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

Abstract

The present invention belongs to the technical field of drive devices, and specifically discloses a rotor, motor, compressor, and refrigerator capable of enhancing demagnetization resistance. The rotor comprises: a rotor core provided with magnet slots; a plurality of permanent magnets disposed in the magnet slots, and a plurality of permanent magnets disposed around the rotor core; a magnetic isolation bridge disposed between the magnet slots where adjacent permanent magnets are located; and a first diffusion region and / or a second diffusion region disposed on the plane where the width and thickness of the permanent magnets are located. The demagnetization performance of the rotor is related to the thickness of the magnetic isolation bridge and the size of the diffusion region. The present invention derives and verifies the operational relationship between the various parameters. The motor designed accordingly achieves improved local demagnetization resistance of the permanent magnets while ensuring demagnetization reliability and without increasing the volume of the permanent magnets, thereby reducing the production cost of the motor.

Description

Technical Field

[0001] The present invention belongs to the technical field of drive devices, and in particular relates to a rotor, a motor, a compressor and a refrigerator capable of enhancing resistance to demagnetization. Background Art

[0002] At present, most air-conditioning compressors 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 characteristics 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.

[0003] Furthermore, the rare earth element content in a magnet affects its remanence and coercivity. Coercivity directly reflects its resistance to demagnetization. When magnets of the same size are used in the same motor, magnets with lower coercivity have poor rotor demagnetization resistance, resulting in a higher risk of rotor demagnetization and more pronounced demagnetization. Consequently, as rare earth material prices rise, the price of rare earth magnets and the cost of motors skyrocket. While ensuring reliable motor operation, reducing the costs of both magnets and motors is imperative.

[0004] Therefore, it is urgent to design a rotor that can effectively solve the above technical defects, improve the rotor's anti-demagnetization ability while ensuring demagnetization reliability and not increasing the volume of permanent magnets, and thus improve the motor's anti-demagnetization ability to reduce production costs. Summary of the Invention

[0005] The present invention aims to address at least one of the technical problems existing in the aforementioned prior art. To this end, the present invention provides a rotor, motor, compressor, and refrigerator that enhance demagnetization resistance. By controlling the specific operational relationship between relevant parameters such as the thickness of the magnetic isolation bridge and the diffusion size of the rare earth elements in the permanent magnet, the present invention improves the local demagnetization resistance of the permanent magnet while ensuring demagnetization reliability and without increasing the volume of the permanent magnet. This, in turn, improves the demagnetization resistance of the motor, thereby reducing the production cost of the motor.

[0006] To overcome the above technical problems, a first aspect of the present invention provides a rotor.

[0007] A rotor comprising:

[0008] a rotor core, wherein the rotor core is provided with magnet slots;

[0009] A plurality of permanent magnets, wherein the permanent magnets are disposed in the magnet slots and the plurality of permanent magnets are disposed around the rotor core;

[0010] A magnetic isolation bridge is provided between magnet slots where adjacent permanent magnets are located;

[0011] A diffusion zone is provided on the plane where the width and thickness of the permanent magnet are located, and the diffusion zone includes:

[0012] A first diffusion region is provided on one side of the width centerline of the permanent magnet; and / or

[0013] A second diffusion region is provided on the other side of the width centerline of the permanent magnet;

[0014] Both the first diffusion region and the second diffusion region contain rare earth elements;

[0015] Wherein: the thickness y2 of the magnetic isolation bridge, the maximum length L of the first diffusion region along the width direction of the permanent magnet 1max , the maximum length W of the first diffusion region along the thickness direction of the permanent magnet 1max , and variable c satisfy the following formulas (1) and (2):

[0016] Formula (1): 2 c ·y2·L 1max =k1, formula (2): y2·W 1max =k3;

[0017] In the above formula: 0.2≤k1≤19.2, 0.2≤k3≤19.2; the variable c is selected from 0 or 1.

[0018] The rotor of the present invention includes a rotor core, multiple permanent magnets and a magnetic isolation bridge, and the rotor core is provided with magnet slots; the permanent magnets are arranged in the magnet slots, and each permanent magnet is correspondingly arranged in the corresponding magnet slot. Each of the permanent magnets is connected end to end and arranged around the rotor core, and the number of permanent magnets is determined by the size of the rotor core; the magnetic isolation bridge is arranged between the magnet slots where adjacent permanent magnets are located, and plays a role in magnetic isolation, which can avoid magnetic leakage in the area between the two permanent magnets, reduce the disorder of the magnetic circuit inside the rotor, and is conducive to optimizing the rotor structure and improving the reliability of the rotor.

[0019] Diffusion zones are provided on the planes defining the width and thickness of the permanent magnet. These diffusion zones include a first diffusion zone and / or a second diffusion zone, wherein the first diffusion zone is provided on one side of the centerline of the permanent magnet's width, and the second diffusion zone is provided on the other side of the centerline. Both the first and second diffusion zones contain rare earth elements. Because rare earth elements have excellent energy density, coercivity, and remanence, after being prepared into a slurry and applied to the surface of the permanent magnet substrate, they penetrate and diffuse into the interior of the permanent magnet substrate, forming diffusion zones. The higher the rare earth element content in the slurry, the stronger the permanent magnet's demagnetization resistance. Furthermore, after the slurry containing rare earth elements is applied to the surface of the permanent magnet substrate, it is subjected to a high-temperature treatment (approximately 800-950°C for 10-18 hours) to further enhance the bonding between the rare earth elements and the permanent magnet substrate, form a stable grain boundary state, and improve the coercivity and temperature stability of the permanent magnet, thereby enhancing the permanent magnet's demagnetization resistance and, consequently, the motor's demagnetization resistance.

[0020] The study found that the demagnetization performance of the rotor is related to the thickness of the magnetic isolation bridge and the size of the diffusion zone. When the thickness of the magnetic isolation bridge increases, the anti-demagnetization performance of the rotor is improved. Under the premise of achieving the same anti-demagnetization performance, the area of ​​the diffusion zone needs to be reduced. That is, the thickness of the magnetic isolation bridge and the L of the diffusion zone are related. 1max or W 1max Therefore, by reasonably setting the thickness y2 of the magnetic isolation bridge, the maximum length L of the first diffusion zone along the width direction of the permanent magnet, 1max , the maximum length W of the first diffusion region along the magnet thickness direction 1max By establishing a relationship between the two and making it satisfy the operational relationship of the above formulas (1) and (2), it is possible to improve the local anti-demagnetization ability of the permanent magnet and the anti-demagnetization ability of the rotor, 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.

[0021] Preferably, in formula (1) and formula (2), 1.6≤k1≤1.8, 0.4≤k3≤0.6.

[0022] As a further improvement of the above technical solution, the maximum length L of the second diffusion region along the width direction of the permanent magnet is 2max , the maximum length W of the second diffusion region along the thickness direction of the permanent magnet 2max , and satisfy the following formulas (3) and (4):

[0023] Formula (3): 2 c ·y2·L 2max =k2, formula (4): y2·W 2max =k4;

[0024] In the above formula: 0.2≤k2≤19.2, 0.2≤k4≤19.2; the variable c is selected from 0 or 1.

[0025] Specifically, when the maximum length of the second diffusion zone along the width and thickness directions of the permanent magnet satisfies formulas (3) and (4), the first diffusion zone can be supplemented, thereby further improving the local anti-demagnetization capability of the permanent magnet while ensuring demagnetization reliability and without increasing the volume of the permanent magnet.

[0026] Preferably, in formula (3) and formula (4), 1.6≤k1≤1.8, 0.4≤k3≤0.6.

[0027] As a further improvement of the above solution, the permanent magnet is in a straight line shape, and the variable c is 0.

[0028] Specifically, the shape of the permanent magnet is chosen primarily to accommodate the performance requirements of different motors, thereby expanding the product's range of applications. When the permanent magnet can be in a straight line, this is primarily due to its proximity to the rotor's outer diameter, providing a large effective magnetic flux and allowing for easy saturation of magnetization. Consequently, the rotor generates a magnetic density with a high average and maximum value. Furthermore, the straight-line permanent magnet exhibits reduced torque ripple, resulting in higher performance under high-torque conditions. Furthermore, when the permanent magnet is in a straight line, the corresponding variable c in the above formula is 0.

[0029] As a further improvement of the above solution, the permanent magnet is V-shaped and the variable c is 1.

[0030] Specifically, the permanent magnets are V-shaped, meaning two adjacent permanent magnets are symmetrically arranged in a V-shape and form a group of permanent magnets. A magnetic isolation bridge is provided between the permanent magnets in adjacent groups, while no magnetic isolation bridge is provided between two permanent magnets in the same group. This V-shaped arrangement of permanent magnets is more conducive to enhancing the rotor's anti-demagnetization capability than a straight-line arrangement of permanent magnets. Furthermore, when the permanent magnets are V-shaped, the corresponding variable c in the above formula is 1.

[0031] As a further improvement of the above solution, the thickness y2 of the magnetic isolation bridge is in the range of 0.2-2 mm.

[0032] Specifically, the thickness of the magnetic isolation bridge is controlled to meet the requirements for magnetic separation between the permanent magnets. The thickness of the magnetic isolation bridge must be greater than 0.2 mm to ensure that the bridge can withstand the damage to the rotor structure caused by the centrifugal force generated by the high-speed rotation of the rotor, thereby ensuring the mechanical strength of the permanent magnets and improving the reliability of the rotor. At the same time, the thickness of the magnetic isolation bridge is limited to less than 2 mm to reduce the risk of permanent magnet magnetic leakage and manufacturing costs.

[0033] As a further improvement to the above solution, the value ranges of the parameters in the first diffusion region satisfy any one or both of the following conditions: 1 mm ≤ L1max ≤25mm; 1mm≤W 1max ≤5mm.

[0034] Preferably, the value ranges of the parameters in the first diffusion zone satisfy any one or both of the following conditions: 1.2 mm ≤ L 1max ≤1.8mm; 1.5mm≤W 1max ≤2.3mm.

[0035] As a further improvement of the above technical solution, the value ranges of the parameters in the second diffusion region satisfy any one or both of the following: 1mm≤L 2max ≤25mm; 1mm≤W 2max ≤5mm.

[0036] Preferably, the value ranges of the parameters in the second diffusion region satisfy any one or both of the following: 1.2 mm ≤ L 2max ≤1.8mm; 1.5mm≤W 2max ≤2.3mm.

[0037] Specifically, on the basis of limiting the value range of y2, the maximum length L of each parameter in the diffusion zone along the width direction of the permanent magnet is further limited. 1max , the maximum length W of the first diffusion region along the thickness direction of the permanent magnet 1max , the maximum length L of the second diffusion region along the width direction of the permanent magnet 2max , the maximum length W of the second diffusion region along the thickness direction of the permanent magnet 2max The range of values ​​is set so that 0.2≤k1≤19.2, 0.2≤k2≤19.2, 0.2≤k3≤19.2, and 0.2≤k4≤19.2 in each formula are satisfied. This improves the local anti-demagnetization capability of the permanent magnet and the anti-demagnetization capability of the rotor, thereby improving the anti-demagnetization capability of the motor and reducing the production cost of the motor while ensuring demagnetization reliability and not increasing the volume of the permanent magnet.

[0038] As a further improvement of the above solution, 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.

[0039] Specifically, the first diffusion zone and the second diffusion zone can be distributed in the entire area or partially along the axial direction of the permanent magnet, which means: the distribution of the first diffusion zone and the second diffusion zone along the length direction of the permanent magnet can be distributed in the entire area or in a partial area, which mainly depends on the requirements of the permanent magnet for anti-demagnetization performance. The partial area distribution is mainly to reduce the diffusion area, thereby reducing costs.

[0040] As a further improvement of the above solution, the diffusion regions on cross sections of the permanent magnet having different widths and thicknesses are the same or different.

[0041] Specifically, by installing multiple permanent magnets on the rotor assembly, the rotor assembly's resistance to demagnetization can be enhanced, further reducing the likelihood of irreversible demagnetization. For a single permanent magnet, the diffusion zones can be the same or different across the width and thickness planes along different lengths of the permanent magnet, as long as the overall resistance to demagnetization is maintained.

[0042] As a further improvement of the above technical solution, the permanent magnet is magnetized radially or parallelly.

[0043] Specifically, the permanent magnets can be magnetized in either a radial or parallel direction. It is essential that the magnetization direction of each permanent magnet on the rotor is consistent, and that the magnetization directions of the first, second, third, and non-diffusion regions within each permanent magnet are consistent. If the non-diffusion region demagnetizes due to an external magnetic field, the first, second, and third diffusion regions, which have stronger demagnetization resistance, can maintain their own magnetism. Thus, the first, second, and third diffusion regions magnetize the non-diffusion region, preventing irreversible demagnetization of the permanent magnet.

[0044] As a further improvement of the above technical solution, the rotor core is formed by stacking multiple silicon steel sheets.

[0045] Specifically, the rotor core is constructed from multiple laminated silicon steel sheets. This lamination process helps reduce eddy current losses. During operation, the rotor core is exposed to a changing magnetic field, and the resulting currents within it lead to energy losses known as eddy current losses. This stacking of silicon steel sheets effectively reduces iron losses and improves rotor reliability.

[0046] As a further improvement of the above technical solution, the rare earth element includes at least one of dysprosium, terbium, praseodymium, neodymium, and cerium.

[0047] Specifically, because these rare earth elements have excellent energy density, coercive force, and remanent magnetism, after being prepared into a slurry and applied to the surface of the permanent magnet substrate, they will penetrate and diffuse into the interior of the permanent magnet substrate to form a diffusion zone. The higher the content of rare earth elements in the slurry, the stronger the permanent magnet's anti-demagnetization ability. At the same time, after the surface of the permanent magnet substrate is coated with the slurry containing rare earth elements, it is necessary to perform a high-temperature treatment (about 800-950°C, 10-18 hours) to further enhance the bonding force between the rare earth elements and the permanent magnet substrate, form a stable grain boundary state, improve the coercive force of the permanent magnet and its temperature stability, thereby improving the permanent magnet's anti-demagnetization ability, and thus improving the motor's anti-demagnetization ability. Rare earth elements (dysprosium, terbium, praseodymium, neodymium, and cerium) are infiltrated and diffused into permanent magnets. During high-temperature treatment, they can form intermetallic compounds with transition metal elements in the permanent magnets. The strong exchange interaction between the transition metal elements gives the compounds a higher Curie temperature. The large magnetic moment of the transition metal atoms ensures that the compounds have a higher saturation magnetization intensity, and the localized 4f electrons of the rare earth elements can provide strong anisotropy. The combined effect of the two types of elements is beneficial to improving the coercive force of the permanent magnet, thereby enhancing the permanent magnet's anti-demagnetization ability, and further improving the motor's anti-demagnetization ability.

[0048] Preferably, the rare earth element includes at least one of dysprosium, terbium and neodymium.

[0049] As a further improvement of the above technical solution, the rare earth elements are uniformly distributed or non-uniformly distributed in the diffusion zone.

[0050] Specifically, the distribution of rare earth elements in the permanent magnet refers to the distribution of rare earth elements in the diffusion region. The rare earth elements in the diffusion region may be evenly distributed or unevenly distributed, which mainly depends on the diffusion process.

[0051] As a further improvement of the above technical solution, the content of the rare earth element in the first diffusion region accounts for a mass percentage g1 of the permanent magnet of 1.0%-2.3%.

[0052] Specifically, the low-cost requirements of the motor are met by controlling the mass percentage of rare earth elements in the first diffusion region. The weight percentage of rare earth elements in the first diffusion region must be greater than 1.0% to ensure that the first diffusion region meets the minimum requirement for the coercive force of the permanent magnet, thereby ensuring that the first diffusion region can enhance the demagnetization resistance of the entire permanent magnet. Furthermore, the weight percentage of rare earth elements in the first diffusion region must be less than 2.3%. This ensures that the first diffusion region has strong demagnetization resistance while reducing the cost of the permanent magnet, thereby meeting the low-cost requirements of the motor.

[0053] As a further improvement of the above technical solution, the content of the rare earth element in the second diffusion region accounts for a mass percentage g2 of the permanent magnet of 1.0%-2.3%.

[0054] Specifically, the weight percentage of rare earth elements in the second diffusion zone is the same as that in the first diffusion zone, and the second diffusion zone can serve as a supplement to the first diffusion zone or as a standalone diffusion zone. Furthermore, the weight percentage of rare earth elements in the second diffusion zone must be greater than 1.0% to ensure that the second diffusion zone meets the minimum coercivity requirement for the permanent magnet, thereby ensuring that the second diffusion zone can enhance the demagnetization resistance of the entire permanent magnet. Furthermore, the weight percentage of rare earth elements in the second diffusion zone must be less than 2.3%, which can reduce the cost of the permanent magnet while ensuring the second diffusion zone has strong demagnetization resistance, thereby meeting the low-cost requirements of the motor.

[0055] As a further improvement of the above technical solution, the permanent magnet further includes a non-diffusion zone, the weight of the rare earth element in the non-diffusion zone accounts for a percentage of the weight of the permanent magnet of g3, and g3 <g1,g3<g2。

[0056] Specifically, the non-diffusion zone refers to the area of ​​the permanent magnet where the rare earth element-containing slurry has not penetrated or diffused, that is, the area where 3D diffusion technology is not used. The mass proportion of rare earth elements in the non-diffusion zone is less than the mass proportion of rare earth elements in the first and second diffusion zones, that is, the coercive force of both diffusion zones is greater than that of the non-diffusion zone. Therefore, the coercive magnetic field strength that the first and second diffusion zones can withstand is greater than the coercive magnetic field strength that the non-diffusion zone can withstand. Therefore, when the non-diffusion zone faces the risk of demagnetization, its own magnetic induction strength can be maintained, thereby preventing irreversible demagnetization in the non-diffusion zone, thereby improving the permanent magnet's anti-demagnetization capability, extending the permanent magnet's service life, and improving its reliability.

[0057] As a further improvement of the above technical solution, the permanent magnet further includes a plurality of third diffusion zones, the third diffusion zones being arranged between the first diffusion zone and the second diffusion zone, and the weight of the rare earth element in each of the third diffusion zones accounts for a percentage of the weight of the permanent magnet of g. i , g i >g3.

[0058] Specifically, in addition to the first and / or second diffusion regions, the permanent magnet may also include several third diffusion regions, which can serve as supplements to the first and second diffusion regions. Furthermore, the mass fraction of rare earth elements in each diffusion region is greater than that of the non-diffusion region, meaning that the coercivity of the third diffusion region is greater than that of the non-diffusion region. By providing third and non-diffusion regions with different mass fractions, each permanent magnet can be formed with third and non-diffusion regions having different demagnetization capabilities. This enhances the permanent magnet's anti-demagnetization properties through the gradient anti-demagnetization region, thereby reducing the risk of irreversible demagnetization.

[0059] Preferably, the permanent magnet includes the first diffusion region, the second diffusion region and the third diffusion region, and the third diffusion region is arranged 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 circular shape.

[0060] Preferably, 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 arranged at four corners of the permanent magnet.

[0061] Preferably, 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.

[0062] Specifically, the first, second, and third diffusion regions can be incorporated into the permanent magnet simultaneously or separately. In a permanent magnet motor, the permanent magnet is susceptible to demagnetization at its ends and in the middle of its width, along the plane of its width and thickness. Furthermore, the permanent magnet is also susceptible to demagnetization at its ends along its length. Therefore, placing diffusion regions in locations prone to demagnetization can improve demagnetization resistance while reducing costs.

[0063] A second aspect of the present invention provides an electric motor.

[0064] Specifically, a motor includes:

[0065] A rotor as described in any technical solution of the first aspect of the present invention.

[0066] The motor provided by the present invention comprises a stator and a rotor according to any of the technical solutions of the first aspect above, wherein: the stator comprises a stator core and a winding; the stator core is provided with a protrusion for fixing the winding; the winding is formed by a coil wrapped around the protrusion; the stator core is disposed around the outer side of the rotor core, forming a gap. Because the motor includes the rotor according to any of the technical solutions above, it has all the beneficial effects achieved by the rotor. To avoid repetition, it is not further described here.

[0067] A third aspect of the present invention provides a compressor.

[0068] Specifically, a compressor includes:

[0069] The rotor as described in any technical solution of the first aspect of the present invention; or

[0070] The motor as described in the second aspect of the present invention.

[0071] The compressor provided by the present invention includes the rotor described in any of the technical solutions of the first aspect or the motor described in any of the technical solutions of the second aspect. Since the compressor includes the rotor or motor of any of the technical solutions described above, it has all the beneficial effects achieved by the rotor or motor. To avoid repetition, they are not further described here.

[0072] A fourth aspect of the present invention provides a refrigerator.

[0073] Specifically, a refrigerator includes:

[0074] The motor according to the second aspect of the present invention; or

[0075] A compressor as described in the third aspect of the present invention.

[0076] The refrigerator provided by the present invention includes the motor described in the second aspect or the compressor described in the third aspect. Since the refrigerator includes the motor or compressor of the above technical solution, it has all the beneficial effects that can be achieved by the motor or compressor. To avoid repetition, they are not described here.

[0077] Compared with the prior art, the above technical solution of the present invention has at least the following technical effects or advantages:

[0078] (1) The present invention is based on the fact that the demagnetization performance of the rotor is related to the thickness of the magnetic isolation bridge and the size of the diffusion zone, and the thickness of the magnetic isolation bridge is related to the L of the diffusion zone. 1max or W 1max The thickness y2 of the reasonable magnetic isolation bridge and the maximum length L of the first diffusion zone along the width direction of the permanent magnet are derived and verified. 1max , the maximum length W of the first diffusion region along the magnet thickness direction 1max By making the relationship between them satisfy the above formula, 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 further improving the anti-demagnetization ability of the motor, thereby reducing the production cost of the motor.

[0079] (2) The rotor provided by the present invention has a permanent magnet whose demagnetization rate at 50A / 130°C can reach 2.57%. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 This is a schematic structural diagram of an inline rotor according to an embodiment of the present invention;

[0081] Figure 2 This is a schematic diagram of the dimensions of a certain type of rotor according to an embodiment of the present invention;

[0082] Figure 3 A schematic structural diagram of a V-shaped rotor according to an embodiment of the present invention;

[0083] Figure 4 This is a schematic diagram of the dimensions of a V-shaped stator according to an embodiment of the present invention;

[0084] Figure 5 This is a schematic diagram of the V-shaped rotor direction of an embodiment of the present invention;

[0085] Figure 6 This is a schematic structural diagram of a permanent magnet diffusion region in a rotor according to an embodiment of the present invention;

[0086] Figure 7 This is a schematic structural diagram of a U-shaped diffusion zone of a permanent magnet according to an embodiment of the present invention;

[0087] Figure 8 This is a schematic structural diagram of a quadrangular diffusion region of a permanent magnet according to an embodiment of the present invention;

[0088] Figure 9 This is a schematic structural diagram of three-strip diffusion regions of a permanent magnet according to an embodiment of the present invention;

[0089] Figure 10 This is a schematic structural diagram of a single diffusion zone of a permanent magnet according to an embodiment of the present invention;

[0090] Figure 11 The figure is a schematic structural diagram of a motor according to an embodiment of the present invention.

[0091] In the accompanying drawings: 100-motor, 110-rotor, 111-rotor core, 112-permanent magnet, 113-magnetic isolation bridge, 1111-magnet slot, 120-stator, 121-stator 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 DESCRIPTION

[0092] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments to facilitate understanding of the present invention by those skilled in the art. It is necessary to point out that the embodiments are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above-mentioned invention contents shall still fall within the scope of protection of the present invention.

[0093] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0094] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, 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.

[0095] Refer to the following Figure 1-11 A rotor, a motor, and a compressor according to some embodiments of the present invention are described.

[0096] Example 1

[0097] like Figure 1 As shown, according to the first aspect of the present invention, an embodiment proposes a rotor 110, including a rotor core 111, a plurality of permanent magnets 112 and a magnetic isolation bridge 113, and a magnet slot 1111 is provided on the rotor core 111; the permanent magnets 112 are arranged in the magnet slot 1111, and each permanent magnet 112 is correspondingly arranged in the corresponding magnet slot 1111, and a plurality of permanent magnets 112 are arranged around the rotor core 111, and the number of permanent magnets 112 is determined by the size of the rotor core 111; the magnetic isolation bridge 113 is arranged between the magnet slots 1111 where adjacent permanent magnets 112 are located, and plays a role of magnetic isolation, which can avoid magnetic leakage in the area between two permanent magnets 112, reduce the internal magnetic circuit disorder of the rotor 110, and is conducive to optimizing the structure of the rotor 110 and improving the reliability of the rotor 110.

[0098] like Figure 5As shown, a diffusion region 1121 is provided on the plane corresponding to the width and thickness of permanent magnet 112. Diffusion region 1121 includes a first diffusion region 11211 and / or a second diffusion region 11212. First diffusion region 11211 is provided on one side of the width centerline of permanent magnet 112, while second diffusion region 11212 is provided on the other side of the width centerline of permanent magnet 112. First diffusion region 11211 and second diffusion region 11212 are formed by coating a layer of slurry containing rare earth elements on the surface of the permanent magnet 112 substrate during the manufacturing process to enhance the demagnetization resistance of permanent magnet 112. To meet different anti-demagnetic performance requirements, a slurry containing a rare earth element can be applied on one side of the width centerline of the permanent magnet 112 to form a first diffusion zone 11211; a slurry containing a rare earth element can be applied on the other side of the width centerline of the permanent magnet 112 to form a second diffusion zone 11212; or a slurry containing a rare earth element can be applied on both sides of the width centerline of the permanent magnet 112 to form the first diffusion zone 11211 and the second diffusion zone 11212. In addition, the content of rare earth elements in the slurry can be controlled to meet different anti-demagnetization performance requirements.

[0099] Furthermore, both the first diffusion zone 11211 and the second diffusion zone 11212 contain rare earth elements. Since rare earth elements have excellent energy density, coercive force and residual magnetism properties, after being prepared into a slurry and coated on the surface of the permanent magnet 112 matrix, they will penetrate and diffuse into the interior of the permanent magnet 112 matrix to form a diffusion zone 1121, thereby improving the anti-demagnetization ability of the permanent magnet 112, and thereby improving the anti-demagnetization ability of the motor.

[0100] like Figure 2 As shown, the demagnetization performance of the rotor 110 is related to the thickness of the magnetic isolation bridge 113 and the size of the diffusion zone 1121, wherein: when the thickness of the magnetic isolation bridge 113 increases, the anti-demagnetization performance of the rotor 110 is improved. Under the premise of achieving the same anti-demagnetization performance, the area of ​​the diffusion zone 1121 needs to be reduced; that is, the thickness of the magnetic isolation bridge 113 and the L of the diffusion zone 1121 are related. 1max 、W 1max 、L 2max or W 2max Therefore, by reasonably setting the thickness y2 of the magnetic isolation bridge 113 and the maximum length L of the first diffusion region 11211 along the width direction of the permanent magnet, 1max , the maximum length W of the first diffusion region 11211 along the magnet thickness direction 1max , the maximum length L of the second diffusion region 11212 along the width direction of the permanent magnet 2max , the maximum length W of the second diffusion region 11212 along the thickness direction of the permanent magnet 112 2maxThe relationship between them can be made to satisfy the following operational relationship of formula (1)-(2) or formula (1)-(4), thereby improving the local anti-demagnetization capability of the permanent magnet 112 and the anti-demagnetization capability of the rotor 110, thereby improving the anti-demagnetization capability of the motor and reducing the production cost of the motor while ensuring the demagnetization reliability and without increasing the volume of the permanent magnet 112.

[0101] Formula (1): 2 c ·y2·L 1max =k1, formula (2): y2·W 1max =k3;

[0102] Formula (3): 2 c ·y2·L 2max =k2, formula (4): y2·W 2ma x=k4;

[0103] In the above formula: 0.2≤k1≤19.2, 0.2≤k2≤19.2, 0.2≤k3≤19.2, 0.2≤k4≤19.2; the variable c is selected from 0 or 1.

[0104] Example 2

[0105] like Figure 1 As shown, in one embodiment of the present invention, based on the above embodiment 1, further, the permanent magnet 112 is a straight line, and the variable c is 0.

[0106] In this embodiment, the shape of permanent magnet 112 is selected primarily to accommodate the performance requirements of different motors, thereby expanding the product's range of applications. When permanent magnet 112 is inline, this is primarily due to the fact that the magnetic density generated by the rotor of inline permanent magnet 112 has higher average and maximum magnetic density values, and that inline permanent magnet 112 exhibits lower torque ripple, resulting in higher performance under high-torque conditions. Furthermore, when permanent magnet 112 is inline, the corresponding variable c in the above formula is 0.

[0107] like Figure 3 As shown, further, the permanent magnet 112 is V-shaped, and the variable c is 1. The shape of the permanent magnet 112 is V-shaped, that is, two adjacent permanent magnets 112 are symmetrically distributed in a V-shape and constitute a group of permanent magnets 112. The magnetic isolation bridge 113 is set between the permanent magnets 112 of adjacent groups, and no magnetic isolation bridge 113 is set between the two permanent magnets 112 in the same group. The V-shaped permanent magnets 112 are more conducive to enhancing the anti-demagnetization ability of the rotor than the straight-line permanent magnets 112. At the same time, when the permanent magnet 112 is V-shaped, the corresponding variable c in the above formula is 1.

[0108] Example 3

[0109] like Figure 2 and 4 As shown, in one embodiment of the present invention, based on the above embodiment 1 or 2, further, the thickness y2 of the magnetic isolation bridge 113 is in the range of 0.2-2 mm.

[0110] In this embodiment, the thickness of the magnetic isolation bridge 113 is controlled to meet the requirement for magnetic isolation of the permanent magnets 112. The thickness of the magnetic isolation bridge 113 needs to be greater than 0.2 mm to ensure that the 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 the permanent magnets 112 and improving the reliability of the rotor 110. At the same time, the thickness of the magnetic isolation bridge 113 is limited to less than 2 mm to reduce the risk of magnetic leakage of the same group of permanent magnets 112 and reduce the manufacturing cost.

[0111] Furthermore, the value ranges of the parameters in the diffusion region 1121 arbitrarily satisfy one or more of the following: 1 mm ≤ L 1max ≤25mm; 1mm≤L 2max ≤25mm; 1mm≤W 1max ≤5mm; 1mm≤W 2max On the basis of limiting the value range of y2, further limiting the maximum length L of each parameter in the diffusion zone 11211 along the width direction of the permanent magnet 112 1max , the maximum length W of the first diffusion region 11211 along the thickness direction of the permanent magnet 112 1max , the maximum length L of the second diffusion region 11212 along the width direction of the permanent magnet 112 2max , the maximum length W of the second diffusion region 11212 along the thickness direction of the permanent magnet 112 2max The range of values ​​is set so that 0.2≤k1≤19.2, 0.2≤k2≤19.2, 0.2≤k3≤19.2, and 0.2≤k4≤19.2 in each formula are satisfied. This improves the local anti-demagnetization capability of the permanent magnet 112 and the anti-demagnetization capability of the rotor 110, thereby improving the anti-demagnetization capability of the motor and reducing the production cost of the motor while ensuring demagnetization reliability and without increasing the volume of the permanent magnet 112.

[0112] Example 4

[0113] like Figure 1 、 3 As shown in Figures 6 and 7 , in one embodiment of the present invention, based on any one of the above embodiments 1 to 3, further, 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 .

[0114] In this embodiment, the first diffusion zone 11211 and the second diffusion zone 11212 can be distributed in the entire area or partially distributed along the axial direction of the permanent magnet 112, which means: the distribution of the first diffusion zone 11211 and the second diffusion zone 11212 along the length direction of the permanent magnet 112 can be distributed in the entire area or in a partial area along the length direction, 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 zone 1121, thereby reducing costs.

[0115] Furthermore, the diffusion regions 1121 of the permanent magnets 112 can be the same or different across the cross-sections of their width and thickness. By arranging multiple permanent magnets 112 on the rotor assembly 110, the rotor assembly 110's anti-demagnetization capability can be enhanced, further reducing the likelihood of irreversible demagnetization of the rotor assembly 110. Furthermore, for a single permanent magnet 112, the diffusion regions 1121 can be the same or different across the width and thickness planes along different lengths of the permanent magnet 112, as long as the overall anti-demagnetization capability of the permanent magnet 112 is maintained.

[0116] The permanent magnets 112 are magnetized radially or parallely. The magnetization direction of the permanent magnets 112 can be radial or parallely. It is sufficient to ensure that the magnetization direction of each permanent magnet 112 on the rotor 110 is consistent, and that the magnetization directions of the first diffusion region 11211, second diffusion region 11212, third diffusion region 11213, and non-diffusion region 11214 in each permanent magnet 112 are consistent. When the non-diffusion region 11214 is demagnetized by an external magnetic field, the first diffusion region 11211, second diffusion region 11212, and third diffusion region 11213, which have stronger demagnetization resistance, can maintain their own magnetism. Thus, the non-diffusion region 11214 is magnetized by the first diffusion region 11211, second diffusion region 11212, and third diffusion region 11213, thereby preventing irreversible demagnetization of the permanent magnets 112.

[0117] Furthermore, the rotor core 111 is formed from a plurality of stacked silicon steel sheets. The use of a stacked process for rotor core 111 helps reduce eddy current losses. During operation, rotor core 111 is exposed to a changing magnetic field, and the induced current within it results in energy loss, known as eddy current loss. The stacked silicon steel sheets effectively reduce iron loss and improve the reliability of rotor 110.

[0118] Example 5

[0119] like Figure 1 and 3As shown, in one embodiment of the present invention, based on any one of the above embodiments 1 to 4, further, the rare earth element includes at least one of dysprosium, terbium, praseodymium, neodymium, and cerium, and the rare earth element is uniformly distributed or non-uniformly distributed in the permanent magnet 112.

[0120] In this embodiment, these rare earth elements have excellent energy density, coercive force, and remanent magnetism. After being prepared into a slurry and applied to the surface of the permanent magnet 112 substrate, they will penetrate and diffuse into the interior of the permanent magnet 112 substrate to form a diffusion zone 1121. The higher the rare earth element content in the slurry, the stronger the demagnetization resistance of the permanent magnet 112. At the same time, after the surface of the permanent magnet 112 substrate is coated with the slurry containing rare earth elements, it is also necessary to perform a high-temperature treatment (approximately 800-950°C, 10-18 hours) to further enhance the bonding force between the rare earth elements and the permanent magnet 112 substrate, form a stable grain boundary state, improve the coercive force of the permanent magnet 112 and its temperature stability, thereby improving the demagnetization resistance of the permanent magnet 112 and, in turn, the demagnetization resistance of the motor. Rare earth elements (dysprosium, terbium, praseodymium, neodymium, and cerium) are infiltrated and diffused into the permanent magnet 112. During high-temperature treatment, 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, which ensures that the compound has a higher saturation magnetization intensity. The localized 4f electrons of the rare earth elements can provide strong 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.

[0121] 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, depending mainly on the diffusion process and the requirements for the demagnetization resistance of the permanent magnet 112. When the demagnetization resistance requirements of the permanent magnet 112 are high, a slurry with a high rare earth element content needs to be coated on the permanent magnet 112. In this case, the slurry has a high concentration and poor permeability and diffusion, which easily leads to uneven distribution of rare earth elements, thereby forming diffusion regions with relatively stronger demagnetization resistance in some regions, thereby improving the overall demagnetization resistance of the motor 100. When the demagnetization resistance requirements of the permanent magnet 112 are low, a slurry with a low rare earth element content can be coated on the permanent magnet 112. In this case, the slurry has a low concentration and good permeability and diffusion, which easily leads to even distribution of rare earth elements, thereby forming a balanced demagnetization resistance region in the diffusion region, which can also effectively improve the overall demagnetization resistance of the motor 100.

[0122] Example 6

[0123] like Figure 1 and 3As shown, in one embodiment of the present invention, based on any one of the above embodiments 1 to 5, further, the percentage g1 of the weight of the rare earth elements in the first diffusion region 11211 to the weight of the permanent magnet 112 is 1.0%-2.3%.

[0124] In this embodiment, the low-cost requirement of the motor is met by controlling the mass percentage range of the rare earth elements in the first diffusion region 11211. The weight percentage of the rare earth elements in the first diffusion region 11211 must be greater than 1.0% to ensure that the first diffusion region 11211 has the minimum coercivity requirement for the permanent magnet 112, thereby ensuring that the first diffusion region 11211 can enhance the demagnetization resistance 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 2.3%. This can reduce the cost of the permanent magnet 112 while ensuring that the first diffusion region 11211 has strong demagnetization resistance, thereby meeting the low-cost requirement of the motor.

[0125] Furthermore, the weight percentage g2 of the rare earth elements in the second diffusion region 11212 relative to the weight of the permanent magnet 112 is between 1.0% and 2.3%. The weight percentage of the rare earth elements in the second diffusion region 11212 is the same as that in the first diffusion region 11211, and the second diffusion region 11212 can serve as a supplement to the first diffusion region 11211 or as an independent diffusion region. Furthermore, the weight percentage of the rare earth elements in the second diffusion region 11212 must be greater than 1.0% to ensure that the second diffusion region 11212 meets the minimum coercivity requirement of the permanent magnet 112, thereby ensuring that the second diffusion region 11212 can enhance the demagnetization resistance of the entire permanent magnet 112. Furthermore, the weight percentage of the rare earth elements in the second diffusion region 11212 must be less than 2.3%. This ensures that the second diffusion region 11212 has strong demagnetization resistance while reducing the cost of the permanent magnet 112, thereby meeting the low-cost requirements of the motor.

[0126] Further, the permanent magnet 112 further includes a non-diffusion region 11214, and the percentage of the weight of rare earth elements in the non-diffusion region 11214 accounting for the weight of the permanent magnet 112 is g3, and g3 < g1, g3 < g2. The non-diffusion region 11214 refers to the region in the permanent magnet 112 where the slurry containing rare earth elements does not penetrate or diffuse. The mass ratio of rare earth elements in the non-diffusion region 11214 is less than that in the first diffusion region 11211 and the second diffusion region, that is, the coercive force of the two diffusion regions 1121 is greater than that of the non-diffusion region 11214. Therefore, the intensity of the coercive magnetic field that the first diffusion region 11211 and the second diffusion region 11212 can resist is greater than that of the non-diffusion region 11214. Thus, when the non-diffusion region 11214 faces the risk of demagnetization, it can maintain its own magnetic induction intensity, and then prevent the non-diffusion region 11214 from undergoing irreversible demagnetization, so as to improve the demagnetization resistance ability of the permanent magnet 112, while extending the service life of the permanent magnet 112 and improving its reliability.

[0127] As Figure 6 shown, further, the permanent magnet 112 further includes a plurality of third diffusion regions 11213, and the percentage of the weight of rare earth elements in each third diffusion region 11213 accounting for the weight of the permanent magnet 112 is g i , g i > g3. 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, which can be used as a supplement to the first diffusion region 11211 and the second diffusion region 11212. At the same time, the mass ratio of rare earth elements in each diffusion region 1121 is greater than that in 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 the third diffusion region 11213 and the non-diffusion region 11214 with different mass ratios, third diffusion regions 11213 and non-diffusion regions 11214 with different demagnetization resistance capabilities can be formed on each permanent magnet 112, so as to strengthen the demagnetization resistance performance of the permanent magnet 112 through the gradient demagnetization resistance regions, and further reduce the occurrence of irreversible demagnetization problems in the permanent magnet 112.

[0128] As Figure 7-10 shown, further, the first diffusion region 11211, the second diffusion region 11212 and the third diffusion region 11213 can be set in the permanent magnet 112 simultaneously, or can be set in the permanent magnet 112 separately. For a permanent magnet motor, on the plane where the width and thickness of the permanent magnet 112 are located, the permanent magnet 112 is prone to demagnetize at both ends of the width and in the middle position of the width; in addition, the permanent magnet 112 is also prone to demagnetize at both ends in the length direction. Therefore, setting diffusion regions at the positions where the permanent magnet 112 is prone to demagnetize can improve the demagnetization resistance while ensuring cost reduction.

[0129] As Figure 7 As shown, 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.

[0130] like Figure 8 As shown, 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 .

[0131] like Figure 9 As shown, 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, forming a three-strip shape.

[0132] like Figure 10 As shown, the permanent magnet 112 only includes the second diffusion region 11212 .

[0133] Example 7

[0134] like Figure 11 According to a second aspect of the present invention, an embodiment provides a motor 100 comprising a stator 120 and a rotor 110 according to any of the technical solutions of the first aspect. The stator 120 comprises a stator core 121 and a winding 122. The stator core 121 is provided with a protrusion 1211 for securing the winding 122. The winding 122 is formed by a coil wrapped around the protrusion 1211. The stator core 121 is disposed around the outside of the rotor core 111, forming a gap. Since the motor 100 includes the rotor 110 according to any of the technical solutions described above, it has all the beneficial effects achievable by the rotor 110.

[0135] Example 8

[0136] like Figure 11 As shown, according to the third aspect of the present invention, 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.

[0137] Example 9

[0138] like Figure 11As shown, according to the fourth aspect of the present invention, an embodiment proposes a refrigerator, including the motor 100 of any technical solution of the second aspect or the 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.

[0139] Furthermore, the refrigerator further comprises a pipeline, the pipeline being connected to the compressor, and the refrigerant circulates through the pipeline and the compression mechanism to achieve heat exchange and refrigeration. Specifically, the refrigerator is an air conditioner.

[0140] The following describes specific applications of some embodiments of the present invention and comparative rotors based on the rotors of the above-mentioned embodiments 1-6.

[0141] Application Example 1

[0142] A rotor 110 includes a rotor core 111, permanent magnets 112, and a magnetic isolation bridge 113. The rotor core 111 is provided with magnet slots 1111, in which permanent magnets 112 are installed. The permanent magnets 112 are V-shaped, i.e., two adjacent permanent magnets 112 are symmetrically distributed in the V shape and form a group of permanent magnets 112. The magnetic isolation bridge 113 is provided between the magnet slots 1111 of adjacent groups of permanent magnets 112. No magnetic isolation bridge 113 is provided between the magnet slots 1111 of two permanent magnets 112 in the same group. A diffusion region 1121 is provided on the plane corresponding to the width and thickness of the permanent magnets 112. The diffusion region 1121 includes a first diffusion region 11211 and a second diffusion region 11212. The first diffusion region 11211 is provided on one side of the width centerline of the permanent magnet 112, and the second diffusion region 11212 is provided on the other side of the width centerline of the permanent magnet 112. The rotor core 111 is made of a plurality of stacked silicon steel sheets, and the permanent magnets 112 are radially magnetized.

[0143] A permanent magnet with dimensions and grades of 1.9×13×40 / 42SH was selected. A slurry containing the rare earth element neodymium was applied to both ends of the magnet along its length and subjected to high-temperature treatment. This formed a first diffusion region 11211 and a second diffusion region 11212, which were evenly distributed along the entire axial direction of the permanent magnet 112, resulting in the permanent magnet 112 of this application example. The rare earth element neodymium accounted for 1.5% by weight in the first diffusion region 11211, and 1.5% by weight in the second diffusion region 11212. The non-diffusion region contained no rare earth element neodymium.

[0144] The thickness y2 of the magnetic isolation bridge 113 is 0.5 mm, and the maximum length L of the first diffusion region 11211 along the width direction of the permanent magnet 112 is 1max The maximum length W of the first diffusion region 11211 along the thickness direction of the permanent magnet 112 is 3 mm. 1maxThe maximum length L of the second diffusion region 11212 along the width direction of the permanent magnet 112 is 1.9 mm. 2max The maximum length W of the second diffusion region 11212 along the thickness direction of the permanent magnet 112 is 3 mm. 2max Substituting 1.9 mm and constant c into the above formulas (1)-(4) yields: k1=k2=3 mm 2 、k3=k4=0.95mm 2 .

[0145] Comparative Example 1

[0146] A rotor 110 includes a rotor core 111, permanent magnets 112, and a magnetic isolation bridge 113. The rotor core 111 is provided with magnet slots 1111, in which permanent magnets 112 are installed. The permanent magnets 112 are V-shaped, i.e., two adjacent permanent magnets 112 are symmetrically distributed in the V shape and form a group of permanent magnets 112. The magnetic isolation bridge 113 is provided between the magnet slots 1111 of adjacent groups of permanent magnets 112. No magnetic isolation bridge 113 is provided between the magnet slots 1111 of two permanent magnets 112 in the same group. A diffusion region 1121 is provided on the plane corresponding to the width and thickness of the permanent magnets 112. The diffusion region 1121 includes a first diffusion region 11211 and a second diffusion region 11212. The first diffusion region 11211 is provided on one side of the width centerline of the permanent magnet 112, and the second diffusion region 11212 is provided on the other side of the width centerline of the permanent magnet 112. The rotor core 111 is made of a plurality of stacked silicon steel sheets, and the permanent magnets 112 are radially magnetized.

[0147] 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 the present invention.

[0148] Performance Testing

[0149] The demagnetization rate of the motor 100 and the intrinsic coercive force of the permanent magnet of Application Example 1 and Comparative Example 1 were tested. The specific testing process of the demagnetization rate is as follows:

[0150] First, place the magnetized rotor 110 at room temperature and measure the magnetic flux of the rotor 110. After the initial magnetic flux is tested, the rotor 110 is placed in a constant temperature box for more than 4 hours, and the temperature of the constant temperature box is set to the specified temperature (130°C). Then, the test DC motor is connected to the DC power supply, and the demagnetization current is set according to the pre-set demagnetization current value (43A, 50A, etc.). When ready, the rotor 110 is taken out of the constant temperature box, and the demagnetization test fixture is installed. The rotor rotates one circle under the DC demagnetization current. 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 after demagnetization are measured.

[0151] Calculate the demagnetization rate, the calculation formula is as follows: (calculation time Need to use Same temperature):

[0152]

[0153] in: is the magnetic flux of the rotor 110 at the beginning of the demagnetization test; 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:

[0154] Table 1: Performance comparison table of application example 1 and comparative example 1

[0155] Demagnetization rate (%) At 130℃ / 50A Intrinsic coercivity Application Example 1 2.57 1920KA / m Comparative Example 1 3.81 2070KA / m

[0156] As shown in Table 1, the permanent magnet with a specific diffusion zone provided by the present invention has an intrinsic coercive force increased by 150 kA / m compared to the permanent magnet without diffusion. At the same time, the demagnetization rate of the motor provided by the present invention at 50 A / 130°C can reach 2.57%, which is a 35.33% decrease in the demagnetization rate compared to ordinary motors, greatly reducing the production cost of the motor.

[0157] In addition, through a large number of experiments, it is found that when the parameters of the motor are the thickness y2 of the magnetic isolation bridge 113, the maximum length L of the first diffusion region 11211 along the width direction of the permanent magnet 1max , the maximum length W of the first diffusion region 11211 along the magnet thickness direction 1max , the maximum length L of the second diffusion region 11212 along the width direction of the permanent magnet 2max , the maximum length W of the second diffusion region 11212 along the thickness direction of the permanent magnet 112 2max If the calculation relationship of the above formulas (1)-(4) is not satisfied, it is not conducive to reducing the cost of the motor. 2 , k2 is less than 0.2mm 2 , k3 is less than 0.2mm 2 , k4 is less than 0.2mm 2, the demagnetization effect of the motor is not good; when k1 is greater than 19.2mm 2 , k2 is greater than 19.2mm 2 , k3 greater than 19.2mm 2 , k4 is greater than 19.2mm 2 The demagnetization effect of the motor is similar to that of embodiment 1, but the cost is much higher than that of embodiment 1. Therefore, the cost performance of the motor is not high, and the cost is increased.

[0158] In the present invention, the term "plurality" refers to two or more, 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 invention. 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 appropriate manner in any one or more embodiments or examples.

[0159] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

[0160] For those skilled in the art to which the present invention belongs, a number of simple deductions or substitutions can be made without departing from the concept of the present invention, without having to resort to creative work. Therefore, based on the disclosure of the present invention, simple improvements made to the present invention by those skilled in the art should be within the scope of protection of the present invention. The above embodiments are preferred embodiments of the present invention, and any structures similar to the present invention and any equivalent changes made should fall within the scope of protection of the present invention.

Claims

1. A rotor, characterized in that: include: A rotor core (111), wherein the rotor core (111) is provided with a magnet slot (1111); a plurality of permanent magnets (112), the permanent magnets (112) being disposed in the magnet slots (1111), and the plurality of permanent magnets (112) being disposed around the rotor core (111); A magnetic isolation bridge (113) is provided between the magnet slots (1111) where adjacent permanent magnets (112) are located; A diffusion region (1121) is provided on a plane where the width and thickness of the permanent magnet (112) are located. The diffusion region (1121) comprises: A first diffusion region (11211) is arranged on one side of the 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 y2 of the magnetic isolation bridge (113), the maximum length L of the first diffusion region (11211) along the width direction of the permanent magnet (112) 1max , the maximum length W of the first diffusion region (11211) along the thickness direction of the permanent magnet (112) 1max and variable c satisfy the following formula (1) and formula (2): Parameters in the above formula are: 0.2≤k1≤19.2, 0.2≤k3≤19.2; variable c is selected from 0 or 1.

2. The rotor according to claim 1, characterized in that The maximum length L of the second diffusion region (11212) along the width direction of the permanent magnet (112) 2max , the maximum length W of the second diffusion region (11212) along the thickness direction of the permanent magnet (112) 2max The following formulas (3) and (4) are satisfied: Parameters in the above formula are: 0.2≤k2≤19.2, 0.2≤k4≤19.

2.

3. The rotor according to claim 1 or 2, characterized in that: The permanent magnet (112) is in the shape of a straight line, and the variable c is 0.

4. The rotor according to claim 1 or 2, characterized in that The permanent magnet (112) is V-shaped, and the variable c is 1.

5. The rotor according to claim 1 or 2, characterized in that: The thickness y2 of the magnetic isolation bridge (113) has a value range of 0.2-2 mm.

6. The rotor according to claim 1, characterized in that The first diffusion region (11211) and the second diffusion region (11212) are distributed over the entire region or partially along the axial direction of the permanent magnet (112).

7. The rotor according to claim 1, characterized in that The diffusion regions (1121) on cross sections of the permanent magnet (112) having different widths and thicknesses are the same or different.

8. The rotor according to claim 1, wherein: The permanent magnet (112) is magnetized radially or parallelly.

9. The rotor according to claim 1, characterized in that The rotor core (111) is formed by stacking a plurality of silicon steel sheets.

10. The rotor according to claim 1, wherein: The rare earth element includes at least one of dysprosium, terbium, praseodymium, neodymium and cerium.

11. The rotor according to claim 1 or 10, characterized in that The rare earth elements are uniformly distributed or non-uniformly distributed in the diffusion zone (1121).

12. The rotor according to claim 1 or 2, characterized in that: The content of the rare earth element in the first diffusion zone (11211) accounts for a mass percentage g1 of 1.0%-2.3% of the permanent magnet (112).

13. The rotor according to claim 12, characterized in that The content of the rare earth element in the second diffusion zone (11212) accounts for a mass percentage g2 of 1.0%-2.3% of the permanent magnet (112).

14. The rotor according to claim 13, characterized in that The permanent magnet (112) further includes a non-diffusion region (11214), wherein the content of the rare earth element in the non-diffusion region (11214) accounts for a mass percentage of g3 of the permanent magnet (112), and g3 <g1,g3<g2。 15. The rotor according to claim 14, characterized in that The permanent magnet (112) further comprises a plurality of third diffusion regions (11213), wherein the third diffusion regions are arranged between the first diffusion region (11211) and the second diffusion region (11212), and the content of the rare earth element in each of the third diffusion regions (11213) accounts for a mass percentage of g of the permanent magnet (112). i , and g i >g3.

16. A motor, characterized in that: include: A rotor as claimed in any one of claims 1 to 15.

17. A compressor, characterized in that: include: A rotor according to any one of claims 1 to 15; or The motor as claimed in claim 16.

18. A refrigerator, characterized in that: include: The motor according to claim 16; or The compressor of claim 17.

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