Integrated error magnetic tile, permanent magnet motor rotor and permanent magnet motor

Abstract

The application discloses an integrated staggered-pole magnetic tile for a rotor of a permanent magnet motor. In view of the problems of the existing segmented staggered-pole structure, such as the need of splicing of multiple independent magnets, the large number of parts, the large assembly cumulative error, the existence of gaps between segments leading to magnetic leakage and the easy falling off, the magnetic tile is made into an integrally-formed arc-tile-shaped permanent magnet, two circumferential sides of the arc-tile-shaped permanent magnet each include at least three straight edge segments extending in the axial direction and transition edges connecting adjacent straight edge segments, and each straight edge segment is staggered in the same circumferential direction from one end to the other end in the axial direction. As a result, the staggered-pole structure is directly formed by the shape of a single part, the staggering amount is ensured by a forming die, the assembly cumulative error is eliminated, the staggered-pole effect is stable in batches, the segments are integrally connected, the magnetic circuit is continuous in the axial direction, the magnetic leakage is reduced, each magnetic pole only needs one part, the assembly is simplified and the falling off is not easy, and the rotor is high in reliability.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to an integrated staggered-pole magnet, a permanent magnet motor rotor, and a permanent magnet motor. Background Technology

[0002] Permanent magnet motors are widely used in new energy vehicles, home appliances, and industrial servo systems due to their advantages such as high power density, high efficiency, and good control performance. In surface-mount permanent magnet motors, permanent magnets are mounted on the outer circumferential surface of the rotor core in the form of magnetic tiles. Because the slotting in the stator core causes a periodic change in the air gap permeability along the circumference, cogging torque is generated between the permanent magnets and the stator teeth, causing torque pulsation, vibration, and noise in the motor, affecting the motor's operational smoothness and control accuracy.

[0003] To reduce cogging torque, existing technologies divide the permanent magnet of each pole into several independent block magnets along the axial direction. These blocks are then staggered circumferentially during assembly to simulate a skewed pole effect. While this approach avoids the manufacturing defects of stator skewed slots, it still presents several problems: First, each pole requires multiple independent magnets, significantly increasing the number of parts, complicating assembly processes, and reducing production efficiency. Second, the misalignment angle between magnet blocks depends on assembly fixtures, leading to large cumulative assembly errors and poor consistency in misalignment angles, making it difficult to maintain a stable cogging torque reduction effect in mass production. Third, unavoidable assembly gaps and adhesive layers exist between adjacent magnet blocks, resulting in axial discontinuity in the magnetic circuit, increased magnetic leakage, decreased air gap magnetic flux density, and losses in the motor's back EMF and output torque. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides an integrated misaligned magnetic tile, permanent magnet motor rotor and permanent magnet motor with fewer parts, smaller assembly error, continuous magnetic circuit and good reliability.

[0005] The technical solution adopted by this invention to solve its technical problem is: An integrated staggered-pole magnetic tile is used for the rotor of a permanent magnet motor. The magnetic tile is a one-piece molded permanent magnet, shaped like an arc tile centered on the axis of the rotor. The magnetic tile has two circumferential sides, each of which includes at least three axially extending straight edge segments and a transition edge connecting two adjacent straight edge segments. On the same circumferential side, each straight edge segment is staggered sequentially from one axial end to the other axial end of the magnetic tile along the same circumferential direction, so that the magnetic poles of the magnetic tile are divided into multiple segments with sequentially staggered circumferential positions along the axial direction, forming an integrated staggered-pole structure.

[0006] Furthermore, the transition edge is a stepped edge extending generally circumferentially, such that each circumferential side extends in a stepped manner along the axial direction; or, the transition edge is a beveled edge or an arc edge extending obliquely relative to the axial direction.

[0007] Furthermore, on the same circumferential side, the central angles α between adjacent straight side segments that are offset around the axis are all equal.

[0008] Furthermore, the transition edges on one circumferential side of the magnetic tile are axially offset from each other; the magnetic tile rotates 180° around a straight line passing through its geometric center and extending radially along the rotor to coincide with itself, so that the two circumferential sides are centrally symmetrical about the geometric center.

[0009] Furthermore, on the same circumferential side, the axial lengths of the two straight edge segments located at both ends of the axial direction are not equal, and the axial lengths of the remaining straight edge segments located between the two straight edge segments are all equal, so that each transition edge on one circumferential side is offset by the same distance in the same axial direction relative to each transition edge on the other circumferential side in axial order, and circumferential protrusions and circumferential recesses are formed on the circumferential sides of the magnetic tile.

[0010] A permanent magnet motor rotor includes a rotor core and a plurality of integral staggered pole magnets as described above; the plurality of magnets are arranged circumferentially at intervals on the outer circumferential surface of the rotor core, and a circumferential interval is formed between two circumferentially adjacent magnets, which extends axially in accordance with the shape of the circumferential side.

[0011] Furthermore, in two circumferentially adjacent magnetic tiles, the circumferential protrusion of one magnetic tile extends circumferentially into the circumferential recess of the other magnetic tile, so that the two adjacent magnetic tiles are circumferentially positioned relative to each other.

[0012] Furthermore, the outer circumferential surface of the rotor core is provided with a plurality of axially extending positioning protrusions, each of which is correspondingly housed within the circumferential intervals; the positioning protrusions extend in an axial direction in a shape that matches the shape of the circumferential side of the magnetic tile, and the two sides of the positioning protrusions respectively fit against the circumferential side of two adjacent magnetic tiles.

[0013] Furthermore, the magnetic tile is fixed to the outer circumferential surface of the rotor core by adhesive bonding; the rotor core is formed by stacking multiple silicon steel sheets along the axial direction, and the center of the rotor core is provided with a shaft hole for cooperating with the motor shaft.

[0014] A permanent magnet motor includes a housing, a stator, a motor shaft, and a permanent magnet motor rotor; the stator is fixed inside the housing and surrounds the outer periphery of the permanent magnet motor rotor, the stator core of the stator is provided with a plurality of straight slots extending axially, and the stator windings are wound in the straight slots.

[0015] The beneficial effects of this invention are: The integrated misaligned magnetic tile provided by this invention integrates the segmented misaligned structure, which requires multiple independent magnets to be spliced ​​together in the prior art, into a single integral molded part. The circumferential side of the magnetic tile includes multiple straight edge segments arranged sequentially along the axial direction and circumferentially offset from each other, as well as transition edges connecting adjacent straight edge segments, thereby directly forming multiple circumferentially misaligned magnetic pole segments on the magnetic tile itself. Therefore: First, each magnetic pole requires only one part, significantly reducing the number of parts and assembly steps, thus reducing manufacturing costs. Second, the offset between adjacent straight edge segments is directly guaranteed by the forming mold, eliminating reliance on assembly tooling and avoiding the cumulative assembly errors in splicing schemes. The reduction effect of cogging torque is stable, controllable, and consistent in mass production. Third, the misaligned segments are integrally connected, eliminating assembly gaps and adhesive layers between segments. This ensures axial continuity of the magnetic circuit, reduces magnetic leakage, and improves the motor's back EMF and output torque compared to splicing schemes. Fourth, the single part is fixed to the rotor core as a whole, avoiding the risk of individual magnets falling off or shifting, significantly improving the reliability of the rotor structure. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a three-dimensional structural schematic diagram of a permanent magnet motor according to the present invention; Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure along the central axis; Figure 3 yes Figure 1 A schematic diagram of the cross-sectional structure along the radial direction; Figure 4 This is a schematic diagram of the installation of the magnetic tile and rotor core of the present invention; Figure 5 This is a schematic diagram of the structure of the magnetic tile of the present invention; Figure 6 This is a schematic diagram of the stator core structure of the present invention.

[0018] 100. Magnetic tile; 130. Circumferential side; 131. Straight edge section; 132. Transition edge; 140. Circumferential protrusion; 150. Circumferential recess; 200, Rotor core; 210, Positioning ridge; 220, Shaft hole; 300, Circumferential spacing; 400, Stator; 410, Stator core; 411, Straight slot; 420, Winding; 500, Housing; 600, Motor shaft. Detailed Implementation

[0019] The following will clearly and completely describe the concept, specific structure, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. Furthermore, all connections / linkages involved in the patent do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this invention can be combined interactively without contradicting each other.

[0020] For ease of description, the following definitions are used in this paper. A straight edge segment refers to a circumferential side segment of a magnetic tile that extends straight along the axial direction; a transition edge refers to the segment connecting two adjacent straight edge segments. A transition edge can be a stepped edge extending approximately circumferentially, or a sloping edge or arc edge extending obliquely relative to the axial direction. This paper uses a stepped edge as the main example for illustration; the central angle between two adjacent straight edge segments is the angle between them around the rotor axis. When the transition edge is a stepped edge, this central angle is the central angle subtended by the two ends of the stepped edge around the rotor axis. Axial length refers to the axial dimension of the corresponding structure; radial thickness refers to the radial dimension between the inner and outer arc surfaces of the magnetic tile.

[0021] like Figure 2 , Figure 4 and Figure 5 As shown, this embodiment provides an integrated staggered-pole magnetic tile 100 for the rotor of a permanent magnet motor. The magnetic tile 100 is a one-piece molded permanent magnet, shaped like an arc tile centered on the rotor's axis. The magnetic tile 100 has two circumferential sides 130, each circumferential side 130 including at least three axially extending straight edge segments 131 and a transition edge 132 connecting two adjacent straight edge segments 131. On the same circumferential side 130, each straight edge segment 131 is staggered sequentially from one axial end to the other axial end of the magnetic tile 100 along the same circumferential direction, thereby dividing the magnetic poles of the magnetic tile 100 into multiple segments with sequentially staggered circumferential positions along the axial direction, forming an integrated staggered-pole structure.

[0022] It should be noted that the effect of this invention in reducing cogging torque comes from the staggered pole structure itself, which segments the magnetic poles along the axial direction and staggers each segment sequentially along the same circumferential direction, rather than from the specific shape of the transition edge 132. In this embodiment, the transition edge 132 is a stepped edge extending approximately circumferentially, so that each circumferential side 130 extends in a right-angled stepped shape along the axial direction. This shape facilitates the design and manufacturing of the forming mold, and the boundaries of each segment of the magnetic poles are clear and the staggered angle is easy to control.

[0023] In other embodiments, the transition edge 132 can also be a beveled edge extending obliquely relative to the axial direction, or a circular arc edge, that is, a smooth transition between two adjacent straight edge segments 131 with a beveled or circular arc surface; in this case, the magnetic poles of each segment of the magnetic tile are also staggered sequentially along the circumference, which can also achieve the effect of weakening the cogging torque, and the beveled or circular arc edge transition is beneficial to reducing stress concentration at the edge, which can be selected according to the characteristics of the magnet forming process. Unless otherwise specified, the following description uses a stepped edge as an example, and the relevant descriptions are also applicable to the case of beveled or circular arc edges after adaptive adjustments.

[0024] On the same circumferential side 130, the central angles α of the staggered circles around the axis between two adjacent straight edge segments 131 are all equal, that is, the staggered angles at each level are evenly distributed.

[0025] Wherein, the central angle α satisfies: 0.5°≤α≤20°, and preferably the central angle α satisfies 3°≤α≤5°.

[0026] In this embodiment, there are three straight edge segments 131 on each circumferential side 130. It is understood that the number of straight edge segments 131 is not limited to three, but can also be four, five, six or even eight. The more segments there are, the closer the stepped staggered pole shape of the magnetic tile 100 is to a continuous oblique pole, and the better the effect of weakening the cogging torque. However, the complexity of the forming mold increases accordingly. The appropriate number of segments can be selected based on the requirements for weakening the cogging torque and the manufacturing cost.

[0027] In this embodiment, the two circumferential sides 130 of the magnetic tile 100 are centrally symmetrical about the geometric center of the magnetic tile 100, that is, the magnetic tile 100 coincides with itself after rotating 180° around a straight line passing through its geometric center and extending radially along the rotor. Based on this central symmetry, the two circumferential sides 130 are congruent in shape, and the central angles covered by the arc sections on the magnetic tile 100 corresponding to each straight edge segment 131 around the axis are equal, and the air gap magnetic flux density amplitude of each section is consistent; at the same time, the same molding die can ensure the consistency of the contours of the two sides, and when multiple magnetic tiles 100 are arranged in sequence around the rotor axis, they have a definite geometric fit relationship with each other.

[0028] like Figure 5 As shown, in this embodiment, the transition edges 132 on one circumferential side 130 of the magnetic tile 100 and the transition edges 132 on the other circumferential side 130 are staggered from each other along the axial direction, that is, the transition edges on both sides are not at the same axial height.

[0029] Specifically, on the same circumferential side 130, the axial lengths of the two straight edge segments 131 located at the two ends are not equal, while the axial lengths of all other straight edge segments 131 located between these two straight edge segments 131 are equal. It can be understood that, under the premise of central symmetry of both sides, if the straight edge segments at both ends are of equal length and the straight edge segments in the middle are of equal length, then the transition edges on both sides will necessarily be at the same axial height, and adjacent magnetic tiles will only form a stepped gap of equal width and will not be able to fit together. According to the length setting of this embodiment, let the axial lengths of each straight edge segment 131 on the same circumferential side 130 from one end to the other be La, L, ..., L, Lb, where La ≠ Lb. Then, due to central symmetry, the axial lengths of each straight edge segment 131 on the other circumferential side 130 in the same axial order are Lb, L, ..., L, La. At this time, each transition edge 132 on one circumferential side 130 is offset by the same distance |La-Lb| relative to the corresponding transition edges 132 on the other circumferential side 130 in the same axial direction. Taking the case of five straight edge segments 131 as an example, the four pairs of transition edges 132 on both sides are exactly offset by |La-Lb|, and the offset direction is consistent. Within each pair of axially staggered intervals of the transition edges 132 on both sides, the magnetic tile 100 locally widens or narrows the arc width corresponding to a central angle α in the circumferential direction, thereby forming a circumferential protrusion 140 and a circumferential recess 150 on both sides of the magnetic tile 100, such as Figure 4 As shown, adjacent magnetic tiles 100 are designed to fit together. Conversely, if the axial lengths of the middle straight edge segments are not equal, the offset distances of the corresponding transition edges on both sides will be different. The offset at some positions may be zero or even reversed, and the protruding and recessed parts cannot maintain a consistent fitting relationship along the entire axial length. Therefore, the setting of "unequal lengths of the straight edge segments at both ends and equal lengths of the middle straight edge segments" ensures that regardless of whether the number of straight edge segments 131 is three, five, or more, adjacent magnetic tiles 100 can fit together at equal intervals along the entire axial length.

[0030] In this embodiment, the magnetic tile 100 is a sintered neodymium iron boron magnet integrally formed. The stepped, displaced-pole shape is directly obtained through molding and sintering processes, with the central angle α of each stage directly guaranteed by the molding die. Specifically, the magnetic tile 100 employs magnetic field orientation during molding, meaning that magnetic powder particles are aligned along a predetermined direction under the influence of an orientation magnetic field before being pressed and formed. It is then densified by sintering, thereby enabling the magnetic tile 100 to obtain high remanence and magnetic energy product. After molding and machining, the magnetic tile 100 is magnetized. The magnetization method can be parallel magnetization or radial magnetization; this application does not limit this.

[0031] It is understood that in other embodiments, the magnetic tile 100 can also be a one-piece injection-molded magnet, a hot-pressed magnet, or other types of one-piece permanent magnet. When the magnetic tile 100 is an injection-molded magnet, a stepped, staggered pole shape can be directly injection-molded using an injection molding process; when the magnetic tile 100 is a hot-pressed magnet, a stepped, staggered pole shape can be directly pressed using a hot-pressing process. Regardless of the molding process used, as long as the magnetic tile 100 is a one-piece molded structure without any splicing interfaces between multiple magnet segments, the central angle α at each level can be directly guaranteed by the corresponding molding die.

[0032] Optionally, a chamfer or rounded corner is provided at the junction of the straight edge segment 131 and the transition edge 132 to avoid stress concentration and prevent the magnet from chipping or breaking off during molding and assembly; such chamfers or rounded corners do not affect the determination of the central angle α.

[0033] To verify the technical effect of this embodiment, the inventors conducted comparative tests on the following three schemes under the same stator, the same total amount of magnets, and the same working conditions: Scheme A is an integral straight magnet tile with no misalignment; Scheme B is a multi-segment independent magnet splicing misalignment scheme of the prior art; Scheme C is the integral misalignment magnet tile of this embodiment.

[0034] Table 1.

[0035] As shown in Table 1, the cogging torque of both Scheme B and Scheme C is significantly lower than that of Scheme A, which verifies the effectiveness of the misaligned structure. Compared with Scheme B, Scheme C eliminates the assembly gap and adhesive layer between segments, resulting in a continuous magnetic circuit in the axial direction, reduced leakage flux, a 7% reduction in no-load back EMF, and an increase in rated output torque of approximately (5)%. Furthermore, the misalignment angle of Scheme C is directly guaranteed by the integrated molding die, eliminating assembly cumulative error. The batch consistency of the cogging torque reduction effect is significantly better than that of Scheme B.

[0036] like Figure 2 and Figure 4 As shown, this embodiment provides a permanent magnet motor rotor, including a rotor core 200 and multiple integrated staggered-pole magnetic tiles 100 as described in Embodiment 1. In this embodiment, the number of magnetic tiles 100 is six, and the six magnetic tiles 100 are arranged circumferentially on the outer circumferential surface of the rotor core 200. The polarities of adjacent magnetic tiles 100 are alternately arranged circumferentially to form a six-pole rotor. A circumferential gap 300 is formed between two circumferentially adjacent magnetic tiles 100; the circumferential gap 300 extends axially in accordance with the shape of the circumferential side 130 of the magnetic tile 100: when the circumferential side 130 extends in a stepped shape, the circumferential gap 300 extends axially in a stepped shape accordingly; when the transition edge of the circumferential side 130 is a slanted edge or a rounded edge, the circumferential gap 300 extends in a zigzag or wavy shape accordingly.

[0037] In this embodiment, among two circumferentially adjacent magnetic tiles 100, the circumferential protrusion 140 of one magnetic tile 100 extends circumferentially into the circumferential recess 150 of the other magnetic tile 100, forming a mortise-and-tenon-like fitting. Figure 5 As shown in Embodiment 1, since the straight edge segments at both ends of the same circumferential side 130 are of unequal length and the straight edge segments in the middle are of equal length, and the axial offset distance of each pair of transition edges 132 is equal everywhere, the protrusions 140 and recesses 150 of two adjacent magnetic tiles 100 can fit together and abut against each other along the entire axial length. With the help of this fitting, the two adjacent magnetic tiles 100 are circumferentially positioned against each other and serve as assembly references for each other: the fit between the protrusions 140 and the recesses 150 directly ensures the circumferential offset relationship between adjacent magnetic tiles 100; when the magnetic tiles 100 are installed backwards or axially misaligned, the protrusions 140 and adjacent magnetic tiles interfere with each other and cannot fit together properly, thus achieving foolproof assembly; when the motor is running, the fitting structure can also restrict the circumferential slippage of the magnetic tiles 100, resist the displacement caused by electromagnetic tangential force and temperature cycling, and reduce the shear burden on the adhesive layer.

[0038] Further, or as another circumferential positioning method, the outer circumferential surface of the rotor core 200 is provided with a plurality of axially extending positioning protrusions 210. The number of positioning protrusions 210 is equal to the number of circumferential intervals 300, and each positioning protrusion 210 is correspondingly accommodated within each circumferential interval 300. The positioning protrusions 210 extend in an axial direction in a shape adapted to the shape of the circumferential side 130 of the magnetic tile 100, that is, the orientation of the two circumferential side walls of the positioning protrusion 210 is consistent with the orientation of the circumferential side 130 of two adjacent magnetic tiles 100; in this embodiment where the circumferential side 130 is stepped, the positioning protrusions 210 extend in a stepped shape accordingly along the axial direction. During assembly, the two sides of the positioning protrusions 210 respectively fit against the circumferential side 130 of two adjacent magnetic tiles 100, thereby circumferentially positioning each part of the magnetic tile 100 along the axial direction. It is understandable that either the magnetic tile fitting positioning or the positioning protrusion positioning can be used, or they can be used in combination. With the help of the above-mentioned fitting structure, the circumferential position and angular attitude of the magnetic tile 100 are uniquely determined after it is in place. The relative angular accuracy between each magnetic tile 100 is jointly guaranteed by the lamination accuracy of the rotor core 200 and the forming accuracy of the magnetic tile 100. No additional assembly tooling is required, which further ensures the consistency of the entire rotor misalignment structure.

[0039] In this embodiment, the magnetic tile 100 is fixed to the outer peripheral surface of the rotor core 200 by adhesive bonding. Specifically, anaerobic adhesive is applied between the magnetic tile 100 and the outer peripheral surface of the rotor core 200. After the magnetic tile 100 is attached and positioned, it is baked at high temperature for about 40 minutes to cure the anaerobic adhesive, thereby firmly bonding the magnetic tile 100 to the outer peripheral surface of the rotor core 200. The rotor core 200 is formed by stacking multiple silicon steel sheets along the axial direction. The positioning protrusions 210 are formed by stacking corresponding protrusions on the outer edges of each silicon steel sheet along the axial direction. The circumferential positions of the protrusions of the silicon steel sheets in different axial sections are staggered sequentially, thus naturally forming a stepped positioning protrusion 210 after stacking, without the need for secondary processing of the core. The rotor core 200 has a shaft hole 220 at its center for mating with the motor shaft 600.

[0040] like Figures 1-3 , Figure 6 As shown, this embodiment provides a permanent magnet motor, including a housing 500, a stator 400, a motor shaft 600, and a permanent magnet motor rotor as described in Embodiment 2. The stator 400 is fixed inside the housing 500 and surrounds the outer periphery of the permanent magnet motor rotor, forming an air gap between them; the motor shaft 600 is fixedly inserted into the shaft hole 220 of the rotor core 200 and rotatably supported on the housing 500 by bearings. The stator 400 includes a stator core 410 and windings 420. The stator core 410 has a plurality of straight slots 411 extending axially, and the windings 420 are wound in the straight slots 411.

[0041] It should be noted that the stator 400 of this invention does not require any structural changes to the misaligned structure of the rotor. In the prior art, a stator skewed slot scheme is often used to reduce cogging torque, that is, the stator slot is tilted at a certain angle relative to the axis. However, skewed slots will lead to difficulties in winding winding, a decrease in slot fill factor, an increase in winding end length, an increase in copper loss, and a loss of effective back EMF of the winding. This invention fully integrates the "skewed pole" function into the integrated misaligned pole shape of the magnet 100. The stator core 410 retains the conventional straight slot 411 extending straight along the axial direction, and the winding 420 can be wound according to conventional processes. This takes into account both the reduction of cogging torque and the simplification of the stator manufacturing process, while avoiding the back EMF loss caused by skewed slots.

[0042] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. An integrated staggered-pole magnetic tile for use in the rotor of a permanent magnet motor, characterized in that, The magnetic tile is a one-piece permanent magnet, shaped like an arc tile centered on the axis of the rotor. The magnetic tile has two circumferential sides, each of which includes at least three straight edge segments extending axially and a transition edge connecting two adjacent straight edge segments. On the same circumferential side, each straight edge segment is staggered sequentially from one end of the magnetic tile to the other end along the same circumferential direction, so that the magnetic poles of the magnetic tile are divided into multiple segments with sequentially staggered circumferential positions along the axial direction, forming an integrated staggered pole structure.

2. The integrated misaligned magnetic tile according to claim 1, characterized in that, The transition edge is a stepped edge extending generally circumferentially, such that each circumferential side extends in a stepped manner along the axial direction; or, the transition edge is a beveled edge or an arc edge extending obliquely relative to the axial direction.

3. The integrated misaligned magnetic tile according to claim 1 or 2, characterized in that, On the same circumferential side, the central angle α between two adjacent straight side segments, which is offset around the axis, is equal.

4. The integrated misaligned magnetic tile according to any one of claims 1-3, characterized in that, The transition edges on one circumferential side of the magnetic tile are staggered from each other along the axial direction; the magnetic tile rotates 180° around a straight line passing through its geometric center and extending radially along the rotor to coincide with itself, so that the two circumferential sides are centrally symmetrical about the geometric center.

5. The integrated misaligned magnetic tile according to claim 4, characterized in that, On the same circumferential side, the axial lengths of the two straight edge segments located at both ends of the axial direction are not equal, and the axial lengths of the remaining straight edge segments located between the two straight edge segments are all equal, so that each transition edge on one circumferential side is offset by the same distance in the same axial direction relative to each transition edge on the other circumferential side in axial order, and circumferential protrusions and circumferential recesses are formed on the circumferential sides of the magnetic tile.

6. A permanent magnet motor rotor, characterized in that, It includes a rotor core and a plurality of integral staggered pole magnetic tiles as described in any one of claims 1-5; the plurality of magnetic tiles are arranged circumferentially at intervals on the outer circumferential surface of the rotor core, and a circumferential interval is formed between two circumferentially adjacent magnetic tiles, which extends axially to match the shape of the circumferential side.

7. The permanent magnet motor rotor according to claim 6, characterized in that, The magnetic tile is an integral staggered magnetic tile as described in claim 5; in two circumferentially adjacent magnetic tiles, the circumferential protrusion of one magnetic tile extends circumferentially into the circumferential recess of the other magnetic tile, so that the two adjacent magnetic tiles are circumferentially positioned relative to each other.

8. The permanent magnet motor rotor according to claim 6, characterized in that, The outer circumferential surface of the rotor core is provided with a plurality of axially extending positioning protrusions, each of which is correspondingly housed within the circumferential intervals; the positioning protrusions extend in an axial direction to match the shape of the circumferential side of the magnetic tile, and the two sides of the positioning protrusions respectively fit against the circumferential side of two adjacent magnetic tiles.

9. The permanent magnet motor rotor according to claim 6, characterized in that, The magnetic tiles are fixed to the outer circumference of the rotor core by adhesive bonding; the rotor core is formed by stacking multiple silicon steel sheets along the axial direction, and the center of the rotor core is provided with a shaft hole for cooperating with the motor shaft.

10. A permanent magnet motor, characterized in that, It includes a housing, a stator, a motor shaft, and a permanent magnet motor rotor as described in any one of claims 6-9; the stator is fixed inside the housing and surrounds the outer periphery of the permanent magnet motor rotor, the stator core of the stator is provided with a plurality of straight slots extending in a straight direction along the axial direction, and the stator windings are wound in the straight slots.

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