motor.

[0045] It should be noted that the ends of the first magnetic barrier 113 and the second magnetic barrier 114 refer to the ends of the first magnetic barrier 113 and the second magnetic barrier 114 away from the first mounting groove 112 .

[0046] It should be noted that if Fig. 9 As shown, the principles and steps for selecting the preset angle are as follows: In the asymmetric rotor structure 100 involved in the present invention, the first magnetic barrier 113 and the second magnetic barrier 114 have a modulation effect on the air gap magnetic field. The expression of the air gap magnetic field is related to the offset angle (i.e., the preset angle) of the first magnetic barrier 113 and the second magnetic barrier 114. The above offset angle is defined as .

[0047] The air gap magnetic field generated by the first iron core 11 and the second iron core 12 can be expressed as equation (1) and equation (2) respectively: (1) (2) in, is the radial air gap magnetic field generated by the first core 11, is the tangential air gap magnetic field generated by the first core 11, is the radial air gap magnetic field generated by the second core 12, is the tangential air gap magnetic field generated by the second core 12, is the harmonic amplitude of the radial air gap magnetic field, is the harmonic amplitude of the tangential air gap magnetic field, is the number of pole pairs of the permanent magnet motor, is the number of slots in the permanent magnet motor, is the rotational mechanical angular frequency of the permanent magnet motor, is the radius of the circle where the air gap magnetic field is located, is the spatial position angle, For time, The variable that identifies the rotation direction of the permanent magnet motor, is the harmonic order of the exciting magnetic field of the magnet 14, is the harmonic order of the air gap permeance generated by the stator slot opening of the permanent magnet motor, is the harmonic order of the air gap permeability generated by the first magnetic barrier 113 and the second magnetic barrier 114 .

[0048] According to the Maxwell stress tensor method, the relationship between the electromagnetic force and the air gap magnetic field in a permanent magnet motor can be expressed as formula (3): (3) in, is the radial electromagnetic force, is the tangential electromagnetic force, is the radial air gap magnetic field, is the tangential air gap magnetic field, is the magnetic permeability of vacuum.

[0049] Substituting equations (1) and (2) into equation (3), respectively, we can derive the radial and tangential electromagnetic force expressions generated by the first iron core 11 and the second iron core 12, namely equations (4) and (5): (4) (5) in, is the radial electromagnetic force generated by the first core 11, is the tangential electromagnetic force generated by the first core 11, is the radial electromagnetic force generated by the second core 12, is the tangential electromagnetic force generated by the second core 12, is the harmonic amplitude of the radial electromagnetic force, is the harmonic amplitude of the tangential electromagnetic force, is the harmonic order of the exciting magnetic field of the magnet 14, is the harmonic order of the exciting magnetic field of the magnet 14, is the harmonic order of the air gap permeance generated by the stator slot opening of the permanent magnet motor, is the harmonic order of the air gap permeance generated by the stator slot opening of the permanent magnet motor, is the harmonic order of the air gap permeance generated by the first magnetic barrier 113 and the second magnetic barrier 114, is the harmonic order of the air gap permeability generated by the first magnetic barrier 113 and the second magnetic barrier 114 .

[0050] The tangential electromagnetic force is the excitation source of the motor torque. The motor torque can be The calculation is performed by integrating the loop along the circumferential direction of the air gap. Therefore, the cogging torque of the permanent magnet motor can be expressed as formula (6): (6) in, is the cogging torque of the permanent magnet motor, is the effective stack length of the permanent magnet motor, is the air gap radius of the permanent magnet motor.

[0051] Substituting equations (4) and (5) into equation (6), the cogging torque expression generated by the first iron core 11 and the second iron core 12 can be derived, that is, equation (7): (7) in, is the cogging torque generated by the first core 11, is the cogging torque generated by the second core 12, which can be further simplified as formula (8): (8) in, is the harmonic order of the cogging torque, is the number of poles of the permanent magnet motor and number of slots The least common multiple of .

[0052] In order to weaken the harmonic order by using the torque phase difference generated by the first iron core 11 and the second iron core 12 The torque harmonic component, the offset angle of the first magnetic barrier 113 and the second magnetic barrier 114 The conditions in formula (9) must be met: (9).

[0053] Therefore, the offset angles of the first magnetic barrier 113 and the second magnetic barrier 114 are It can be expressed as formula (10): (10).

[0054] like Fig.10 and Fig.11 As shown, through the above settings, the offset angles of the first magnetic barrier 113 and the second magnetic barrier 114 can be obtained. , so that the offset first magnetic barrier 113 and the second magnetic barrier 114 can have a phase shift effect on the air gap magnetic field harmonics of the permanent magnet motor using the asymmetric rotor structure 100. The phase shift effect makes the phases of the line back electromotive force harmonics generated by the first iron core 11 and the second iron core 12 inconsistent. Since the number of the second iron core 12 of the present application is the same as that of the first iron core 11, the fifth and seventh time harmonics in the line back electromotive force of the permanent magnet motor can be significantly weakened, and the sinusoidality of the line back electromotive force waveform of the permanent magnet motor can be improved, thereby improving the line back electromotive force of the permanent magnet motor. At the same time, the phase shift effect makes the phases of the cogging torque and torque pulsation harmonics generated by the first iron core 11 and the second iron core 12 inconsistent. Since the number of the second iron core 12 of the present application is the same as that of the first iron core 11, the cogging torque and torque pulsation of the permanent magnet motor can be significantly weakened, and there will be no difference in the torque performance of the permanent magnet motor during forward and reverse rotation.

[0055] In addition, since the asymmetric rotor structure 100 has an offset effect on the air gap magnetic field, the actual axis of the demagnetization magnetic field generated by the d-axis demagnetization current does not coincide with the d-axis axis of the magnetic steel 14. Therefore, the actual d-axis demagnetization magnetic field borne by the magnetic steel 14 in the asymmetric rotor structure 100 is smaller and less prone to demagnetization, so that the permanent magnet motor using the asymmetric rotor structure 100 has a stronger anti-demagnetization capability.

[0056] In this embodiment, the asymmetric rotor structure 100 may cause inconsistency in the axial magnetic circuit of the permanent magnet motor, which may cause axial unbalanced magnetic pulling force, thereby aggravating bearing damage of the permanent magnet motor and shortening its service life.

[0057] To avoid the above problems, Figure 2 and Figure 3 As shown, a symmetry plane 105 perpendicular to the axial direction of the first iron core 11 is defined, the symmetry plane 105 divides the asymmetric rotor structure 100 in half, at least one first iron core 11 and at least one second iron core 12 are arranged on both sides of the symmetry plane 105, the first iron cores 11 on both sides of the symmetry plane 105 are symmetrically arranged about the symmetry plane 105, and the second iron cores 12 on both sides of the symmetry plane 105 are symmetrically arranged about the symmetry plane 105. Through the above arrangement, the number of the first iron cores 11 on both sides of the symmetry plane 105 can be made consistent, and the number of the second iron cores 12 on both sides of the symmetry plane 105 can be made consistent, thereby eliminating the axial unbalanced magnetic pull.

[0058] In addition, in the present application, the modulation effect of the asymmetrically arranged first magnetic barrier 113 and the second magnetic barrier 114 will only change the phase of the electromagnetic force harmonics, and will not change the specific time and space orders of the electromagnetic force harmonics, nor will it introduce additional electromagnetic force low-order spatial harmonics, and thus will not cause the problem of worsening electromagnetic vibration of the low-order mode of the permanent magnet motor.

[0059] At the same time, through the asymmetrical arrangement of the first magnetic barrier 113 and the second magnetic barrier 114 and the mirror-symmetrical arrangement of the first iron core 11 and the second iron core 12, the electromagnetic vibration generated by the first iron core 11 and the electromagnetic vibration generated by the second iron core 12 can offset each other, thereby reducing the vibration noise generated during the operation of the permanent magnet motor and improving the operating reliability and comfort of the permanent magnet motor.

[0060] The present application involves a permanent magnet motor using an asymmetric rotor structure 100, wherein the electromagnetic force harmonics generated by the first iron core 11 and the second iron core 12 of the asymmetric rotor structure 100 have different phases, and thus the electromagnetic vibration phases generated by the first iron core 11 and the second iron core 12 are also inconsistent, so that the electromagnetic vibrations generated by the first iron core 11 and the second iron core 12 can offset each other to a certain extent, thereby effectively suppressing the electromagnetic vibration of the motor as a whole, thereby reducing the vibration noise generated during the operation of the permanent magnet motor and improving the operation reliability and use comfort of the permanent magnet motor.

[0061] It should be noted that for the traditional segmented skewed pole rotor, the skew angle between each segment of the core needs to be controlled by a positioning tool. On the one hand, the positioning tool will increase the complexity and processing cost of the stacking process of the permanent magnet motor; on the other hand, the accuracy of the positioning tool has a significant impact on the performance of the permanent magnet motor, and will increase the inconsistency of the motor performance introduced by the stacking process. In particular, when the number of poles of the permanent magnet motor is large, the optimal skew angle is generally small, and the segmented skewed pole rotor has higher requirements for the accuracy of the positioning tool. For the asymmetric rotor structure 100 involved in the present application, the first core 11 and the second core 12 are mirror-symmetrical, so the stacking process does not require additional positioning tooling, which can effectively reduce the complexity of the process, save processing costs, and improve the performance consistency of the permanent magnet motor.

[0062] It should be noted that when the stack length of the permanent magnet motor remains constant, for the traditional segmented skew-pole motor rotor, the adjustment of the number of axial segments will cause the magnetic steel and the positioning tooling to be adjusted accordingly, resulting in additional processing and production costs. For the asymmetric rotor structure 100 involved in the present application, the number of axial segments of the first core 11 and the second core 12 can be flexibly adjusted, that is, the number and stack length of the first core 11 and the second core 12 can be adjusted, and will not cause the above problems. Among them, the stack length refers to the total length of the rotor core. For the asymmetric rotor structure 100 in the present application, the stack length refers to the total length of the first core 11 and the second core 12 along the axial direction of the first core 11.

[0063] It should be noted that in the traditional segmented skewed pole rotor, there are angular differences in the positions of the mounting grooves of the magnetic steel in each segment of the core, so the number of axial segments of the magnetic steel needs to be equal to the number of axial segments of the core, further increasing the complexity and processing cost of the slicing finishing, dimensional inspection, and electroplating processes in the magnetic steel production process. And when performing the magnetic steel assembly process, it is necessary to first insert the magnetic steel into the mounting groove, and then perform the skewed pole operation through the positioning tooling, so the magnetism of the magnetic steel will cause great inconvenience to the skewed pole operation. In the asymmetric rotor structure 100 involved in the present application, the structures of the first core 11 and the second core 12 are consistent, so the second core 12 also has a second mounting groove 121 that is consistent with the first mounting groove 112, and the positions of the first mounting groove 112 and the second mounting groove 121 are completely consistent, so the magnetic steel 14 does not need to be additionally segmented axially, and the magnetic steel 14 can be directly inserted after the lamination process of the first core 11 and the second core 12 is completed. In addition, since the magnetic steel 14 has no additional axial segmentation, the number of assembly times is significantly reduced, which can effectively reduce the process complexity and save processing costs.

[0064] In addition, in the traditional segmented skew-pole rotor, the positions of the magnetic steels in each rotor segment are inconsistent, and the magnetic steels in a certain rotor segment will contact the iron core in the adjacent rotor segment, thereby generating serious axial magnetic leakage in the radial magnetic rib area, thereby causing the torque output capacity of the permanent magnet motor to decrease. In the asymmetric rotor structure 100 involved in the present application, the positions of the magnetic steels 14 in the first iron core 11 and the second iron core 12 are completely consistent, and the magnetic steels 14 in the first iron core 11 and the second iron core 12 will not contact the adjacent first iron core 11 or second iron core 12, so that the axial magnetic leakage in the radial magnetic rib area is significantly reduced. In addition, in the asymmetric rotor structure 100 involved in the present application, a magnetic isolation plate 15 made of non-magnetic material is also installed between the first iron core 11 and the second iron core 12, so that the axial magnetic leakage is further reduced, which is beneficial to the improvement of the torque output capacity of the motor.

[0065] It should be noted that the permanent magnet motor rotor will generate large centrifugal stress when rotating at high speed. In traditional rotors, the stress is mainly concentrated at the circumferential magnetic bridge position. The asymmetric rotor structure 100 involved in the present application can effectively increase the stress-bearing area, which helps to alleviate the situation of excessive local stress. In addition, in the asymmetric rotor structure 100 involved in the present application, two adjacent sections of the iron core form a stable triangular area at the radial magnetic rib position, which helps to improve stress and deformation, and can improve the mechanical strength of the asymmetric rotor structure 100 to a certain extent, reduce the risk of structural and material failure, and increase the safety and reliability of the permanent magnet motor using the asymmetric rotor structure 100 under high-speed operating conditions.

[0066] like Figure 3 and Fig.12As shown, as an implementation method, the second core 12 is provided with a plurality of second mounting grooves 121, each second mounting groove 121 corresponds to a first mounting groove 112, and each magnetic steel 14 is installed in a first mounting groove 112 of each first core 11 and a second mounting groove 121 of each second core 12 corresponding to the first mounting groove 112. Through the above arrangement, the positions of the first mounting groove 112 and the second mounting groove 121 can be completely consistent, so the magnetic steel 14 does not need to be additionally segmented in the axial direction, and the magnetic steel 14 can be directly inserted after the lamination process of the first core 11 and the second core 12 is completed. In addition, since the magnetic steel 14 has no additional axial segmentation, the number of assembly times is significantly reduced, which can effectively reduce the process complexity and save processing costs. In addition, the magnetic steel 14 in the first core 11 will not contact the adjacent second core 12, and the magnetic steel in the second core 12 will not contact the adjacent first core 11, so the axial leakage magnetic flux of the asymmetric rotor structure 100 at the radial magnetic rib position is significantly reduced.

[0067] like Figure 2 , Figure 3 and Fig.13 As shown, as an implementation, the asymmetric rotor structure 100 further includes a plurality of magnetic isolation plates 15 made of non-magnetic conductive material.

[0068] For example, if the first core 11 and the second core 12 are arranged adjacent to each other, a magnetic isolation plate 15 is arranged between the adjacent first core 11 and the second core 12, and the magnetic isolation plate 15 is fixed to the adjacent first core 11 and the second core 12, the axial magnetic leakage between the first core 11 and the second core 12 can be further reduced, and the torque output of the permanent magnet motor using the asymmetric rotor structure 100 can be improved. In order to improve the mechanical strength of the asymmetric rotor structure 100, the first core 11 and the magnetic isolation plate 15, and the second core 12 and the magnetic isolation plate 15 can be connected and fixed by gluing.

[0069] As an implementation method, each magnetic isolation plate 15 is provided with a plurality of third mounting grooves 151, each third mounting groove 151 corresponds to a first mounting groove 112, and each magnetic steel 14 is installed in a first mounting groove 112 of each first iron core 11 and a third mounting groove 151 of each magnetic isolation plate 15 corresponding to the first mounting groove 112. Among them, the rotating shaft 13 is passed through the plurality of first iron cores 11, the plurality of second iron cores 12 and the plurality of magnetic isolation plates 15, and is fixed to the plurality of first iron cores 11, the plurality of second iron cores 12 and the plurality of magnetic isolation plates 15. Through the above arrangement, the positions of the first mounting groove 112, the second mounting groove 121 and the third mounting groove 151 can be completely consistent, so the magnetic steel 14 does not need to be additionally segmented in the axial direction, and the magnetic steel 14 can be directly inserted after the lamination process of the first iron core 11, the second iron core 12 and the magnetic isolation plate 15 is completed. In addition, since the magnetic steel 14 has no additional axial segmentation, the number of assembly times is significantly reduced, which can effectively reduce the process complexity and save processing costs. Furthermore, the first iron core 11 will not contact the second iron core 12, so the axial magnetic leakage at the radial magnetic rib portion is significantly reduced.

[0070] As an optional implementation, the number of the second cores 12 and the number of the first cores 11 are both multiples of 2. That is, the total number of the first cores 11 and the second cores 12 can be a multiple of 4.

[0071] For example, the number of the first core 11 and the number of the second core 12 are both 2. From one end to the other end of the rotating shaft 13 along its axial direction, the arrangement of the two first cores 11 and the two second cores 12 is: first core 11-second core 12-second core 12-first core 11, or, second core 12-first core 11-first core 11-second core 12.

[0072] Exemplarily, the description is given assuming that the number of the first iron core 11 and the number of the second iron core 12 are both 4. From one end to the other end of the rotating shaft 13 along its axial direction, the arrangement of the four first cores 11 and the four second cores 12 is: first core 11-second core 12-second core 12-first core 11-first core 11-second core 12-second core 12-first core 11, or, second core 12-first core 11-first core 11-second core 12-second core 12-first core 11-first core 11-second core 12, or, first core 11-second core 12-first core 11-second core 12-second core 12-first core 11-second core 12-first core 11-second core 12-first core 11, or, second core 12-first core 11-second core 12-first core 11-first core 11-second core 12-first core 11-second core 12.

[0073] Through the above arrangement, the torque pulsation generated by the first iron core 11 and the second iron core 12 can be offset by the mirror-symmetrical arrangement of the first iron core 11 and the second iron core 12, and the electromagnetic vibration generated by the first iron core 11 and the electromagnetic vibration generated by the second iron core 12 can be offset by each other, thereby reducing the vibration noise generated during the operation of the permanent magnet motor and improving the operation reliability and comfort of the permanent magnet motor. At the same time, the electromagnetic force harmonics received by the first iron core 11 and the second iron core 12 have different phases, so the electromagnetic vibration phases generated by the first iron core 11 and the second iron core 12 are also inconsistent, so that the electromagnetic vibrations generated by the first iron core 11 and the second iron core 12 can offset each other to a certain extent, thereby effectively suppressing the electromagnetic vibration of the motor as a whole, thereby reducing the vibration noise generated during the operation of the permanent magnet motor and improving the operation reliability and comfort of the permanent magnet motor.

[0074] In this embodiment, the length of a single first core 11 along the axial direction of the first core 11 and the length of a single second core 12 along the axial direction of the first core 11 may be inconsistent, that is, it is only necessary to satisfy that the total length of all first cores 11 along the axial direction of the first core 11 is equal to the total length of all second cores 12 along the axial direction of the first core 11. Through the above configuration, the lengths of the first core 11 and the second core 12 can be adjusted according to actual needs, thereby increasing the diversity of the asymmetric rotor structure 100 to meet the structural requirements and usage requirements of different permanent magnet motors.

[0075] like Figure 3 and Fig. 9 As shown, as an implementation method, the diameter of the first core 11 perpendicular to the preset straight line 101 is defined as the bisecting diameter 106, the bisecting diameter 106 bisects the first mounting slot 112, and the first magnetic barrier 113 and the second magnetic barrier 114 are located on both sides of the bisecting diameter 106. The end face of the first magnetic barrier 113 away from the first mounting slot 112 is defined as the first end face, the end face of the second magnetic barrier 114 away from the first mounting slot 112 is defined as the second end face, the orthographic projection of the first end face on the projection plane 104 is the first end face projection, the orthographic projection of the second end face on the projection plane 104 is the second end face projection, the orthographic projection of the axis of the first core 11 on the projection plane 104 is the axis projection point, the line connecting the midpoint of the first end face projection and the axis projection point is the first connecting line, the line connecting the midpoint of the second end face projection and the axis projection point is the second connecting line, the orthographic projection of the bisecting diameter 106 on the projection plane 104 is the diameter projection line, and the acute angle between the first connecting line and the diameter projection line is the first included angle , the acute angle between the second connecting line and the diameter projection line is the second included angle , the first angle The angle is different from the second angle angle.

[0076] It should be noted that at the first angle Greater than the second angle In the case of , if the first connecting line rotates around the axis projection point to the projection line close to the straight line by a preset angle , and the second connecting line rotates around the axis projection point away from the straight line projection line by a preset angle , the diameter projection line bisects the angle between the first connecting line and the second connecting line. Among them, the preset angle The calculation of has been described above and will not be repeated here.

[0077] Compared with the conventional symmetrical rotor structure, in the asymmetrical rotor structure 100 involved in the present application, The end of the first magnetic barrier 113 of the first core 11 (i.e., the end where the first end face is located) and the end of the second magnetic barrier 114 of the first core 11 (i.e., the end where the second end face is located) are both centered on the axis of the rotating shaft 13 and are offset by a preset angle in the counterclockwise direction. The ends of the two magnetic barriers of the second core 12 are centered on the axis of the rotating shaft 13 and are offset by a preset angle in the clockwise direction. , thereby effectively adjusting the phase difference of the cogging torque, torque pulsation and electromagnetic vibration generated by the first core 11 and the second core 12, so that the cogging torque, torque pulsation and electromagnetic vibration generated by the first core 11 and the second core 12 cancel each other out, thereby reducing the overall cogging torque, torque pulsation and electromagnetic vibration of the permanent magnet motor using the asymmetric rotor structure 100, thereby improving the NVH performance of the permanent magnet motor.

[0078] like Figure 1 and Figure 2 As shown, as an implementation, the asymmetric rotor structure 100 further includes a fastener 16 and two end pressure plates 17 made of non-magnetic conductive material, all first cores 11 and all second cores 12 are located between the two end pressure plates 17, the end pressure plates 17 are provided with fixing holes 171, the fastener 16 is passed through the fixing holes 171 and is fixedly connected to the first core 11 or the second core 12 adjacent to the end pressure plate 17. The rotating shaft 13 is passed through the plurality of first cores 11, the plurality of second cores 12, the plurality of magnetic isolation plates 15 and the two end pressure plates 17, and is fixed to the plurality of first cores 11, the plurality of second cores 12, the plurality of magnetic isolation plates 15 and the two end pressure plates 17. Through the above-mentioned arrangement, the end pressure plate 17 can axially limit the magnetic steel 14, the first iron core 11, the second iron core 12 and the magnetic isolation plate 15 to prevent the magnetic steel 14 from falling off from the first iron core 11, the second iron core 12 and the magnetic isolation plate 15; at the same time, the end pressure plate 17 can also be used as a deweighting part during the dynamic balancing correction of the asymmetric rotor structure 100. For example, holes can be punched on the end pressure plate 17 to achieve the dynamic balancing of the asymmetric rotor structure 100.

[0079] like Figure 3 and Fig. 9 As shown, as an implementation method, multiple preset areas 111 are uniformly arranged around the axis of the first core 11 along the circumference of the first core 11. Specifically, the extension direction of the first mounting grooves 112 of the multiple preset areas 111 is perpendicular to the extension direction of a diameter of the first core 11, and the angles between the two diameters corresponding to each two adjacent first mounting grooves 112 are consistent. Through the above arrangement, the first mounting grooves 112, the first magnetic barriers 113, and the second magnetic barriers 114 on the first core 11 can be uniformly distributed on the first core 11, and the second mounting grooves 121 on the second core 12 can be uniformly distributed on the second core 12, so that the asymmetric rotor structure 100 has rotational symmetry.

[0080] As an implementation, the present application further provides a permanent magnet motor, which includes the above-mentioned asymmetric rotor structure 100.

[0081] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. An asymmetric rotor structure, characterized in that: The asymmetric rotor structure comprises: A plurality of first cores, each of which is cylindrical, and each of which includes a plurality of preset areas, which are arranged around the axis of the first core, and each of which is provided with a first mounting groove, a first magnetic barrier, and a second magnetic barrier, wherein the first mounting groove, the first magnetic barrier, and the second magnetic barrier are all arranged to penetrate the first core along the axis of the first core, and the first magnetic barrier and the second magnetic barrier are respectively connected to two ends of the first mounting groove, and the first mounting groove extends along a preset straight line direction, the first magnetic barrier extends along the first straight line direction, and the second magnetic barrier extends along the second straight line direction, defining a projection plane perpendicular to the axis of the first core, the orthographic projection of the first straight line on the projection plane is a first projection line, the orthographic projection of the second straight line on the projection plane is a second projection line, and the orthographic projection of the preset straight line on the projection plane is a preset projection line, and the angle between the first projection line and the preset projection line is different from the angle between the second projection line and the preset projection line; A plurality of second cores, wherein the second cores and the first cores are mirror-symmetrical structures, and the number of the second cores is the same as that of the first cores; a rotating shaft, the rotating shaft being passed through the plurality of the first iron cores and the plurality of the second iron cores and being fixed to the plurality of the first iron cores and the plurality of the second iron cores; A plurality of magnetic steels, each of which is installed in one of the first installation slots of each of the first iron cores, and each of which is passed through all of the second iron cores and fixed to the second iron cores; A symmetry plane perpendicular to the axial direction of the first iron core is defined, the symmetry plane bisects the asymmetric rotor structure, at least one first iron core and at least one second iron core are arranged on both sides of the symmetry plane, the first iron cores located on both sides of the symmetry plane are symmetrically arranged with respect to the symmetry plane, and the second iron cores located on both sides of the symmetry plane are symmetrically arranged with respect to the symmetry plane.

2. The asymmetric rotor structure according to claim 1, characterized in that: The second iron core is provided with a plurality of second mounting grooves, each of the second mounting grooves corresponds to one of the first mounting grooves, and each of the magnetic steels is installed in one of the first mounting grooves of each of the first iron cores and one of the second mounting grooves of each of the second iron cores corresponding to the first mounting grooves.

3. The asymmetric rotor structure according to claim 1 or 2, characterized in that: The asymmetric rotor structure further comprises a plurality of magnetic isolation plates made of non-magnetic conductive materials; If the first iron core and the second iron core are arranged adjacent to each other, a magnetic isolation plate is arranged between the adjacent first iron core and the second iron core, and the magnetic isolation plate is fixed to the adjacent first iron core and the second iron core.

4. The asymmetric rotor structure according to claim 3, characterized in that: Each of the magnetic isolation plates is provided with a plurality of third mounting grooves, each of the third mounting grooves corresponds to one of the first mounting grooves, and each of the magnetic steels is mounted on one of the first mounting grooves of each of the first iron cores and one of the third mounting grooves of each magnetic isolation plate corresponding to the first mounting groove; The rotating shaft passes through the plurality of first iron cores, the plurality of second iron cores and the plurality of magnetic isolation plates, and is fixed to the plurality of first iron cores, the plurality of second iron cores and the plurality of magnetic isolation plates.

5. The asymmetric rotor structure according to claim 1, characterized in that: The number of the second iron cores and the number of the first iron cores are both multiples of 2.

6. The asymmetric rotor structure according to claim 1, characterized in that: The total length of all the first cores along the axial direction of the first core is equal to the total length of all the second cores along the axial direction of the first core.

7. The asymmetric rotor structure according to claim 1, characterized in that: Define the diameter of the first iron core perpendicular to the preset straight line as the bisecting diameter, the bisecting diameter bisects the first mounting slot, and the first magnetic barrier and the second magnetic barrier are located on both sides of the bisecting diameter; define the end face of the first magnetic barrier away from the first mounting slot as the first end face, the end face of the second magnetic barrier away from the first mounting slot as the second end face, the orthographic projection of the first end face on the projection plane as the first end face projection, the orthographic projection of the second end face on the projection plane as the second end face projection, the orthographic projection of the axis of the first iron core on the projection plane as the axis projection point, the line connecting the midpoint of the first end face projection and the axis projection point as the first connecting line, the line connecting the midpoint of the second end face projection and the axis projection point as the second connecting line, the orthographic projection of the bisecting diameter on the projection plane as the diameter projection line, the acute angle between the first connecting line and the diameter projection line as the first angle, the acute angle between the second connecting line and the diameter projection line as the second angle, and the angle of the first angle is different from the angle of the second angle; When the first angle is greater than the second angle, if the first connecting line rotates around the axis projection point by a preset angle toward the straight line projection line, and the second connecting line rotates around the axis projection point by the preset angle away from the straight line projection line, the diameter projection line bisects the angle formed by the first connecting line and the second connecting line.

8. The asymmetric rotor structure according to claim 1, characterized in that: The asymmetric rotor structure further includes a fastener and two end pressure plates made of non-magnetic conductive material, all the first iron cores and all the second iron cores are located between the two end pressure plates, the end pressure plates are provided with fixing holes, the fasteners are passed through the fixing holes and fixedly connected to the first iron core or the second iron core adjacent to the end pressure plates; The rotating shaft passes through the plurality of first iron cores, the plurality of second iron cores and the two end pressure plates, and is fixed to the plurality of first iron cores, the plurality of second iron cores and the two end pressure plates.

9. The asymmetric rotor structure according to claim 1, characterized in that: The plurality of preset areas are uniformly arranged around the axis of the first core along the circumference of the first core; The extension directions of the first installation slots in the plurality of preset areas are all perpendicular to the extension direction of a diameter of the first core, and the angles between the two diameters corresponding to every two adjacent first installation slots are all consistent.

10. A permanent magnet motor, characterized in that: The permanent magnet motor comprises the asymmetric rotor structure according to any one of claims 1 to 9.

Images