Rotor punching sheet, rotor structure and permanent magnet motor

Abstract

The utility model provides a rotor punching sheet, a rotor structure and a permanent magnet motor. The rotor punching sheet is provided with a plurality of magnetic steel grooves which are sequentially arranged at intervals along the circumferential direction of the rotor punching sheet; the first arc sections and the second arc sections are arranged on the edge of the rotor punching sheet, and the first arc sections and the second arc sections are sequentially and alternately arranged in the circumferential direction of the rotor punching sheet; the concave sections are arranged on the edge of the rotor punching sheet, the concave sections are arranged in a concave mode towards the middle of the rotor punching sheet, and any two adjacent first arc sections and second arc sections are connected through one concave section; wherein the circle center of the first arc section does not coincide with the center of the rotor punching sheet, the circle center of the second arc section does not coincide with the center of the rotor punching sheet, and the maximum distance from the first arc section to the center of the rotor punching sheet is equal to the maximum distance from the second arc section to the center of the rotor punching sheet. The rotor punching sheet provided by the utility model solves the technical problem that a permanent magnet motor is easy to damage due to poor structural strength of a permanent magnet motor rotor in the prior art.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor design field, specifically, a rotor lamination, rotor structure and permanent magnet motor. BACKGROUND

[0002] Now, permanent magnet motor has been widely applied in each field of people's production and life, and the motor research and development personnel in the field is also in continuous efforts in improving the motor structure. However, the permanent magnet motor in the related art still has unreasonable places on the mechanism, which has a negative impact on the use of the permanent magnet motor.

[0003] Specifically, the permanent magnet motor in the related art usually designs larger cutting edge or groove structure at the rotor edge, thereby optimizing the rotor structure, making the motor back electromotive force sinusoidal, thereby ensuring the motor performance, but the larger cutting edge or groove at the rotor edge can seriously affect the structural rigidity of the rotor, making the rotor structure strength poor, especially when the motor runs at high speed, the rotor magnetic bridge is prone to rupture, the magnet is prone to fly out and the like, eventually leading to motor locked-rotor and even burning.

[0004] It can be seen that the permanent magnet motor in the related art has the technical problem that the poor rotor structure strength leads to the easy damage of the permanent magnet motor, and currently no effective solution has been proposed for this technical problem. SUMMARY

[0005] The main purpose of the utility model is to provide a rotor lamination, rotor structure and permanent magnet motor, to solve the technical problem that the poor rotor structure strength of the permanent magnet motor in the related art leads to the easy damage of the permanent magnet motor.

[0006] In order to achieve the above purpose, according to one aspect of the utility model, a rotor lamination is provided, which is provided with: a plurality of magnetic steel grooves, the plurality of magnetic steel grooves are arranged along the circumference of the rotor lamination; a plurality of first circular segments and a plurality of second circular segments, the plurality of first circular segments and the plurality of second circular segments are arranged at the edge of the rotor lamination, the first circular segments and the second circular segments are alternately arranged along the circumference of the rotor lamination; a plurality of recessed segments, the plurality of recessed segments are arranged at the edge of the rotor lamination, the recessed segments are recessed towards the middle part of the rotor lamination, and any two adjacent first circular segments and second circular segments are connected by a recessed segment; wherein the center of the first circular segment is not coincident with the center of the rotor lamination, the center of the second circular segment is not coincident with the center of the rotor lamination, and the maximum distance from the first circular segment to the center of the rotor lamination is equal to the maximum distance from the second circular segment to the center of the rotor lamination.

[0007] Further, the center of the first circular arc segment is located on a q-axis, and the center of the second circular arc segment is located on a d-axis, the q-axis is a symmetry line of two adjacent magnetic steel grooves, the q-axis passes through the center of the rotor punching sheet, the d-axis is a symmetry line of a single magnetic steel groove, and the d-axis passes through the center of the rotor punching sheet.

[0008] Further, the rotor punching sheet satisfies 0.88≤R2 / R1≤1, where R1 is the radius of the first circular arc segment, and R2 is the radius of the second circular arc segment.

[0009] Further, the rotor punching sheet satisfies L1+R1=L2+R2=L3, where L1 is the distance from the center of the first circular arc segment to the center of the rotor punching sheet, R1 is the radius of the first circular arc segment, L2 is the distance from the center of the second circular arc segment to the center of the rotor punching sheet, R2 is the radius of the second circular arc segment, and L3 is the radius of the circumscribed circle of the rotor punching sheet.

[0010] Further, the number of the first circular arc segments and the number of the second circular arc segments are equal to the number of the magnetic steel grooves, and the plurality of second circular arc segments correspond to the plurality of magnetic steel grooves one by one.

[0011] Further, along a direction towards the outside of the rotor punching sheet, the opening size of each recess segment gradually increases.

[0012] Further, the rotor punching sheet satisfies 0.90≤L4 / L3≤0.98, where L4 is the minimum distance from the recess segment to the center of the rotor punching sheet, and L3 is the radius of the circumscribed circle of the rotor punching sheet; and / or the recess depth of the recess segment ranges from 1.5mm to 3mm.

[0013] Further, the magnetic steel groove is a V-shaped groove, and the rotor punching sheet satisfies 0.20≤α1 / α≤0.35, where α1 is the sum of the central angles occupied by a single second circular arc segment and a single recess segment, and α is the included angle between the two sides of the V-shaped groove.

[0014] Further, the included angle α between the two sides of the V-shaped groove satisfies 120°≤α≤140°.

[0015] According to another aspect of the present application, a rotor structure is provided, which comprises a plurality of rotor punching sheets stacked in sequence, wherein the rotor punching sheet is the rotor punching sheet described above.

[0016] According to another aspect of the present application, a permanent magnet motor is provided, which comprises the rotor structure described above.

[0017] The rotor punching sheet of the embodiment of the utility model is provided with: multiple magnetic steel grooves, the multiple magnetic steel grooves are sequentially and spacedly arranged along the circumference of the rotor punching sheet;Multiple first circular segments and multiple second circular segments, the multiple first circular segments and the multiple second circular segments are all arranged at the edge of the rotor punching sheet, the first circular segment and the second circular segment are sequentially and alternately arranged along the circumference of the rotor punching sheet;Multiple recessed segments, the multiple recessed segments are arranged at the edge of the rotor punching sheet, the recessed segment is recessed towards the middle part of the rotor punching sheet, and any two adjacent first circular segments and second circular segments are connected through a recessed segment;Among them, the center of the first circular segment does not coincide with the center of the rotor punching sheet, the center of the second circular segment does not coincide with the center of the rotor punching sheet, and the maximum distance from the first circular segment to the center of the rotor punching sheet is equal to the maximum distance from the second circular segment to the center of the rotor punching sheet.The rotor punching sheet with this structure design, by sequentially and alternately arranging the first circular segment and the second circular segment at the edge of the rotor punching sheet, and connecting the adjacent first circular segment and the second circular segment through the recessed segment, this structure that adopts the circular arc mode to reduce the outer edge of the rotor, compared with the mode of cutting edge or cutting recess directly on the rotor q axis, has smaller influence on the overall structure of the rotor, can effectively ensure the structural strength of the rotor, and after cutting the edge of the rotor punching sheet through the first circular segment, the second circular segment and the recessed segment, the motor counter electromotive force waveform can be adjusted, the harmonic can be reduced, so that the counter electromotive force is sinusoidal, and the motor performance is ensured.Therefore, the rotor punching sheet with the structure design of the embodiment of the utility model can effectively improve the structural strength of the rotor on the basis of ensuring the motor performance, and solves the technical problem that the poor structural strength of the permanent magnet motor rotor in the related art leads to easy damage of the permanent magnet motor. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings accompanying the specification of this application serve to provide further understanding of the utility model, and the illustrative embodiments of the utility model and the description thereof serve to explain the utility model, and do not constitute undue limitation on the utility model. In the drawings:

[0019] Figure 1 It is a structural schematic view of the embodiment of the rotor punching sheet of the utility model;

[0020] Figure 2 It is an enlarged schematic view of the local area in Figure 1

[0021] Figure 3 It is a size marking schematic view of the embodiment of the rotor punching sheet of the utility model;

[0022] Figure 4 It is a waveform schematic view of the induction voltage (coil A) - induction voltage (coil B) of the permanent magnet motor in the related art with time;

[0023] Figure 5 ​The waveform diagram showing the change of the induced voltage (coil A) - the induced voltage (coil B) of the permanent magnet motor of the embodiment of the utility model with time.

[0024] Figure 6 The comparison table of counter electromotive force, THD, fundamental wave and harmonic content of the permanent magnet motor in the related art and the permanent magnet motor of the embodiment of the utility model.

[0025] The above-mentioned drawings include the following reference signs:

[0026] 1, magnetic steel slot; 2, first arc segment; 3, second arc segment; 4, recess segment; 5, shaft hole. DETAILED DESCRIPTION

[0027] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The utility model will be described in detail below with reference to the drawings and in combination with the embodiments.

[0028] Please refer to Figures 1 to 3 In order to achieve the above-mentioned purpose, the embodiment of the utility model provides a rotor punching sheet, which is provided with: a plurality of magnetic steel slots 1, the plurality of magnetic steel slots 1 are arranged along the circumference of the rotor punching sheet; a plurality of first arc segments 2 and a plurality of second arc segments 3, the plurality of first arc segments 2 and the plurality of second arc segments 3 are arranged on the edge of the rotor punching sheet, the first arc segment 2 and the second arc segment 3 are arranged alternately along the circumference of the rotor punching sheet; a plurality of recess segments 4, the plurality of recess segments 4 are arranged on the edge of the rotor punching sheet, the recess segment 4 is recessed towards the middle part of the rotor punching sheet, and any two adjacent first arc segments 2 and second arc segments 3 are connected through a recess segment 4; wherein, the center of the first arc segment 2 does not coincide with the center of the rotor punching sheet, the center of the second arc segment 3 does not coincide with the center of the rotor punching sheet, and the maximum distance from the first arc segment 2 to the center of the rotor punching sheet is equal to the maximum distance from the second arc segment 3 to the center of the rotor punching sheet.

[0029] The rotor lamination adopting the structural design cuts the rotor outer edge in a circular arc mode, which has less influence on the overall structure of the rotor compared with the mode of cutting the edge or groove directly on the rotor q-axis, can effectively ensure the structural strength of the rotor, and after cutting the edge of the rotor lamination through the first circular arc segment 2, the second circular arc segment 3 and the recessed segment 4, the motor back electromotive force waveform can be adjusted, the harmonic can be reduced, and thus the back electromotive force can be sinusoidal, and the motor performance can be ensured. Therefore, the rotor lamination adopting the structural design of the embodiment of the utility model can effectively improve the structural strength of the rotor on the basis of ensuring the motor performance, and solves the technical problem that the poor structural strength of the permanent magnet motor rotor in the related art leads to the easy damage of the permanent magnet motor.

[0030] Specifically, the back electromotive force, i.e., the induced electromotive force generated on the stator winding by the rotation of the rotor magnetic field, in the related art, the back electromotive force harmonic (spur) is reduced by setting a larger groove or cutting edge at a specific position of the rotor, and is closer to a sinusoidal curve, i.e., the back electromotive force is sinusoidal, which is beneficial to ensure the motor efficiency. In the present application, the groove, cutting edge and other structures on the rotor are avoided, and the first circular arc segment 2, the second circular arc segment 3 and the recessed segment 4 are used to adjust the back electromotive force waveform to make it close to a sinusoidal wave, which effectively improves the strength of the motor rotor structure on the basis of ensuring the motor performance, avoids the rupture of the rotor magnetic bridge due to the low structural strength of the stator under the condition of high-speed operation of the motor, and thus avoids the situation that the magnets fly out, and the motor is blocked or burned out, and effectively improves the safety and service life of the motor.

[0031] For the specific structure of the rotor lamination, as shown in the embodiments in Figure 1 and Figure 2 , the rotor lamination is in a ring structure, the center of which is provided with a shaft hole 5, the center of the shaft hole is the center of the rotor lamination, a plurality of magnetic steel grooves 1 are sequentially arranged around the shaft hole 5, the position of the second circular arc segment 3 corresponds to the magnetic steel groove 1, the first circular arc segment 2 is located between the two adjacent second circular arc segments 3, and the first circular arc segment 2 and the second circular arc segment 3 are connected by the recessed segment 4.

[0032] Specifically, the center of the first circular arc segment 2 is located on the q-axis, the center of the second circular arc segment 3 is located on the d-axis, the q-axis is the symmetry line of the two adjacent magnetic steel grooves 1, the q-axis passes through the center of the rotor lamination, and the d-axis is the symmetry line of a single magnetic steel groove 1, and the d-axis passes through the center of the rotor lamination.

[0033] That is, the q-axis axis is located between two adjacent magnetic steel slots 1, and the two adjacent magnetic steel slots 1 are symmetrical relative to the q-axis axis; the d-axis axis is the symmetry line of a single magnetic steel slot 1, that is, the two parts of the magnetic steel slot 1 are symmetrical relative to the d-axis axis. In the embodiment, by designing the center of the first circular segment 2 on the q-axis axis and the center of the second circular segment 3 on the d-axis axis, the rotor structure has better symmetry, has better effect on the sine of the motor back electromotive force, and thus is beneficial to guarantee the performance of the motor.

[0034] As shown in Figure 3 In a preferred embodiment, the structure of the rotor lamination satisfies 0.88≤R2 / R1≤1, where R1 is the radius of the first circular segment 2, and R2 is the radius of the second circular segment 3.

[0035] In the embodiment, the size relationship between R2 and R1 is further designed to satisfy 0.88≤R2 / R1≤1. Specifically, it is proved by practice that the d-axis cutting circular arc has a greater influence on the sine of the back electromotive force, and the smaller R2 is, the greater the improvement effect on the sine is. By designing R2 to be not greater than R1, the effect of the sine of the back electromotive force can be effectively improved. However, the applicant further found that if R2 is too small, the magnetic field will be weakened too much, the back electromotive force will be attenuated too much, and the motor performance will be adversely affected. In the embodiment, by designing R2 / R1 to satisfy 0.88≤R2 / R1≤1, the effect of the sine of the back electromotive force can be improved on the basis of having a smaller influence on the attenuation of the motor back electromotive force, thereby effectively improving the motor performance.

[0036] The rotor lamination structure satisfies L1+R1=L2+R2=L3, where L1 is the distance from the center of the first circular segment 2 to the center of the rotor lamination, R1 is the radius of the first circular segment 2, L2 is the distance from the center of the second circular segment 3 to the center of the rotor lamination, R2 is the radius of the second circular segment 3, and L3 is the radius of the circumscribed circle of the rotor lamination.

[0037] That is, in the embodiment, the sum of L1 and R1 is equal to the radius L3 of the circumscribed circle of the stator lamination, and the sum of L2 and R2 is also equal to the radius L3 of the circumscribed circle of the stator lamination, thereby ensuring that the rotor maintains a suitable and equal gap with the stator at the d-axis and the q-axis, which is not only beneficial to make the magnetic flux density distribution more uniform, reduce the harmonic content, and optimize the back electromotive force, but also beneficial to facilitate processing and manufacturing. Specifically, in actual implementation, R1 can also be equal to R2. The rotor outer diameter arc cutting is mainly related to the center positions of R1 and R2, and the center positions are determined by L1 and L2. As long as L1 and L2 are not 0, the function of adjusting the back electromotive force waveform can be played, thereby better realizing the sine of the back electromotive force. In specific implementation, L1 and L2 can be flexibly selected according to actual conditions, and when L1=L2, R1=R2.

[0038] As a preferred embodiment, the number of the first arc segments 2 and the number of the second arc segments 3 are equal to the number of the magnetic steel slots 1, and the plurality of second arc segments 3 correspond to the plurality of magnetic steel slots 1 one by one.

[0039] In the embodiment, the number of the first arc segments 2 and the number of the second arc segments 3 are equal to the number of the magnetic steel slots 1, and the position of the second arc segments 3 corresponds to the position of the magnetic steel slots 1 one by one, and by designing the first arc segments 2 and the second arc segments 3 to be the same as the number of the rotor poles, the balance of the magnetic field is facilitated to be ensured, thereby reducing the back electromotive force harmonic.

[0040] Specifically, as shown in FIG. 4, along the direction towards the outside of the rotor lamination, the opening size of each recess segment 4 gradually increases. That is, as the recess segment 4 goes deeper, the opening size thereof becomes smaller and smaller, and such a structure design is advantageous to weaken the q-axis leakage magnetic flux, thereby improving the back electromotive force and ensuring the motor performance. Figure 2

[0041] In specific implementation, the specific shape of the recess segment 4 can be various, and specifically, the shape of the recess segment 4 can be a regular shape, for example, the cross-sectional shape thereof can be a straight line, a circular arc, a curve, etc. connected to form, or the shape of the recess segment 4 can be an irregular shape, which can be selected and designed according to specific conditions to better adjust the back electromotive force waveform. In a preferred embodiment, the cross section of the recess segment 4 is connected by two straight lines to form an angle, which is advantageous to simplify the mold design and facilitate processing and manufacturing.

[0042] Specifically, the rotor lamination structure satisfies 0.90≤L4 / L3≤0.98, wherein L4 is the minimum distance between the recess segment 4 and the center of the rotor lamination, and L3 is the circumscribed circle radius of the rotor lamination; and / or the recess depth of the recess segment 4 ranges from 1.5 mm to 3 mm.

[0043] The recess depth of the recess segment 4 has a direct influence on the back electromotive force sinusoidal effect and the overall strength of the rotor structure, and specifically, if the depth of the recess segment 4 is too small, it is not conducive to adjusting the back electromotive force waveform, which makes the back electromotive force sinusoidal effect poor, thereby reducing the motor efficiency, and if the depth of the recess segment 4 is too large, it will cause great damage to the rotor structure, which reduces the strength of the rotor structure, thereby increasing the risk of the motor running at high speed and making the motor prone to damage. In the embodiment, by designing the value of L4 / L3 to be 0.90≤L4 / L3≤0.98 or directly designing the recess depth of the recess segment 4 to be within the range of 1.5 mm to 3 mm, the back electromotive force waveform optimization effect can be ensured on the basis of ensuring the strength of the rotor structure, thereby improving the motor performance.

[0044] ​In the embodiment, the magnetic steel slot 1 is a V-shaped slot, and the rotor lamination structure satisfies 0.20≤α1 / α≤0.35, wherein α1 is the sum of the central angles of the single second circular arc segment 3 and the single recessed segment 4, and α is the included angle between the two sides of the V-shaped slot.

[0045] The value of α1 / α is further designed to be 0.20≤α1 / α≤0.35, and the motor cogging torque is better in the structure design range. If the value is too small, the cogging torque is not obviously improved, and if the value is too large, the magnetic bridge may be interfered, and the structure strength of the magnetic bridge is affected.

[0046] Specifically, the included angle α between the two sides of the V-shaped slot satisfies 120°≤α≤140°. That is, the opening range of the V-shaped slot is 120°≤α≤140°, if the opening is too large, the V-shaped magnet cannot play the characteristics of high power density and strong demagnetization resistance, and if the opening is too small, the torque ripple is deteriorated, and the motor performance is not good.

[0047] In addition, the embodiment of the utility model provides a rotor structure, rotor structure includes the plurality of rotor laminations of stacking in sequence, wherein the rotor lamination is above-mentioned rotor lamination, thereby effectively improving the strength of rotor structure on the basis of guaranteeing not to influence motor performance, thereby improving motor life.

[0048] Finally, the embodiment of the utility model also provides a permanent magnet motor, the permanent magnet motor includes above-mentioned rotor structure. Through adopting the rotor lamination of the structure design of above-mentioned, can effectively improve the strength of rotor structure on the basis of guaranteeing motor performance, solve the technical problem that permanent magnet motor rotor structure strength is poor in related art and leads to permanent magnet motor easy to damage. In a preferred embodiment, the permanent magnet motor is a concentrated winding type motor, and the slot pole number can be various, for example, 12-slot 8-pole, 9-slot 6-pole.

[0049] As Figures 4 to 6 shown, Figure 4 for the induction voltage (coil A) - induction voltage (coil B) waveform diagram of the permanent magnet motor of related art, Figure 5 for the induction voltage (coil A) - induction voltage (coil B) waveform diagram of the permanent magnet motor of the embodiment of the utility model, by comparing Figure 4 and Figure 5 It can be found that the back electromotive force waveform of the permanent magnet motor (new scheme) of the embodiment of the utility model is better than that of the permanent magnet motor (original scheme) in related art, and the sine condition is better, so it can be known that the permanent magnet motor of the embodiment of the utility model has better performance.

[0050] Figure 6The comparison table of counter electromotive force, THD, fundamental wave and each harmonic content of the permanent magnet motor in the related art and the permanent magnet motor of the embodiment of the utility model can be seen. It can be seen that compared with the permanent magnet motor (original scheme) in the related art, the THD (namely total harmonic distortion, the full name in English is Total Harmonic Distortion) of the permanent magnet motor (new scheme) of the embodiment of the utility model is smaller, and each harmonic content is also partly better controlled, which is beneficial to improve the sinusoidal effect of the counter electromotive force of the permanent magnet motor, thereby optimizing the performance of the permanent magnet motor.

[0051] From the above description, it can be seen that the above-mentioned embodiments of the utility model realize the following technical effects:

[0052] The rotor punching sheet of the embodiment of the utility model is provided with: a plurality of magnetic steel grooves 1, the plurality of magnetic steel grooves 1 are sequentially and spacedly arranged along the circumference of the rotor punching sheet; a plurality of first arc segments 2 and a plurality of second arc segments 3, the plurality of first arc segments 2 and the plurality of second arc segments 3 are all arranged at the edge of the rotor punching sheet, the first arc segment 2 and the second arc segment 3 are sequentially and alternately arranged along the circumference of the rotor punching sheet; a plurality of recess segments 4, the plurality of recess segments 4 are arranged at the edge of the rotor punching sheet, the recess segment 4 is recessed towards the middle part of the rotor punching sheet, and any two adjacent first arc segments 2 and second arc segments 3 are connected through a recess segment 4; wherein the center of the first arc segment 2 does not coincide with the center of the rotor punching sheet, the center of the second arc segment 3 does not coincide with the center of the rotor punching sheet, and the maximum distance from the first arc segment 2 to the center of the rotor punching sheet is equal to the maximum distance from the second arc segment 3 to the center of the rotor punching sheet. The rotor punching sheet adopting this structure design sequentially and alternately arranges the first arc segment 2 and the second arc segment 3 at the edge of the rotor punching sheet, and connects the adjacent first arc segment 2 and the second arc segment 3 through the recess segment 4. Compared with the mode of directly cutting the edge or recess groove on the rotor q-axis, this structure of cutting the rotor outer edge in the form of arc has smaller influence on the overall structure of the rotor, can effectively ensure the structural strength of the rotor, and after cutting the edge of the rotor punching sheet through the first arc segment 2, the second arc segment 3 and the recess segment 4, the motor counter electromotive force waveform can be adjusted, the harmonic can be reduced, thereby making the counter electromotive force sinusoidal, and ensuring the motor performance. Therefore, the rotor punching sheet adopting the structure design of the embodiment of the utility model can effectively improve the structural strength of the rotor on the basis of ensuring the motor performance, and solves the technical problem that the poor structural strength of the permanent magnet motor rotor in the related art leads to the easy damage of the permanent magnet motor.

[0053] For purposes of the description hereinafter, the terms "upper", "lower", "right", "left", "rear", "front", "vertical" and "horizontal" as can be perceived herein relative to the accompanying drawings refer to the orientation of the components being described. However, it is to be understood that the exemplary embodiments described herein can assume different alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices illustrated in the attached drawings, and described in the following specification are exemplary embodiments only and should not be typically construed as limiting the scope of the present application.

[0054] It is also important to note that the term "or" as used herein is intended to mean any possible combination of the features, steps or elements it modifies, including one as well as one or more. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0055] It is to be understood that the terminology used herein is for the purpose of describing the exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0056] The preferred embodiments of the present application have been described herein above with the intent of illustrating the principles of operation of the application by reference to one or more preferred embodiments. Any change in making materials or changes in the order of any steps are considered to be within the scope of the present application.

Claims

1. A rotor lamination, characterized by The rotor lamination is provided with: a plurality of magnetic steel grooves (1), a plurality of the magnetic steel grooves (1) are sequentially and spacedly arranged along the circumference of the rotor lamination; a plurality of first circular arc segments (2) and a plurality of second circular arc segments (3), the plurality of first circular arc segments (2) and the plurality of second circular arc segments (3) are both arranged at the edge of the rotor lamination, the first circular arc segments (2) and the second circular arc segments (3) are sequentially and alternately arranged along the circumference of the rotor lamination; a plurality of recessed segments (4), a plurality of the recessed segments (4) are arranged at the edge of the rotor lamination, the recessed segments (4) are recessed towards the middle part of the rotor lamination, and any two adjacent first circular arc segments (2) and second circular arc segments (3) are connected by one recessed segment (4); wherein the center of the first circular arc segment (2) does not coincide with the center of the rotor lamination, the center of the second circular arc segment (3) does not coincide with the center of the rotor lamination, and the maximum distance from the first circular arc segment (2) to the center of the rotor lamination is equal to the maximum distance from the second circular arc segment (3) to the center of the rotor lamination.

2. The rotor lamination of claim 1, wherein, The center of the first circular arc segment (2) is located on the q-axis, the center of the second circular arc segment (3) is located on the d-axis, the q-axis is the symmetry line of two adjacent magnetic steel grooves (1), the q-axis passes through the center of the rotor lamination, and the d-axis is the symmetry line of a single magnetic steel groove (1), the d-axis passes through the center of the rotor lamination.

3. The rotor lamination of claim 2, wherein, The structure of the rotor lamination satisfies 0.88≤R2 / R1≤1, wherein R1 is the radius of the first circular arc segment (2), and R2 is the radius of the second circular arc segment (3).

4. The rotor lamination of claim 1, wherein, The rotor lamination structure satisfies L1+R1=L2+R2=L3, wherein L1 is the distance from the center of the first circular arc segment (2) to the center of the rotor lamination, R1 is the radius of the first circular arc segment (2), L2 is the distance from the second circular arc segment (3) to the center of the rotor lamination, R2 is the radius of the second circular arc segment (3), and L3 is the radius of the circumscribed circle of the rotor lamination.

5. The rotor lamination of claim 1, wherein, The number of the first circular arc segments (2) and the number of the second circular arc segments (3) are equal to the number of the magnetic steel grooves (1), and a plurality of the second circular arc segments (3) correspond one by one to a plurality of the magnetic steel grooves (1).

6. The rotor lamination of any of claims 1-5, wherein, In the direction towards the outside of the rotor lamination, the opening size of each recessed segment (4) gradually increases.

7. The rotor lamination of any one of claims 1 to 5, wherein, The rotor lamination structure satisfies 0.90≤L4 / L3≤0.98, wherein L4 is the minimum distance from the recessed segment (4) to the center of the rotor lamination, and L3 is the radius of the circumscribed circle of the rotor lamination; and / or, The recessed depth of the recessed segment (4) ranges from 1.5mm to 3mm.

8. The rotor lamination of claim 5, wherein, The magnetic steel groove (1) is a V-shaped groove, and the rotor lamination structure satisfies 0.20≤α1 / α≤0.35, wherein α1 is the sum of the central angles occupied by a single second circular arc segment (3) and a single recessed segment (4), and α is the included angle between the two sides of the V-shaped groove.

9. The rotor lamination of claim 8, wherein, An included angle a between two sides of the V-shaped groove satisfies 120°≤a≤140°.

10. A rotor structure, characterized by The rotor structure comprises a plurality of rotor laminations stacked in sequence, wherein the rotor laminations are the rotor laminations according to any one of claims 1 to 9.

11. A permanent magnet electric machine characterized by, The permanent magnet motor comprises the rotor structure according to claim 10. The permanent magnet motor comprises the rotor structure according to claim 10.

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