CN116633048A - Rotor of motor, motor and vehicle - Google Patents

Abstract

The invention discloses a rotor of a motor, the motor and a vehicle, wherein the rotor comprises: a permanent magnet; the rotor core is provided with a plurality of mounting grooves which are distributed at intervals along the circumferential direction of the rotor core, the permanent magnets are mounted in the mounting grooves, an opening groove is formed between each mounting groove and the outer circumferential surface of the rotor core, a connecting line of an inner end midpoint a and an outer end midpoint b of the permanent magnets is a central line ab, a connecting line of an inner end midpoint c and an outer end midpoint d of the corresponding opening groove is a central line cd, and the central line cd is positioned on the leading side of the central line ab in the rotating direction of the rotor. According to the rotor of the motor, the center line cd of the open slot is positioned on the leading side of the center line ab of the permanent magnet along the rotating direction of the rotor, so that torque pulsation and iron loss are effectively reduced, the efficiency of the motor is improved, and vibration noise is reduced.

Description

Rotor of motor, motor and vehicle

Technical Field

The invention relates to the technical field of vehicles, in particular to a rotor of a motor, the motor and a vehicle.

Background

In the related art, the spoke type permanent magnet synchronous motor structure has the advantage of providing larger magnetic flux of each pole, is beneficial to improving the power density of the motor, but has larger torque fluctuation and lower motor efficiency when the saturation degree of a large load is higher under the condition of the same air gap magnetic flux density.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, an object of the present invention is to propose a rotor of an electric machine, which can improve the efficiency of the electric machine and improve the torque ripple.

The invention also provides a motor with the rotor.

The invention further provides a vehicle with the motor.

A rotor of an electric machine according to an embodiment of the present invention includes: a permanent magnet; the rotor core is provided with a plurality of mounting grooves which are distributed at intervals along the circumferential direction of the rotor core, the permanent magnets are mounted in the mounting grooves, an opening groove is formed between each mounting groove and the outer circumferential surface of the rotor core, a connecting line of an inner end midpoint a and an outer end midpoint b of the permanent magnets is a central line ab, a connecting line of an inner end midpoint c and an outer end midpoint d of the corresponding opening groove is a central line cd, and the central line cd is positioned on the leading side of the central line ab in the rotating direction of the rotor.

According to the rotor of the motor, the center line cd of the open slot is positioned on the leading side of the center line ab of the permanent magnet along the rotating direction of the rotor, so that torque pulsation and iron loss are effectively reduced, the efficiency of the motor is improved, and vibration noise is reduced.

In addition, the rotor of the motor according to the above embodiment of the present invention may have the following additional technical features:

according to some embodiments of the invention, a first core segment and a second core segment are formed between the mounting groove and the outer circumferential surface of the rotor core, the first core segment is located on the leading side of the second core segment, and the open groove is formed between the first core segment and the second core segment, wherein the extending dimensions of the first core segment and the second core segment along the circumferential direction of the rotor core are L1 and L2, L1 is greater than or equal to 0, and L1 is less than L2.

According to some embodiments of the invention, the pole pair number of the rotor is p, the plurality of mounting grooves are uniformly spaced along the circumferential direction of the rotor core, and the included angle α between the center line cd and the center line ab satisfies:

0°＜α≤360°/4p。

according to some embodiments of the invention, the open slot communicates with the mounting slot.

According to some embodiments of the invention, the mounting slot is spaced from the open slot by a first magnetic barrier bridge.

According to some embodiments of the invention, the rotor core includes a plurality of laminated silicon steel sheets, and a dimension of the first magnetism isolating bridge in a radial direction of the rotor core is greater than or equal to a thickness of the silicon steel sheets.

According to some embodiments of the invention, at least a portion of the open slot decreases inwardly along a width of the rotor core in a circumferential direction.

According to some embodiments of the invention, the open slot includes a first slot segment and a second slot segment in communication with each other, the first slot segment being located outside the second slot segment, the first slot segment decreasing inwardly in width along the circumferential direction of the rotor core, the second slot segment being equal in width therearound along the circumferential direction of the rotor core.

According to some embodiments of the invention, the groove wall surface of the first groove section is an arc surface, and the outer circumferential surface of the rotor core includes arc surfaces connecting adjacent two adjacent ends of the first groove section.

According to some embodiments of the invention, a line connecting an inner end midpoint a of the permanent magnet and a center point o of the rotor core is a line oa, an outer end midpoint b of the permanent magnet is located on an advance side of the line oa, and an included angle gamma between the line oa and the center line ab is greater than or equal to 0 °.

The motor according to the embodiment of the invention comprises a rotor of the motor according to the embodiment of the invention.

The vehicle according to the embodiment of the invention comprises a driving motor, and the driving motor is the motor according to the embodiment of the invention.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

fig. 1 is a schematic structural view of an electric motor according to a first embodiment of the present invention;

FIG. 2 is a schematic view of a partially enlarged structure of FIG. 1;

fig. 3 is a schematic structural view of comparative example 1;

FIG. 4 is a schematic view of a partially enlarged structure of FIG. 3;

FIG. 5 is a schematic structural view of comparative example 2;

FIG. 6 is a schematic view of the partially enlarged structure of FIG. 5;

FIG. 7 is a magneto-dense comparative chart of the first example, comparative example 1 and comparative example 2;

fig. 8 is a comparative iron loss plot of the first example, comparative example 1 and comparative example 2;

fig. 9 is a torque pulsation comparison chart of the first embodiment, the comparative example 1, and the comparative example 2;

fig. 10 is a torque harmonic component diagram of the first embodiment, comparative example 1, and comparative example 2;

fig. 11 is a partially enlarged structural schematic illustration of a rotor according to a second embodiment of the present invention;

fig. 12 is a partially enlarged structural schematic view of a rotor according to a third embodiment of the present invention;

fig. 13 is a partially enlarged structural schematic diagram of a rotor according to a fourth embodiment of the present invention.

Reference numerals:

a motor 1000;

a rotor 100; a stator 200;

a permanent magnet 10;

a rotor core 20; a mounting groove 21; an open groove 22; a first groove section 221; a second trough section 222; a first core segment 23; a second core segment 24; a first magnetically isolated bridge 25; an air tank 26; a second magnetically isolated bridge 27;

permanent magnet 10' of comparative example; a rotor core 20'; a mounting groove 21'; open slot 22'.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

In the description of the invention, "a first feature" may include one or more such features, and "a plurality" may mean two or more, and that a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, or may include both the first and second features not being in direct contact but being in contact with each other through additional features therebetween, with the first feature "above", "over" and "above" the second feature including both the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature.

A rotor 100 of an electric machine 1000 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

Referring to fig. 1 and 2, a rotor 100 of an electric machine 1000 according to an embodiment of the present invention may include: permanent magnet 10 and rotor core 20.

Specifically, the rotor core 20 has a plurality of mounting grooves 21, the plurality of mounting grooves 21 are spaced apart in the circumferential direction of the rotor core 20, and the permanent magnets 10 are mounted in the mounting grooves 21 to form a plurality of magnetic poles. The permanent magnet 10 has an inner end close to the center point of the rotor core 20 and an outer end distant from the center point of the rotor core 20, i.e., the permanent magnet 10 generally forms a spoke type structure.

The motor 1000 with the spoke type structure permanent magnet 10 has the advantage of providing greater magnetic flux per pole, has greater reluctance torque, and is beneficial to improving the power density of the motor 1000.

For example, as shown in fig. 1 and 2, in a cross section perpendicular to the axis of the rotor 100, the permanent magnet 10 has a rectangular shape in cross section, and the length of the rectangular shape extends in the radial direction of the rotor core 20, in other words, the line connecting the inner end midpoint a and the outer end midpoint b of the permanent magnet 10 is the center line ab of the permanent magnet 10, and is collinear with the radial line passing through the center point of the permanent magnet 10.

As another example, as shown in fig. 13, in a cross section perpendicular to the axis of the rotor 100, the permanent magnet 10 has a rectangular shape, and the length of the rectangular shape is inclined at an angle with respect to the radial direction of the rotor core 20. In other words, the center line ab of the permanent magnet 10 is disposed at an angle to a radial line passing through the center point of the permanent magnet 10.

However, applicants have found that motor efficiency and noise are also important criteria for measuring motor 1000 performance, and how to provide a design to improve torque ripple and efficiency issues is of paramount importance. For this reason, the embodiment of the invention proposes a rotor slot offset structure to improve the efficiency and vibration noise of the permanent magnet synchronous motor 1000.

Specifically, as shown in fig. 1 and 2, an open groove 22 is provided between each mounting groove 21 and the outer peripheral surface of the rotor core 20, the open groove 22 has a notch formed in the outer peripheral surface of the rotor core 20, and the open groove 22 at least partially overlaps with the projection of the permanent magnet 10 in the mounting groove 21 in the radial direction, that is, the open groove 22 and the permanent magnet 10 in the corresponding mounting groove 21 are not staggered at least partially in the circumferential direction of the rotor core 20.

The connection line between the inner end midpoint a and the outer end midpoint b of the permanent magnet 10 is the center line ab of the permanent magnet 10, and the connection line between the inner end midpoint c and the outer end midpoint d of the corresponding open slot 22 is the center line cd of the open slot 22. The center line cd is located on the leading side of the center line ab in the rotation direction of the rotor 100. For example, as shown in fig. 1, the rotor 100 rotates in a counterclockwise direction with the center line cd located counterclockwise from the center line ab. That is, the open slots 22 are offset relative to the permanent magnets 10 in the direction of rotation of the rotor 100 such that the center line ab of the permanent magnets 10 does not coincide with the center line cd of the corresponding open slot 22.

Through simulation analysis, as the concentrated winding type motor rotates along with the rotor, the establishment of winding current and the improvement of an air gap magnetic field are obviously saturated at the tooth part of the stator, and the iron loss is increased. The armature reaction further aggravates the distortion of the air gap field, so that the harmonic content of the motor is larger, and the torque fluctuation is obvious.

In the embodiment of the invention, through the arrangement of the open slot 22 which is offset along the rotation direction of the rotor 100, on one hand, the magnetic resistance of the magnetic circuit at the outer side of the permanent magnet 10 is increased, and the magnetic leakage is reduced, and on the other hand, silicon steel sheets with enough size are arranged at the outer side of the permanent magnet 10, so that the structural strength is ensured, and the permanent magnet 10 cannot fly out under the action of centrifugal force under the condition of high rotation speed.

The beneficial effects of the examples of the present invention are analyzed below in conjunction with the comparative examples and test results.

As shown in fig. 1 and 2, a motor 1000 according to a first embodiment of the present invention is shown in which a rotor 100 is positioned in a stator hole of a stator 200, a center line ab of a permanent magnet 10 is collinear with a radial line oa passing through a midpoint a of an inner end of the permanent magnet 10, an open groove 22 is provided on an outer side of a mounting groove 21, and a center line cd of the open groove 22 is offset in a rotation direction (i.e., in a counterclockwise direction) of the rotor 100 with respect to the center line ab of the permanent magnet 10.

As shown in fig. 3 and 4, which illustrate the motor of comparative example 1, a rotor is disposed in a stator hole of a stator, the rotor includes a rotor core 20' and a permanent magnet 10', the rotor core 20' is provided with a mounting groove 21' for mounting the permanent magnet 10', and an open groove 22' is provided at an outer side of the mounting groove 21 '. In comparison with the rotor 100 of the first embodiment of the present invention, the difference is that the center line cd of the open slot 22 'thereof is collinear with the center line ab of the permanent magnet 10', i.e., no offset occurs.

As shown in fig. 5 and 6, which illustrate the motor of comparative example 2, a rotor is disposed in a stator hole of a stator, the rotor includes a rotor core 20' and a permanent magnet 10', the rotor core 20' is provided with a mounting groove 21' for mounting the permanent magnet 10', and an open groove 22' is provided at an outer side of the mounting groove 21 '. In comparison with the rotor 100 of the first embodiment of the present invention, the difference is that the center line cd of the open slot 22 'thereof is offset with respect to the center line ab of the permanent magnet 10' against the rotation direction of the rotor (i.e., in the clockwise direction).

A magneto-dense comparative diagram of the first embodiment of the present invention, comparative example 1 and comparative example 2 is shown in fig. 7. It can be seen that the magnetic density maximum value of comparative example 1 was 1.701T and the magnetic density average value was 0.594T. In comparison with comparative example 1, after the offset of the open slot 22, the magnetic density of adjacent three teeth of the stator tooth portion is changed in addition to the saturation of the rotor 100. According to the rotor pole shoe, the magnetic density saturation degree of the rear side of the rotor pole shoe is relieved, the magnetic density of the corresponding stator tooth part is relieved, the torque pulsation is reduced, and the maximum magnetic density value and the average magnetic density value are respectively reduced to 1.632T and 0.486T, so that the iron loss is reduced. In comparative example 2, the saturation degree of the magnetic density at the rear side of the rotor pole shoe is deteriorated, the torque pulsation is increased, the magnetic density of the corresponding stator tooth part is deteriorated, the average magnetic density of the adjacent three teeth is increased, the maximum magnetic density and the average magnetic density are respectively increased to 1.704T and 0.604T, and the iron loss is slightly increased.

From this, it is necessary to keep the rotation direction of the rotor 100 consistent with the offset direction of the open groove 22, so that torque ripple and core loss can be effectively reduced.

Fig. 8 and 9 show iron loss and torque ripple comparison charts of the first embodiment of the present invention, comparative example 1 and comparative example 2. While the torque is fourier-decomposed, as shown in fig. 10, the torque harmonic components of the first embodiment of the present invention, comparative example 1 and comparative example 2 are shown.

It can be seen that the frequency multiplication of 6 in the first embodiment of the present invention is significantly reduced compared with comparative example 1, so that the torque ripple is reduced, the maximum value of the torque ripple in the heavy load region is reduced from 41% to 32%, and the torque ripple of the motor 1000 is greatly reduced; the iron loss of the heavy load area is reduced from 1.91W to 1.83W, so that the efficiency is improved, and the performance of the motor 1000 in the heavy load area is further improved. Therefore, the offset of the open slot 22 along the rotation direction of the rotor 100 effectively improves the saturation condition of the teeth of the motor 1000 in the heavy load region, and the iron loss is reduced. In comparative example 2, the motor tooth saturation condition in the heavy load region is aggravated by the offset in the motor rotation direction, the iron loss ratio is high, and the torque ripple is increased from 41% to 45%, so that the motor performance cannot be improved.

According to the rotor 100 of the motor 1000 of the embodiment of the present invention, the center line cd of the open slot 22 is located on the leading side of the center line ab of the permanent magnet 10 along the rotation direction of the rotor 100, so that torque pulsation and core loss are effectively reduced, which is beneficial to improving the efficiency of the motor 1000 and reducing vibration noise.

In some embodiments of the present invention, as shown in fig. 2, a first core segment 23 and a second core segment 24 may be formed between the mounting groove 21 and the outer circumferential surface of the rotor core 20, wherein the first core segment 23 is located on the leading side of the second core segment 24, such as the first core segment 23 is located on the side of the second core segment 24 along the rotation direction of the rotor 100. An open slot 22 is formed between the first core segment 23 and the second core segment 24. The extension dimension of the first core segment 23 along the circumferential direction of the rotor core 20 is L1, the extension dimension of the second core segment 24 along the circumferential direction of the rotor core 20 is L2, L1 is more than or equal to 0, and L1 is less than L2.

That is, the two sides of the open slot 22 along the circumferential direction of the rotor core 20 do not exceed the two side edges of the permanent magnet 10, and the extending dimension of the open slot 22 along the circumferential direction of the rotor core 20 is smaller than the extending dimension of the permanent magnet 10 along the circumferential direction of the rotor core 20, so that the first core section 23 and the second core section 24 can limit the permanent magnet 10 by the outer side of the permanent magnet 10, and the outer side of the permanent magnet 10 is provided with silicon steel sheets of sufficient size on the premise of ensuring that the magnetic circuit resistance reduces magnetic leakage, thereby ensuring the structural strength of the rotor core 20, and ensuring that the rotor 100 can work at higher rotation speed without the problem that the permanent magnet 10 flies out due to centrifugal force.

In some embodiments of the present invention, as shown in fig. 1 and 2, the number of poles of the rotor 100 is p, the number of poles is 2p, the plurality of mounting slots 21 are uniformly spaced along the circumferential direction of the rotor core 20, and each permanent magnet 10 corresponds to a center angle of 360 °/2p. The angle α between the center line cd of the open slot 22 and the center line ab of the permanent magnet 10 satisfies: alpha is more than 0 DEG and less than or equal to 360 DEG/4 p.

If the offset angle of the open slot 22 is too large, and the open slot 22 and the permanent magnet 10 are completely offset in the circumferential direction of the rotor core 20, the magnetic path reluctance of the outer side of the permanent magnet 10 is small, and the flux leakage increases, and at this time, the overall average torque decreases, and the performance of the motor 1000 is degraded. In addition, when the offset angle of the open slot 22 is large, the size of the permanent magnet 10 along the circumferential direction of the rotor 100 needs to be large to ensure the same average torque, which results in an increase in the amount of the permanent magnet 10 and an increase in cost.

In the range of the included angle, the average torque is guaranteed, and meanwhile, the excessive consumption of the permanent magnet 10 and the excessive cost are avoided.

For example, in some specific embodiments, as shown in fig. 1 and 2, the first core segment 23 and the second core segment 24 are formed outside the mounting groove 21, the extension dimension L1 of the first core segment 23 along the circumferential direction of the rotor core 20 is 0.5mm, the extension dimension L2 of the second core segment 24 along the circumferential direction of the rotor core 20 is 2mm, the extension dimension of the open groove 22 along the circumferential direction of the rotor core 20 is 1.5mm, the extension dimension of the permanent magnet 10 along the circumferential direction of the rotor core 20 is 4mm, and the sum of the extension dimensions of the first core segment 23, the second core segment 24, and the open groove 22 along the circumferential direction of the rotor core 20 is equal.

In this embodiment, the magnetic circuit reluctance of the outer side of the permanent magnet 10 is increased, the flux leakage is reduced, the torque ripple and the core loss are effectively reduced, the performance of the motor 1000 is improved, the problem of vibration noise of the motor 1000 is improved, and the mechanical strength of the rotor 100 is high, and the rotational speed at which the motor 1000 is allowed to operate is higher.

It should be noted that, in the embodiment of the present invention, the specific structure of the open slot 22 may be flexibly set according to the actual situation.

In some embodiments, as shown in fig. 1 and 2, the open groove 22 may communicate with the mounting groove 21, in other words, the open groove 22 has an inner end notch formed in a groove wall surface of the mounting groove 21. In the embodiment comprising the first core segment 23 and the second core segment 24, the first core segment 23 and the second core segment 24 are completely disconnected. In the above embodiment, the leakage flux is smaller, and the torque performance is better.

In other embodiments, as shown in fig. 11, the mounting slot 21 is spaced from the open slot 22 by a first magnetic barrier bridge 25. In other words, the outer core portion of the permanent magnet 10 is not completely broken, and a first magnetic barrier bridge 25 is formed, and in the embodiment including the first core segment 23 and the second core segment 24, the first core segment 23 and the second core segment 24 are integrally connected by the first magnetic barrier bridge 25. By providing the first magnetism isolating bridge 25, the mechanical strength of the rotor core 20 can be improved, and the permanent magnet 10 is prevented from being thrown out due to a large centrifugal force under high-speed operation.

In some embodiments, the rotor core 20 includes a plurality of laminated silicon steel sheets, and the dimension of the first magnetic bridge 25 along the radial direction of the rotor core 20 may be greater than or equal to the thickness of the silicon steel sheets, and the thickness of the first magnetic bridge 25 is smaller, so that magnetic leakage may be reduced to avoid affecting torque performance. Moreover, by matching the first magnetism isolating bridge 25 with the open slot 22 on the outer side of the first magnetism isolating bridge 25, the reliability of the rotor 100 can be greatly improved on the premise of avoiding the great reduction of the torque performance.

In some embodiments of the present invention, as shown in fig. 2, the width of the open slot 22 along the circumferential direction of the rotor core 20 may be equal everywhere, and the structure is simple and the torque performance is good.

In other embodiments of the present invention, as shown in fig. 12, at least a portion of the open slot 22 decreases inwardly along the width of the rotor core 20 in the circumferential direction. In other words, the width of the outer end of the open slot 22 in the circumferential direction of the rotor core 20 is larger than the width of the inner end in the circumferential direction of the rotor core 20. In this embodiment, by changing the shape of the open groove 22, torque pulsation can be further improved, and vibration noise can be reduced. During machining, a segment of decreasing width may be obtained by cutting a portion of open groove 22 of equal width throughout.

In some embodiments, as shown in fig. 12, the open slot 22 includes a first slot segment 221 and a second slot segment 222 in communication with each other, wherein the first slot segment 221 is located outside of the second slot segment 222. The width of the first slot segment 221 along the circumferential direction of the rotor core 20 decreases inward, and the width of the second slot segment 222 along the circumferential direction of the rotor core 20 is equal everywhere. The two groove sections are matched, so that torque pulsation is improved, excessive torque performance reduction can be avoided, and the dual requirements of motor 1000 performance and vibration noise are met.

It should be noted that the shape of the groove wall surface of the first groove section 221 may be flexibly set according to actual situations. As shown in fig. 12, the groove wall surface of the first groove section 221 is an arc surface, that is, the width of the first groove section 221 decreases gradually, which is more beneficial to improving the torque pulsation and ensuring the torque average value.

Correspondingly, the outer circumferential surface of the rotor core 20 includes circular arc surfaces connecting the adjacent two first slot segments 221 near each other ends. That is, the portion of the rotor core 20 located between the adjacent two center lines cd is generally of a T-shaped structure, the outer circumferential surface of which includes three arc segments connected to each other, forming a three-segment arc cutting structure.

In some embodiments of the present invention, as shown in fig. 13, the permanent magnet 10 may be deflected by a certain angle in the rotation direction of the rotor 100 to function to improve torque ripple. Specifically, the inner end midpoint a of the permanent magnet 10 is connected with the center point o of the rotor core 20 to form a connection oa, the outer end midpoint b of the permanent magnet 10 is located on the leading side of the connection oa, and the included angle γ between the connection oa and the center line ab of the permanent magnet 10 is greater than or equal to 0 °. When the included angle gamma is equal to 0 DEG, the permanent magnet 10 does not deflect, and when the included angle gamma is greater than 0 DEG, the permanent magnet 10 deflects to a certain degree, namely, the permanent magnet 10 deflects around the midpoint a of the inner end of the permanent magnet 10 by an angle gamma.

The pulsation can be improved by the deflection of the permanent magnet 10, and the larger the deflection angle is, the better the torque pulsation improving effect is, but the torque average value is reduced in the improving process. For example, the torque average is reduced by 10% for the same torque ripple request by γ=10° versus γ=5°. By matching the deflection of the permanent magnet 10 with the deflection of the open slot 22, the torque average value can be basically not reduced, and meanwhile, the torque pulsation is effectively improved, so that the torque pulsation has better effect compared with the traditional permanent magnet rotation scheme.

In some embodiments of the present invention, as shown in fig. 1 and 2, a plurality of air slots 26 distributed along the circumferential direction of the rotor core 20 are provided inside the plurality of mounting slots 21, and a second magnetism isolating bridge 27 is formed between two adjacent air slots 26. The air grooves 26 are matched with the second magnetism isolating bridges 27, so that the magnetic leakage of the inner ends of the permanent magnets 10 can be reduced, the magnetic resistance of the magnetic circuit is increased, and meanwhile, the structural strength of the rotor core 20 is ensured.

The shape and number of the air grooves 26 are not particularly limited in the present invention. For example, in some embodiments, as shown in fig. 1 and 2, the air slots 26 are provided in one-to-one correspondence with the mounting slots 21, and the center lines of the air slots 26 and the mounting slots 21 may be collinear, so that the plurality of permanent magnets 10 and the plurality of second magnetic barrier bridges 27 are alternately arranged in the circumferential direction of the rotor core 20.

The motor 1000 according to the embodiment of the present invention includes the rotor 100 of the motor 1000 according to the embodiment of the present invention. Since the rotor 100 of the motor 1000 according to the embodiment of the present invention has the above-described advantageous technical effects, the motor 1000 according to the embodiment of the present invention effectively reduces torque ripple and core loss by the center line cd of the open slot 22 being located on the leading side of the center line ab of the permanent magnet 10 along the rotation direction of the rotor 100, which is advantageous for improving the efficiency of the motor 1000 and reducing vibration noise.

The vehicle according to the embodiment of the invention includes a drive motor, which is the motor 1000 according to the embodiment of the invention. Since the motor 1000 according to the embodiment of the present invention has the above advantageous technical effects, the vehicle according to the embodiment of the present invention, through the center line cd of the open slot 22 being located on the leading side of the center line ab of the permanent magnet 10 along the rotation direction of the rotor 100, effectively reduces torque ripple and core loss, is advantageous for improving the efficiency of the motor 1000 and reducing vibration noise.

Other configurations and operations of the vehicle and motor 1000 according to embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail herein.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In the description herein, reference to the terms "embodiment," "specific embodiment," "example," and the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims (12)

1. A rotor for an electric machine, comprising:

a permanent magnet;

a rotor core having a plurality of mounting grooves spaced apart in a circumferential direction of the rotor core, the permanent magnets being mounted in the mounting grooves, an open groove being provided between each of the mounting grooves and an outer circumferential surface of the rotor core,

the connection line between the inner end midpoint a and the outer end midpoint b of the permanent magnet is a central line ab, the connection line between the inner end midpoint c and the outer end midpoint d of the corresponding open slot is a central line cd, and the central line cd is located on the leading side of the central line ab in the rotating direction of the rotor.

2. The rotor of the motor according to claim 1, wherein a first core segment and a second core segment are formed between the mounting groove and an outer circumferential surface of the rotor core, the first core segment being located on a leading side of the second core segment and the open groove being formed between the second core segment,

the extension sizes of the first iron core section and the second iron core section along the circumferential direction of the rotor iron core are L1 and L2 respectively, wherein L1 is more than or equal to 0, and L1 is less than L2.

3. The rotor of an electric machine according to claim 2, wherein the pole pair number of the rotor is p, the plurality of mounting grooves are uniformly spaced along the circumferential direction of the rotor core, and an angle α between the center line cd and the center line ab satisfies:

0°＜α≤360°/4p。

4. the rotor of an electric machine of claim 1, wherein the open slot communicates with the mounting slot.

5. The rotor of an electric machine of claim 1, wherein the mounting slot is spaced from the open slot by a first magnetically isolated bridge.

6. The rotor of an electric machine according to claim 5, wherein the rotor core includes a plurality of laminated silicon steel sheets, and a dimension of the first magnetism isolating bridge in a radial direction of the rotor core is greater than or equal to a thickness of the silicon steel sheets.

7. The rotor of an electric machine according to claim 1, wherein at least a portion of the open slot decreases inward in width along a circumferential direction of the rotor core.

8. The rotor of an electric machine according to claim 7, wherein the open slot includes a first slot section and a second slot section communicating with each other, the first slot section being located outside the second slot section,

the first slot segments decrease inward in width along the circumferential direction of the rotor core, and the second slot segments are equal everywhere in width along the circumferential direction of the rotor core.

9. The rotor of claim 8, wherein the wall surfaces of the first slot segments are arc surfaces, and the outer circumferential surface of the rotor core includes arc surfaces connecting adjacent ends of the first slot segments.

10. The rotor of an electric machine according to claim 1, characterized in that the inner end midpoint a of the permanent magnet is connected to the center point o of the rotor core as a connection oa, the outer end midpoint b of the permanent magnet is located on the leading side of the connection oa, and the angle γ of the connection oa to the center line ab is greater than or equal to 0 °.

11. An electric machine, characterized by comprising a rotor of an electric machine according to any one of claims 1-10.

12. A vehicle comprising a drive motor, the drive motor being the motor according to claim 11.