Rotor assembly, rotor structure and electric machine

Abstract

The application relates to a rotor assembly, a rotor structure and a motor, the motor comprising a stator structure and a rotor structure, the rotor structure being formed by rotationally stacking an even number of rotor assemblies, the rotor assembly comprising a rotor core and a magnetic tile, the rotor core comprising an outer convex circular arc part and an inner concave circular arc part, a plurality of outer convex circular arc parts and a plurality of inner concave circular arc parts being arranged in sequence and staggered along the circumference of the rotor core, a magnetic tile being attached to each inner concave circular arc surface, and adjacent outer convex circular arc parts and magnetic tiles forming a pair of magnetic poles; the magnetic tile and the inner concave circular arc surface need to satisfy:;; the adjacent outer convex circular arc parts and the magnetic tile form a pair of magnetic poles, compared with the pair of magnetic poles using two magnetic tiles, the number of magnetic tiles used is effectively reduced; the angle of the inner concave circular arc surface and the outer convex circular arc surface and the width of the magnetic tile are limited, so that the area of the outer convex circular arc part is larger than the area of the magnetic tile, the width of the magnetic tile is reduced, the width of the magnetic tile is not too small, the volume of the magnetic tile is reduced, and the amount of permanent magnet material is reduced.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a rotor assembly, rotor structure, and motor. Background Technology

[0002] Surface-mounted rotor structures are a common rotor structure for permanent magnet synchronous motors. Compared with embedded rotor structures, they have higher permanent magnet torque and are therefore widely used.

[0003] In the prior art, the surface-mounted rotor structure includes a rotor core and magnetic tiles. The magnetic tiles are evenly distributed on the surface of the rotor core. Each magnetic pole of the motor requires at least one magnetic tile. The large amount of permanent magnet material used increases the cost of the permanent magnet in the rotor structure.

[0004] Therefore, there is an urgent need for a rotor assembly, rotor, and motor to solve the above-mentioned technical problems. Summary of the Invention

[0005] The first objective of this invention is to provide a rotor assembly, rotor, and motor to at least solve one of the aforementioned problems.

[0006] To achieve the above objectives, the present invention provides a rotor assembly, including a rotor core and a magnetic tile. The rotor core includes a convex arc portion and a concave arc portion, and there are multiple convex arc portions and multiple concave arc portions arranged alternately along the circumference of the rotor core. The convex arc portion includes a convex arc surface, and the concave arc portion includes a concave arc surface. The magnetic tile is attached to each concave arc surface, and adjacent convex arc portions and magnetic tiles form a pair of magnetic poles. The magnetic tile and the concave arc surface must simultaneously satisfy the following: ; ; ; Wherein, Q1 is the angle formed by the two ends of the concave arc surface and the center O of the rotor core, and Q2 is the angle formed by the two ends of the convex arc surface and the center O of the rotor core. The radius of the concave arc surface is R1, b1 is the width of the concave arc surface, and b2 is the width of the magnetic tile.

[0007] Furthermore, the magnetic tile has a first arc surface and a second arc surface arranged opposite to each other, the first arc surface is attached to the concave arc surface, and the diameter of the first arc surface and the diameter of the second arc surface are equal.

[0008] Furthermore, the first arc surface and the second arc surface are connected by a transition surface, and a chamfer is provided at the connection between the transition surface and the second arc surface.

[0009] Furthermore, the chamfer size ranges from C0.5 to C3.

[0010] Furthermore, the thickness t1 of the magnetic tile must satisfy: ; Where t1 is the thickness of the magnetic tile, R2 is the radius of the circle containing the maximum outer diameter of the rotor core, and D is the distance between the center O1 of the concave arc surface and the center O of the rotor core.

[0011] Furthermore, an anti-demagnetization groove is formed on the concave arc surface, and the dimensions of the anti-demagnetization groove must meet the following requirements: ; ; Wherein, b3 is the width of the anti-demagnetization groove, and t2 is the depth of the anti-demagnetization groove.

[0012] Furthermore, the anti-demagnetization groove is circular, triangular, trapezoidal, or rectangular in shape.

[0013] A second objective of this invention is to provide a rotor structure that at least solves one of the aforementioned problems.

[0014] To achieve the above objectives, the present invention provides a rotor structure, wherein the rotor structure is formed by an even number of rotor assemblies as described in any of the above embodiments, which are rotated and stacked along the axial direction of the rotor assemblies, and adjacent rotor assemblies are staggered by an angle Q3; the second arc surfaces on the magnetic tiles corresponding to the adjacent rotor assemblies have different magnetic polarities.

[0015] A third objective of this invention is to provide an electric motor that at least solves one of the aforementioned problems.

[0016] To achieve the above objectives, the present invention provides an electric motor, comprising: Stator structure; The rotor structure described in the above scheme is located within the stator structure.

[0017] Furthermore, the air gap between the stator structure and the rotor structure must simultaneously satisfy the following: ; ; Wherein, R2 is the radius of the circle containing the maximum outer diameter of the rotor core, R3 is the radius of the circle containing the minimum outer diameter of the stator core of the stator structure, and R4 is the distance between the end of the convex arc surface and the center O of the rotor core.

[0018] The beneficial effects of this invention are as follows: The rotor assembly provided by the present invention includes a rotor core and a magnetic tile. The rotor core includes an outwardly convex arc portion and an inwardly concave arc portion. There are multiple outwardly convex arc portions and multiple inwardly concave arc portions. The multiple outwardly convex arc portions and multiple inwardly concave arc portions are arranged alternately along the circumference of the rotor core. The outwardly convex arc portion includes an outwardly convex arc surface, and the inwardly concave arc portion includes an inwardly concave arc surface. A magnetic tile is attached to each inwardly concave arc surface. Adjacent outwardly convex arc portions and magnetic tiles form a pair of magnetic poles. The magnetic tile and the concave arc surface must simultaneously satisfy the following: ; ; ; Where Q1 is the angle formed by the two ends of the concave arc surface and the center O of the rotor core, and Q2 is the angle formed by the two ends of the convex arc surface and the center O of the rotor core. R1 is the radius of the concave arc surface, b1 is the width of the concave arc surface, and b2 is the width of the magnetic tile.

[0019] Adjacent convex arc portions and magnetic tiles form a pair of magnetic poles. Compared to the existing technology where a pair of magnetic poles requires two magnetic tiles, this effectively reduces the number of magnetic tiles used. The angle limitation of the concave arc surface and the convex arc surface, as well as the width limitation of the magnetic tile, make the area occupied by the convex arc portion larger than the area of ​​the magnetic tile. This reduces the width of the magnetic tile without making it too small. While meeting the magnetic requirements of the magnetic tile, it also reduces the volume of the magnetic tile, reduces the amount of permanent magnet material used, and lowers the cost of permanent magnets in the rotor structure.

[0020] The motor provided by this invention includes a stator structure and a rotor structure. The rotor structure is disposed within the stator structure and is formed by stacking an even number of rotor assemblies along the axial direction of the rotor assemblies. Adjacent rotor assemblies are staggered by an angle Q3. The magnetic poles on the second arc surface of the corresponding magnet tiles of adjacent rotor assemblies have different polarities. This arrangement can significantly improve the sinusoidal nature of the motor's back EMF waveform, thereby increasing the sinusoidal nature of the air gap magnetic field and reducing vibration and noise. The rotor assembly arrangement reduces the amount of permanent magnet material used, thus lowering the cost of permanent magnets in the rotor structure. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the rotor assembly provided in an embodiment of the present invention; Figure 2 This is a top view of the rotor assembly provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the magnetic poles of the rotor assembly provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the rotor lamination structure provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the rotor lamination structure provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the magnetic tile provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the circular anti-demagnetization groove provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the triangular anti-demagnetization groove provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the trapezoidal structure of the anti-demagnetization groove provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of a rectangular anti-demagnetization groove provided in an embodiment of the present invention; Figure 11 This is a schematic diagram of the rotor structure provided in an embodiment of the present invention; Figure 12 This is the back EMF diagram of the motor before optimization provided in the embodiments of the present invention; Figure 13 This is the optimized back EMF diagram of the motor provided in this embodiment of the invention; Figure 14 This is a diagram showing the working magnetic flux density distribution of the magnetic tile before optimization, provided in an embodiment of the present invention. Figure 15 This is the optimized working magnetic flux density distribution diagram of the magnetic tile provided in the embodiment of the present invention.

[0022] In the picture: 100. Rotor structure; 110. Rotor assembly; 1. Rotor core; 11. Outwardly convex arc portion; 111. Outwardly convex arc surface; 12. Inwardly concave arc portion; 121. Inwardly concave arc surface; 13. Weight reduction groove; 14. Shaft cavity; 2. Magnetic tile; 21. First arc surface; 22. Second arc surface; 23. Transition surface; 24. Chamfer; 3. Anti-demagnetizing groove; 4. Rotor laminations; 41. Outwardly convex arc; 42. Inwardly concave arc; 43. Anti-demagnetizing hole; 44. Weight reduction hole; 45. Shaft hole. Detailed Implementation

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings, not all of them.

[0024] This invention defines certain directional terms. Unless otherwise stated, the directional terms used, such as "up," "down," "left," "right," "inner," and "outer," are used for ease of understanding and therefore do not constitute a limitation on the scope of protection of this invention.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] like Figures 1-10 As shown, this embodiment provides a rotor assembly 110, which includes a rotor core 1 and a magnetic tile 2. The rotor core 1 includes an outwardly convex arc portion 11 and an inwardly concave arc portion 12. There are multiple outwardly convex arc portions 11 and multiple inwardly concave arc portions 12. The multiple outwardly convex arc portions 11 and multiple inwardly concave arc portions 12 are arranged alternately in sequence. The outwardly convex arc portion 11 includes an outwardly convex arc surface 111, and the inwardly concave arc portion 12 includes an inwardly concave arc surface 121. A magnetic tile 2 is attached to each inwardly concave arc surface 121. The outwardly convex arc portion 11 and the magnetic tile 2 adjacent to the magnetic tile 2 form a pair of magnetic poles. The magnetic tile 2 and the concave arc surface 121 need to simultaneously satisfy the following: ; ; ; Where Q1 is the angle formed by the two ends of the concave arc surface 121 and the center O of the rotor core 1, and Q2 is the angle formed by the two ends of the convex arc surface 111 and the center O of the rotor core 1. R1 is the radius of the concave arc surface 121, b1 is the width of the concave arc surface 121, and b2 is the width of the magnetic tile 2.

[0028] The adjacent convex arc portion 11 and the magnetic tile 2 form a pair of magnetic poles. Compared with the prior art, which requires two magnetic tiles for a pair of magnetic poles, this effectively reduces the number of magnetic tiles 2 used. The angle limitation of the concave arc surface 121 and the convex arc surface 111, as well as the width limitation of the magnetic tile 2, make the area occupied by the convex arc portion 11 larger than the area of ​​the magnetic tile 2. This reduces the width of the magnetic tile 2 without making it too small. While meeting the magnetic requirements of the magnetic tile 2, it also reduces the volume of the magnetic tile 2, reduces the amount of permanent magnet material used, and reduces the cost of the permanent magnet in the rotor structure 100.

[0029] Furthermore, the magnetic tile 2 has a first arc surface 21 and a second arc surface 22 arranged opposite to each other. The first arc surface 21 is attached to the concave arc surface 121, and the diameters of the first arc surface 21 and the second arc surface 22 are equal. The magnetic tile 2 is manufactured by wire cutting. The blank used to manufacture the magnetic tile 2 is a large piece of magnetic steel. Multiple single magnetic tiles 2 are cut from the blank in sequence. The arrangement of the first arc surface 21 and the second arc surface 22 being arc surfaces of equal diameter can reduce the waste between two adjacent magnetic tiles 2 cut from the blank, thereby improving the utilization rate of the processing material of the magnetic tile 2 and reducing the material cost of a single magnetic tile 2.

[0030] The rotor assembly 110 provided in this embodiment reduces the number and volume of the magnet tiles 2, lowers the cost per magnet tile 2, and improves the utilization rate of permanent magnet materials, thereby reducing the cost of the rotor structure 100 and the motor from multiple aspects.

[0031] It should be noted that the material of the convex arc portion 11 itself is not magnetic. The reason why the convex arc portion 11 can be used as a magnetic pole is because the magnetism generated by the conduction of the magnetic tile 2 is used as a magnetic pole. For example, as... Figure 3 As shown, the magnetic tile 2 has two magnetic poles. Assuming the first arc surface 21 is the S pole and the second arc surface 22 is the N pole, the magnetic polarity of the first arc surface 21 is conducted to the convex arc portion 11, making the convex arc portion 11 act as the S pole, thus facilitating the formation of a pair of magnetic poles with the magnetic tile 2. Alternatively, the first arc surface 21 can be the N pole and the second arc surface 22 can be the S pole, with the magnetic polarity of the first arc surface 21 conducted to the convex arc portion 11, making the convex arc portion 11 act as the N pole, thus facilitating the formation of a pair of magnetic poles with the magnetic tile 2.

[0032] like Figure 1 and Figure 2 As shown, a weight-reducing groove 13 is provided on the rotor core 1, which is used to reduce the weight of the rotor core 1.

[0033] Furthermore, there are multiple weight-reducing slots 13, which are spaced apart along the circumference of the rotor core 1 and are symmetrically distributed on the rotor core 1.

[0034] Preferably, the number of weight-reducing grooves 13 can be equal to the number of poles of the motor to increase aesthetics. That is, the number of poles of the motor is 2P, the number of magnets 2 is P, the number of convex arc portions 11 and concave arc portions 12 is also P, and the number of weight-reducing grooves 13 is preferably 2P.

[0035] Furthermore, angle .

[0036] Furthermore, a shaft cavity 14 is provided on the rotor core 1, which is used to accommodate the motor shaft.

[0037] like Figure 4 and Figure 5 As shown, the rotor core 1 is formed by stacking multiple rotor laminations 4 along the axial direction of the rotor core 1. Along the direction perpendicular to the axial direction of the rotor core 1, the cross-section of the rotor core 1 is identical to that of the rotor laminations 4.

[0038] Furthermore, the rotor lamination 4 includes an outwardly convex arc 41 and an inwardly concave arc 42. The circle containing the outwardly convex arc 41 is M2, and the center of circle M2 is O2. The circle containing the inwardly concave arc 42 is M1, and the center of circle M1 is O1. Along the circumference of the rotor lamination 4, there are multiple outwardly convex arcs 41 and multiple inwardly concave arcs 42. The multiple outwardly convex arcs 41 and multiple inwardly concave arcs 42 are arranged alternately in sequence. The outwardly convex arcs 41 on the multiple rotor laminations 4 form the outwardly convex arc surface 111 of the rotor core 1, and the multiple inwardly concave arcs 42 on the multiple rotor laminations 4 form the inwardly concave arc surface 121 of the rotor core 1.

[0039] Furthermore, the center O1 of circle M1 and the center O2 of circle M2 are both on the diameter of rotor core 1.

[0040] Furthermore, the rotor lamination 4 is provided with weight reduction holes 44, and the weight reduction holes 44 on multiple rotor laminations 4 form the weight reduction grooves 13 of the rotor core 1.

[0041] Furthermore, the rotor laminations 4 are provided with shaft holes 45, and the shaft holes 45 on the multiple rotor laminations 4 form the shaft cavity 14 of the rotor core 1.

[0042] like Figure 4As shown, the two endpoints of the concave arc 42 are A1 and A2, and the included angle Q1 is ∠A1OA2; the two endpoints of the convex arc 41 are B1 and B2, and the included angle Q2 is ∠B1OB2. ; .

[0043] like Figure 6 As shown, the first arc surface 21 and the second arc surface 22 are connected by a transition surface 23, and a chamfer 24 is provided at the connection between the transition surface 23 and the second arc surface 22. The chamfer 24 can significantly improve the minimum working magnetic flux density of the magnet 2 over its entire domain under the action of the armature magnetic field generated by a large current (such as the armature magnetic field of the stator structure), and make the minimum working magnetic flux density of the magnet 2 over its entire domain greater than the demagnetization inflection point value of the magnet 2. If the minimum working magnetic flux density of the magnet 2 over its entire domain is less than the demagnetization inflection point value of the magnet 2, the magnet 2 will undergo irreversible demagnetization. Therefore, the chamfer 24 can improve the demagnetization resistance of the magnet 2, ensure that the magnetic properties of the magnet 2 remain unchanged, and thus ensure the life and reliability of the motor.

[0044] Furthermore, the chamfer 24 has a size range of C0.5-C3. Within this size range, the magnetic tile 2 exhibits the best resistance to demagnetization.

[0045] Furthermore, transition surfaces 23 are provided on both sides of the first arc surface 21 and the second arc surface 22. That is to say, there are also two chamfers 24, which are respectively provided on both sides of the first arc surface 21 and the second arc surface 22.

[0046] Furthermore, the thickness t1 of the magnetic tile 2 must satisfy: ; Where t1 is the thickness of the magnetic tile 2, R2 is the radius of the circle M3 containing the maximum outer diameter of the rotor core 1, and D is the distance between the center O1 of the concave arc surface 121 and the center O of the rotor core 1, i.e., D .

[0047] The thickness limitation of magnet 2 ensures that it will not exceed the circle M3 containing the maximum outer diameter of rotor core 1. The air gap size of the motor refers to the minimum value of the air gap, that is, the minimum value between rotor core 1 and magnet 2 and the stator core of the motor stator structure. The size of the motor air gap is limited by the motor manufacturing process, therefore, the size of the motor air gap cannot be changed. The thickness limitation of magnet 2 ensures that the air gap is within the normal range.

[0048] Furthermore, , .

[0049] like Figures 7-10 As shown, an anti-demagnetization groove 3 is provided on the concave arc surface 121. The dimensions of the anti-demagnetization groove 3 must meet the following requirements: ; ; Where b3 is the width of the anti-demagnetization groove 3 and t2 is the depth of the anti-demagnetization groove 3.

[0050] The size limitation of the anti-demagnetizing groove 3 can significantly improve the minimum working magnetic flux density of the magnet 2 across its entire domain under the influence of the armature magnetic field generated by a large current (such as the armature magnetic field of the stator structure), and ensure that the minimum working magnetic flux density of the magnet 2 across its entire domain is greater than the material demagnetization inflection point value of the magnet 2. If the minimum working magnetic flux density of the magnet 2 across its entire domain is less than the material demagnetization inflection point value of the magnet 2, the magnet 2 will undergo irreversible demagnetization. Therefore, the anti-demagnetizing groove 3 can improve the anti-demagnetization capability of the magnet 2, ensure that the magnetic properties of the magnet 2 remain unchanged, and thus ensure the life and reliability of the motor.

[0051] Furthermore, the anti-demagnetizing groove 3 is circular, triangular, trapezoidal, or rectangular in shape.

[0052] Furthermore, each concave arc surface 121 is provided with an anti-demagnetization groove 3.

[0053] Preferably, the anti-demagnetization groove 3 is located at the center of the concave arc surface 121, which makes the anti-demagnetization ability of the magnetic tile 2 better.

[0054] Furthermore, anti-demagnetizing holes 43 are provided on the rotor laminations 4, and the anti-demagnetizing holes 43 on multiple rotor laminations 4 form anti-demagnetizing grooves 3 of the rotor core 1.

[0055] like Figure 11 As shown, this embodiment also provides a rotor structure 100, which is formed by stacking an even number of the aforementioned rotor assemblies 110 along the axial direction of the rotor assemblies 110. Adjacent rotor assemblies 110 are staggered by an angle Q3. The second arc surfaces 22 on the magnetic tiles 2 corresponding to adjacent rotor assemblies 110 have different magnetic pole polarities. The even number of rotor assemblies 110 solves the problem of asymmetrical back EMF waveforms and poor sine strength caused by magnetic field asymmetry between the N and S poles due to the stacking of rotor assemblies 110. The number of rotor assemblies 110 and the staggered angle Q3 significantly improve the sine strength of the motor's back EMF waveform, thereby improving the sine strength of the air gap magnetic field and reducing vibration and noise.

[0056] For example, if the magnetic pole of the second arc surface 22 of the magnetic tile 2 in the rotor assembly 110 located at the top layer is the N pole, then the magnetic pole of the second arc surface 22 of the magnetic tile 2 in the rotor assembly 110 located at the second layer is the S pole, the magnetic pole of the second arc surface 22 of the magnetic tile 2 in the rotor assembly 110 located at the third layer is the N pole, the magnetic pole of the second arc surface 22 of the magnetic tile 2 in the rotor assembly 110 located at the fourth layer is the S pole, and so on... and vice versa. This is intended to solve the problem of asymmetrical back EMF waveform and poor sinusoidality caused by the magnetic field asymmetry between the N pole and the S pole due to the stacking of rotor assemblies 110.

[0057] This embodiment also provides an electric motor, which includes a stator structure and the aforementioned rotor structure 100, with the rotor structure 100 disposed within the stator structure. The rotor structure 100 provides advantages such as low cost, low noise, and high resistance to demagnetization.

[0058] Furthermore, the air gap between the stator structure and the rotor structure 100 must simultaneously satisfy the following requirements: ; ; Wherein, R2 is the radius of the circle containing the maximum outer diameter of rotor core 1, R3 is the radius of the circle containing the minimum outer diameter of stator core of stator structure, and R4 is the distance between the end of the convex arc surface 111 and the center O of rotor core 1.

[0059] By defining the shape and size of the convex arc surface 111 and the concave arc surface 121, a non-uniform air gap design is achieved. The air gap of a single rotor assembly 110 is non-uniform, and the size of the air gap affects the magnetic reluctance. Only when the magnitude of the magnetic reluctance is sinusoidal can the magnetic field be sinusoidal, that is, the back electromotive force is more sinusoidal, thereby reducing the vibration and noise of the motor.

[0060] To verify the sinusoidal back EMF of the motor provided in this embodiment, the back EMF diagrams before and after optimization are compared, as follows: Figure 12 and Figure 13 As shown, before optimization, the rotor structure 100 includes one rotor assembly 110, and the back EMF diagram is obviously poorly sinusoidal, resulting in high noise from the motor. After optimization, the rotor structure 100 includes an even number of rotor assemblies 110, and the adjacent rotor assemblies 110 are staggered at an angle. The back EMF diagram is obviously more sinusoidal, reducing the vibration and noise of the motor.

[0061] If the rotor structure 100 includes an even number of rotor assemblies 110, and there is no angular misalignment between adjacent rotor assemblies 110, then no back EMF will be generated; if the rotor structure 100 includes an odd number of rotor assemblies 110, and there is no angular misalignment between adjacent rotor assemblies 110, the back EMF diagram of the motor will be as follows: Figure 12As shown, the sinusoidal nature of the back EMF deteriorates. If the rotor structure 100 includes an odd number of rotor assemblies 110, and adjacent rotor assemblies 110 are angularly offset, it is equivalent to adding another rotor assembly 110 on top of an even number of rotor assemblies 110, which will further worsen the sinusoidal nature of the motor's back EMF. Therefore, it is crucial and necessary to ensure that the even number of rotor assemblies 110 and the angular offset between adjacent rotor assemblies 110 are properly configured.

[0062] To verify the demagnetization resistance of the magnetic tile 2 in this embodiment, simulation analysis was performed on the magnetic tile before optimization and the magnetic tile 2 after optimization, such as... Figure 14 and Figure 15 As shown, before optimization, the concave arc surface 121 did not have anti-demagnetizing grooves 3, and the magnetic tile 2 did not have chamfers 24. Under the influence of the armature magnetic field generated by a large current (such as the armature magnetic field of the stator structure), the minimum working magnetic flux density of the magnetic tile 2 across its entire surface was approximately 0.03. After optimization, the concave arc surface 121 has anti-demagnetizing grooves 3, and the magnetic tile 2 has chamfers 24. Under the influence of the armature magnetic field generated by a large current (such as the armature magnetic field of the stator structure), the minimum working magnetic flux density of the magnetic tile 2 across its entire surface was approximately 0.24. Therefore, after optimization, the minimum working magnetic flux density of the magnetic tile 2 across its entire surface was significantly improved. The anti-demagnetizing grooves 3 and chamfers 24 can improve the anti-demagnetizing capability of the magnetic tile 2, ensuring that the magnetic properties of the magnetic tile 2 remain unchanged, thereby ensuring the lifespan and reliability of the motor.

[0063] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A rotor assembly characterized by, The rotor core (1) includes a rotor core (1) and a magnetic tile (2). The rotor core (1) includes an outwardly convex arc portion (11) and an inwardly concave arc portion (12). There are multiple outwardly convex arc portions (11) and multiple inwardly concave arc portions (12). The multiple outwardly convex arc portions (11) and multiple inwardly concave arc portions (12) are arranged alternately along the circumference of the rotor core (1). The outwardly convex arc portion (11) includes an outwardly convex arc surface (111), and the inwardly concave arc portion (12) includes an inwardly concave arc surface (121). The magnetic tile (2) is attached to each inwardly concave arc surface (121). Adjacent outwardly convex arc portions (11) and magnetic tiles (2) form a pair of magnetic poles. The magnetic tile (2) and the concave arc surface (121) must simultaneously satisfy the following: ； ； ； Wherein, Q1 is the angle formed by the two ends of the concave arc surface (121) and the center O of the rotor core (1), and Q2 is the angle formed by the two ends of the convex arc surface (111) and the center O of the rotor core (1). R1 is the radius of the concave arc surface (121), b1 is the width of the concave arc surface (121), and b2 is the width of the magnetic tile (2).

2. The rotor assembly according to claim 1, characterized in that, The magnetic tile (2) has a first arc surface (21) and a second arc surface (22) arranged opposite to each other. The first arc surface (21) is attached to the concave arc surface (121). The diameter of the first arc surface (21) and the diameter of the second arc surface (22) are equal.

3. The rotor assembly according to claim 2, characterized in that, The first arc surface (21) and the second arc surface (22) are connected by a transition surface (23), and a chamfer (24) is provided at the connection between the transition surface (23) and the second arc surface (22).

4. The rotor assembly according to claim 3, characterized in that, The chamfer (24) has a size range of C0.5-C3.

5. The rotor assembly according to claim 1, characterized in that, The thickness t1 of the magnetic tile (2) must satisfy: ； Wherein, t1 is the thickness of the magnetic tile (2), R2 is the radius of the circle containing the maximum outer diameter of the rotor core (1), and D is the distance between the center O1 of the concave arc surface (121) and the center O of the rotor core (1).

6. The rotor assembly according to claim 1, characterized in that, An anti-demagnetization groove (3) is provided on the concave arc surface (121), and the dimensions of the anti-demagnetization groove (3) must meet the following requirements: ； ； Wherein, b3 is the width of the anti-demagnetizing groove (3), and t2 is the depth of the anti-demagnetizing groove (3).

7. The rotor assembly according to claim 6, characterized in that, The anti-demagnetization groove (3) is circular, triangular, trapezoidal or rectangular in shape.

8. A rotor structure, characterized in that, The rotor structure is formed by stacking an even number of rotor assemblies (110) as described in any one of claims 1-7 along the axial direction of the rotor assembly (110), with adjacent rotor assemblies (110) staggered by an angle of Q3; the second arc surface (22) on the magnetic tile (2) corresponding to the two adjacent rotor assemblies (110) has different magnetic polarities.

9. An electric motor, characterized in that, include: Stator structure; The rotor structure (100) as described in claim 8 is disposed within the stator structure.

10. The motor according to claim 9, characterized in that, The air gap between the stator structure and the rotor structure (100) must simultaneously satisfy the following: ； ； Wherein, R2 is the radius of the circle containing the maximum outer diameter of the rotor core (1), R3 is the radius of the circle containing the minimum outer diameter of the stator core of the stator structure, and R4 is the distance between the end of the convex arc surface (111) and the center O of the rotor core (1).

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