Rotor structure and motor

Abstract

The present invention provides a rotor structure and a motor, wherein the rotor structure includes a rotor core, on which first permanent magnets and second permanent magnets are alternately arranged in a circumferential direction, and both the first permanent magnets and the second permanent magnets are magnetized in a radial direction of the rotor core; a third permanent magnet is provided on the rotor core between each second permanent magnet and an adjacent first permanent magnet, and each third permanent magnet is magnetized in a tangential direction of the rotor core; the second permanent magnets and the first permanent magnets have opposite polarities on a side close to an outer circumferential surface of the rotor core, and the polarities of opposing faces of two adjacent third permanent magnets are the same; for the same third permanent magnet, the radial geometric midline of the third permanent magnet forms an angle α with the radial geometric midline of the adjacent second permanent magnet, and forms an angle β with the radial geometric midline of the adjacent first permanent magnet, and α / β=0.55-0.98, thereby increasing the reluctance torque of the motor, thereby increasing the total output torque of the motor and improving the torque density of the motor.

Description

Technical Field

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

[0002] Currently, one approach to improving the torque output capability of motors is to use rare earth materials. Their high remanence and coercivity can effectively improve the torque output capability and demagnetization resistance of motors. However, using large amounts of rare earth materials can lead to excessively high motor costs. Another approach is to use ferrite materials. Compared to motors using rare earth materials, motors using ferrite materials have a relatively lower torque density, so this issue needs to be addressed. Summary of the Invention

[0003] Therefore, the present invention provides a rotor structure and a motor, the main technical problem to be solved is: how to improve the torque density of the motor.

[0004] To solve the above-mentioned problem, the present invention provides a rotor structure, comprising a rotor core, on which second permanent magnets and first permanent magnets are alternately arranged in a circumferential direction, and both the second permanent magnets and the first permanent magnets are magnetized in a radial direction of the rotor core; a third permanent magnet is provided on the rotor core between each second permanent magnet and an adjacent first permanent magnet, and each third permanent magnet is magnetized in a tangential direction of the rotor core; the second permanent magnets and the first permanent magnets have opposite polarities on the side closest to the outer circumferential surface of the rotor core, and the polarities of the opposing surfaces of two adjacent third permanent magnets are the same;

[0005] For the same third permanent magnet, the angle between the radial geometric centerline of the third permanent magnet and the radial geometric centerline of the adjacent second permanent magnet is α, and the angle between the radial geometric centerline of the third permanent magnet and the radial geometric centerline of the adjacent first permanent magnet is β, where α / β=0.55-0.98.

[0006] In some embodiments, the polarity of the second permanent magnet on the side close to the outer peripheral surface of the rotor core is the first polarity, and the polarities of the opposite surfaces of the third permanent magnets on both sides of the second permanent magnet are also the first polarity; the polarity of the first permanent magnet on the side close to the outer peripheral surface of the rotor core is the second polarity, and the polarities of the opposite surfaces of the third permanent magnets on both sides of the first permanent magnet are also the second polarity; one of the first polarity and the second polarity is the N pole, and the other is the S pole.

[0007] In some embodiments, each of the third permanent magnets has a first side close to the outer circumference of the rotor core and a second side away from the outer circumference of the rotor core; wherein,

[0008] The first side and the second side of each of the third permanent magnets are both high-coercivity permanent magnet layers, and each of the third permanent magnets has a low-coercivity permanent magnet layer between the high-coercivity permanent magnet layer on the first side and the high-coercivity permanent magnet layer on the second side;

[0009] Alternatively, the two adjacent third permanent magnets are respectively taken as the first a permanent magnet and the first b permanent magnet, the first side of one of the first a permanent magnet and the first b permanent magnet is a high coercive force permanent magnet layer, and the second side is a low coercive force permanent magnet layer, and the first side of the other one of the two is a low coercive force permanent magnet layer, and the second side is a high coercive force permanent magnet layer.

[0010] In some embodiments, in a cross section perpendicular to the axis of the rotor core, the width of the low coercive force permanent magnet layer perpendicular to its magnetization direction is L1, the length of the second permanent magnet perpendicular to its magnetization direction is L4, and the length of the first permanent magnet perpendicular to its magnetization direction is L5, wherein 0.23≤L4 / L1≤0.75, 0.23≤L5 / L1≤0.92, and L4 / L5=0.9-1.1.

[0011] In some embodiments, the thickness of the low coercive force permanent magnet layer along its magnetization direction is h1; wherein,

[0012] When the first side of the third permanent magnet is a high coercive force permanent magnet layer, the high coercive force permanent magnet layer on the first side is taken as the first outer layer permanent magnet, and the thickness of the first outer layer permanent magnet along its magnetization direction is h2, h2 / h1=0.13-0.52;

[0013] And / or, when the second side of the third permanent magnet is a high-coercivity permanent magnet layer, the high-coercivity permanent magnet layer on the second side is a first inner permanent magnet, and the thickness of the first inner permanent magnet along its magnetization direction is h3, where h3 / h1=0.13-0.62;

[0014] And / or, in a cross section perpendicular to the axis of the rotor core, the width of the low coercive force permanent magnet layer perpendicular to its magnetization direction is L1, and h1 / L1=0.25-0.77.

[0015] In some embodiments, the ratio of the coercive force of the high-coercive force permanent magnet layer to the coercive force of the low-coercive force permanent magnet layer is 1.5-6.5.

[0016] In some embodiments, the second permanent magnet is a high-coercivity permanent magnet; and / or the first permanent magnet is a high-coercivity permanent magnet.

[0017] In some embodiments, when the third permanent magnet has a low-coercive force permanent magnet layer, a ratio of the coercive force of the high-coercive force permanent magnet to the coercive force of the low-coercive force permanent magnet layer is 1.5-6.5.

[0018] In some embodiments, the thickness of the second permanent magnet in its magnetization direction is W1, the thickness of the first permanent magnet in its magnetization direction is W2, and W1 / W2=0.75-1.25.

[0019] In some embodiments, the rotor core is provided with first magnetic steel slots for accommodating each third permanent magnet, and the number of the first magnetic steel slots is equal to the number of the third permanent magnets and corresponds one to one; wherein,

[0020] A first connecting bridge is formed between each of the first magnetic steel slots and the outer peripheral surface of the rotor core. The width of each of the first connecting bridges along the radial direction of the rotor core is g1. The outer diameter of the rotor core is R1, and 0.008≥g1 / R1≥0.1.

[0021] and / or, a second connecting bridge is formed between each of the first magnetic steel slots and the inner circumferential surface of the rotor core, the width of each of the second connecting bridges along the radial direction of the rotor core is g2, the outer diameter of the rotor core is R1, and 0.005≥g2 / R1≥0.09;

[0022] And / or, each first magnetic steel slot has an air slot section on one side close to the inner circumferential surface of the rotor core.

[0023] In some embodiments, in a cross section perpendicular to the axis of the rotor core, each of the third permanent magnets has a first side opposite to the outer peripheral surface of the rotor core, and the minimum distance between each of the first sides and the axis of the rotor core is r1, and each of the second permanent magnets and each of the first permanent magnets has a second side opposite to the outer peripheral surface of the rotor core, and the minimum distance between each of the second sides and the axis of the rotor core is r2, 1.1≥r1 / r2≥0.8.

[0024] In some embodiments, the rotor core is provided with second magnetic steel slots for accommodating the second permanent magnets and third magnetic steel slots for accommodating the first permanent magnets, the number of the second magnetic steel slots being equal to and corresponding to the number of the second permanent magnets, and the number of the third magnetic steel slots being equal to and corresponding to the number of the first permanent magnets;

[0025] Each of the second magnetic steel slots and each of the third magnetic steel slots has a limiting slot section on the same side along the circumferential direction of the rotor core. The limiting slot section of each second magnetic steel slot is used to limit the position of the corresponding second permanent magnet in the circumferential direction of the rotor core, and the limiting slot section of each third magnetic steel slot is used to limit the position of the corresponding first permanent magnet in the circumferential direction of the rotor core.

[0026] The present invention also provides a motor, which includes any one of the rotor structures described above.

[0027] The rotor structure and motor provided by the present invention have the following beneficial effects:

[0028] 1. The present invention limits α / β to 0.55-0.98, thereby making the reluctance torque of the motor larger, thereby increasing the total output torque of the motor and improving the torque density of the motor.

[0029] 2. The present invention arranges the polarities of the third permanent magnet, the second permanent magnet and the first permanent magnet so that the adjacent magnetic poles of the rotor structure of the present invention have the same polarity to form a parallel magnetic circuit, thereby increasing the air gap flux density and further improving the torque density of the motor.

[0030] 3. The present invention overcomes the problems of poor anti-demagnetization ability of low-coercive force permanent magnet motors and excessive cost of using high-coercive force permanent magnets alone by simultaneously adopting high-coercive force and low-coercive force permanent magnets, and achieves a higher torque density while using a small amount of high-coercive force permanent magnets; it also ensures that low-coercive force permanent magnets will not demagnetize under heavy loads, reduces leakage flux on the air gap side and near-axis side of the rotor, and improves the utilization rate of the permanent magnets. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. The drawings described below are merely exemplary. Those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0032] Figure 1 is a structural schematic diagram of a rotor structure provided by one embodiment of the present invention;

[0033] Figure 2 1 is a schematic diagram of polarity arrangement of permanent magnets in a rotor structure according to an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of a magnetic circuit structure reflecting a rotor structure provided by an embodiment of the present invention;

[0035] Figure 4 1 is a schematic structural diagram of a rotor structure with a limiting slot segment provided by an embodiment of the present invention;

[0036] Figure 5 This is a schematic structural diagram of a rotor structure provided by one embodiment of the present invention, in which high coercive force permanent magnet layers are not provided on both the first side and the second side of the third permanent magnet;

[0037] Figure 6 is a schematic diagram reflecting the dimensions of a rotor structure provided by an embodiment of the present invention;

[0038] Figure 7 1 is a schematic diagram showing the dimensions of a rotor structure with a limiting slot segment, provided by an embodiment of the present invention;

[0039] Figure 8 This is a schematic structural diagram reflecting the dimensions of a rotor structure in which high-coercive-force permanent magnet layers are not provided on both the first and second sides of the third permanent magnet, provided by one embodiment of the present invention;

[0040] Figure 9 A technical effect diagram showing the change of the reluctance torque of a motor with α / β is shown.

[0041] The accompanying drawings are:

[0042] 1. Rotor core; 2. Second permanent magnet; 3. Third permanent magnet; 4. First connecting bridge; 5. Second connecting bridge; 6. First permanent magnet; 20. Second magnetic steel slot; 21. Side of the second permanent magnet close to the outer circumference of the rotor core; 30. First magnetic steel slot; 31. First outer layer of permanent magnets; 32. Low coercive force permanent magnet layer; 33. First inner layer of permanent magnets; 34. First side; 35. Second side; 60. Third magnetic steel slot; 61. Side of the first permanent magnet close to the outer circumference of the rotor core; 101. Outer circumference; 102. Inner circumference; 201. Second magnetic steel slot The limiting groove section of the steel groove; 301, the air groove section; 302, the first side; 303, the second side; 601, the limiting groove section of the third magnetic steel groove; 3a, the first c permanent magnet; 3b, the second c permanent magnet; 3c, the first d permanent magnet; 3d, the second d permanent magnet; 3a1, the first surface; 3b1, the second surface; 3c1, the third surface; 3d1, the fourth surface; m1, the radial geometric center line of the third permanent magnet; m2, the radial geometric center line of the second permanent magnet; m3, the radial geometric center line of the second permanent magnet; 30a, the first a permanent magnet; 30b, the first b permanent magnet. DETAILED DESCRIPTION

[0043] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0045] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0046] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0047] See also Figure 1As shown, according to an embodiment of the present invention, a rotor structure is provided, comprising a rotor core 1, on which second permanent magnets 2 and first permanent magnets 6 are alternately arranged in a circumferential direction, and both the second permanent magnets 2 and the first permanent magnets 6 are magnetized in the radial direction of the rotor core 1. A third permanent magnet 3 is provided on the rotor core 1 between each second permanent magnet 2 and an adjacent first permanent magnet 6, and each third permanent magnet 3 is magnetized in the tangential direction of the rotor core 1.

[0048] Among them, Figure 2 As shown, the polarities of the second permanent magnet 2 and the first permanent magnet 6 are opposite on the side close to the outer peripheral surface 101 of the rotor core. The polarities of the two adjacent third permanent magnets 3 facing each other are the same. Figure 6 As shown, for the same third permanent magnet 3, the angle between the radial geometric center line m1 of the third permanent magnet and the radial geometric center line m2 of the adjacent second permanent magnet is α, and the angle between the radial geometric center line m1 of the third permanent magnet and the radial geometric center line m3 of the adjacent first permanent magnet is β, where α / β=0.55-0.98.

[0049] In the above example, by limiting α / β to 0.55-0.98, the adjacent second permanent magnets 2 and first permanent magnets 6 are not symmetrical about the radial geometric center line m1 of the third permanent magnet therebetween. Figure 9 A technical effect diagram of the change of the reluctance torque of a motor with α / β is shown. It can be seen from the figure that when α / β = 0.55-0.98, the reluctance torque of the motor is relatively large. In this way, the reluctance torque of the motor can be increased, thereby increasing the total output torque of the motor and improving the torque density of the motor.

[0050] In some embodiments, as Figure 2 As shown, the polarity of the second permanent magnet on the side 21 closest to the outer circumference of the rotor core is the first polarity, and the polarity of the third permanent magnets 3 on both sides of the second permanent magnet 2, which are opposite to each other, is also the first polarity. The polarity of the first permanent magnet on the side 61 closest to the outer circumference of the rotor core is the second polarity, and the polarity of the third permanent magnets 3 on both sides of the first permanent magnet 6, which are opposite to each other, is also the second polarity. One of the first polarity and the second polarity is the north pole, and the other is the south pole.

[0051] It should be noted that the third permanent magnets 3 on both sides of the second permanent magnet 2 refer to the third permanent magnets 3 on both sides of the second permanent magnet 2 in the circumferential direction of the rotor core 1. Similarly, the third permanent magnets 3 on both sides of the first permanent magnet 6 refer to the third permanent magnets 3 on both sides of the first permanent magnet 6 in the circumferential direction of the rotor core 1.

[0052] For ease of understanding, Figure 2As shown, the third permanent magnets 3 on either side of the second permanent magnet 2 are respectively a first c permanent magnet 3a and a second c permanent magnet 3b. The first face 3a1 of the first c permanent magnet faces the second face 3b1 of the second c permanent magnet. The polarity of the second permanent magnet on the side 21 closest to the outer circumference of the rotor core is the first polarity, and the polarity of both the first face 3a1 and the second face 3b1 is also the first polarity. Similarly, the third permanent magnets 3 on either side of the first permanent magnet 6 are respectively a first d permanent magnet 3c and a second d permanent magnet 3d. The third face 3c1 of the first d permanent magnet faces the fourth face 3d1 of the second d permanent magnet. The polarity of the first permanent magnet on the side 61 closest to the outer circumference of the rotor core is the second polarity, and the polarity of both the third face 3c1 and the fourth face 3d1 is also the second polarity.

[0053] In the above example, by setting the polarities of the third permanent magnet 3, the second permanent magnet 2 and the first permanent magnet 6, the adjacent magnetic poles of the rotor structure of the present invention have the same polarity to form a parallel magnetic circuit, thereby increasing the air gap magnetic density and further improving the torque density of the motor.

[0054] like Figure 1 As shown, each of the third permanent magnets 3 has a first side 302 close to the outer circumference of the rotor core and a second side 303 away from the outer circumference of the rotor core. The first side 302 and / or the second side 303 of each third permanent magnet 3 may be a high coercive force permanent magnet layer.

[0055] In one example, if Figure 1 As shown, the first side 302 and the second side 303 of each third permanent magnet 3 are both high coercive force permanent magnet layers, and each third permanent magnet 3 has a low coercive force permanent magnet layer 32 between the high coercive force permanent magnet layer on the first side 302 and the high coercive force permanent magnet layer on the second side 303 .

[0056] In the above example, if Figure 1 As described above, the high coercive force permanent magnet layer on the first side 302 of each third permanent magnet forms the first outer permanent magnet 31, and the high coercive force permanent magnet layer on the second side 303 of each third permanent magnet forms the first inner permanent magnet 33. The above-mentioned low coercive force permanent magnet layer 32 is formed between the first outer permanent magnet 31 and the first inner permanent magnet 33 of each third permanent magnet. The low coercive force permanent magnet layer 32 is the first middle permanent magnet. The use of the low coercive force permanent magnet layer 32 can save costs. Figure 3As shown, the first outer layer permanent magnet 31, the second permanent magnet 2 and the first permanent magnet 6 are connected in series as magnetic excitation sources to form a first main magnetic circuit, the first middle layer permanent magnet, the second permanent magnet 2 and the first permanent magnet 6 are connected in series as magnetic excitation sources to form a second main magnetic circuit, and the first inner layer permanent magnet 33, the second permanent magnet 2 and the first permanent magnet 6 are connected in series as magnetic excitation sources to form a third main magnetic circuit. The high coercive force permanent magnets in the three main magnetic circuits increase the magnetic flux of the main magnetic circuit, and the air gap magnetic density is increased by the magnetic concentration effect of the three magnetic circuits in parallel, thereby increasing the torque density of the motor.

[0057] In addition, if Figure 1 As shown, a first connecting bridge 4 is formed between the first outer permanent magnet 31 and the outer peripheral surface 101 of the rotor core, and a second connecting bridge 5 is formed between the first inner permanent magnet 33 and the inner peripheral surface 102 of the rotor core. The first outer permanent magnet 31 and the first inner permanent magnet 33 are high coercive force permanent magnets. The large magnetic field strength of their permanent magnets can easily saturate the first connecting bridge 4 and the second connecting bridge 5, thereby suppressing the magnetic lines of force of the third permanent magnet 3, the second permanent magnet 2 and the first permanent magnet 6 from passing through the leakage magnetic path, thereby reducing the air gap leakage magnetic flux of the rotor and the leakage magnetic flux close to the shaft side, and improving the utilization rate of the permanent magnets.

[0058] It should be noted here that: for the same third permanent magnet 3 , its first outer layer permanent magnet 31 , first middle layer permanent magnet and first inner layer permanent magnet 33 are sequentially arranged in abutment with each other.

[0059] In another example, Figure 5 As shown, the two adjacent third permanent magnets 3 are respectively taken as the first a permanent magnet 30a and the first b permanent magnet 30b, the first side 302 of one of the first a permanent magnet 30a and the first b permanent magnet 30b is a high coercive force permanent magnet layer, and the second side 303 is a low coercive force permanent magnet layer 32, and the first side 302 of the other one is a low coercive force permanent magnet layer 32, and the second side 303 is a high coercive force permanent magnet layer.

[0060] Among them, the design in the above example can reduce the amount of high-coercive-force permanent magnets. If both radial sides of each third permanent magnet 3 are designed as high-coercive-force permanent magnet layers, the cost will be higher. However, for two adjacent third permanent magnets 3, since the polarity of the opposite surfaces of the two adjacent third permanent magnets 3 is the same, as long as only the radial outer side of one of the first a permanent magnet 30a and the first b permanent magnet 30b is designed as a high-coercive-force permanent magnet layer, and only the radial inner side of the other is designed as a high-coercive-force permanent magnet layer, the above-mentioned effect of reducing leakage magnetic flux can be achieved. Although there is a risk of demagnetization on one side of the third permanent magnet 3 designed as a low-coercive-force permanent magnet layer 32 in the radial direction, the overall cost is low, and the anti-demagnetization performance is still better than that of a motor without high-coercive-force permanent magnets at all. In this way, a balance can be achieved between the anti-demagnetization performance of the motor and lower cost.

[0061] It should be noted here that: in the above two examples, the third permanent magnet 3 of the present invention has both a high-coercive force permanent magnet layer and a low-coercive force permanent magnet layer 32, which overcomes the problems of poor anti-demagnetization ability of a single low-coercive force permanent magnet motor and excessive cost of using a single high-coercive force permanent magnet, and achieves a higher torque density while using a small amount of high-coercive force permanent magnets.

[0062] In some embodiments, as Figure 6-8 As shown, in a cross section perpendicular to the axis of the rotor core 1, the width of the low-coercivity permanent magnet layer 32 perpendicular to its magnetization direction is L1, the length of the second permanent magnet 2 perpendicular to its magnetization direction is L4, and the length of the first permanent magnet 6 perpendicular to its magnetization direction is L5. Here, 0.23 ≤ L4 / L1 ≤ 0.75, 0.23 ≤ L5 / L1 ≤ 0.92, and L4 / L5 = 0.9-1.1.

[0063] In the above example, by limiting the lengths of the second permanent magnet 2 and the first permanent magnet 6 perpendicular to their respective magnetization directions and the length of the third permanent magnet 3 perpendicular to its magnetization direction, the utilization of the second permanent magnet 2 and the first permanent magnet 6 can be improved.

[0064] In some embodiments, the thickness of the low coercive force permanent magnet layer 32 along its magnetization direction is h1.

[0065] in,

[0066] like Figure 6-8 As shown, when the first side 302 of the third permanent magnet 3 is a high coercive force permanent magnet layer, the high coercive force permanent magnet layer of the first side 302 is taken as the first outer permanent magnet 31, and the thickness of the first outer permanent magnet 31 along its magnetization direction is h2, h2 / h1=0.13-0.52.

[0067] In the above example, by limiting h2 / h1 to 0.13-0.52, the high coercivity permanent magnet layer on the first side 302 of the third permanent magnet 3 can be reasonably utilized to magnetically saturate the first connecting bridge 4 to reduce magnetic leakage of the rotor at the first connecting bridge 4 .

[0068] In some embodiments, as Figure 6-8 As shown, when the second side 303 of the third permanent magnet 3 is a high coercive force permanent magnet layer, the high coercive force permanent magnet layer of the second side 303 is taken as the first inner layer permanent magnet 33, and the thickness of the first inner layer permanent magnet 33 along its magnetization direction is h3, h3 / h1=0.13-0.62.

[0069] In the above example, by limiting h3 / h1 to 0.13-0.62, the high coercive force permanent magnet layer on the second side 303 of the third permanent magnet 3 can be reasonably utilized to magnetically saturate the second connecting bridge 5 to reduce magnetic leakage of the rotor at the second connecting bridge 5 .

[0070] In some embodiments, as Figure 6-8 As shown, in a cross section perpendicular to the axis of the rotor core 1 , the width of the low coercive force permanent magnet layer 32 perpendicular to its magnetization direction is L1 , wherein h1 / L1 = 0.25-0.77.

[0071] In the above example, by limiting h1 / L1 to 0.25-0.77, the utilization rate of the low-coercive-force permanent magnet layer 32 can be improved, and oversaturation of the rotor can be avoided.

[0072] In some embodiments, the ratio of the coercive force of the high-coercive force permanent magnet layer to the coercive force of the low-coercive force permanent magnet layer 32 is 1.5-6.5, which ensures that the magnetism and coercive force strength of the high-coercive force permanent magnet layer are large enough to reduce rotor leakage and improve anti-demagnetization capability.

[0073] In some embodiments, the second permanent magnet 2 may be a high-coercivity permanent magnet, which can provide a larger permanent magnetic flux linkage, thereby increasing the permanent magnet torque of the motor.

[0074] In some embodiments, the first permanent magnet 6 may be a high-coercivity permanent magnet, which can provide a larger permanent magnetic flux linkage, thereby increasing the permanent magnet torque of the motor.

[0075] In some embodiments, as Figure 1 As shown, when the rotor structure further includes a first outer layer of permanent magnets 31, and the second permanent magnets 2 and the first permanent magnets 6 are all high-coercivity permanent magnets, the first outer layer of permanent magnets 31, the second permanent magnets 2, and the first permanent magnets 6 are placed near the outer circumferential surface 101 of the rotor core. Since the first outer layer of permanent magnets 31, the second permanent magnets 2, and the first permanent magnets 6 are all high-coercivity permanent magnets, their high coercivity can be utilized to improve the rotor structure's anti-demagnetization capability, thereby preventing demagnetization of the first middle layer of permanent magnets with low coercivity.

[0076] In some embodiments, when the aforementioned third permanent magnet 3 has a low-coercive force permanent magnet layer 32, the ratio of the coercive force of the aforementioned high-coercive force permanent magnet to the coercive force of the low-coercive force permanent magnet layer 32 is 1.5-6.5, so as to ensure that the magnetic properties and coercive force strength of the high-coercive force permanent magnet layer are large enough to reduce rotor leakage and improve anti-demagnetization ability.

[0077] In some embodiments, as Figure 6-8As shown, the thickness of the second permanent magnet 2 in its magnetizing direction is W1, and the thickness of the first permanent magnet 6 in its magnetizing direction is W2, wherein W1 / W2=0.75-1.25.

[0078] In the above example, by limiting the thickness of both the second permanent magnet 2 and the first permanent magnet 6 in the magnetizing direction, the salient pole ratio of the rotor can be increased, thereby improving the utilization rate of the reluctance torque.

[0079] like Figure 1-5 As shown, the rotor core 1 is provided with first magnetic steel slots 30 for accommodating the third permanent magnets 3 . The number of the first magnetic steel slots 30 is equal to the number of the third permanent magnets 3 and corresponds one to one.

[0080] The number of the first magnetic steel slots 30 can be 2p, where p is a positive integer greater than or equal to 1. The first magnetic steel slots 30 extend through both axial ends of the rotor core 1, and are evenly arranged around the axis of the rotor core 1. The radial geometric centerline of the first magnetic steel slot 30 coincides with the radial geometric centerline m1 of the third permanent magnet therein and is on the same straight line.

[0081] In some embodiments, as Figure 6-8 As shown, a first connecting bridge 4 is formed between each of the first magnetic steel slots 30 and the outer peripheral surface 101 of the rotor core. The radial width of each first connecting bridge 4 along the rotor core 1 is g1, and the outer diameter of the rotor core 1 is R1. Here, 0.008 ≥ g1 / R1 ≥ 0.1.

[0082] In the above example, limiting the width of the first connecting bridge 4 is conducive to making the first connecting bridge 4 reach magnetic saturation, thereby reducing magnetic leakage on the air gap side of the rotor structure.

[0083] like Figure 6-8 As shown, a second connecting bridge 5 is formed between each of the aforementioned first magnetic steel slots 30 and the inner circumferential surface 102 of the rotor core 1. The radial width of each second connecting bridge 5 along the rotor core 1 is g2, and the outer diameter of the rotor core 1 is R1. Here, 0.005 ≥ g2 / R1 ≥ 0.09.

[0084] In the above example, limiting the width of the second connecting bridge 5 is conducive to achieving magnetic saturation of the second connecting bridge 5, thereby reducing magnetic leakage on the proximal axis side of the rotor structure.

[0085] In some embodiments, as Figure 1-5 As shown, each of the first magnetic steel slots 30 has an air slot section 301 on one side thereof close to the inner circumferential surface 102 of the rotor core 1 .

[0086] In the above example, the air slot section 301 can play a magnetic isolation role, reducing the magnetic leakage of the third permanent magnet 3 on the side close to the rotor inner circumferential surface 102 .

[0087] In some embodiments, as Figure 6-8 As shown, in a cross section perpendicular to the axis of the rotor core 1, each of the aforementioned third permanent magnets 3 has a first edge 34 opposite the outer circumferential surface 101 of the rotor core, and the minimum distance between each first edge 34 and the axis of the rotor core 1 is r1. Furthermore, each of the second permanent magnets 2 and each of the first permanent magnets 6 has a second edge 35 opposite the outer circumferential surface 101 of the rotor core, and the minimum distance between each second edge 35 and the axis of the rotor core 1 is r2. Here, 1.1 ≥ r1 / r2 ≥ 0.8.

[0088] In the above example, by limiting 1.1≥r1 / r2≥0.8, the permanent magnet layer of the third permanent magnet 3 close to the outer peripheral surface 101 of the rotor core can suppress the leakage of the magnetic lines of force of the second permanent magnet 2 between the third permanent magnet 3 and the second permanent magnet 2, and can also suppress the leakage of the magnetic lines of force of the first permanent magnet 6 between the third permanent magnet 3 and the first permanent magnet 6.

[0089] In some embodiments, as Figure 4-5 As shown, the aforementioned rotor core 1 is provided with second magnetic steel slots 20 for accommodating the second permanent magnets 2 and third magnetic steel slots 60 for accommodating the first permanent magnets 6. The number of the second magnetic steel slots 20 is equal to the number of the second permanent magnets 2, and corresponds one to one. The number of the third magnetic steel slots 60 is equal to the number of the first permanent magnets 6, and corresponds one to one. Among them, each second magnetic steel slot 20 and each third magnetic steel slot 60 has a limiting groove section on the same side of the circumferential direction of the rotor core 1, and the limiting groove section 201 of each second magnetic steel slot is used to limit the position of the corresponding second permanent magnet 2 in the circumferential direction of the rotor core 1, and the limiting groove section 601 of each third magnetic steel slot is used to limit the position of the corresponding first permanent magnet 6 in the circumferential direction of the rotor core 1.

[0090] In the above example, the limiting slot sections on both the second magnetic steel slot 20 and the third magnetic steel slot 60 are designed to be on the same side in the circumferential direction of the rotor core 1 , thereby facilitating processing.

[0091] It should be noted here that: the aforementioned rotor core 1 is further provided with an axial hole, the hole wall of which forms the inner circumferential surface 102 of the rotor core.

[0092] The present invention further provides a motor, which may include any of the above-described rotor structures. Due to the motor employing the above-described rotor structure, the polarity of the third permanent magnet 3, the second permanent magnet 2, and the first permanent magnet 6 is configured so that adjacent magnetic poles of the rotor structure of the present invention have the same polarity, forming a parallel magnetic circuit. This increases the air gap flux density and, in turn, the torque density of the motor.

[0093] Among them, the present invention uses high-coercive force permanent magnets and low-coercive force permanent magnets at the same time through the design of the rotor structure. On the premise of improving the torque density of the motor, it also ensures that the low-coercive force permanent magnets will not be demagnetized under heavy load, and reduces the leakage flux on the air gap side and the near-axis side of the rotor, thereby improving the utilization rate of the permanent magnets.

[0094] It is easy for those skilled in the art to understand that, under the premise of no conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A rotor structure, characterized in that: The invention comprises a rotor core (1), wherein first permanent magnets (6) and second permanent magnets (2) are alternately arranged in a circumferential direction on the rotor core (1), and both the first permanent magnets (6) and the second permanent magnets (2) are magnetized in the radial direction of the rotor core (1); a third permanent magnet (3) is provided between each second permanent magnet (2) and an adjacent first permanent magnet (6) on the rotor core (1), and each third permanent magnet (3) is magnetized in the tangential direction of the rotor core (1); the second permanent magnet and the first permanent magnet have opposite polarities on the side close to the outer peripheral surface of the rotor core, and the polarities of the two adjacent third permanent magnets are the same on the opposite sides; For the same third permanent magnet (3), the angle between the radial geometric center line (m1) of the third permanent magnet and the radial geometric center line (m2) of the adjacent second permanent magnet is α, and the angle between the radial geometric center line (m1) of the third permanent magnet and the radial geometric center line (m3) of the adjacent first permanent magnet is β, wherein α / β=0.55-0.

98.

2. The rotor structure according to claim 1, characterized in that: The polarity of the second permanent magnet on the side (21) close to the outer peripheral surface of the rotor core is the first polarity, and the polarities of the third permanent magnets (3) on both sides of the second permanent magnet (2) on the opposite sides are also the first polarity; the polarity of the first permanent magnet on the side (61) close to the outer peripheral surface of the rotor core is the second polarity, and the polarities of the third permanent magnets (3) on both sides of the first permanent magnet (6) on the opposite sides are also the second polarity; one of the first polarity and the second polarity is an N pole, and the other is an S pole.

3. The rotor structure according to claim 1 or 2, characterized in that: Each of the third permanent magnets (3) has a first side (302) close to the outer peripheral surface of the rotor core and a second side (303) away from the outer peripheral surface of the rotor core; wherein, The first side (302) and the second side (303) of each of the third permanent magnets are both high-coercive force permanent magnet magnetic layers, and each of the third permanent magnets (3) has a low-coercive force permanent magnet layer (32) between the high-coercive force permanent magnet layer on the first side (302) and the high-coercive force permanent magnet layer on the second side (303); Alternatively, the two adjacent third permanent magnets (3) are respectively taken as the first a permanent magnet (30a) and the first b permanent magnet (30b), the first side (302) of one of the first a permanent magnet (30a) and the first b permanent magnet (30b) is a high coercive force permanent magnet layer, and the second side (303) is a low coercive force permanent magnet layer (32), and the first side (302) of the other of the two is a low coercive force permanent magnet layer (32), and the second side (303) is a high coercive force permanent magnet layer.

4. The rotor structure according to claim 3, characterized in that: In a cross section perpendicular to the axis of the rotor core (1), the width of the low coercive force permanent magnet layer (32) perpendicular to its magnetization direction is L1, the length of the second permanent magnet (2) perpendicular to its magnetization direction is L4, and the length of the first permanent magnet (6) perpendicular to its magnetization direction is L5, wherein 0.23≤L4 / L1≤0.75, 0.23≤L5 / L1≤0.92, and L4 / L5=0.9-1.

1.

5. The rotor structure according to claim 3, characterized in that: The thickness of the low coercive force permanent magnet layer (32) along its magnetization direction is h1; wherein, When the first side (302) of the third permanent magnet is a high coercive force permanent magnet layer, the high coercive force permanent magnet layer of the first side (302) is taken as the first outer layer permanent magnet (31), and the thickness of the first outer layer permanent magnet (31) along its magnetization direction is h2, and h2 / h1=0.13-0.52; And / or, when the second side (303) of the third permanent magnet is a high coercive force permanent magnet layer, the high coercive force permanent magnet layer of the second side (303) is taken as the first inner layer permanent magnet (33), and the thickness of the first inner layer permanent magnet (33) along its magnetization direction is h3, h3 / h1=0.13-0.62; And / or, in a cross section perpendicular to the axis of the rotor core (1), the width of the low coercive force permanent magnet layer (32) perpendicular to its magnetization direction is L1, and h1 / L1=0.25-0.

77.

6. The rotor structure according to claim 3, characterized in that: The ratio of the coercive force of the high-coercive force permanent magnet layer to the coercive force of the low-coercive force permanent magnet layer (32) is 1.5-6.

5.

7. The rotor structure according to any one of claims 1, 2, 4-6, characterized in that: The second permanent magnet (2) is a high-coercive force permanent magnet; and / or the first permanent magnet (6) is a high-coercive force permanent magnet.

8. The rotor structure according to claim 7, characterized in that: When the third permanent magnet (3) has a low-coercive force permanent magnet layer (32), the ratio of the coercive force of the high-coercive force permanent magnet to the coercive force of the low-coercive force permanent magnet layer (32) is 1.5-6.

5.

9. The rotor structure according to any one of claims 1, 2, 4-6, and 8, characterized in that: The thickness of the second permanent magnet (2) in its magnetizing direction is W1, the thickness of the first permanent magnet (6) in its magnetizing direction is W2, and W1 / W2=0.75-1.

25.

10. The rotor structure according to any one of claims 1, 2, 4-6, and 8, characterized in that: The rotor core (1) is provided with first magnetic steel slots (30) for accommodating each third permanent magnet (3), and the number of the first magnetic steel slots (30) is equal to the number of the third permanent magnets (3) and corresponds one to one; wherein, A first connecting bridge (4) is formed between each of the first magnetic steel slots (30) and the outer peripheral surface (101) of the rotor core, and a width of each of the first connecting bridges (4) along the radial direction of the rotor core (1) is g1. The outer diameter of the rotor core (1) is R1, and 0.008≥g1 / R1≥0.

1. and / or, a second connecting bridge (5) is formed between each of the first magnetic steel slots (30) and the inner circumferential surface (102) of the rotor core, the width of each of the second connecting bridges (5) along the radial direction of the rotor core (1) is g2, the outer diameter of the rotor core (1) is R1, and 0.005≥g2 / R1≥0.09; And / or, each first magnetic steel slot (30) has an air slot section (301) on one side close to the inner circumferential surface (102) of the rotor core.

11. The rotor structure according to any one of claims 1, 2, 4-6, and 8, characterized in that: In a cross section perpendicular to the axis of the rotor core (1), each of the third permanent magnets (3) has a first side (34) opposite to the outer peripheral surface (101) of the rotor core, and the minimum distance between each of the first sides (34) and the axis of the rotor core (1) is r1, and each of the second permanent magnets (2) and each of the first permanent magnets (6) has a second side (35) opposite to the outer peripheral surface (101) of the rotor core, and the minimum distance between each of the second sides (35) and the axis of the rotor core (1) is r2, and 1.1≥r1 / r2≥0.

8.

12. The rotor structure according to any one of claims 1, 2, 4-6, and 8, characterized in that: The rotor core (1) is provided with second magnetic steel slots (20) for accommodating the second permanent magnets (2) and third magnetic steel slots (60) for accommodating the first permanent magnets (6), the number of the second magnetic steel slots (20) being equal to the number of the second permanent magnets (2) and corresponding one to one, and the number of the third magnetic steel slots (60) being equal to the number of the first permanent magnets (6) and corresponding one to one; Each of the second magnetic steel slots (20) and each of the third magnetic steel slots (60) has a limiting slot section on the same side of the circumferential direction of the rotor core (1); the limiting slot section (201) of each second magnetic steel slot is used to limit the position of the corresponding second permanent magnet (2) in the circumferential direction of the rotor core (1); and the limiting slot section (601) of each third magnetic steel slot is used to limit the position of the corresponding first permanent magnet (6) in the circumferential direction of the rotor core (1).

13. A motor, characterized in that: The rotor structure comprises the rotor structure according to any one of claims 1 to 12.

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