CN205407440U - Rotor core and have its PMSM - Google Patents

Abstract

The utility model provides a rotor iron core and a permanent magnet synchronous motor with the same. The rotor core includes: a core body, grooves are formed on the outer peripheral wall of the core body along the axial direction of the core body, the grooves include a first groove and a second groove connected to each other, the first groove The depth along the radial direction of the iron core body is greater than the depth of the second groove along the radial direction of the iron core body. The air gap at the first groove is the largest, the magnetic resistance is large, the magnetic density of the air gap is small, and the torque ripple of the stator cogging is reduced. The depth of the first groove and the second groove is different, and the transition through the second groove makes the The fundamental magnetic field increases and is closer to sine, reducing the cogging torque, increasing the output of the motor, reducing harmonics, reducing the electromagnetic force of the motor and operating vibration noise.

Description

Rotor core and permanent magnet synchronous motor with same

technical field

The utility model relates to a rotor iron core and a permanent magnet synchronous motor with the same.

Background technique

In a motor in the prior art, the outer circumference of the rotor is provided with V-shaped grooves and trimming grooves, and the trimming grooves are asymmetrical. Its rotor is composed of multiple axially misaligned iron cores, so that the cogging torque and the torque generated by the winding are 180° out of phase to reduce torque ripple. However, the process of the motor is complex, which is not convenient for mass production, and this may lead to a decrease in the performance of the motor and an increase in the cost of the motor.

Another type of motor in the prior art has a permanent magnet motor stator and rotor structure with built-in V-shaped grooves, which can reduce loss, reduce torque ripple, reduce noise, and improve motor efficiency. But for this motor, the problem of vibration and noise caused by the third-order electromagnetic force generated by the 9-slot, 6-pole fractional-slot motor is not considered, and this method is not suitable for the distributed winding motor.

Utility model content

The main purpose of the utility model is to provide a rotor iron core capable of reducing vibration noise and improving working performance and a permanent magnet synchronous motor with the same.

In order to achieve the above object, according to one aspect of the utility model, a rotor core is provided, including: a core body, a groove is opened on the outer peripheral wall of the core body along the axial direction of the core body, and the groove includes The first groove and the second groove are connected, and the depth of the first groove along the radial direction of the iron core body is greater than the depth of the second groove along the radial direction of the iron core body.

Further, the rotor core also includes: a plurality of magnetic steel grooves, which are opened on the core body, and magnetic steel is provided in the magnetic steel grooves, and every two adjacent magnetic steel grooves provided with magnetic steel form a magnetic pole area, There is an intermagnetic area between two adjacent magnetic pole areas, and the groove is arranged at the intermagnetic area.

Further, the line connecting the center of the intermagnetic area and the center of the iron core body is the Q axis, and the grooves are arranged symmetrically about the Q axis.

Further, the groove includes a first groove and two second grooves, the Q axis passes through the center of the first groove, and the two second grooves are respectively arranged on two sides of the first groove with the Q axis as a symmetrical axis. end.

Further, there are a plurality of grooves, and the plurality of grooves are evenly spaced along the circumferential direction of the iron core body, and the same magnetic pole area also includes two second grooves respectively located in different grooves and two second grooves respectively located in different grooves. Part of the first groove in the groove.

Further, the included angle between the adjacent ends of the two second grooves in the same magnetic pole region and the center of the iron core body is α, where 0.33τ≤α≤0.66τ, τ is the pole distance, τ=180°/p, p is the number of pole pairs of the motor.

Further, the depth of the second groove is S1, wherein, 0.33δ≤S1≤0.66δ, and δ is the length of the air gap.

Further, the connecting line between the center of the intermagnetic area and the center of the iron core body is the Q axis, and the clamping line between the opposite ends of the two first grooves in the same magnetic pole area and the center of the iron core body The angle is β, where 0.66τ<β≤0.8τ, τ is the pole pitch, τ=180°/p, and p is the number of pole pairs of the motor.

Further, one magnetic pole area has two magnetic steel slots, each magnetic steel slot has a first magnetic steel slot end adjacent to another magnetic steel slot in the same magnetic pole area and a first magnetic steel slot end adjacent to another magnetic pole area. The end of the second magnetic steel slot, the second magnetic steel slot end is provided with a magnetic isolation bridge hole connected with the magnetic steel slot, and the angle between the opposite inner end faces of the two magnetic isolation bridge holes in the same magnetic pole area is μ, where μ≥0.8τ.

Further, the radial depth of the first groove is S2, wherein, 0.66δ≤S2≤δ, δ is the length of the air gap.

Further, a connecting portion communicating with the two first magnetic steel slots is also provided between the ends of the two first magnetic steel slots in the same magnetic pole region, and the connecting portion has an arc section protruding toward the outer edge of the iron core body.

Further, the magnetic steel groove has a first magnetic steel groove wall and a second magnetic steel groove wall arranged oppositely, and the first magnetic steel groove wall at the end of the first magnetic steel groove is bent towards the direction of the second magnetic steel groove wall The second magnetic steel slot wall located at the end of the second magnetic steel slot is bent and extended toward the direction of the first magnetic steel slot wall to form the second stop portion.

Further, the plurality of magnetic steel grooves in the same magnetic pole region form a V shape with gradually increasing spacing along the radial direction of the iron core body, and the included angle of the V shape is θ, wherein 90°≤θ≤150°.

Further, the groove bottom walls of the first groove and the second groove are arc-shaped and arranged concentrically with the iron core body.

According to another aspect of the present utility model, there is also provided a permanent magnet synchronous motor, which includes a rotor core, and the rotor core is the above-mentioned rotor core.

Further, the permanent magnet synchronous motor further includes a stator core, the stator core is provided with a winding coil and a rotor shaft hole, and the rotor core is rotatably disposed in the inner ring of the stator core.

Applying the technical solution of the utility model, the rotor core has a first groove and a second groove with different depths along the radial direction of the core body. The air gap at the first groove is the largest, the magnetic resistance is large, the magnetic density of the air gap is small, and the torque ripple of the stator cogging is reduced. The depth of the first groove and the second groove is different, and the transition through the second groove makes the The fundamental magnetic field increases and is closer to sinusoidal, reducing the cogging torque, increasing the output of the motor, reducing harmonics, reducing the electromagnetic force of the motor and operating vibration noise.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide a further understanding of the utility model, and the schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute improper limitations to the utility model. In the attached picture:

Fig. 1 shows a schematic structural view of a rotor core according to the present invention;

Fig. 2 shows the enlarged view of place A of Fig. 1;

Fig. 3 shows a partial structural schematic diagram of a magnetic pole region of the rotor core according to the present invention;

Fig. 4 shows a schematic diagram of the assembly of the rotor core and the stator core according to the present invention;

Fig. 5 shows the torque contrast diagram of prior art scheme and the embodiment of the present utility model;

Figure 6 shows a comparison diagram of the radial electromagnetic force at each frequency between the prior art solution and the embodiment of the technical solution;

Fig. 7 shows a comparison of iron loss curves between the prior art solution and the embodiment of the present technical solution.

detailed description

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

The main purpose of the utility model is to provide a rotor iron core capable of reducing vibration noise and improving working performance and a permanent magnet synchronous motor with the same.

As shown in Figure 1, the utility model provides a rotor core.

Specifically, as shown in FIGS. 1 to 3 , the rotor core includes a core body 10 , and a groove 20 is opened on the outer peripheral wall of the core body 10 along the axial direction of the core body 10 . The groove 20 includes at least one first groove 21 and at least one second groove 22 which communicate with each other. The depth S2 of the first groove 21 along the radial direction of the iron core body 10 is greater than that of the second groove 22 along the direction of the iron core body. 10 Depth S1 in radial direction.

The air gap at the first groove 21 at the groove 20 is the largest, the magnetic resistance is large, the air gap magnetic density is small, and the torque ripple of the stator cogging is reduced. The depth of the first groove 21 and the second groove 22 is different. Through the transition of the second groove 22, the fundamental magnetic field increases and becomes closer to sine, the cogging torque is reduced, the output of the motor is increased, the harmonics are reduced, and the electromagnetic force and operating vibration noise of the motor are reduced.

Further, the groove bottom walls of the first groove 21 and the second groove 22 are arc-shaped and arranged concentrically with the iron core body 10 . The depth of the groove is more controllable and uniform in depth. The groove between the rotor magnetic poles can effectively reduce the reluctance pulsation, reduce the cogging torque and torque pulsation, make it easier to control, and effectively reduce vibration and noise.

As shown in FIG. 1 , the rotor core further includes a plurality of magnetic steel slots 30 . The magnetic steel slots 30 are opened on the core body 10 , and the magnetic steel slots 30 are provided with a magnetic steel 31 . Every two adjacent magnetic steel grooves 30 provided with magnetic steel 31 form a magnetic pole area, and there is a distance between adjacent two magnetic pole areas to form an intermagnetic area, and the groove 20 is disposed at the intermagnetic area. The air gap at the groove 20 is larger, the reluctance increases, and the magnetic field concentrates toward the center of the intermagnetic area, so that the fundamental air gap magnetic field increases, the fundamental magnetic field is closer to sinusoidal, the cogging torque is reduced, and the motor output is increased. Large, the harmonics are reduced, and the electromagnetic force of the motor and the vibration and noise of the operation are reduced.

Further, the line connecting the center of the intermagnetic area and the center of the iron core body 10 is the Q axis, and the grooves 20 are arranged symmetrically about the Q axis. Preferably, as shown in Figures 2 and 3, the groove 20 includes a first groove 21 and two second grooves 22, the Q axis passes through the center of the first groove 21, and the two second grooves 22 The Q axis is a symmetrical axis and is respectively arranged at two ends of the first groove 21 . The structure is simple, stable, easy to implement, and can effectively reduce the reluctance ripple between the magnetic poles, reduce the sudden change of the magnetic field, and achieve the purpose of reducing iron loss and torque ripple.

As shown in Figure 1, there are multiple grooves 20, and the multiple grooves 20 are evenly spaced along the circumference of the iron core body 10, and the same magnetic pole area also includes two second grooves respectively located in different grooves 20 22 and two parts of the first groove 21 respectively located in different grooves 20 . Two second grooves 22 are included in the same magnetic pole region, and the two second grooves 22 are respectively located in two adjacent magnetic pole regions. Two first grooves 21 are also included in the same magnetic pole region, and the two first grooves 21 are incomplete, and are respectively part of the first grooves 21 in two adjacent magnetic pole regions.

As shown in FIG. 1 , the included angle between the adjacent ends of the two second grooves 22 in the same magnetic pole area and the center of the core body 10 is α, where 0.33τ≤α≤0.66 τ, τ is the pole pitch, τ=180°/p, p is the number of pole pairs of the motor.

Preferably, as shown in FIG. 3 , the depth of the second groove 22 is S1 , where 0.33δ≦S1≦0.66δ, and δ is the length of the air gap.

As shown in Figure 1, the line connecting the center of the magnetic space area and the center of the iron core body 10 is the Q axis, and the distance between the opposite ends of the two first grooves 21 in the same magnetic pole area and the center of the iron core body 10 The angle between the connecting lines is β, where 0.66τ<β≤0.8τ, τ is the pole pitch, τ=180°/p, and p is the number of pole pairs of the motor.

As shown in Fig. 1 and Fig. 3, a magnetic pole area has two magnetic steel slots 30, each magnetic steel slot 30 has a first magnetic steel slot end 32a adjacent to another magnetic steel slot 30 in the same magnetic pole area And there is also a second magnetic steel slot end 32b adjacent to the other magnetic pole region. In detail, as shown in FIG. 3 , there is at least one set of magnetic steel slot sets in a magnetic pole area, and the set of magnetic steel slot sets includes two magnetic steel slots 30 . Each magnetic steel slot 30 has a first magnetic steel slot end 32a and a second magnetic steel slot end 32b, and the two first magnetic steel slot ends of the two magnetic steel slots 30 in the group of magnetic steel slots 32a are arranged close to each other, and the two second magnetic steel groove ends 32b of the two magnetic steel grooves 30 in the group of magnetic steel grooves are set away from each other.

As shown in Figure 1, the second magnetic steel slot end 32b is provided with a magnetic isolation bridge hole 33 that communicates with the magnetic steel slot 30, and the clip between the opposite inner end faces of the two magnetic isolation bridge holes 33 in the same magnetic pole region The angle is μ, where μ≥0.8τ.

Further, as shown in FIG. 2 and FIG. 3 , the depth in the radial direction of the first groove 21 is S2 , where 0.66δ≤S2≤δ, δ is the length of the air gap.

As shown in FIG. 3 , a connecting portion 34 communicating with the two magnetic steel grooves 30 is also provided between the two first magnetic steel slot ends 32 a in the same magnetic pole area, and the connecting portion 34 has a direction toward the core body 10 . The arc segment 35 protruding from the outer edge.

Preferably, as shown in FIG. 3 , the magnetic steel slot 30 has a first magnetic steel slot wall 36 and a second magnetic steel slot wall 37 oppositely arranged, and the first magnetic steel slot wall positioned at the end 32a of the first magnetic steel slot 36 is bent and extended toward the second magnetic steel slot wall 37 , and the bent and extended part forms the first stopper portion 38 . The second magnetic steel slot wall 37 at the end portion 32 b of the second magnetic steel slot bends and extends toward the first magnetic steel slot wall 36 to form a second stopper portion 39 . The first stop portion 38 and the second stop portion 39 are the top shoulder structure of the magnetic steel groove 30, or the first stop portion 38 and the second stop portion 39 are the limit card points of the magnetic steel groove 30. It is for preventing the magnetic steel 31 from shifting and vibrating.

Further, a plurality of magnetic steel slots 30 in the same magnetic pole area form a V shape with gradually increasing spacing along the radial direction of the iron core body 10, and the included angle of the V shape is θ, where 90°≤θ≤150° .

As shown in FIG. 4 , the present invention also provides a distributed winding permanent magnet synchronous motor, which includes a rotor core 50 , which is the rotor core in the above-mentioned embodiment. The rotor core has a first groove and a second groove with different depths along the radial direction of the core body, which can effectively reduce the iron loss of the motor and improve the efficiency of the motor. Moreover, the cogging torque and torque ripple are small, and the radial electromagnetic force is small, which can effectively reduce the vibration and noise of the motor. The process is easy to realize and the manufacturing cost is low.

Further, as shown in FIG. 4, the permanent magnet synchronous motor also includes a stator core 20, the stator core 20 is provided with a winding coil 60 and a rotor shaft hole 70, and the rotor core 50 is rotatably arranged in the stator core 20 In the ring, the rotor core 50 is also provided with a rivet hole 80 for fixing.

Specifically, in this embodiment, a specific implementation manner is described in conjunction with a 36-slot, 6-pole motor.

FIG. 1 is a structural diagram of the rotor punching of the rotor core 50 of the motor. As shown in FIG. 3 , the motor is composed of a stator core 20 and a rotor core 50 , and a winding coil 60 is wound on the stator core 10 . The rotor core 50 is provided with a magnetic steel groove 30 for placing the magnetic steel 31 , and a rotor shaft hole 70 and a rivet hole 80 matched with the rotating shaft. Magnetic bridge holes 33 are provided at the end of the magnetic steel slot 30 , and a first groove 21 and a second groove 22 are formed on the outer peripheral wall of the rotor core 50 , and the depth of the first groove 21 is greater than that of the second groove 22 . In order to prevent the magnetic steel 31 from shifting and vibrating, both ends of the magnetic steel 31 are provided with a limit card point, that is, a first stop portion 38 and a second stop portion 39, and two pieces of magnetic steel 31 are provided with a circular arc section 35. The connection part 34 is used to further reduce the magnetic flux leakage here.

As shown in Figure 1, the angle between the two second grooves 22 under the same magnetic pole is α, the angle between the two first grooves 21 is β, and the angle between the two magnetic isolation bridge holes 33 under the same rotor magnetic pole is μ , the angle between the magnetic steel slots 30 in the same magnetic pole region is θ.

Preferably, the angle α between two second grooves 22 in the same magnetic pole area should satisfy 0.33τ≤α≤0.66τ, where τ is the pole pitch, ie 180°/p, and p is the number of pole pairs of the motor. The depth S1 of the second groove 22 satisfies 0.33δ≤S1≤0.66δ, where δ is the length of the air gap. The air gap length is the distance between the rotor core 50 and the stator core 20 . The pole distance τ in this embodiment is the angle between two adjacent Q axes.

The settings in the above embodiment can ensure that the stator corresponding to α includes at least one stator tooth pitch, and at the same time, the reluctance at the groove 20 increases, and the magnetic field concentrates at the center of the magnetic pole, so that the fundamental air gap magnetic field increases, and the fundamental magnetic field It is closer to sine, reduces cogging torque, increases motor output, reduces harmonics, reduces motor electromagnetic force and operating vibration noise. At the same time, the depth S1 of the second groove 22 satisfies 0.33δ≤S1≤0.66δ, that is, the depth of the second groove 22 should not be too shallow, and the effect of being too shallow is not obvious. But it can't be too deep, otherwise it will have a great impact on the rotor air gap, resulting in a decrease in motor output and performance, and the desired effect cannot be achieved.

Further, the angle between the two first grooves 21 in the same magnetic pole area is β, and the angle β needs to satisfy 0.66τ<β≤μ, μ is the angle of the magnetic bridge at both ends of a pole, μ≥0.8τ, that is, 0.66 τ<β≤0.8τ, the depth S2 of the first groove 21 satisfies 0.66δ≤S2≤δ.

In this embodiment, β is required to be greater than the angle α between the second grooves 22 and smaller than μ, while the depth S2 of the first groove 21 is greater than the depth of the second groove 22 and smaller than the width of the air gap. This design can ensure a proper size of the first groove 21, can effectively reduce the reluctance pulsation between the magnetic poles, reduce the sudden change of the magnetic field, can achieve the purpose of reducing iron loss and torque pulsation, and reduce the electromagnetic force of the motor and operating vibration noise . If the size of the first groove 21 and the second groove 22 in the groove 20 is larger than the required range, the effect of reducing the torque ripple of the motor is not obvious, or the insufficient output of the motor causes the current to increase and the efficiency of the motor to decrease.

In this embodiment, the first grooves 21 and the second grooves 22 are located on the Q-axis between the rotor magnetic poles, and are evenly distributed along the circumference of the rotor core.

Furthermore, the same magnetic pole consists of two pieces of magnetic steel 31 to form a V-shaped structure, or a plurality of pieces of magnetic steel 31 can be used to form a V-shaped structure, and the V-shaped included angle θ satisfies 90°≤θ≤150°. The permanent magnets are installed so that their polarities N and S are placed alternately on the side facing the stator core 20, and the magnetic steel 31 magnetization direction is perpendicular to the magnetic steel surface, so that the two magnetic steels 31 have a magnetization effect, Make the magnetic field more concentrated to the center of the magnetic pole, increase the fundamental wave of the air gap magnetic field, and reduce the cogging torque. When 90°≤θ≤150°, the effect is the best.

As shown in Figure 5, the torque comparison between the original technical solution and the implementation example of this technical solution is shown. Under the condition that other parameters and the amount of magnetic steel are kept the same, the torque comparison after optimization and implementation according to this technical solution can be seen. After optimization according to the technical proposal, the torque ripple of the motor decreases by 61%, and the output of the motor does not decrease. Reducing the torque ripple can effectively reduce the vibration and noise of the motor and facilitate the precise control of the motor, increasing the reliability of the motor.

As shown in Figure 6, it is the comparison of the radial electromagnetic force of each frequency between the original technical scheme and the implementation example of this technical scheme. It can be seen that after adopting this technical scheme, 36f (electromagnetic force frequency, f is the mechanical frequency of the rotor) radial electromagnetic force The force drops significantly, thereby significantly reducing the problem of vibration and noise caused by the electromagnetic force.

Figure 7 shows the iron loss curve comparison between the original technical solution and the implementation example of this technical solution. After adopting this technical solution, the pulsation of the iron loss curve is reduced, and the average value of iron loss is greatly reduced, which can improve the efficiency of the motor and reduce the iron loss of the motor. The temperature rise caused by the motor increases the reliability of the motor operation.

From the above description, it can be seen that the above-mentioned embodiments of the utility model have achieved the following technical effects:

The air gap at the first groove 21 at the groove 20 is the largest, the magnetic resistance is large, the air gap magnetic density is small, and the torque ripple of the stator cogging is reduced. The depth of the first groove 21 and the second groove 22 is different. Through the transition of the second groove 22, the fundamental magnetic field increases and becomes closer to sine, the cogging torque is reduced, the output of the motor is increased, the harmonics are reduced, and the electromagnetic force and operating vibration noise of the motor are reduced.

The above descriptions are only preferred embodiments of the utility model, and are not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (16)

1. A rotor core, characterized in that it comprises: The iron core body (10), the outer peripheral wall of the iron core body (10) is provided with a groove (20) along the axial direction of the iron core body (10), and the groove (20) includes a connected The first groove (21) and the second groove (22), the depth of the first groove (21) along the radial direction of the iron core body (10) is greater than that of the second groove (22 ) along the radial direction of the iron core body (10). 2. The rotor core according to claim 1, wherein the rotor core further comprises: A plurality of magnetic steel grooves (30) are provided on the iron core body (10), and magnetic steel (31) is arranged in the magnetic steel groove (30), and every two magnetic steel grooves (31) are provided with Two adjacent magnetic steel grooves (30) form a magnetic pole region, and there is a magnetic intermagnetic region between two adjacent magnetic steel grooves, and the groove (20) is arranged at the magnetic interregion. 3. The rotor core according to claim 2, characterized in that, the line connecting the center of the intermagnetic area and the center of the core body (10) is the Q axis, and the groove (20) is The Q axis is set symmetrically. 4. The rotor core according to claim 3, characterized in that, the groove (20) includes one first groove (21) and two second grooves (22), the The Q axis passes through the center of the first groove (21), and the two second grooves (22) are respectively arranged at two ends of the first groove (21) with the Q axis as a symmetrical axis. 5. The rotor core according to claim 4, characterized in that there are multiple grooves (20), and the multiple grooves (20) are spaced along the circumference of the core body (10) Evenly arranged, the same magnetic pole region also includes two second grooves (22) respectively located in different grooves (20) and two parts respectively located in different grooves (20) The first groove (21). 6. The rotor core according to claim 5, characterized in that the adjacent ends of the two second grooves (22) in the same magnetic pole area are in contact with the core body (10) The included angle of the line between the centers of is α, where 0.33τ≤α≤0.66τ, τ is the pole pitch, τ=180°/p, and p is the number of pole pairs of the motor. 7. The rotor core according to claim 1 or 6, characterized in that, the depth of the second groove (22) is S1, where 0.33δ≤S1≤0.66δ, δ is the air gap length. 8. The rotor core according to claim 2, characterized in that, the line connecting the center of the magnetic inter-magnetic region and the center of the core body (10) is the Q axis, and two of the same magnetic pole regions The angle between the opposite end of the first groove (21) and the center of the iron core body (10) is β, where 0.66τ<β≤0.8τ, τ is a pole distance, τ=180°/p, p is the number of pole pairs of the motor. 9. The rotor core according to claim 8, characterized in that one magnetic pole region has two magnetic steel slots (30), and each magnetic steel slot (30) has the same magnetic pole. The first magnetic steel slot end (32a) adjacent to the other magnetic steel slot (30) in the area and the second magnetic steel slot end (32b) adjacent to the other magnetic pole area, The end of the second magnetic steel slot (32b) is provided with a magnetic isolation bridge hole (33) connected to the magnetic steel slot (30), and the two magnetic isolation bridge holes (33) in the same magnetic pole area ) The angle between the opposite inner end faces is μ, where μ≥0.8τ. 10. The rotor core according to claim 1, characterized in that, the depth in the radial direction of the first groove (21) is S2, where 0.66δ≤S2≤δ, δ is gas gap length. 11. The rotor core according to claim 9, characterized in that, between the two first magnetic steel slot ends (32a) in the same magnetic pole area, there are also two magnetic steel slot ends (32a) The slot (30) communicates with a connecting portion (34), and the connecting portion (34) has an arc segment (35) protruding toward the outer edge of the iron core body (10). 12. The rotor core according to claim 9, characterized in that, the magnetic steel slot (30) has a first magnetic steel slot wall (36) and a second magnetic steel slot wall (37) oppositely arranged, located at The first magnetic steel groove wall (36) at the first magnetic steel groove end (32a) is bent and extended toward the second magnetic steel groove wall (37) to form a first stopper ( 38); the second magnetic steel groove wall (37) at the end (32b) of the second magnetic steel groove is bent and extended towards the direction of the first magnetic steel groove wall (36) to form a second stop (39). 13. The rotor core according to claim 2, characterized in that, a plurality of the magnetic steel slots (30) in the same magnetic pole area form a distance apart along the radial direction of the core body (10) A gradually increasing V-shape, the included angle of the V-shape is θ, wherein, 90°≤θ≤150°. 14. The rotor core according to claim 1, characterized in that, the groove bottom walls of the first groove (21) and the second groove (22) are arc-shaped and are aligned with the core The body (10) is arranged concentrically. 15. A distributed winding permanent magnet synchronous motor, characterized in that it comprises a rotor core (50), and the rotor core (50) is the rotor core according to any one of claims 1-14. 16. The distributed volume permanent magnet synchronous motor according to claim 15, characterized in that, the permanent magnet synchronous motor also includes a stator core (20), and the stator core (20) is provided with a winding coil (60) and a rotor shaft hole (70), the rotor core (50) is rotatably arranged in the inner ring of the stator core (20).