Rotor and permanent magnet motor

Abstract

The invention relates to the technical field of motors, in particular to a rotor and a permanent magnet motor, firstly, ferrite magnetic steel and neodymium iron boron magnetic steel are integrated, the advantages of different materials are combined, a neodymium iron boron high remanence material is utilized on the outer side of a rotor punching sheet to improve magnetic flux output, and a neodymium iron boron high coercive force material is utilized to improve demagnetization resistance; adaptive materials can be selected according to functional requirements of each part of the rotor, high-performance magnetic materials are used in key areas of magnetic poles, low-cost auxiliary magnetic materials (ferrite) are used in non-key areas of the magnetic poles, the performance and the cost are balanced, the defects that single-material magnetic steel (neodymium iron boron material) is high in cost and easy to demagnetize due to being too thin are effectively overcome, and compared with a single-magnet structure, the structure is simple and convenient. And the cost can be reduced by about 15%.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more particularly to a rotor and permanent magnet motor. Background Technology

[0002] Permanent magnet synchronous motors are widely used in new energy vehicles, industrial drives, and other fields due to their high power density, high efficiency, and excellent speed regulation performance. Traditional permanent magnet motors generally use permanent magnets made of a single material (such as neodymium iron boron), improving performance by optimizing the magnetic circuit structure. However, neodymium iron boron materials are expensive and their prices fluctuate wildly, accounting for more than 30% of the total cost of the motor; at the same time, they are prone to irreversible demagnetization under high temperature or strong demagnetizing field environments, which seriously restricts the reliability and service life of the motor. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a rotor and a permanent magnet motor to solve the technical problems in the prior art.

[0004] In view of the above objectives, a first aspect of the present invention provides a rotor, including a rotor core, the rotor core being annular, and a plurality of sets of magnet slot assemblies being provided on the rotor core, with a weight reduction slot provided between two adjacent sets of magnet slot assemblies. Each set of magnet slot assemblies includes one first magnet slot and two second magnet slots. The first magnet slot is U-shaped, with the bottom of the U-shape facing the center of the rotor core and the top facing the outside of the rotor core. The two second magnet slots are symmetrically arranged on both sides of the first magnet slot. The second magnet slot is an elongated strip that gradually widens in width. The narrower end is adjacent to one side of the first magnet slot, and the wider end is adjacent to the outside of the rotor core. As the second magnet slot extends from the narrower end to the wider end, it continuously moves away from the centerline of the first magnet slot. The first magnet trough contains a first magnet of a suitable shape and made of ferrite, and the second magnet trough contains a second magnet of a suitable shape and made of neodymium iron boron.

[0005] As an optional implementation, the first magnet is U-shaped, with the width of the central recess being [missing information]. The width of the two protrusions is The width difference between the two is The overall length of the first magnet in question is The length of the indentation in the middle is The lengths of the two protrusions are respectively and , in, .

[0006] As an optional implementation, the second magnet is a long strip that gradually widens in the width direction, and the length of the second magnet is... The width of the narrower end is The width of the narrower end is Both ends satisfy , , .

[0007] As an optional implementation, the first magnet and the second magnet satisfy the following: ,and 3.5.

[0008] As an optional implementation, it further includes a first magnetic separator and a second magnetic separator. The first magnetic separator is connected through to the wider end of the second magnetic slot, and the second magnetic separator is connected through to the narrower end of the second magnetic slot. The sidewall of the first magnetic separator and the outer wall of the rotor core form a thickness of [missing information]. The first magnetic bridge, in two adjacent sets of magnetic steel groove assemblies, forms a thickness of [missing information]. The second magnetic separator bridge, the sidewall of the second magnetic separator bridge and the sidewall of the first magnetic steel groove form a joint with a thickness of [thickness value missing]. The third bridge, the first bridge, the second bridge and the third bridge satisfy the following: ; in, It is an air gap.

[0009] As a second aspect of the invention, a permanent magnet motor is provided, comprising a rotor and a stator, wherein the rotor is as described above.

[0010] As an optional implementation, the stator is provided with a plurality of centrally symmetrical stator slots, the slot type being stator slots, and the number of slots being [number missing]. The number of rotor stages is ,satisfy .

[0011] As an optional implementation, the stator inner diameter is The stator outer diameter is The air gap is g, which satisfies the condition.

[0012] As an optional implementation, the stator includes multiple arc modules, with a matching connecting block between adjacent arc modules. The connecting block includes modules with widths of... , and The first boss, the first groove, and the second boss, wherein a radius of [missing information] is formed in the first groove. The arc-shaped groove, with a radius of [missing information] formed outward on the second boss. The arc-shaped boss, the distance between the side wall of the second boss and the side wall of the stator slot is The distance between the sidewall of the stator slot and the outer sidewall of the stator is ,in, , And satisfy .

[0013] As an optional implementation, the maximum value of the stator tooth width is The minimum value is The length of the groove is ,satisfy < / * < .

[0014] The beneficial effects of this invention: This invention provides a rotor and a permanent magnet motor. First, by integrating ferrite magnets and neodymium iron boron magnets, the advantages of different materials are combined. The outer side of the rotor laminations uses neodymium iron boron high remanence material to increase magnetic flux output, and neodymium iron boron high coercivity material to increase anti-demagnetization ability. Appropriate materials can be selected according to the functional requirements of each part of the rotor. High-performance magnetic materials are used in critical magnetic pole areas, while low-cost auxiliary magnetic materials (ferrite) are used in non-critical areas, balancing performance and cost. This effectively optimizes the defects of high cost and easy demagnetization of single-material magnets (neodymium iron boron material). Compared with a single magnet structure, the cost can be reduced by about 15%. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a permanent magnet motor according to an embodiment of the present invention (only the stator and rotor core laminations and magnets are shown in the figure); Figure 2 This is a schematic diagram of the rotor laminations and magnets according to an embodiment of the present invention; Figure 3 for Figure 2 Detailed partial view; Figure 4 This is a schematic diagram of the first magnet according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the second magnet in an embodiment of the present invention; Figure 6 A schematic diagram of a single-stage rotor lamination; Figure 7 This is a schematic diagram of the stator of a permanent magnet motor according to an embodiment of the present invention; Figure 8 This is a detailed view of a portion of the arc module; Figure 9 for Figure 8 Detailed drawing of Part A; Figure 10 The graph shows the effect of the h2 / h1 ratio on the back EMF of the unloaded line. Figure 11 The graph shows the effect of the h5 / h3 ratio on the back EMF of the unloaded line. Figure 12 The graph shows the effect of the h3 / h1 ratio on efficiency. Figure 13 The graph shows the effect of the bt1 / bt2 ratio on the cogging torque (mNm).

[0017] The diagram is marked as follows: 100. Rotor core; 11. First magnet slot; 12. Second magnet slot; 13. Weight reduction slot; 14. First magnetic bridge; 15. Second magnetic bridge; 30. First magnet; 40. Second magnet; 200. Stator; 21. Arc module; 22. Stator slot; 23. First boss; 24. First groove; 25. Second boss; 26. Arc-shaped slot; 27. Arc-shaped boss. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 as well as Figure 7 As shown, as a first aspect of the present invention, a permanent magnet motor is provided, including a rotor and a stator 200, wherein the rotor includes a rotor core 100, the rotor core 100 is annular, and multiple sets of magnet slot assemblies are provided on the rotor core 100, and a weight reduction slot 13 is provided between two adjacent sets of magnet slot assemblies. Each set of magnet slot assemblies includes a first magnet slot 11 and two second magnet slots 12. The first magnet slot 11 is U-shaped, with the bottom of the U-shape facing the center of the rotor core 100 and the top facing the outside of the rotor core 100. The two second magnet slots 12 are symmetrically arranged on both sides of the first magnet slot 11. The second magnet slot 12 is an elongated strip that gradually widens in the width direction. The narrower end is adjacent to one side of the first magnet slot 11, and the wider end is adjacent to the outside of the rotor core 100. As the second magnet slot 12 extends from the narrower end to the wider end, it continuously moves away from the centerline of the first magnet slot 11. The first magnet trough 11 contains a first magnet 30 of ferrite material that is adapted to the shape, and the second magnet trough 12 contains a second magnet 40 of neodymium iron boron material that is adapted to the shape.

[0021] In this embodiment of the invention, ferrite magnets and neodymium iron boron magnets are integrated to combine the advantages of different materials. Neodymium iron boron high remanence material is used on the outer side of the rotor lamination to increase magnetic flux output, and neodymium iron boron high coercivity material is used to increase anti-demagnetization ability. Appropriate materials can be selected according to the functional requirements of each part of the rotor. High-performance magnetic materials are used in critical magnetic pole areas, while low-cost auxiliary magnetic materials (ferrite) are used in non-critical areas, balancing performance and cost. This effectively optimizes the defects of high cost and easy demagnetization of single-material magnets (neodymium iron boron material). Compared with a single magnet structure, the cost can be reduced by about 15%.

[0022] Secondly, in this embodiment of the invention, the bottom wide slot structure of the "U"-shaped first magnet slot 11 (ferrite magnet) is close to the center of the rotor, forming a magnetic focusing effect to compensate for the low remanence defect of ferrite; the width of the gradually widening second magnet slot 12 (neodymium iron boron) gradually increases, so that the high coercivity region (wide end) of the magnet is as close to the air gap as possible, directly strengthening the anti-demagnetization ability of the rotor surface; the gradually widening and diverging layout of the second magnet slot 12 (continuously moving away from the center line of the first magnet slot 11) optimizes the direction of the magnetic lines of force, so that the neodymium iron boron magnetic flux can efficiently penetrate the air gap; and the narrow end of the gradually widening neodymium iron boron slot corresponds to the low magnetic field region, reducing the amount of neodymium iron boron used, while the wide end is concentrated in the high magnetic field region to improve the utilization rate, effectively saving the amount of neodymium iron boron used compared with the uniform cross-section design.

[0023] As an optional implementation method, such as Figure 4 and Figure 6 As shown, the first magnet 30 is shaped like a concave "U", with the width of the concave portion in the middle being [missing information]. The width of the two protrusions is The width difference between the two is The overall length of the first magnet 30 is The length of the indentation in the middle is The lengths of the two protrusions are respectively and ,in, In this embodiment of the invention, by... The proportional constraint ensures a balance between mechanical strength and magnetic flux output, through The proportional constraint suppresses leakage flux and reduces iron loss, through The proportional constraints result in a symmetrical length design, which offsets thermal deformation stress, while the adaptability of the combined stamping process improves manufacturing efficiency.

[0024] As an optional implementation method, such as Figure 5 As shown, the second magnet 40 is a long strip that gradually widens in the width direction, and the length of the second magnet is... The width of the narrower end is The width of the narrower end is Both ends satisfy , , In this embodiment of the invention, by using the above-mentioned dimensional constraints, the anti-demagnetization capability is enhanced at the narrower end, and the volume of the narrow end is compressed ( The amount of neodymium iron boron used is reduced. In addition, the gradually widened structure linearly modulates the magnetic field distribution to weaken harmonic distortion, and the stepped stiffness distribution increases the rotor critical speed to avoid resonance.

[0025] As an optional implementation method, such as Figure 4 and Figure 5 As shown, the first magnet 30 and the second magnet 40 satisfy the following: ,and 3.5. In this embodiment of the invention, the magnetic circuit coupling problem is solved by constraining the above-mentioned proportional relationship. On the one hand, the ferrite provides a sufficient bias magnetic field, and on the other hand, the proportion of ferrite magnetic flux is limited to avoid shielding by the NdFeB magnetic field. The proportional coefficient optimizes the permeability matching of the magnet-steel interface to suppress eddy currents and stabilizes the inductance ratio to widen the constant power speed regulation range.

[0026] As an optional implementation method, such as Figure 3As shown, it also includes a first magnetic bridge 14 and a second magnetic bridge 15. The first magnetic bridge 14 is connected to the wider end of the second magnetic slot 12, and the second magnetic bridge 15 is connected to the narrower end of the second magnetic slot 12. The sidewall of the first magnetic bridge 14 forms a thickness between itself and the outer wall of the rotor core. The first magnetic bridge, in two adjacent sets of magnetic steel groove assemblies, forms a thickness of [missing information]. The second magnetic bridge 15 and the sidewall of the first magnetic groove 14 form a joint with a thickness of [thickness value missing]. The third bridge, the first bridge, the second bridge and the third bridge satisfy the following: ;in, It is an air gap.

[0027] In this embodiment of the invention, the limitation of the above parameter ratios, on the one hand, establishes a high magnetoresistance barrier to block magnetic leakage, on the other hand, limits the total thickness to avoid the risk of magnetic saturation, automatically adapts the air gap size to improve heat dissipation efficiency, and at the same time can cut off the high-order harmonic path to reduce noise.

[0028] As an optional implementation method, such as Figure 1 and Figure 7 As shown, the stator 200 is provided with a plurality of centrally symmetrical stator slots 22, the slot type of the stator slots 22 is parallel slots 22, and the number of slots is [number missing]. The number of rotor stages is ,satisfy In this embodiment of the invention, by matching specific pole-slot combinations to suppress the main harmonic orders, the peak value of the cogging torque is effectively reduced and the electromagnetic vibration noise is decreased, while avoiding the winding process complexity caused by fractional slot design.

[0029] As an optional implementation method, such as Figure 7 As shown, the inner diameter of the stator 200 is The stator outer diameter is 200. The air gap is g, which satisfies In this embodiment of the invention, by limiting the above-mentioned proportions, on the one hand, it prevents the rotor magnet from being too weak, resulting in insufficient magnetic flux density, and on the other hand, it limits the magnet from being too strong, causing local saturation. The optimized magnetic circuit matching improves the stability of the output torque.

[0030] As an optional implementation method, such as Figure 8 and Figure 9 As shown, the stator 200 includes multiple arc modules 21, and a matching connecting block is provided between two adjacent arc modules 21. The connecting block includes components with widths of... , and The first boss 23, the first groove 24, and the second boss 25, wherein the first groove 24 has a radius of [missing information]. The arc-shaped groove 26, the second boss 25 has an outwardly formed radius of The arc-shaped boss 27, the distance between the side wall of the second boss 25 and the side wall of the stator slot 22 is The distance between the sidewall of the stator slot 22 and the outer sidewall of the stator 200 is ,in, , and satisfy Thus, by defining this structure and specifying the proportions of certain parameters, a stepped dimensional difference is used to compensate for thermal deformation displacement, optimizing the stability of the connection between the arc modules. Furthermore, The range control keeps the magnetic flux density of the stator yoke within the optimal range, simultaneously improving structural stiffness and magnetic circuit efficiency.

[0031] As an optional implementation method, such as Figure 7 As shown, the maximum value of the stator tooth width 200 is The minimum value is The length of the groove is ,satisfy < / * < In this way, magnetic saturation losses caused by excessively narrow tooth roots are avoided on the one hand, and the surge in tooth cogging torque caused by excessively wide tooth tips on the other hand is limited.

[0032] As a second aspect of the present invention, a rotor is provided, the rotor including a rotor core 100, the rotor core 100 being annular, the rotor core 100 being provided with a plurality of sets of magnet slot assemblies, and a weight reduction slot 13 being provided between two adjacent sets of magnet slot assemblies. Each set of magnet slot assemblies includes a first magnet slot 11 and two second magnet slots 12. The first magnet slot 11 is U-shaped, with the bottom of the U-shape facing the center of the rotor core 100 and the top facing the outside of the rotor core 100. The two second magnet slots 12 are symmetrically arranged on both sides of the first magnet slot 11. The second magnet slot 12 is an elongated strip that gradually widens in the width direction. The narrower end is adjacent to one side of the first magnet slot 11, and the wider end is adjacent to the outside of the rotor core 100. As the second magnet slot 12 extends from the narrower end to the wider end, it continuously moves away from the centerline of the first magnet slot 11. The first magnet trough 11 contains a first magnet 30 of ferrite material that is adapted to the shape, and the second magnet trough 12 contains a second magnet 40 of neodymium iron boron material that is adapted to the shape.

[0033] Figure 10 for The curve showing the effect of the ratio on the back EMF of the unloaded line was obtained using Maxwell software simulation. From the trend of this curve, we can obtain... The ratio has a positive promoting effect on the direction of the back EMF of the unloaded line; Figure 11 for The curve showing the effect of the ratio on the back EMF of the unloaded line was obtained using Maxwell software simulation. From the trend of this curve, we can obtain... The ratio has a positive promoting effect on the direction of the back EMF of the unloaded line; Figure 12 for The curve showing the effect of the ratio on efficiency was obtained using Maxwell software simulation. The trend of this curve can be used to obtain... The ratio has a positive effect on the trend of efficiency; Figure 13 for / The curve showing the effect of the ratio on cogging torque (mNm) was obtained using Maxwell software simulation. The trend of this curve can be used to obtain... / The ratio has a suppressive effect on the direction of cogging torque.

[0034] In this embodiment of the invention, ferrite magnets and neodymium iron boron magnets are integrated to combine the advantages of different materials. Neodymium iron boron high remanence material is used on the outer side of the rotor lamination to increase magnetic flux output, and neodymium iron boron high coercivity material is used to increase anti-demagnetization ability. Appropriate materials can be selected according to the functional requirements of each part of the rotor. High-performance magnetic materials are used in critical magnetic pole areas, while low-cost auxiliary magnetic materials (ferrite) are used in non-critical areas, balancing performance and cost. This effectively optimizes the defects of high cost and easy demagnetization of single-material magnets (neodymium iron boron material). Compared with a single magnet structure, the cost can be reduced by about 15%.

[0035] Secondly, in this embodiment of the invention, the bottom wide slot structure of the "U"-shaped first magnet slot (ferrite magnet) is close to the center of the rotor, forming a magnetic focusing effect to compensate for the low remanence defect of ferrite; the width of the gradually widening second magnet slot (neodymium iron boron) gradually increases, so that the high coercivity region (wide end) of the magnet is as close to the air gap as possible, directly strengthening the anti-demagnetization ability of the rotor surface; the gradually widening second magnet slot + divergent layout (continuously moving away from the center line of the first magnet slot) optimizes the direction of magnetic lines of force, so that the neodymium iron boron magnetic flux can efficiently penetrate the air gap; and the narrow end of the gradually widening neodymium iron boron slot corresponds to the low magnetic field region, reducing the amount of neodymium iron boron used, while the wide end is concentrated in the high magnetic field region to improve the utilization rate, effectively saving the amount of neodymium iron boron used compared with the uniform cross-section design.

[0036] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0037] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A rotor comprising a rotor core, characterized in that, The rotor core is annular, and multiple sets of magnet slot assemblies are provided on the rotor core. A weight reduction slot is provided between two adjacent sets of magnet slot assemblies. Each set of magnet slot assemblies includes one first magnet slot and two second magnet slots. The first magnet slot is U-shaped, with the bottom of the U-shape facing the center of the rotor core and the top facing the outside of the rotor core. The two second magnet slots are symmetrically arranged on both sides of the first magnet slot. The second magnet slot is an elongated strip that gradually widens in width. The narrower end is adjacent to one side of the first magnet slot, and the wider end is adjacent to the outside of the rotor core. As the second magnet slot extends from the narrower end to the wider end, it continuously moves away from the centerline of the first magnet slot. The first magnet trough contains a first magnet of a suitable shape and made of ferrite, and the second magnet trough contains a second magnet of a suitable shape and made of neodymium iron boron.

2. The rotor according to claim 1, characterized in that, The first magnet is U-shaped, with the width of the central recess being [missing information]. The width of the two protrusions is The width difference between the two is The overall length of the first magnet in question is The length of the indentation in the middle is The lengths of the two protrusions are respectively and , in, .

3. The rotor according to claim 1, characterized in that, The second magnet is a long strip that gradually widens in width, and its length is [missing information]. The width of the narrower end is The width of the narrower end is Both ends satisfy , , .

4. The rotor according to claim 1, characterized in that, The first magnet and the second magnet satisfy the following: ,and 3.

5.

5. The rotor according to claim 1, characterized in that, It also includes a first magnetic separator and a second magnetic separator. The first magnetic separator is connected to the wider end of the second magnetic slot, and the second magnetic separator is connected to the narrower end of the second magnetic slot. The sidewall of the first magnetic separator forms a thickness between itself and the outer wall of the rotor core. The first magnetic bridge, in two adjacent sets of magnetic steel groove assemblies, forms a thickness of [missing information]. The second magnetic separator bridge, the sidewall of the second magnetic separator bridge and the sidewall of the first magnetic steel groove form a joint with a thickness of [thickness value missing]. The third bridge, the first bridge, the second bridge and the third bridge satisfy the following: ； in, This is an air gap.

6. A permanent magnet motor, comprising a rotor and a stator, characterized in that, The rotor is the rotor as described in any one of claims 1-5.

7. The permanent magnet motor according to claim 6, characterized in that, The stator is provided with a plurality of centrally symmetrical stator slots, the slots being parallel slots, and the number of slots being [number missing]. The number of rotor stages is ,satisfy .

8. The permanent magnet motor according to claim 6, characterized in that, The stator inner diameter is The stator outer diameter is The air gap is g, which satisfies .

9. The permanent magnet motor according to claim 6, characterized in that, The stator includes multiple arc modules, and a matching connecting block is provided between two adjacent arc modules. The connecting block includes components with widths of... , and The first boss, the first groove, and the second boss, wherein a radius of [missing information] is formed in the first groove. The arc-shaped groove, with a radius of [missing information] formed outward on the second boss. The arc-shaped boss, the distance between the side wall of the second boss and the side wall of the stator slot is The distance between the sidewall of the stator slot and the outer sidewall of the stator is ,in, , And satisfy .

10. The permanent magnet motor according to claim 6, characterized in that, The maximum value of the stator tooth width is The minimum value is The length of the groove is ,satisfy < / < .

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