Permanent magnet motor and motor rotor

Abstract

The present invention relates to a permanent magnet motor and a motor rotor, wherein the motor rotor comprises: a rotor core; a plurality of permanent magnets which are circumferentially spaced and distributed on the rotor core, and two adjacent permanent magnets of the same polarity are arranged opposite to each other; wherein a rotor pole is arranged between two adjacent permanent magnets on the rotor core, and each rotor pole is provided with a magnetic isolation groove, and the magnetic isolation groove comprises magnetic isolation sections which are respectively located on both sides of the radial center line of the rotor pole; each magnetic isolation section has a radial outermost end close to the outer circumferential surface of the rotor pole and a radial innermost end away from the outer circumferential surface of the rotor pole, and each magnetic isolation section extends non-linearly from the radial outermost end to the radial innermost end in a direction deviating from the radial center line of the rotor pole, so that the magnetic permeability of the rotor pole in the circumferential and radial directions is more uniform, the waveform of the air gap magnetic density is improved, the motor torque pulsation is reduced, and the vibration and noise of the motor are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a permanent magnet motor and a motor rotor. Background Art

[0002] The permanent magnet motor includes a motor stator and a motor rotor, which is rotatably mounted inside the motor stator. The motor rotor also includes a rotor core and permanent magnets, which are mounted on the rotor core to generate a magnetic field.

[0003] Permanent magnet motors can be categorized as radial permanent magnet motors and tangential permanent magnet motors based on the arrangement of their permanent magnets. Tangential permanent magnet motors achieve a larger air gap flux density, resulting in higher torque. However, because the permanent magnet poles do not directly face the stator, regulating the air gap magnetic field is more difficult in tangential permanent magnet motors. The air gap flux density and back EMF contain high harmonic content, resulting in greater torque ripple and vibration. Summary of the Invention

[0004] Based on this, it is necessary to provide a motor rotor that reduces motor vibration to address the problem of large motor vibration.

[0005] A motor rotor, comprising:

[0006] rotor core;

[0007] A plurality of permanent magnets are circumferentially spaced and distributed on the rotor core, with adjacent two permanent magnets having the same polarity arranged opposite to each other;

[0008] Wherein, a rotor pole is arranged between two adjacent permanent magnets on the rotor core, and a magnetic isolation groove is opened on each rotor pole, and the magnetic isolation groove includes magnetic isolation sections respectively located on both sides of the radial center line of the rotor pole;

[0009] Each magnetic isolation section has a radial outermost end close to the outer circumferential surface of the rotor pole and a radial innermost end away from the outer circumferential surface of the rotor pole, and each magnetic isolation section extends non-linearly from the radial outermost end to the radial innermost end in a direction deviating from the radial center line of the rotor pole.

[0010] In the above-mentioned motor rotor, a magnetic isolation groove is provided on the rotor pole between two adjacent permanent magnets to guide the direction of the magnetic flux in the rotor pole. Specifically, the magnetic isolation groove includes magnetic isolation segments located on both sides of the radial centerline of the rotor pole, and the magnetic isolation segments extend non-linearly from the radial outermost end to the radial innermost end in a direction deviating from the radial centerline of the rotor pole, that is, each magnetic isolation segment is inclined on one side of the radial centerline of the rotor pole and extends non-linearly, so that each magnetic isolation segment has a certain gradient in the circumferential direction of the motor rotor and also has a certain gradient in the radial direction of the motor rotor. The magnetic isolation groove can block and guide the magnetic circuit in the circumferential and radial directions of the rotor pole, making the magnetic permeability of the rotor pole in the circumferential and radial directions more uniform, improving the direction of the magnetic flux in the rotor pole, improving the waveform of the air gap magnetic density, reducing the proportion of back electromotive force harmonics, reducing the motor torque pulsation, and reducing the vibration and noise of the motor.

[0011] In one embodiment, the radially outermost end and the radially innermost end are staggered in both radial and circumferential directions of the rotor pole.

[0012] In one embodiment, the magnetic shielding section bends and extends between the radially outermost end and the radially innermost end.

[0013] In one embodiment, the magnetic isolation section includes a first bent section and a second bent section connected to each other, the first bent section and the second bent section are staggered in the radial and circumferential directions of the rotor magnetic pole, and one end of the first bent section is the radial outermost end, and one end of the second bent section is the radial innermost end;

[0014] The radial length of the first bending section is M, the radial length of the second bending section is N, and the ratio of M / N satisfies the following relationship: 0.9≥M / N≥0.2.

[0015] In one embodiment, the magnetic isolation segments on both sides of the radial center line of the rotor pole are disconnected from each other.

[0016] In one embodiment, there is a spacing distance between the radial outermost ends on both sides of the radial center line of the rotor pole, and the spacing distance is less than 1.5 times the length of the air gap between the motor rotor and the motor stator.

[0017] In one embodiment, an auxiliary magnetic isolation groove is opened on the radial center line of the rotor magnetic pole, the auxiliary magnetic isolation groove is close to the outer peripheral surface of the rotor magnetic pole, and the auxiliary magnetic isolation groove is disconnected from the magnetic isolation groove.

[0018] In one embodiment, the magnetic isolation segments on both sides of the radial center line of the rotor pole are connected to each other.

[0019] In one embodiment, the radial outermost ends on both sides of the radial center line of the rotor pole are connected to each other.

[0020] In one embodiment, the magnetic isolation segments on both sides of the radial center line of the rotor magnetic pole are symmetrical to each other; or

[0021] The magnetic isolation segments on both sides of the radial center line of the rotor magnetic pole are staggered in the radial direction of the rotor magnetic pole (12).

[0022] In one embodiment, the magnetic isolation slot further includes a branch segment, which is connected to the magnetic isolation segment and extends in a direction close to the radial center line of the rotor pole.

[0023] In one embodiment, the branch segments are provided on both sides of the radial center line of the rotor pole, and the branch segments on both sides of the radial center line of the rotor pole are connected to or disconnected from each other.

[0024] The present invention further provides a permanent magnet motor, comprising a motor stator and the motor rotor, wherein the motor rotor is rotatably sleeved in the motor stator. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of magnetic flux of a motor rotor according to one embodiment of the present invention;

[0026] Figure 2 for Figure 1 The schematic diagram of the structure of the motor rotor shown;

[0027] Figure 3 A schematic structural diagram of a motor rotor in another embodiment of the present invention;

[0028] Figure 4 A schematic structural diagram of a motor rotor in another embodiment of the present invention;

[0029] Figure 5 A schematic structural diagram of a motor rotor in yet another embodiment of the present invention;

[0030] Figure 6 A schematic structural diagram of a motor rotor in yet another embodiment of the present invention;

[0031] Figure 7 A schematic structural diagram of a motor rotor in yet another embodiment of the present invention;

[0032] Figure 8 A schematic structural diagram of a motor rotor in yet another embodiment of the present invention;

[0033] Figure 9 A schematic structural diagram of a motor rotor in yet another embodiment of the present invention;

[0034] Figure 10 A schematic structural diagram of a motor rotor in yet another embodiment of the present invention;

[0035] Figure 11 A schematic structural diagram of a motor rotor in yet another embodiment of the present invention;

[0036] Figure 12 A schematic structural diagram of a motor rotor in yet another embodiment of the present invention;

[0037] Figure 13 A schematic structural diagram of a motor rotor in yet another embodiment of the present invention;

[0038] Figure 14 A schematic structural diagram of a permanent magnet motor according to an embodiment of the present invention;

[0039] Figure 15 A comparison diagram of back EMF harmonics between a motor rotor in an embodiment of the present invention and a conventional motor rotor;

[0040] Figure 16 for Figure 15 The comparison diagram of the torque pulsation of the motor rotor shown and the existing motor rotor. DETAILED DESCRIPTION

[0041] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0042] It should be noted that when an element is referred to as being “fixed to” another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or there may be an intermediate element.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0044] like Figure 1As shown, in one embodiment of the present invention, a motor rotor 100 is provided. The motor rotor 100 includes a rotor core 10 and a plurality of permanent magnets 30. The plurality of permanent magnets 30 are circumferentially spaced and distributed on the rotor core 10, with adjacent permanent magnets 30 having the same polarity facing each other. Specifically, the motor rotor 100 is used in a tangential permanent magnet motor, and each permanent magnet 30 on the rotor core 10 extends radially of the rotor core 10.

[0045] Furthermore, a rotor pole 12 is arranged between two adjacent permanent magnets 30 on the rotor core 10, and a magnetic isolation groove 13 is opened on each rotor pole 12. The magnetic isolation groove 13 includes magnetic isolation sections 132 respectively located on both sides of the radial center line a of the rotor pole 12; each magnetic isolation section 132 has a radial outermost end 131 close to the outer peripheral surface of the rotor pole 12 and a radial innermost end 133 away from the outer peripheral surface of the rotor pole 12, and each magnetic isolation section 132 extends non-linearly from the radial outermost end 131 to the radial innermost end 133 in a direction deviating from the radial center line a of the rotor pole 12.

[0046] In the above-mentioned motor rotor 100, a magnetic isolation groove 13 is provided on the rotor pole 12 between two adjacent permanent magnets 30 to guide the direction of the magnetic flux in the rotor pole 12. Specifically, the magnetic isolation groove 13 includes magnetic isolation segments 132 located on both sides of the radial center line a of the rotor pole 12. The magnetic isolation segment 132 extends non-linearly from the radial outermost end 131 to the radial innermost end 133 in a direction deviating from the radial center line a of the rotor pole 12, that is, each magnetic isolation segment 132 is inclined on one side of the radial center line a of the rotor pole 12 and extends non-linearly. In this way, each magnetic isolation segment 132 has a certain gradient in the circumferential direction of the motor rotor 100 and also has a certain gradient in the radial direction of the motor rotor 100. The magnetic isolation groove 13 can block and guide the magnetic circuit of the rotor pole 12 in the circumferential and radial directions, so that the magnetic permeability of the rotor pole 12 in the circumferential and radial directions is more uniform, the direction of the magnetic flux in the rotor pole 12 is improved, the waveform of the air gap magnetic density is improved, and the proportion of back electromotive force harmonics is reduced (such as Figure 15 ), reduce the motor torque ripple (as shown in Figure 16 (as shown), to reduce the vibration and noise of the motor.

[0047] Specifically, the radial outermost end 131 and the radial innermost end 133 of each magnetic isolation segment 132 are staggered in the radial and circumferential directions of the rotor pole 12, so that the magnetic isolation segment 132 extending between the radial outermost end 131 and the radial innermost end 133 guides the magnetic flux in the radial and circumferential directions of the rotor pole 12, so that the magnetic permeability of the rotor pole 12 in the radial and circumferential directions is more uniform, thereby better improving the air gap magnetic field.

[0048] In this specific embodiment, the magnetic isolation section 132 bends and extends between the radially outermost end 131 and the radially innermost end 133 . The magnetic isolation section 132 includes a plurality of bending points, forming a stepped magnetic isolation section 132 .

[0049] like Figure 2 As shown, the magnetic isolation section 132 includes a first bend section 135 and a second bend section 137 that are interconnected. The first bend section 135 and the second bend section 137 are staggered in the radial and circumferential directions of the rotor pole 12. One end of the first bend section 135 is the radial outermost end 131, and the first bend section 135 is close to the outer circumference of the rotor pole 12; one end of the second bend section 137 is the radial innermost end 133, and the second bend section 137 is close to the center of the rotor pole 12. The radial length of the first bend section is M, the radial length of the second bend section is N, and the ratio of M / N satisfies the following relationship: 0.9 ≥ M / N ≥ 0.2, so as to improve the effect of the magnetic isolation hole in guiding the magnetic flux. Furthermore, the bending angle C at the bend in the magnetic isolation section 132 is an obtuse angle, and the range of the bending angle C is: 130° ≥ C ≥ 98°. If the above-mentioned bending angle C is designed to be too small, it is difficult for the magnetic isolation groove 13 to extend in the direction of the radial center line a that deviates from the rotor pole 12. At the same time, if the bending angle C is set too large, the magnetic isolation groove 13 is more likely to approach the outer peripheral surface of the rotor, which is not conducive to the guidance of the magnetic flux direction. Therefore, when the bending angle C is within the range of 130°≥C≥98°, the air gap magnetic field improvement effect is better and the back electromotive force harmonic reduction effect is better.

[0050] It can be understood that in some other embodiments, the magnetic isolation segment 132 can also be serrated; or the magnetic isolation segment 132 can extend in a curve between the radial outermost end 131 and the radial innermost end 133 to form a wavy magnetic isolation segment 132. The specific shape of the magnetic isolation segment 132 is not limited here.

[0051] like Figure 2 As shown, the projected length of the magnetic isolation section 132 on the adjacent permanent magnet 30 is a first length E, and the portion of the permanent magnet 30 excluding the first length E is a second length F. Optionally, the ratio of E / F satisfies the following relationship: 0.8≥E / F≥0.3. The magnetic isolation section 132 extends obliquely and bends between the outer circumference of the rotor pole 12 and the permanent magnet 30. If the magnetic isolation section 132 is too long, the magnetic flux of the motor will be reduced. If the magnetic isolation section 132 is too short, it will not have a good magnetic isolation effect. When the ratio of E / F satisfies the following relationship: 0.8≥E / F≥0.3, the air gap magnetic field is improved while ensuring the output torque of the motor.

[0052] like Figure 5As shown, in other embodiments, the magnetic isolation slot 13 further includes a branch segment 134, which is connected to the magnetic isolation segment 132 and extends toward the radial centerline a of the rotor pole 12. In this way, the branch segment 134 increases the magnetic resistance near the radial centerline a of the rotor pole 12, further improving the uniformity of the magnetic permeability of the magnetic circuit during motor operation, reducing the harmonic content of the motor's back EMF, and reducing the vibration and noise of the motor. Optionally, the angle between the branch segment 134 and the magnetic isolation segment 132 is an acute angle J.

[0053] like Figure 2-8 As shown, in some embodiments, the magnetic isolation segments 132 on either side of the radial centerline a of the rotor magnetic pole 12 are disconnected from each other. The magnetic isolation segments 132 on either side of the radial center of the rotor magnetic pole 12 are not connected to each other. The magnetic flux bypasses the magnetic isolation segments 132 on both sides and passes between the magnetic isolation segments 132 on both sides. This increases the air gap magnetic flux density, improves the motor flux linkage, and ensures the motor's output capacity while ensuring low motor vibration noise. Specifically, a spacing A is defined between the radial outermost ends 131 on either side of the radial centerline a of the rotor magnetic pole 12. The spacing A is less than 1.5 times the length of the air gap between the motor rotor 100 and the motor stator 210.

[0054] like Figure 5-7 As shown, for the motor rotor with branch segments 134, branch segments 134 are provided on both sides of the radial center line a of the rotor pole 12, and the branch segments 134 on both sides of the radial center line a of the rotor pole 12 are disconnected from each other, and magnetic flux is allowed to pass between the branch segments 134 on both sides to ensure the output capacity of the motor.

[0055] like Figure 8 As shown, in other embodiments, an auxiliary magnetic isolation groove 15 is opened on the radial center line a of the rotor pole 12, and the auxiliary magnetic isolation groove 15 is close to the outer peripheral surface of the rotor pole 12 and is disconnected from the magnetic isolation groove 13, so as to increase the magnetic resistance at the radial center line a of the rotor pole 12, change the direction of the magnetic flux, reduce the back electromotive force harmonics, and reduce the vibration and noise of the motor.

[0056] Generally, a plurality of teeth are arranged at circumferential intervals on the inner ring of the motor stator 210, and tooth slots are formed between adjacent teeth. When the motor rotor 100 rotates in the motor stator 210, if the rotor pole 12 faces the teeth of the motor stator 210, the air gap magnetic density is larger, and if the rotor pole 12 faces the tooth slots, the air gap magnetic density is smaller.

[0057] like Figure 9-12As shown, the magnetic isolation segments 132 on both sides of the radial centerline a of the rotor pole 12 are interconnected to form a magnetic isolation slot 13 passing through the radial centerline of the rotor pole 12. The magnetic isolation segments 132 on both sides are connected at the radial centerline a of the rotor pole 12, thereby increasing the area of ​​the magnetic isolation slot 13 and thereby increasing the magnetic resistance. When the rotor pole 12 is facing the stator teeth, the peak value of the air gap magnetic flux is reduced, thereby reducing the harmonic content in the air gap magnetic flux, reducing the back electromotive force harmonic content, reducing the electromagnetic force of the motor, and reducing the vibration and noise of the motor. At the same time, during the operation of the motor, the demagnetizing magnetic field of the demagnetizing armature reaction is reduced, thereby improving the demagnetization capacity of the motor. Moreover, a first magnetic isolation bridge is reserved on the outer peripheral side of the connection point, so that a part of the magnetic flux can pass through the first magnetic isolation bridge, thereby ensuring the air gap magnetic flux density, and ensuring the magnetic flux linkage and output capacity of the motor.

[0058] like Figure 9 As shown, the length of the first magnetic isolation bridge is H, and the arc length of the rotor pole 12 is I. Optionally, the ratio of H / I satisfies the following relationship: 0.25 ≥ H / I ≥ 0.1, which can ensure the output capacity of the motor while reducing the harmonic content of the air gap magnetic flux and reducing motor vibration. When H / I> 0.25, the first magnetic isolation bridge is too long, which greatly hinders the magnetic flux and reduces the output capacity of the motor; when H / I < 0.1, the air gap magnetic field cannot be improved well; when 0.25 ≥ H / I ≥ 0.1, the motor harmonic content is small, the vibration noise is small, the motor flux is high, the motor efficiency is high, and the air gap magnetic flux is large, which can ensure the output capacity of the motor.

[0059] like Figure 9-11 As shown, in some embodiments, the radial outermost ends 131 on both sides of the radial center line a of the rotor pole 12 are connected to each other. Figure 9-10 As shown, the connecting section at the radial center line a of the rotor pole 12 is narrower, as shown in FIG. Figure 11 As shown, the connecting section at the radial center line a of the rotor pole 12 is relatively wide, and the width of the connecting section is not limited here. Figure 12 As shown, in other embodiments, the magnetic isolation slot 13 has a branch segment 134, and a branch segment 134 is provided on both sides of the radial centerline a of the rotor magnetic pole 12, and the branch segments 134 on both sides of the radial centerline a of the rotor magnetic pole 12 are interconnected. In this way, by connecting the magnetic isolation segments 132 on both sides of the radial centerline a of the rotor magnetic pole 12 in a variety of ways, the magnetic resistance near the radial centerline a of the rotor magnetic pole 12 is further increased, the magnetic permeability uniformity of the magnetic circuit during motor operation is further improved, the harmonic content of the motor back electromotive force is reduced, and the vibration noise of the motor is reduced. At the same time, the demagnetization magnetic field of the motor is reduced, and the anti-demagnetization capability of the motor is improved.

[0060] like Figure 2-5As shown, in some embodiments, the magnetic isolation segments 132 on both sides of the radial centerline a of the rotor pole 12 are symmetrical about the radial centerline a, so as to form a second magnetic isolation bridge with uniform width at the outer periphery of the rotor pole 12 and adjacent to the magnetic isolation segments 132. When the second magnetic isolation bridge is left outside the magnetic isolation segment 132, a portion of the magnetic flux can pass along the second magnetic isolation bridge, while the magnetic flux passing through will be limited by the width of the second magnetic isolation bridge. Figure 2 As shown, specifically, the width of the second magnetic isolation bridge is B, and the length of the air gap between the motor rotor 100 and the motor stator 210 is δ. When the ratio of B / δ satisfies the following relationship: 1.5≥B / δ≥1, the magnetic flux passing through is better, the magnetic flux transferred to the air gap is better, the waveform sinusoidality of the air gap magnetic field in the circumferential direction of the motor rotor 100 is better, the back electromotive force harmonics are lower, the motor vibration noise is reduced, the harmonic loss is reduced, and the motor efficiency is improved.

[0061] like Figure 6-7 As shown, in other embodiments, the magnetic isolation segments 132 on either side of the radial centerline a of the rotor pole 12 are staggered in the radial direction of the rotor pole 12, that is, the magnetic isolation segments 132 on either side of the radial centerline a of the rotor pole 12 are asymmetrically arranged about the radial centerline a. In this way, the direction of the magnetic flux within the rotor pole 12 can be improved, and one of the magnetic isolation segments 132 on either side of the radial centerline a of the rotor pole 12 is closer to the center of the rotor core 10, thereby increasing the width of the peripheral magnetic isolation bridge, increasing the magnetic flux linkage of the motor, reducing the motor current, reducing copper loss, and improving the motor efficiency.

[0062] Furthermore, the distances and directions of the offsets of the magnetic isolation segments 132 on the plurality of rotor poles 12 may be different or the same. Figure 6 As shown, the left magnetic isolation segments 132 on some rotor poles 12 of the motor rotor 100 are closer to the outer periphery of the rotor pole 12, while the right magnetic isolation segments 132 on other rotor poles 12 are closer to the outer periphery of the rotor pole 12. Figure 7 As shown, the magnetic isolation section 132 on the left side of each rotor pole 12 of the motor rotor 100 is closer to the outer periphery of the rotor pole 12 and is closer to the outer periphery of the rotor pole 12. Figure 6 The staggered arrangement of the middle magnetic isolation segments 132 is different. It should be noted that the magnetic isolation segments 132 on the left and the magnetic isolation segments 132 on the right are both defined relative to the radial center line a of the rotor pole 12 where they are located.

[0063] like Figure 6As shown, the radial offset distance between the magnetic isolation segments 132 on either side of the radial centerline a of the rotor pole 12 is K, and the distance between the magnetic isolation segment 132 on either side that is closer to the outer periphery of the rotor pole 12 and the outer periphery of the rotor pole 12 is L. Specifically, the offset distance K cannot be too large. If the offset distance K is too large, the tail end of the first magnetic isolation slot 13 or the second magnetic isolation slot 13 will be too close to the slot position of the permanent magnet 30, which will reduce the structural strength of the rotor. Optionally, 3 ≥ K / L ≥ 1.5 to ensure motor reliability while achieving better motor performance.

[0064] like Figure 13 As shown, in some embodiments, the rotor pole 12 is provided with a triangular hole 17 near its outer circumference and the permanent magnet 30 to improve the air gap magnetic field, further reduce the torque pulsation of the motor, reduce the vibration noise of the motor, and at the same time reduce the leakage magnetic field of the permanent magnet 30, thereby improving the efficiency of the motor.

[0065] like Figure 14 As shown, in one embodiment of the present invention, a permanent magnet motor 200 is further provided, comprising a motor stator 210 and the above-mentioned motor rotor 100. The motor rotor 100 is rotatably mounted in the motor stator 210. The permanent magnet motor 200 has good output capacity and low vibration and noise.

[0066] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A motor rotor (100), characterized in that: include: Rotor core (10); A plurality of permanent magnets (30) are distributed on the rotor core (10) at intervals along the circumferential direction, and two adjacent permanent magnets (30) of the same polarity are arranged opposite to each other; Wherein, a rotor pole (12) is arranged between two adjacent permanent magnets (30) on the rotor core (10), and each of the rotor poles (12) is provided with a magnetic isolation groove (13), and the magnetic isolation groove (13) comprises magnetic isolation sections (132) respectively located on both sides of a radial center line (a) of the rotor pole (12); Each of the magnetic isolation sections (132) has a radially outermost end (131) close to the outer circumference of the rotor magnetic pole (12) and a radially innermost end (133) away from the outer circumference of the rotor magnetic pole (12), and each of the magnetic isolation sections (132) extends non-linearly from the radially outermost end (131) to the radially innermost end (133) in a direction deviating from the radial centerline (a) of the rotor magnetic pole (12); The magnetic isolation section (132) comprises a first bending section (135) and a second bending section (137) which are connected to each other, the first bending section (135) and the second bending section (137) being staggered in both the radial direction and the circumferential direction of the rotor magnetic pole (12), and one end of the first bending section (135) is the radial outermost end (131), and one end of the second bending section (137) is the radial innermost end (133); The radial length of the first bending section (135) is M, the radial length of the second bending section (137) is N, and the ratio of M / N satisfies the following relationship: 0.9≥M / N≥0.

2.

2. The motor rotor (100) according to claim 1, characterized in that: The radially outermost end (131) and the radially innermost end (133) of each magnetic isolation segment (132) are both staggered in the radial and circumferential directions of the rotor magnetic pole (12).

3. The motor rotor according to claim 1, characterized in that: The magnetic isolation section (132) bends and extends between the radial outermost end (131) and the radial innermost end (133).

4. The motor rotor according to any one of claims 1 to 3, characterized in that: The magnetic isolation sections (132) on both sides of the radial center line (a) of the rotor magnetic pole (12) are disconnected from each other.

5. The motor rotor according to claim 4, characterized in that: There is a spacing distance (A) between the radial outermost ends (131) on both sides of the radial center line (a) of the rotor magnetic pole (12), and the spacing distance (A) is less than 1.5 times the length of the air gap between the motor rotor (100) and the motor stator (210).

6. The motor rotor (100) according to claim 4, characterized in that: An auxiliary magnetic isolation groove (15) is provided on the radial center line (a) of the rotor magnetic pole (12); the auxiliary magnetic isolation groove (15) is close to the outer peripheral surface of the rotor magnetic pole (12) and is disconnected from the magnetic isolation groove (13).

7. The motor rotor according to any one of claims 1 to 3, characterized in that: The magnetic isolation sections (132) on both sides of the radial center line (a) of the rotor magnetic pole (12) are connected to each other.

8. The motor rotor according to claim 7, characterized in that: The radial outermost ends (131) on both sides of the radial center line (a) of the rotor magnetic pole (12) are connected to each other.

9. The motor rotor (100) according to any one of claims 1 to 3, characterized in that: The magnetic isolation segments (132) on both sides of the radial center line (a) of the rotor magnetic pole (12) are symmetrical about the radial center line (a); or The magnetic isolation segments (132) on both sides of the radial center line (a) of the rotor magnetic pole (12) are staggered in the radial direction of the rotor magnetic pole (12).

10. The motor rotor (100) according to any one of claims 1 to 3, characterized in that: The magnetic isolation groove (13) further comprises a branch section (134), wherein the branch section (134) is connected to the magnetic isolation section (132) and extends in a direction close to a radial center line (a) of the rotor magnetic pole (12).

11. The motor rotor (100) according to claim 10, characterized in that: The branch segments (134) are arranged on both sides of the radial center line (a) of the rotor magnetic pole (12), and the branch segments (134) on both sides of the radial center line (a) of the rotor magnetic pole (12) are connected to or disconnected from each other.

12. A permanent magnet motor (200), characterized in that: It comprises a motor stator (210) and a motor rotor (100) according to any one of claims 1 to 11, wherein the motor rotor (100) is rotatably sleeved in the motor stator (210).

Images