WO2024098921A1 - Rotor capable of enhancing demagnetization resistance, motor, compressor, and refrigerator - Google Patents

Abstract

Disclosed in the present application are a rotor capable of enhancing demagnetization resistance, a motor, a compressor, and a refrigerator. The rotor (110) comprises: a rotor core (111) provided with magnet slots (1111); a plurality of groups of permanent magnets (112) which are arranged in the magnet slots (1111), every group of two permanent magnets (112) being distributed to form a V shape, and the plurality of groups of permanent magnets (112) being arranged around the rotor core (111); first flux barriers (113) each provided between the magnet slots (1111) where the two permanent magnets (112) in the same group are located; and second flux barriers (114) each provided between the magnet slots (1111) where the permanent magnets (112) in adjacent groups are located. A first diffusion region (11211) and/or a second diffusion region (11212) is provided on a plane where the width and thickness of each permanent magnet (112) are located.

Description

Rotor, motor, compressor and refrigerator capable of enhancing resistance to demagnetization

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese patent application No. 202211403489.8 filed on November 10, 2022, entitled “A rotor, motor, compressor and refrigerator capable of enhancing resistance to demagnetization”, the entire contents of which are incorporated by reference into this application.

Technical Field

The present application belongs to the technical field of drive devices, and specifically relates to a rotor, a motor, a compressor and a refrigerator capable of enhancing resistance to demagnetization.

Background technique

At present, domestic and foreign air-conditioning compressors basically use variable frequency motors, which generally use permanent magnet motors. The excitation method of the permanent magnet motor rotor is magnet excitation. Due to the high power density of permanent magnet motors and the need to reduce costs, the anti-demagnetization ability of the rotor magnet is weakened. When the magnet undergoes irreversible demagnetization, it will affect the operating performance and reliability of the motor and compressor, thereby seriously affecting the service life of the product.

At the same time, with the increase in the price of rare earth materials, the price of rare earth magnet materials and the cost of motors have risen sharply. Under the premise of ensuring the reliable operation of the motor, it is urgent to reduce the cost of magnets and motors. The fundamental reason for the increase in magnet prices is the increase in the price of rare earth elements, and the content of rare earth elements affects the remanence and coercivity of the magnet, among which the direct manifestation of coercivity is the ability to resist demagnetization. When the magnets are of the same size and equipped with the same motor, magnets with low coercivity have poor rotor demagnetization resistance, a higher risk of rotor demagnetization, and more obvious demagnetization.

Therefore, it is urgent to design a rotor that can effectively solve the above-mentioned technical defects, improve the anti-demagnetization ability of the rotor while ensuring demagnetization reliability and not increasing the volume of the permanent magnet, and then improve the anti-demagnetization ability of the motor to reduce production costs.

Summary of the invention

The present application aims to at least partially solve one of the technical problems existing in the above-mentioned prior art. To this end, the present application proposes a rotor, a motor, a compressor and a refrigerator capable of enhancing the resistance to demagnetization.

The rotor according to the first aspect of the present application comprises:

A rotor core, wherein the rotor core is provided with magnet slots;

Multiple groups of permanent magnets, the permanent magnets are arranged in the magnet slots, two permanent magnets form a group and are distributed in a V shape, and multiple groups of permanent magnets are arranged around the rotor core;

A first magnetic isolation bridge is arranged between the magnet slots where two permanent magnets in the same group are located;

A second magnetic isolation bridge is arranged between the magnet slots where the permanent magnets of adjacent groups are located;

A diffusion zone is provided on the plane where the width and thickness of the permanent magnet are located, and the diffusion zone includes:

A first diffusion region is arranged on one side of the width center line of the permanent magnet; and/or

A second diffusion region is arranged on the other side of the width center line of the permanent magnet;

The first diffusion region and the second diffusion region both contain rare earth elements;

Wherein: the thickness y ₁ of the first magnetic isolation bridge, the thickness y ₂ of the second magnetic isolation bridge, the maximum length L _1max of the first diffusion zone along the width direction of the permanent magnet, and the maximum length W _1max of the first diffusion zone along the thickness direction of the magnet satisfy the following formulas (1) and (2):

Formula (1): y ₁ ·y ₂ ·L _1max = k ₁ , Formula (2): y ₁ ·y ₂ ·W _1max = k ₃ ;

In the above formula: 0.2≤k ₁ ≤7.7, 0.16≤k ₃ ≤2.

In some embodiments, in formula (1) and formula (2), 1.2≤k ₁ ≤1.8, 0.38≤k ₃ ≤0.57.

In some embodiments, the maximum length L _2max of the second diffusion region along the width direction of the permanent magnet and the maximum length W _2max of the second diffusion region along the thickness direction of the permanent magnet satisfy the following formulas (3) and (4):

Formula (3): y ₁ ·y ₂ ·L _2max = k ₂ , Formula (4): y ₁ ·y ₂ ·W _2max = k ₄ ;

In the above formula: 0.2≤k ₂ ≤7.7, 0.16≤k ₄ ≤2.

In some embodiments, in formula (3) and formula (4), 1.2≤k ₁ ≤1.8, 0.38≤k ₃ ≤0.57.

In some embodiments, the thickness _y1 of the first magnetic isolation bridge ranges from 0.2 to 2 mm.

In some embodiments, the thickness _y2 of the second magnetic isolation bridge ranges from 0.2 to 2 mm.

In some embodiments, the value ranges of the parameters in the first diffusion region satisfy any one or both of the following: 1 mm ≤ _{L 1max} ≤ 25 mm; 1 mm ≤ W _1max ≤ 5 mm.

In some embodiments, the value ranges of the parameters in the first diffusion region satisfy any one or both of the following: 1.4 mm≤L _1max ≤1.7 mm; 1.5 mm≤W _1max ≤2.3 mm.

In some embodiments, the value ranges of the parameters in the second diffusion region satisfy any one or both of the following: 1 mm≤L _2max ≤25 mm; 1 mm≤W _2max ≤5 mm.

In some embodiments, the value ranges of the parameters in the second diffusion region satisfy any one or both of the following: 1.4 mm≤L _2max ≤1.7 mm; 1.5 mm≤W _2max ≤2.3 mm.

In some embodiments, the rare earth element includes at least one of dysprosium, terbium, praseodymium, neodymium, and cerium.

In some embodiments, the rare earth element includes at least one of dysprosium, terbium, and neodymium.

In some embodiments, the rare earth element is uniformly distributed or non-uniformly distributed in the diffusion region.

In some embodiments, the content of the rare earth element in the first diffusion region accounts for _1.05 %-2.0% of the mass percentage of the permanent magnet.

In some embodiments, the content of the rare earth element in the second diffusion region accounts for a mass percentage _g2 of the permanent magnet of 1.05%-2.0%.

In some embodiments, the permanent magnet further includes a non-diffusion region, and the content of rare earth elements in the non-diffusion region accounts for a mass percentage of g ₃ of the permanent magnet, and g ₃ <g ₁ , g ₃ <g ₂ .

In some embodiments, the permanent magnet further includes a plurality of third diffusion regions, the third diffusion regions are disposed between the first diffusion region and the second diffusion region, and the content of the rare earth element in each of the third diffusion regions accounts for a mass percentage of g _i of the permanent magnet, g _i >g ₃ .

In some embodiments, the permanent magnet includes the first diffusion region, the second diffusion region and the third diffusion region, and the third diffusion region is disposed between the first diffusion region and the second diffusion region, and the first diffusion region, the second diffusion region and the third diffusion region form a U-shape.

In some embodiments, the permanent magnet includes the first diffusion region and the second diffusion region, and the first diffusion region and the second diffusion region are respectively disposed at four corners of the permanent magnet.

In some embodiments, the permanent magnet includes the first diffusion region, the second diffusion region and the third diffusion region, and the first diffusion region, the second diffusion region and the third diffusion region are respectively arranged in parallel on both sides and the middle of the permanent magnet in a three-strip shape.

In some embodiments, the first diffusion region and the second diffusion region are distributed over the entire area or partially along the axial direction of the permanent magnet.

In some embodiments, the diffusion regions in cross sections of the permanent magnet having different widths and thicknesses are the same or different.

In some embodiments, the permanent magnet is radially magnetized or parallel magnetized.

In some embodiments, the rotor core is formed by stacking a plurality of silicon steel sheets.

The motor according to the second aspect of the present application includes a rotor as described in any technical solution of the first aspect of the present application.

The compressor according to the third aspect of the present application comprises a rotor as described in any technical solution of the first aspect of the present application or a motor as described in the second aspect of the present application.

The refrigerator according to the fourth aspect of the present application includes the motor as described in the second aspect of the present application, or the compressor as described in the third aspect of the present application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a rotor according to an embodiment of the present application;

FIG2 is a schematic diagram of the dimensions of a rotor according to an embodiment of the present application;

FIG3 is a schematic diagram of the structure and orientation of a V-shaped rotor according to an embodiment of the present application;

FIG4 is a schematic structural diagram of a permanent magnet diffusion zone in a rotor according to an embodiment of the present application;

FIG5 is a schematic structural diagram of a U-shaped diffusion zone of a permanent magnet according to an embodiment of the present application;

FIG6 is a schematic structural diagram of a quadrangular diffusion zone of a permanent magnet according to an embodiment of the present application;

FIG7 is a schematic structural diagram of three-strip diffusion regions of a permanent magnet according to an embodiment of the present application;

FIG8 is a schematic structural diagram of a single diffusion zone of a permanent magnet according to an embodiment of the present application; and

FIG. 9 is a schematic diagram of the structure of a motor according to an embodiment of the present application.

In the accompanying drawings: 100-motor, 110-rotor, 111-rotor core, 112-permanent magnet, 113-first magnetic isolation bridge, 114-second magnetic isolation bridge, 1111-magnet slot, 120-stator, 121-statator core, 122-winding, 1211-protrusion, 1121-diffusion region, 11211-first diffusion region, 11212-second diffusion region, 11213-third diffusion region, 11214-non-diffusion region.

Detailed ways

The present application is described in detail below in conjunction with the accompanying drawings and specific implementation methods, so as to facilitate the understanding of the present application by persons skilled in the art. It is necessary to point out here that the embodiments are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Non-essential improvements and adjustments made to the present application by persons skilled in the art based on the above invention content should still fall within the scope of protection of the present application.

In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and therefore the scope of protection of the present application is not limited to the specific embodiments disclosed below.

In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features.

The rotor, the motor, and the compressor according to some embodiments of the present application are described below with reference to FIGS. 1-9 .

Example 1

As shown in Figure 1, according to the first aspect of the present application, an embodiment proposes a rotor 110, including a rotor core 111, multiple groups of permanent magnets 112, a first magnetic isolation bridge 113 and a second magnetic isolation bridge 114, the rotor core 111 is provided with a permanent magnet 112 slot 1111; the permanent magnet 112 is arranged in the permanent magnet 112 slot 1111, and one permanent magnet 112 is correspondingly arranged in one permanent magnet 112 slot 1111, two permanent magnets 112 are a group and distributed in a V shape, multiple groups of permanent magnets 112 are arranged on the rotor core 111, and the number of groups of permanent magnets 112 is determined by the size of the rotor core 111; the first magnetic isolation bridge 113 is arranged between the permanent magnet 112 slots 1111 where two permanent magnets 112 in the same group are located, and the first isolation bridge 113 is arranged between the two permanent magnets 112 in the same group. The magnetic bridge 113 can play a magnetic isolation role to a certain extent, thereby avoiding magnetic leakage in the area between two permanent magnets 112 in the same group, optimizing the structure of the rotor 110, and improving the reliability of the rotor 110; the second magnetic isolation bridge 114 is arranged between the permanent magnet 112 slots 1111 where adjacent groups of permanent magnets 112 are located. By setting the second magnetic isolation bridge 114, the occurrence of magnetic circuit disorder and magnetic leakage problems in each group inside the rotor 110 can be effectively reduced, so as to further optimize the structure of the rotor 110 and improve the reliability of the rotor 110.

As shown in FIG3 , a diffusion zone 1121 is provided on the plane where the width and thickness of the permanent magnet 112 are located, and the diffusion zone 1121 includes a first diffusion zone 11211 and/or a second diffusion zone 11212, wherein: the first diffusion zone 11211 is provided on one side of the width center line of the permanent magnet 112, and the second diffusion zone 11212 is provided on the other side of the width center line of the permanent magnet 112. The first diffusion zone 11211 and the second diffusion zone 11212 refer to the process of manufacturing the permanent magnet 112, by coating a layer of slurry containing rare earth elements on the surface of the permanent magnet 112 substrate, so as to enhance the anti-demagnetization performance of the permanent magnet 112. In order to meet the requirements of different anti-magnetic properties, a slurry of rare earth elements can be coated on one side of the width center line of the permanent magnet 112 to form a first diffusion zone 11211; a slurry containing rare earth elements can also be coated on the other side of the width center line of the permanent magnet 112 to form a second diffusion zone 11212; or a slurry containing rare earth elements can be coated on both sides of the width center line of the permanent magnet 112 to form a first diffusion zone 11211 and a second diffusion zone 11212. In addition, the content of rare earth elements in the slurry can be controlled to meet the requirements of different anti-demagnetization properties.

The first diffusion zone 11211 and the second diffusion zone 11212 both contain rare earth elements. Since rare earth elements have excellent energy density, coercive force and remanent magnetism, after being prepared into slurry and coated on the surface of the permanent magnet 112 matrix, they will penetrate and diffuse into the permanent magnet 112 matrix to form a diffusion zone (1121). The higher the content of rare earth elements in the slurry, the stronger the anti-demagnetization ability of the permanent magnet. At the same time, after the slurry containing rare earth elements is coated on the surface of the permanent magnet matrix, high-temperature treatment (about 800-950° C., 10-18 hours) is required to further improve the bonding force between the rare earth elements and the permanent magnet matrix, form a stable grain boundary state, improve the coercive force of the permanent magnet and its temperature stability, thereby improving the anti-demagnetization ability of the permanent magnet 112, and then improve the anti-demagnetization ability of the motor.

As shown in Figure 2, the demagnetization performance of the rotor 110 is related to the thickness of the first magnetic isolation bridge 113 and the second magnetic isolation bridge 114 and the size of the diffusion zone 1121, wherein: when the thickness of the first magnetic isolation bridge 113 and the second magnetic isolation bridge 114 increases, the anti-demagnetization performance of the rotor 110 is improved, and under the premise of achieving the same anti-demagnetization performance, the area of the diffusion zone 1121 needs to be reduced; at the same time, the product of the thickness of the first magnetic isolation bridge 113 and the thickness of the second magnetic isolation bridge 114 is inversely proportional to L _1max , W _1max , L _2max or W _2max of the diffusion zone 1121. Therefore, by reasonably setting the relationship among the thickness y ₁ of the first magnetic isolation bridge 113, the thickness y ₂ of the second magnetic isolation bridge 114, the maximum length L _1max of the first diffusion zone 11211 along the width direction of the permanent magnet 112, the maximum length W _1max of the first diffusion zone 11211 along the thickness direction of the permanent magnet 112, the maximum length L _2max of the second diffusion zone 11212 along the width direction of the permanent magnet 112, and the maximum length W _2max of the second diffusion zone 11212 along the thickness direction of the permanent magnet 112, and making them satisfy the following formula (1): -(2) or the operational relationship of formula (1)-(4) can improve the local anti-demagnetization ability of the permanent magnet 112 and the anti-demagnetization ability of the rotor 110, thereby improving the anti-demagnetization ability of the motor and reducing the production cost of the motor, while ensuring the demagnetization reliability and not increasing the volume of the permanent magnet 112.

Formula (1): y ₁ ·y ₂ ·L _1max = k ₁ , Formula (2): y ₁ ·y ₂ ·W _1max = k ₃

Formula (3): y ₁ ·y ₂ ·L _2max = k ₂ , Formula (4): y ₁ ·y ₂ ·W _2max = k ₄

In the above formula: 0.2≤k ₁ ≤7.7, 0.2≤k ₂ ≤7.7, 0.16≤k ₃ ≤2, 0.16≤k ₄ ≤2.

Example 2

As shown in FIG. 1-2 , in one embodiment of the present application, based on the above-mentioned embodiment 1, the thickness y ₁ of the first magnetic isolation bridge 113 is in the range of 0.2-2 mm; the thickness y ₂ of the second magnetic isolation bridge 114 is in the range of 0.2-2 mm.

In this embodiment, the thickness of the first magnetic isolation bridge 113 is controlled to meet the requirement of magnetic isolation of the same group of permanent magnets 112. The thickness of the first magnetic isolation bridge 113 needs to be greater than 0.2 mm to ensure that the first magnetic isolation bridge 113 can meet the damage to the structure of the rotor 110 caused by the centrifugal force generated by the high-speed rotation of the rotor 110, thereby ensuring the mechanical strength of a single group of permanent magnets 112 and improving the reliability of the rotor 110; at the same time, the thickness of the first magnetic isolation bridge 113 is limited to less than 1 mm to reduce the risk of magnetic leakage of the same group of permanent magnets 112 and the manufacturing cost.

The thickness of the second magnetic isolation bridge 114 is controlled to meet the requirement of magnetic isolation between different groups of permanent magnets 112. The thickness of the second magnetic isolation bridge 114 needs to be greater than 0.2 mm to ensure that the second magnetic isolation bridge 114 can meet the damage to the structure of the rotor 110 caused by the centrifugal force generated by the high-speed rotation of the rotor 110, thereby ensuring the mechanical strength of each group of permanent magnets 112 and improving the overall reliability of the rotor 110; at the same time, the thickness of the second magnetic isolation bridge 114 is limited to less than 2 mm to reduce the risk of magnetic leakage between groups of permanent magnets 112 and the manufacturing cost.

The value ranges of the parameters in the diffusion region 1121 arbitrarily satisfy one or more of the following: 1 mm ≤ _{L 1max} ≤ 25 mm; 1 mm ≤ _{L 2max} ≤ 25 mm; 1 mm ≤ W _1max ≤ 5 mm; 1 mm ≤ W _2max ≤ 5 mm. On the basis of limiting the value ranges of _y1 and _y2 , the range values of the parameters in the diffusion zone 1121, the maximum length _L1max of the first diffusion zone 11211 along the width direction of the permanent magnet 112, the maximum length _W1max of the first diffusion zone 11211 along the thickness direction of the permanent magnet 112, the maximum length _L2max of the second diffusion zone 1122 along the width direction of the permanent magnet 112, and the maximum length _W2max of the second diffusion zone 1122 along the thickness direction of the permanent magnet 112 are further limited so as to satisfy _{0.2≤k1≤7.7} , _{0.2≤k2≤7.7 , 0.16≤k3≤2} , _{and 0.16≤k4≤2} in the formulas, thereby achieving the improvement of the local anti-demagnetization capability of the permanent magnet 112 and the anti-demagnetization capability of the rotor 110 under the premise of ensuring the demagnetization reliability and not increasing the volume of the permanent magnet 112, thereby improving the anti-demagnetization capability of the motor and reducing the production cost of the motor.

Example 3

As shown in FIG. 1 , in one embodiment of the present application, based on the above-mentioned embodiment 1 or 2, the rare earth element includes at least one of dysprosium, terbium, praseodymium, neodymium, and cerium, and the rare earth element is evenly or unevenly distributed in the permanent magnet 112. middle.

In this embodiment, these rare earth elements penetrate and diffuse into the permanent magnet 112. During the high-temperature treatment process, they can form intermetallic compounds with the transition metal elements in the permanent magnet 112. The strong exchange interaction between the transition metal elements makes the compound have a higher Curie temperature. The transition metal atoms have a larger magnetic moment to ensure that the compound has a higher saturation magnetization intensity, and the localized 4f electrons of the rare earth elements can provide stronger anisotropy. The combined effect of the two types of elements is beneficial to improving the coercive force of the permanent magnet 112, thereby enhancing the anti-demagnetization ability of the permanent magnet 112, and further improving the anti-demagnetization ability of the motor.

The distribution of rare earth elements in the permanent magnet 112 refers to the distribution of rare earth elements in the diffusion region. The rare earth elements in the diffusion region can be evenly distributed or unevenly distributed, which mainly depends on the diffusion process and the requirements of the permanent magnet 112 for anti-demagnetization performance. When the requirements for the anti-demagnetization performance of the permanent magnet 112 are high, it is necessary to coat the permanent magnet 112 with a slurry with a high content of rare earth elements. At this time, the concentration of the slurry is high, the permeability and diffusivity are poor, and it is easy to form an uneven distribution of rare earth elements, thereby forming a diffusion zone with a relatively stronger anti-demagnetization ability in some areas, thereby improving the overall anti-demagnetization ability of the motor 100; when the requirements for the anti-demagnetization performance of the permanent magnet 112 are not high, the permanent magnet 112 can be coated with a slurry with a low content of rare earth elements. At this time, the concentration of the slurry is low, the permeability and diffusivity are good, and it is easy to form a uniform distribution of rare earth elements, thereby forming a balanced anti-demagnetization area in the diffusion zone, which can also effectively improve the overall anti-demagnetization ability of the motor 100.

Example 4

As shown in FIG. 1 , in one embodiment of the present application, based on any one of the above embodiments 1 to 3, the mass percentage _g1 of the rare earth element in the first diffusion region 11211 in the permanent magnet 112 is controlled to be 1.05%-2.0%.

In this embodiment, the weight percentage range of the rare earth elements in the first diffusion region 11211 is controlled to meet the low cost requirements of the motor. The weight percentage of the rare earth elements in the first diffusion region 11211 needs to be greater than 1.05% to ensure that the first diffusion region 11211 has the minimum requirement for meeting the coercive force of the permanent magnet 112, thereby ensuring that the first diffusion region 11211 can improve the anti-demagnetization ability of the entire permanent magnet 112; at the same time, the weight percentage of the rare earth elements in the first diffusion region 11211 is limited to less than 2.0%, which can reduce the cost of the permanent magnet 112 on the basis of ensuring that the first diffusion region 11211 has a strong anti-demagnetization ability, thereby meeting the low cost requirements of the motor.

The mass percentage _g2 of the rare earth elements in the second diffusion zone 11212 in the permanent magnet 112 is controlled to be 1.05%-2.0%. The weight percentage of the rare earth elements in the second diffusion zone 11212 is the same as the weight percentage of the rare earth elements in the first diffusion zone 11211, and can be used as a supplement to the first diffusion zone 11211 or as an independent diffusion zone. At the same time, the weight percentage of the rare earth elements in the second diffusion zone 11212 must be greater than 1.05% to ensure that the second diffusion zone 11212 has the minimum requirement for meeting the coercive force of the permanent magnet 112, thereby ensuring that the second diffusion zone 11212 can enhance the anti-demagnetization ability of the entire permanent magnet 112; at the same time, the weight percentage of the rare earth elements in the second diffusion zone 11212 must be less than 2.0%, which can ensure that the second diffusion zone 11212 On the basis of having strong anti-demagnetization ability, the cost of the permanent magnet 112 is reduced, thereby meeting the low-cost demand of the motor.

The permanent magnet 112 may further include a non-diffusion zone 11214, and the weight percentage of the rare earth element in the non-diffusion zone 11214 in the permanent magnet 112 is controlled to be g ₃ , and g ₃ <g ₁ , g ₃ <g ₂ . The non-diffusion zone 11214 refers to a region in the permanent magnet 112 where the slurry containing the rare earth element has not penetrated or diffused, and the weight percentage of the rare earth element in the non-diffusion zone 11214 is less than the weight percentage of the rare earth element in the first diffusion zone 11211 and the second diffusion zone, that is, the coercive force of the two diffusion zones is greater than the coercive force of the non-diffusion zone 11214. Therefore, the strength of the coercive magnetic field that the first diffusion zone 11211 and the second diffusion zone 11212 can resist is greater than the strength of the coercive magnetic field that the non-diffusion zone 11214 can resist. Therefore, when the non-diffusion zone 11214 faces the risk of demagnetization, it can maintain its own magnetic induction intensity, thereby preventing the non-diffusion zone 11214 from irreversible demagnetization, thereby improving the anti-demagnetization ability of the permanent magnet 112, and improving its reliability while extending the service life of the permanent magnet 112.

As shown in FIG4 , the permanent magnet 112 may further include a plurality of third diffusion regions 11213, and the weight of the rare earth elements in each third diffusion region 11213 accounts for a percentage of the weight of the permanent magnet 112 of g _i >g ₃ . In addition to the first diffusion region 11211 and/or the second diffusion region 11212, the permanent magnet 112 may further include a plurality of third diffusion regions 11213 to supplement the first diffusion region 11211 and the second diffusion region 11212. At the same time, the mass percentage of the rare earth elements in each diffusion region is greater than that of the non-diffusion region 11214, that is, the coercive force of the third diffusion region 11213 is greater than that of the non-diffusion region 11214. By setting a third diffusion zone 11213 and a non-diffusion zone 11214 with different mass proportions, a third diffusion zone 11213 and a non-diffusion zone 11214 with different demagnetization capabilities can be formed on each permanent magnet 112, so as to enhance the anti-demagnetization performance of the permanent magnet 112 through the gradient anti-demagnetization area, thereby reducing the occurrence of irreversible demagnetization problems of the permanent magnet 112.

As shown in Fig. 5-8, the first diffusion zone 11211, the second diffusion zone 11212 and the third diffusion zone 11213 can be set in the permanent magnet 112 at the same time, or can be set in the permanent magnet 112 separately. For the permanent magnet motor, on the plane where the width and thickness of the permanent magnet 112 are located, the permanent magnet 112 is easy to demagnetize at both ends of the width and the middle of the width; in addition, the permanent magnet 112 is also easy to demagnetize at both ends of the length direction. Therefore, setting the diffusion zone at the position where the permanent magnet 112 is easy to demagnetize can improve the anti-demagnetization and ensure the cost reduction at the same time.

As shown in FIG. 5 , the permanent magnet 112 includes a first diffusion region 11211 , a second diffusion region 11212 , and a third diffusion region 11213 , and the first diffusion region 11211 , the second diffusion region 11212 , and the third diffusion region 11213 form a U-shape.

As shown in FIG. 6 , the permanent magnet 112 includes a first diffusion region 11211 and a second diffusion region 11212 , and the first diffusion region 11211 and the second diffusion region 11212 are respectively disposed at four corners of the permanent magnet 112 .

As shown in FIG. 7 , the permanent magnet 112 includes a first diffusion region 11211 , a second diffusion region 11212 and a third diffusion region 11213 , and the first diffusion region 11211 , the second diffusion region 11212 and the third diffusion region 11213 are respectively arranged in parallel on both sides and the middle of the permanent magnet 112 in a three-strip shape.

As shown in FIG. 8 , the permanent magnet 112 only includes the second diffusion region 11212 .

Example 5

As shown in FIG. 1 , in one embodiment of the present application, based on any one of the above embodiments 1 to 4, the first diffusion region 11211 and the second diffusion region 11212 are distributed in the entire area or partially along the axial direction of the permanent magnet 112 .

In this embodiment, the first diffusion zone 11211 and the second diffusion zone 11212 can be distributed in the entire area along the axial direction of the permanent magnet 112, or they can be distributed partially. Specifically, it refers to: the distribution of the first diffusion zone 11211 and the second diffusion zone 11212 along the length direction of the permanent magnet 112. The distribution along the length direction can be distributed in the entire area or in a partial area, which mainly depends on the requirements of the permanent magnet 112 for anti-demagnetization performance. The partial area distribution is mainly to reduce the diffusion area, thereby reducing costs.

The rotor 110 includes a plurality of permanent magnets 112, and the diffusion regions 1121 of the permanent magnets 112 on the cross section where the width and thickness are located are the same or different. By arranging a plurality of permanent magnets 112 on the rotor assembly 110, the anti-demagnetization capability of the rotor assembly 110 can be enhanced to further reduce the possibility of irreversible demagnetization of the rotor assembly 110. At the same time, for a piece of permanent magnet 112, the diffusion regions 1121 on the planes where the width and thickness are located on different lengths of the permanent magnet 112 can be the same or different, and it is only necessary to ensure the overall anti-demagnetization capability of the permanent magnet 122.

The permanent magnet 112 is magnetized radially or in parallel. The magnetization direction of the permanent magnet 112 can be radial magnetization or parallel magnetization. It is only necessary to ensure that the magnetization direction of each permanent magnet 112 on the rotor 110 is consistent, and the magnetization directions of the first diffusion region 11211, the second diffusion region 11212, the third diffusion region 11213 and the non-diffusion region 11214 in each permanent magnet 112 are consistent. When the non-diffusion region 11214 is demagnetized due to the external magnetic field, the first diffusion region 11211, the second diffusion region 11212 and the third diffusion region 11213 with strong anti-demagnetization ability can ensure their own magnetism, so that the non-diffusion region 11214 is magnetized by the first diffusion region 11211, the second diffusion region 11212 and the third diffusion region 11213 to avoid the irreversible demagnetization of the permanent magnet 112.

The rotor core 111 is formed by stacking a plurality of silicon steel sheets. The rotor core 111 is formed by stacking a plurality of silicon steel sheets. The stacking method of processing the rotor core 111 is conducive to reducing eddy current loss. When the rotor core 111 is working, it is in a changing magnetic field, and the induced current inside it will cause energy loss, which is called eddy current loss. The rotor core 111 is formed by stacking silicon steel sheets, which can effectively reduce iron loss and improve the reliability of the rotor 110.

Example 6

As shown in FIG9 , according to the second aspect of the present application, an embodiment proposes a motor 100, comprising a stator 120 and a rotor 110 of any technical solution of the first aspect, wherein: the stator 120 is composed of a stator core 121 and a winding 122, the stator core 121 is provided with a protrusion 1211 for fixing the winding 122, the winding 122 is formed by a coil surrounding the protrusion 1211, and the stator core 121 is arranged around the outer side of the rotor core 111 and forms a gap. Since the motor 100 includes the rotor 110 of any technical solution above, it has all the beneficial effects that can be achieved by the rotor 110.

Example 7

As shown in Figure 9, according to the third aspect of the present application, an embodiment proposes a compressor, including a rotor 110 of any technical solution of the first aspect or a motor 100 of any technical solution of the second aspect. Since the compressor includes the rotor 110 or the motor 100 of any technical solution, it has all the beneficial effects that can be achieved by the rotor 110 or the motor 100.

Example 8

As shown in Figure 9, according to the fourth aspect of the present application, an embodiment proposes a refrigerator, including a motor 100 of any technical solution of the second aspect or a compressor of any technical solution of the third aspect. Since the refrigerator includes the motor 100 or the compressor of any technical solution, it has all the beneficial effects that can be achieved by the motor 100 or the compressor.

The refrigerator also includes a pipeline, which is connected to the compressor, and the refrigerant circulates through the pipeline and the compression mechanism to achieve heat exchange refrigeration. Specifically, the refrigerator is an air conditioner.

The following describes the specific applications of some embodiments and comparative rotors of the present application based on the rotors of the above-mentioned embodiments 1-5.

Application Example 1

A rotor 110 includes a rotor core 111, permanent magnets 112, a first magnetic isolation bridge 113 and a second magnetic isolation bridge 114, wherein: a magnet slot 1111 is provided on the rotor core 111, the permanent magnets 112 are installed in the magnet slot 1111, two permanent magnets 112 form a group and are distributed in a V shape, and each group of permanent magnets 112 is connected end to end and arranged around the rotor core 111; the first magnetic isolation bridge 113 is arranged between the slots 1111 of the permanent magnet 112 where two permanent magnets 112 in the same group are located, and the second magnetic isolation bridge 114 is arranged between the slots 1111 of the permanent magnet 112 where adjacent groups of permanent magnets 112 are located. A diffusion zone 1121 is provided on the plane where the width and thickness of the permanent magnet 112 are located, and the diffusion zone 1121 includes a first diffusion zone 11211 and a second diffusion zone 11212, wherein: the first diffusion zone 11211 is provided on one side of the width center line of the permanent magnet 112, and the second diffusion zone 11212 is provided on the other side of the width center line of the permanent magnet 112. The rotor core 111 is formed by stacking a plurality of silicon steel sheets, and the permanent magnet 112 is radially magnetized.

A permanent magnet with a size/brand of 1.9×13×40/42SH is selected, and a slurry containing the rare earth element neodymium is coated on both ends of the permanent magnet along the length direction and subjected to high temperature treatment to form a first diffusion zone 11211 and a second diffusion zone 11212, which are evenly distributed in the entire area along the axial direction of the permanent magnet 112, thereby obtaining the permanent magnet 112 of this application example. The weight proportion of the rare earth element neodymium in the first diffusion zone 11211 is 1.5%, the weight proportion of the rare earth element neodymium in the second diffusion zone 11212 is 1.5%, and the non-diffusion zone does not contain the rare earth element neodymium.

Substitute the thickness _y1 of the first magnetic isolation bridge 113 as 0.5 mm, the thickness _y2 of the second magnetic isolation bridge 114 as 0.5 mm, the maximum length _L1max of the first diffusion zone 11211 along the width direction of the permanent magnet 112 as 3 mm, the maximum length _W1max of the first diffusion zone 11211 along the thickness direction of the permanent magnet 112 as 1.9 mm, the maximum length _L2max of the second diffusion zone 11212 along the width direction of the permanent magnet 112 as 3 mm, and the maximum length _W2max of the second diffusion zone 11212 along the thickness direction of the permanent magnet 112 as 1.9 mm into the above formulas (1)-(4): Calculation shows that: k ₁ = k ₂ = 3 mm ³ , k ₃ = k ₄ = 0.475 mm ³ .

Comparative Example 1

A rotor 110 includes a rotor core 111, permanent magnets 112, a first magnetic isolation bridge 113 and a second magnetic isolation bridge 114, wherein: a magnet slot 1111 is provided on the rotor core 111, the permanent magnets 112 are installed in the magnet slot 1111, two permanent magnets 112 form a group and are distributed in a V shape, and each group of permanent magnets 112 is connected end to end and arranged around the rotor core 111; the first magnetic isolation bridge 113 is arranged between the slots 1111 of the permanent magnet 112 where two permanent magnets 112 in the same group are located, and the second magnetic isolation bridge 114 is arranged between the slots 1111 of the permanent magnet 112 where adjacent groups of permanent magnets 112 are located. A diffusion zone 1121 is provided on the plane where the width and thickness of the permanent magnet 112 are located, and the diffusion zone 1121 includes a first diffusion zone 11211 and a second diffusion zone 11212, wherein: the first diffusion zone 11211 is provided on one side of the width center line of the permanent magnet 112, and the second diffusion zone 11212 is provided on the other side of the width center line of the permanent magnet 112. The rotor core 111 is formed by stacking a plurality of silicon steel sheets, and the permanent magnet 112 is radially magnetized.

The only difference between Comparative Example 1 and Application Example 1 is that Comparative Example 1 uses a permanent magnet with a size/brand of 1.9×13×40/42SH, which is not coated with a slurry containing the rare earth element neodymium, does not contain a diffusion zone, and the motor parameters do not satisfy the operational relationship of formulas (1)-(4) of this application.

Performance Testing

The demagnetization rate of the motor 100 and the intrinsic coercive force of the permanent magnet of the application example 1 and the comparative example 1 are tested, wherein the specific testing process of the demagnetization rate is as follows:

First, the magnetized saturated rotor 110 is placed at room temperature, and the magnetic flux φ ₀ of the rotor 110 is measured; then, the rotor 110 after the initial magnetic flux is tested is placed in a constant temperature box for more than 4 hours, and the temperature of the constant temperature box is set at a specified temperature (130° C.); then, the test DC motor is connected to a DC power supply, and the demagnetization current is set according to a preset demagnetization current value (43A, 50A, etc.). When ready, the rotor 110 is taken out of the constant temperature box, and the demagnetization test tooling is installed. Under the DC demagnetization current, the rotor rotates one circle; after completion, the rotor 110 is placed at room temperature for more than 4 hours, and then the temperature of the rotor 110 and the magnetic flux φ ₁ after demagnetization are measured.

Calculate the demagnetization rate using the following formula: (φ _i needs to be calculated at the same temperature as φ ₀ ):

Demagnetization rate = (φ _i - φ ₀ )/φ ₀ × 100%

Where: φ ₀ is the magnetic flux of the rotor 110 at the beginning of the demagnetization test; φ _i is the magnetic flux of the rotor 110 after the demagnetization test at the i-th demagnetization current value. The test results are shown in Table 1:

Table 1: Performance comparison table of application example 1 and comparative example 1

It can be seen from Table 1 that the permanent magnet in the specific diffusion zone provided by the present application has an intrinsic coercive force increased by 150KA/m relative to the permanent magnet without diffusion; at the same time, the demagnetization rate of the motor provided by the present application at 50A/130°C can reach 2.50%, which is 34.38% lower than that of ordinary motors, greatly reducing the production cost of the motor.

In addition, through a large number of experiments, it is found that when the product of the thickness of the first magnetic isolation bridge 113 and the thickness of the second magnetic isolation bridge 114 of the motor is inversely proportional to L _1max , W _1max , L _2max or W _2max of the diffusion zone 1121. Therefore, by reasonably setting the thickness y ₁ of the first magnetic isolation bridge 113, the thickness y ₂ of the second magnetic isolation bridge 114, the maximum length L _1max of the first diffusion zone 11211 along the width direction of the permanent magnet 112, the maximum length W _1max of the first diffusion zone 11211 along the thickness direction of the permanent magnet 112, the maximum length L _2max of the second diffusion zone 11212 along the width direction of the permanent magnet 112, and the maximum length W _2max of the second diffusion zone 11212 along the thickness direction of the permanent magnet 112 do not satisfy the operational relationship of the above formulas (1)-(4), it is not conducive to reducing the cost of the motor. Specifically, when k ₁ is less than 0.2 mm ³ , k ₂ is less than 0.2 mm ³ , k ₃ is less than 0.16 mm ³ , and k ₄ is less than 0.16 mm ³ , the demagnetization effect of the motor is not good; when k ₁ is greater than 7.7 mm ³ , k ₂ is greater than 7.7 mm ³ , k ₃ is greater than 2 mm ³ , and k ₄ is greater than 2 mm ³ , the demagnetization effect of the motor is similar to that of Example 1, but the cost is much higher than that of Example 1, so the cost performance of the motor is not high, and the cost is increased.

Compared with the prior art, the above technical solution of the present application has at least the following technical effects or advantages:

(1) The present application is based on the fact that the demagnetization performance of the rotor is related to the thickness of the first magnetic isolation bridge and the second magnetic isolation bridge and the size of the diffusion zone, and the product of the thickness of the first magnetic isolation bridge and the thickness of the second magnetic isolation bridge is inversely proportional to L1max or W1max of the diffusion zone. It is derived and verified that by reasonably setting the relationship between the thickness of the first magnetic isolation bridge y1, the thickness of the second magnetic isolation bridge y2, the maximum length L1max of the first diffusion zone along the width direction of the permanent magnet, and the maximum length W1max of the first diffusion zone along the thickness direction of the magnet, and making them satisfy the above formulas (1) and (2), it is possible to improve the local anti-demagnetization ability of the permanent magnet while ensuring the demagnetization reliability and not increasing the volume of the permanent magnet, thereby improving the anti-demagnetization ability of the rotor, and then improving the anti-demagnetization ability of the motor, thereby reducing the production cost of the motor.

(2) The rotor provided in the present application has a permanent magnet whose demagnetization rate at 50A/130°C can reach 2.50%.

In this application, the term "multiple groups" refers to two or more groups, unless otherwise expressly limited. In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

For ordinary technicians in the technical field to which this application belongs, several simple deductions or replacements can be made without departing from the concept of this application, without having to go through creative work. Therefore, simple improvements made to this application by those skilled in the art based on the disclosure of this application should be within the protection scope of this application. The above embodiments are preferred embodiments of this application, and all structures similar to this application and equivalent changes made should belong to the protection scope of this application.

Claims (17)

1. A rotor, comprising:

   A rotor core (111), wherein the rotor core (111) is provided with a magnet slot (1111);

   A plurality of groups of permanent magnets (112), wherein the permanent magnets (112) are arranged in the magnet slots (1111), two permanent magnets (112) form a group and are distributed in a V shape, and the plurality of groups of permanent magnets (112) are arranged around the rotor core (111);

   A first magnetic isolation bridge (113) is arranged between the magnet slots (1111) where two permanent magnets (112) in the same group are located; and

   A second magnetic isolation bridge (114) is arranged between the magnet slots (1111) where adjacent groups of permanent magnets (112) are located;

   A diffusion zone (1121) is provided on a plane where the width and thickness of the permanent magnet (112) are located, and the diffusion zone (1121) comprises:

   A first diffusion region (11211) is arranged on one side of a width center line of the permanent magnet (112); and/or

   A second diffusion region (11212) is arranged on the other side of the width center line of the permanent magnet (112);

   The first diffusion region (11211) and the second diffusion region (11212) both contain rare earth elements;

   Wherein: the thickness y ₁ of the first magnetic isolation bridge (113), the thickness y ₂ of the second magnetic isolation bridge (114), the maximum length L _1max of the first diffusion region (11211) along the width direction of the permanent magnet (112), and the maximum length W _1max of the first diffusion region (11211) along the thickness direction of the permanent magnet (112) satisfy the following formulas (1) and (2):
   Formula (1): y ₁ ·y ₂ ·L _1max = k ₁ , Formula (2): y ₁ ·y ₂ ·W _1max = k ₃ ;

   In the above formula: 0.2≤k ₁ ≤7.7, 0.16≤k ₃ ≤2.
2. The rotor according to claim 1, wherein a maximum length L _2max of the second diffusion region (11212) along the width direction of the permanent magnet (112) and a maximum length W _2max of the second diffusion region (11212) along the thickness direction of the permanent magnet (112) satisfy the following formulas (3) and (4):
   Formula (3): y ₁ ·y ₂ ·L _2max = k ₂ , Formula (4): y ₁ ·y ₂ ·W _2max = k ₄ ;

   In the above formula: 0.2≤k ₂ ≤7.7, 0.16≤k ₄ ≤2.
3. The rotor according to claim 1 or 2, wherein the thickness _y1 of the first magnetic isolation bridge (113) is in the range of 0.2-2 mm.
4. The rotor according to any one of claims 1 to 3, wherein the thickness _y2 of the second magnetic isolation bridge (114) is in the range of 0.2-2 mm.
5. The rotor according to any one of claims 1 to 4, wherein the rare earth element comprises at least one of dysprosium, terbium, praseodymium, neodymium and cerium.
6. The rotor according to any one of claims 1 to 5, wherein the rare earth element is uniformly distributed or non-uniformly distributed in the diffusion zone (1121).
7. The rotor according to any one of claims 1 to 6, wherein the content of the rare earth element in the first diffusion zone (11211) accounts for a mass percentage _g1 of 1.05%-2.0% of the permanent magnet (112).
8. The rotor according to claim 7, wherein the content of the rare earth element in the second diffusion zone (11212) accounts for a mass percentage _g2 of 1.05%-2.0% of the permanent magnet (112).
9. The rotor according to claim 8, wherein the permanent magnet (112) further comprises a non-diffusion zone (11214), the content of rare earth elements in the non-diffusion zone (11214) accounts for a mass percentage of g ₃ of the permanent magnet (112), and g ₃ <g ₁ , g ₃ <g ₂ .
10. The rotor according to claim 9, wherein the permanent magnet (112) further comprises a plurality of third diffusion zones (11213), the third diffusion zones being arranged between the first diffusion zone (11211) and the second diffusion zone (11212), and the content of the rare earth element in each of the third diffusion zones (11213) accounts for a mass percentage of g _i of the permanent magnet (112), g _i >g ₃ .
11. The rotor according to any one of claims 1 to 10, wherein the first diffusion region (11211) and the second diffusion region (11212) are distributed in the entire area or partially along the axial direction of the permanent magnet (112).
12. The rotor according to any one of claims 1 to 11, wherein the diffusion regions (1121) on cross sections where the permanent magnets (112) have different widths and thicknesses are the same or different.
13. The rotor according to any one of claims 1 to 12, wherein the permanent magnet (112) is radially magnetized or parallel magnetized.
14. The rotor according to any one of claims 1 to 13, wherein the rotor core (111) is formed by stacking a plurality of silicon steel sheets.
15. A motor comprising a rotor as claimed in any one of claims 1 to 14.
16. A compressor, comprising the rotor according to any one of claims 1 to 14, or the motor according to claim 15.
17. A refrigerator, comprising the motor according to claim 15 or the compressor according to claim 16.