Permanent magnet motor and rotor thereof

Abstract

The utility model provides a permanent magnet motor and a rotor thereof. The rotor comprises a rotor iron core; the plurality of groups of magnetic steel are arranged in the rotor core and are arranged along the circumferential direction of the rotor core, each group of magnetic steel comprises at least one pair of first magnetic steel and second magnetic steel, and the first magnetic steel and the second magnetic steel are divided into a plurality of power sections along the axial direction of the rotor core; the magnetic steel in different groups has the same number of power segments or the magnetic steel in at least a part of groups has different numbers of power segments. On one hand, a magnetic circuit can be designed and optimized, the permanent magnet torque and the reluctance torque can be adjusted to improve the output capability and the magnetic steel utilization rate of the whole machine, and on the other hand, the anti-demagnetization capability of the motor can be improved, and on the other hand, the number of segments and the thickness of the segments are optimized and selected through an axial segmentation mode, the magnetic steel eddy-current loss can be reduced, and the service life of the motor is prolonged. The maximum working temperature of the magnetic steel is reduced, and the demagnetization risk of the magnetic steel is finally reduced; the processing and assembling difficulty of the magnetic steel is reduced; and the magnetic steel processing cost and the rotor assembling cost are reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to motor technical field, concretely relates to a kind of permanent magnet motor and its rotor. BACKGROUND

[0002] At present, the energy crisis situation is grim at home and abroad, to replace traditional fossil fuels with clean energy, realize carbon neutralization is the trend, therefore, new energy vehicles will replace fuel vehicles to become the mainstream form of travel, and the power source of new energy vehicles is motor, among them, permanent magnet synchronous motor becomes the core power of most new energy vehicles with the advantages of high efficiency and high power density.The advantage of sintered neodymium-iron-boron material is high residual magnetism and high coercive force, which can realize high power density of motor, so it is a common magnetic steel material for permanent magnet synchronous motor, but irreversible demagnetization will occur when the temperature exceeds Curie temperature, causing permanent decline in motor performance.

[0003] When motor works continuously, iron loss, copper loss and mechanical wind abrasion loss will cause rotor temperature to rise, and magnetic steel will generate large eddy current in alternating magnetic field, which will further aggravate magnetic steel heating and increase the risk of magnetic steel demagnetization.Currently, 3V magnetic steel arrangement structure is used to improve motor torque density design, which can improve magnetic steel utilization rate and reduce torque fluctuation to cope with vibration noise problem, but this structure still cannot reduce magnetic steel eddy current loss, and magnetic steel faces demagnetization risk. UTILITY MODEL CONTENT

[0004] In view of the above shortcomings of prior art, the purpose of the utility model is to provide a kind of permanent magnet motor and its rotor, to solve the problem that current 3V magnetic steel arrangement structure is still unable to reduce magnetic steel eddy current loss in the design of improving motor torque density, and magnetic steel faces demagnetization risk.

[0005] To achieve the above object and other related purposes, the utility model provides a kind of rotor of permanent magnet motor, comprising:

[0006] Rotor core;

[0007] Multiple groups of magnetic steel are arranged in the rotor core, and are arranged along the circumferential direction of the rotor core, each group of the magnetic steel includes at least a pair of first magnetic steel and second magnetic steel, along the axial direction of the rotor core, the first magnetic steel and the second magnetic steel are divided into multiple power segments, and the power segment number of different groups of magnetic steel is the same or at least part of the power segment number of the magnetic steel of the group is different.

[0008] In an embodiment of the utility model, each group of the magnetic steel includes three pairs of first magnetic steel and second magnetic steel, three pairs of first magnetic steel and second magnetic steel are arranged in radial stratification, and each pair of the first magnetic steel and the second magnetic steel is arranged in V shape.

[0009] In one embodiment of the utility model, the rotor core is formed with a magnetic steel slot, and the magnetic steel is installed in the magnetic steel slot.

[0010] In one embodiment of the utility model, the magnetic steels of different power sections are of integral structure or sectional structure.

[0011] In one embodiment of the utility model, in the same group, the number of sub-sections of the magnetic steels of the same power section and different layers is same or different.

[0012] In one embodiment of the utility model, in the same group, each pair of the magnetic steels comprises a first magnetic steel and a second magnetic steel, and the number of sub-sections of the first magnetic steel and the second magnetic steel in the same layer and the same power section is same or different.

[0013] In one embodiment of the utility model, the thickness of the magnetic steels of different power sections and / or different numbers of sub-sections is different.

[0014] In one embodiment of the utility model, the lengths of the magnetic steels of different power sections are same or the lengths of at least part of the power sections are different.

[0015] In one embodiment of the utility model, the magnetic steel is one or more of sintered neodymium iron boron, bonded neodymium iron boron and ferrite.

[0016] The utility model also provides a permanent magnet motor, comprising: a rotor and a stator, the stator ring is equipped in the outer periphery of the rotor, and the rotor comprises the rotor of the permanent magnet motor of any one of the above embodiments.

[0017] The utility model provides a permanent magnet motor and rotor, be applied to built-in type 3V magnetic steel structure's rotor of permanent magnet synchronous motor, this multilayer layout's magnetic steel structure, on one hand, can design optimization magnetic circuit, adjust permanent magnet torque and reluctance torque's size and promote the output capacity and magnetic steel utilization of complete machine, can also improve motor anti demagnetization capacity, on the other hand, through axial sectional method, the number of sections and sectional thickness are optimized and selected, can reduce magnetic steel eddy current loss, then reduce the highest working temperature of magnetic steel, finally reduce the demagnetization risk of magnetic steel, reduce the difficulty of magnetic steel processing and assembly, and reduce the cost of magnetic steel processing and rotor assembly. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme of the utility model embodiment, the following will be needed to use the drawing for the embodiment description briefly introduces, obviously, the following description in the drawing is only some embodiments of the utility model, for those skilled in the art, under the premise of not paying the creative labor, can also obtain other drawings according to these drawings.

[0019] Fig. 1The topological structure schematic diagram of the rotor in one embodiment of the utility model.

[0020] Fig. 2 The partial structure schematic diagram of the 3V type magnetic steel rotor in one embodiment of the utility model.

[0021] Fig. 3 The axial sectional view of the 3V type magnetic steel structure rotor in one embodiment of the utility model.

[0022] Label explanation:

[0023] 100, rotor; 11, rotor core; 12, magnetic steel; 111, magnetic steel slot; 121, first magnetic steel; 122, second magnetic steel. Specific implementation

[0024] The implementation mode of the utility model is explained below through specific concrete examples, and other advantages and effects of the utility model can be easily understood by those skilled in the art from the content disclosed in the specification. The utility model can also be implemented or applied through other different concrete implementation modes, and each detail in the specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the utility model.

[0025] It should be noted that the diagrams provided in the embodiments only illustrate the basic concept of the utility model in a schematic manner, and only the components related to the utility model are shown in the diagrams, not the number, shape and size of the components during actual implementation. The shape, number and proportion of each component during actual implementation can be changed arbitrarily, and the component layout pattern can also be more complex.

[0026] Please refer to Figs. 1 to 3 As shown in the drawings, the utility model provides a permanent magnet motor and a rotor thereof, to solve the problem that the design of improving motor torque density by changing the magnetic steel arrangement structure still cannot reduce magnetic steel eddy current loss and magnetic steel faces demagnetization risk. Specifically, the rotor 100 includes a rotor core 11 and a plurality of magnetic steels 12, the magnetic steel 12 is arranged in the rotor core 11, and the plurality of magnetic steels are arranged along the circumference of the rotor core 11. Specifically, a magnetic steel slot 111 is formed in the rotor core 11, the magnetic steel 12 is installed in the magnetic steel slot 111, each group of magnetic steels 12 includes at least one pair of first magnetic steels 121 and second magnetic steels 122, for example, each group of magnetic steels 12 includes three pairs of first magnetic steels 121 and second magnetic steels 122, the three pairs of first magnetic steels 121 and second magnetic steels 122 are arranged in layers along the radial direction, and are divided into first layer magnetic steels, second layer magnetic steels and third layer magnetic steels from inside to outside along the radial direction. The first magnetic steels and the second magnetic steels in each layer of magnetic steels 12 are arranged in a "V" shape, that is, the magnetic steels adopt a three-layer V-shaped structure arranged from inside to outside.

[0027] Please refer toFigs. 1 to 3 As shown in the embodiment, the rotor is axially segmented as a whole, and the first magnetic steel 121 and the second magnetic steel 122 are divided into a plurality of power segments along the axial direction of the rotor core 11. The power of different power segments can be the same or different. Further, the magnetic steel 12 of different power segments can be an integral structure or a segmented structure.

[0028] Fig. 3 FIG. 3 is a schematic diagram of axial segmentation of a 3V magnetic steel structure rotor. The example is axially divided into 6 power segments. The selection of the number of axial sub-segments of the magnetic steel on different power segments and the number of axial sub-segments of the magnetic steel of different layers in the same power segment is shown in Table 1.

[0029] Table 1 Number of axial sub-segments of different layers of magnetic steel of different power segments

[0030]

[0031] wherein L represents the number of axial sub-segments of the first magnetic steel 121, R represents the number of axial sub-segments of the second magnetic steel 122, the first number in the subscript represents the number of the power segment where the magnetic steel is located, and the second number represents the layer number of the magnetic steel. L11 to R63 are positive integers between 1 and 6. When the number is 1, it means that the magnetic steel in the power segment and the layer is not segmented.

[0032] Referring to FIG. 4, Figs. 1 to 3 As shown in the embodiment, the axial segmentation of the magnetic steel of each power segment can be further divided into a plurality of sub-segments or not segmented. When segmented, the number of sub-segments of the magnetic steel of the same power segment and different layers in the same group of magnetic steel is the same or different. Specifically, the number of sub-segments of the segmented magnetic steel can all be the same, all be different, or part of them be the same and part of them be different. For example, the number of sub-segments of the first layer magnetic steel, the second layer magnetic steel, and the third layer magnetic steel of the first power segment can all be the same, all be different, or two of them be different. It can be understood that the number of sub-segments of the same power segment and different layers of magnetic steel can be selected according to the different eddy current losses of the magnetic steel.

[0033] Referring to FIG. 5, Figs. 1 to 3 As shown in the embodiment, the number of sub-segments of the first magnetic steel 121 and the second magnetic steel 122 of the same layer and the same power segment in the same group of magnetic steel is the same or different. For example, the number of sub-segments of the first magnetic steel and the second magnetic steel of the first layer magnetic steel of the first power segment can be the same or different, the number of sub-segments of the first magnetic steel and the second magnetic steel of the second layer magnetic steel of the first power segment can be the same or different, and the number of sub-segments of the first magnetic steel and the second magnetic steel of the third layer magnetic steel of the first power segment can be the same or different. It can be understood that the number of sub-segments of the same layer of the first magnetic steel 121 and the second magnetic steel 122 of the same power segment can be selected according to the demagnetization risk faced by the magnetic steel.

[0034] Please see Figs. 1 to 3 As shown, in this embodiment, the number of power segments of the magnets in different groups is the same, or at least the number of power segments of the magnets in some groups is different. That is, in different groups, the number of power segments can be all the same, all different, or partially the same and partially different, which can be selected as needed.

[0035] Please see Figs. 1 to 3 As shown, in this embodiment, the thickness of the magnets in different power segments and / or different numbers of sub-segments is different. For example, the thicknesses of the six power segments in the above embodiment may all be the same, all different, or partially the same and partially different. Alternatively, in any power segment, the thicknesses of the magnets in each number of sub-segments may all be the same, all different, or partially the same and partially different. In this embodiment, the power segments of the first magnet and / or the second magnet in the same group and the same layer can be evenly or unevenly divided, that is, the lengths of different power segments are the same or at least some power segments have different lengths. For example, the lengths of the six power segments in the above embodiment may all be equal, all unequal, or partially equal and partially unequal, which can be selected according to actual needs.

[0036] Please see Figs. 1 to 3 As shown, in this embodiment, the magnet 12 is one or more of sintered NdFeB, bonded NdFeB, and ferrite.

[0037] Understandably, increasing the number of axial sub-segments in the magnet can effectively reduce eddy current losses. Compared to unsegmented magnets, axially segmented magnets can reduce eddy current losses by 70%. The number of sub-segments in different layers of magnets has different effects on reducing eddy current losses. The number of sub-segments can be optimized according to the actual loss situation. That is, the number, thickness, and length of the power segments of the first and second magnets in different groups and layers can be selected according to actual needs, as well as the number, thickness, and length of sub-segments in different groups, layers, and power segments, in order to optimize the rotor design.

[0038] Please see Figs. 1 to 3 Figs. 1 to 3 As shown, this utility model also proposes a permanent magnet motor, which includes a rotor (not shown) and a stator. The stator is ringed around the outer periphery of the rotor, and the rotor includes the rotor 100 as described in the above embodiments. It should be noted that the rotor has a similar or identical structure to the rotor of the permanent magnet motor described in the above embodiments, and will not be described again here to avoid repetition.

[0039] The utility model provides a kind of permanent magnet motor and its rotor, it is applied to the rotor of built-in 3V type magnetic steel structure of permanent magnet synchronous motor, this multilayer layout magnetic steel structure, on the one hand, can design optimization magnetic circuit, adjust the size of permanent magnet torque and reluctance torque and promote the output capacity and magnetic steel utilization of complete machine, while also can improve motor anti demagnetization capability, on the other hand, by the way of axial segmentation, the number of sub segmentation and segmentation thickness are optimized and selected, can reduce magnetic steel eddy current loss, in turn reduce the highest working temperature of magnetic steel, finally reduce the demagnetization risk of magnetic steel;Reduce the difficulty of magnetic steel processing and assembly;And reduce the cost of magnetic steel processing and rotor assembly.

[0040] The above-described embodiments are only used to illustrate the technical solutions of the utility model, rather than limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it still can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of technical features; and these modifications or replacements do not make the essence of corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model, and should be included in the protection scope of the utility model.

[0041] In addition to the technical features described in the specification, the remaining technical features are known to those skilled in the art, and in order to highlight the innovative features of the utility model, the remaining technical features will not be described here.

Claims

1. A rotor of a permanent magnet electric machine, characterized by, Comprising: a rotor core; a plurality of groups of magnetic steels arranged in a circumferential direction of the rotor core, each group of the magnetic steels comprising at least a first magnetic steel and a second magnetic steel, the first magnetic steel and the second magnetic steel being divided into a plurality of power segments in an axial direction of the rotor core, the number of power segments of different groups of the magnetic steels being the same or at least partially different.

2. A rotor of a permanent-magnet electric machine according to claim 1, characterized in that Each group of the magnetic steels comprises three pairs of the first magnetic steel and the second magnetic steel, the three pairs of the first magnetic steel and the second magnetic steel being arranged in a radial direction in layers, and each pair of the first magnetic steel and the second magnetic steel being arranged in a V shape.

3. The rotor of a permanent-magnet electric machine according to claim 1, characterized in that, The rotor core is formed with a magnetic steel slot, and the magnetic steel is installed in the magnetic steel slot.

4. The rotor of a permanent-magnet electric machine according to claim 1, characterized in that, The magnetic steels of different power segments are of an integral structure or of a segmented structure comprising a plurality of sub-segments.

5. A rotor of a permanent-magnet electric machine according to claim 4, characterized in that In the same group, the number of sub-segments of the magnetic steels of the same power segment and different layers is the same or different.

6. A rotor of a permanent-magnet electric machine according to claim 4, characterized in that, In the same group, the number of sub-segments of the first magnetic steel and the second magnetic steel of the same layer and the same power segment is the same or different.

7. A rotor of a permanent-magnet electric machine according to claim 4, characterized in that, The thickness of the magnetic steels of different power segments and / or different numbers of sub-segments is different.

8. The rotor of a permanent-magnet electric machine according to claim 1, characterized in that, The lengths of the magnetic steels of different power segments are the same or at least partially different.

9. The rotor of a permanent-magnet electric machine according to claim 1, characterized in that, The magnetic steels are one or more of sintered neodymium iron boron, bonded neodymium iron boron, and ferrite.

10. A permanent magnet electric machine characterized by, Comprising: a rotor and a stator, the stator being annularly arranged at an outer periphery of the rotor, and the rotor comprising the rotor of the permanent magnet motor according to any one of claims 1 to 9.

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