Motor, compressor and refrigerator capable of improving resistance to demagnetization

Abstract

The present invention belongs to the technical field of drive devices and specifically discloses a motor, compressor, and refrigerator capable of improving demagnetization resistance. The motor comprises: a stator assembly, including a stator core and windings; a rotor assembly, including a rotor core and permanent magnets; a diffusion zone is provided on the plane where the width and thickness of the permanent magnets lie; the diffusion zone includes: a first diffusion zone, provided on one side of the centerline of the permanent magnet's width; and / or a second diffusion zone, provided on the other side of the centerline of the permanent magnet's width; both the first diffusion zone and the second diffusion zone contain rare earth elements. The gap between the stator core and the rotor core is positively correlated with the motor's demagnetization resistance, while the number of equivalent winding turns is negatively correlated with the motor's demagnetization resistance. The present invention derives and verifies the computational relationship between these parameters. The motor designed accordingly improves the 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 motor, a compressor and a refrigerator capable of improving demagnetization resistance. Background Art

[0002] 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 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] At the same time, as rare earth material prices rise, the price of rare earth magnets and motor costs are skyrocketing. While ensuring reliable motor operation, reducing the costs of both magnets and motors is imperative. The fundamental reason for the rise in magnet prices is the rising price of rare earth elements. The rare earth element content affects a magnet's remanence and coercivity, with coercivity directly reflecting its resistance to demagnetization. When magnets of the same size are used in the same motor, magnets with lower coercivity have poorer rotor resistance to demagnetization, resulting in a higher risk of rotor demagnetization and more pronounced demagnetization.

[0004] Therefore, it is urgent to design a motor that can effectively solve the above technical defects, improve the motor's anti-demagnetization ability while ensuring demagnetization reliability and not increasing the volume of permanent magnets, so as 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 motor, compressor, and refrigerator with improved demagnetization resistance. By controlling the specific operational relationships between parameters such as the gap between the stator and rotor cores, the number of equivalent winding turns and parallel branches, and the area of the diffusion zone in the permanent magnet, the present invention improves the local demagnetization resistance of the permanent magnet while ensuring demagnetization reliability and without increasing the size of the permanent magnet. This, in turn, improves the motor's demagnetization resistance, thereby reducing the motor's production cost.

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

[0007] Specifically, a motor includes:

[0008] The stator assembly includes a stator core and a winding, wherein the stator core is provided with a protrusion, and a coil surrounds the protrusion to form the winding;

[0009] A rotor assembly includes a rotor core and a permanent magnet, wherein the rotor core is provided with a mounting slot, the permanent magnet is disposed in the mounting slot, the stator core is disposed around the outside of the rotor core, and a gap is provided between the stator core and the rotor core, and a diffusion region is provided on a plane where the width and thickness of the permanent magnet lie, the diffusion region comprising:

[0010] A first diffusion region is provided on one side of the width centerline of the permanent magnet; and / or

[0011] A second diffusion region is provided on the other side of the width centerline of the permanent magnet;

[0012] Both the first diffusion region and the second diffusion region contain rare earth elements;

[0013] Among them: the number of turns N of the winding, the number of parallel branches a of the winding, the gap δ between the stator core and the rotor core, 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):

[0014]

[0015] In the above formula: 0.2≤k1≤12.5, 0.2≤k3≤6; the variable c is selected from 0 or 1, wherein: when the winding is delta-connected (delta connection), the variable c is 0, and when the winding is star-connected (star connection), c is 1.

[0016] The motor of the present invention includes a stator assembly and a rotor assembly, wherein: the stator assembly includes a stator core and a winding, the stator core is provided with a protrusion, the winding is formed by a coil wrapped around the protrusion, and the number of coil turns N of the winding refers to the number of turns of the coil wrapped around the protrusion; the rotor assembly includes a rotor core and a permanent magnet, the rotor core is provided with a mounting groove, and the permanent magnet is arranged in the mounting groove; the stator core is arranged around the outside of the rotor core, and there is a gap between the stator core and the rotor core.

[0017] Diffusion zones are provided on the planes defining the width and thickness of the permanent magnet. These 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 rare earth element slurry 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, forming a stable grain boundary state, and improving the coercivity and temperature stability of the permanent magnet, thereby enhancing the permanent magnet's demagnetization resistance and, consequently, the motor's demagnetization resistance.

[0018] The study found that the gap between the stator core and the rotor core is positively correlated with the anti-demagnetization performance of the motor, that is, as the gap between the stator core and the rotor core increases, the anti-demagnetization performance of the motor also increases. On the premise of achieving the same anti-demagnetization performance, the area of the diffusion zone needs to be reduced; at the same time, the equivalent winding turns are negatively correlated with the anti-demagnetization performance of the motor, that is, as the equivalent winding turns increase, the anti-demagnetization performance of the motor will decrease. On the premise of achieving the same anti-demagnetization performance, the area of the diffusion zone needs to be increased, and In addition, the area of the diffusion zone is related to the maximum length of each diffusion zone along the thickness direction and the width direction of the permanent magnet. Therefore, by reasonably setting the number of coil turns N of the winding, the number of parallel winding branches a, the gap δ between the stator core and the rotor core, 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 thickness direction of the permanent magnet 1max The relationship between the variable c and the variable c is made to satisfy the operational relationship of the above formulas (1) and (2). Under the premise of ensuring the demagnetization reliability and not increasing the volume of the permanent magnet, the local anti-demagnetization ability of the permanent magnet can be improved, thereby improving the anti-demagnetization ability of the motor and reducing the production cost of the motor.

[0019] Preferably, in formula (1) and formula (2), 0.9≤k1≤1.4, 0.7≤k3≤1.1.

[0020] 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 The following formulas (3) and (4) are satisfied:

[0021]

[0022] In the above formula: 0.2≤k2≤12.5, 0.2≤k4≤6; c=0 when the winding is connected in delta, c=1 when the winding is connected in star.

[0023] 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.

[0024] Preferably, in formula (3) and formula (4), 0.9≤k1≤1.4, 0.7≤k3≤1.1.

[0025] As a further improvement of the above technical solution, the rare earth element includes at least one of dysprosium, terbium, praseodymium, neodymium, and cerium.

[0026] Specifically, these rare earth elements penetrate and diffuse into the permanent magnet. During the high-temperature treatment process, they can form intermetallic compounds with the transition metal elements in the permanent magnet. The strong exchange interaction between the transition metal elements makes the compounds have a higher Curie temperature. The transition metal atoms have a larger magnetic moment, which ensures that the compounds have 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 conducive 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.

[0027] Preferably, the rare earth element includes at least one of dysprosium, terbium and neodymium.

[0028] As a further improvement of the above technical solution, the rare earth elements are uniformly or non-uniformly distributed in the diffusion zone.

[0029] 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.

[0030] 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 0.98%-2.1%.

[0031] 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 0.98% 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 2.1%. 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.

[0032] 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 0.98%-2.1%.

[0033] 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 0.98% to ensure that the second diffusion zone meets the minimum requirement for coercivity of 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 2.1%, 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.

[0034] As a further improvement of the above technical solution, the permanent magnet further includes a non-diffusion zone, the content of rare earth elements in the non-diffusion zone accounts for a mass percentage of g3 of the permanent magnet, and g3 <g1,g3<g2。

[0035] 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.

[0036] 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 content of the rare earth element in each of the third diffusion zones being a percentage of the weight of the permanent magnet being g i , gi >g3.

[0037] 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, and are disposed between the first and second diffusion regions. Furthermore, the mass fraction of rare earth elements in each diffusion region is greater than that in the non-diffusion region, meaning that the coercive force 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] As a further improvement of the above technical solution, the value ranges of the parameters in formula (1) and formula (2) arbitrarily satisfy one or more of the following: 40≤N≤200; 1≤a≤8, 0.35mm≤δ≤1mm; 1mm≤L 1max ≤20mm; 1mm≤W 1max ≤4mm.

[0043] Preferably, the value ranges of the parameters in formula (1) and formula (2) satisfy any one or more of the following: 88≤N≤134; 1≤a≤2; 0.4mm≤δ≤0.6mm; 2.8mm≤L1max ≤4.2mm; 1.5mm≤W 1max ≤2.3mm.

[0044] As a further improvement of the above technical solution, the value ranges of the parameters in formula (3) and formula (4) arbitrarily satisfy one or more of the following: 40≤N≤200; 1≤a≤8, 0.35mm≤δ≤1mm; 1mm≤L 2max ≤20mm; 1mm≤W 2max ≤4mm.

[0045] Preferably, the value ranges of the parameters in formula (3) and formula (4) satisfy any one or more of the following: 88≤N≤134; 1≤a≤2; 0.4mm≤δ≤0.6mm; 2.8mm≤L 2max ≤4.2mm; 1.5mm≤W 2max ≤2.3mm.

[0046] Specifically, by limiting the parameters in the formula (coil turns N, number of winding parallel branches a, gap δ between the stator core and the rotor core, 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 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 and the maximum length W of the second diffusion region along the thickness direction of the permanent magnet 2max ) so as to satisfy the following conditions in the formulas: 0.2≤k1≤12.5, 0.2≤k2≤12.5, 0.2≤k3≤6, 0.2≤k4≤6. This improves the local anti-demagnetization capability of the permanent magnet while ensuring the demagnetization reliability and without increasing the volume of the permanent magnet, thereby improving the anti-demagnetization capability of the motor and reducing the production cost of the motor.

[0047] As a further improvement of the above technical 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.

[0048] 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.

[0049] As a further improvement of the above technical solution, the rotor assembly includes a plurality of permanent magnets, and the diffusion areas on cross sections of the permanent magnets having different widths and thicknesses are the same or different.

[0050] 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.

[0051] As a further improvement of the above technical solution, the permanent magnet is magnetized radially or parallelly.

[0052] 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 assembly 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 non-diffusion region is magnetized by the first, second, and third diffusion regions, thereby preventing irreversible demagnetization of the permanent magnets.

[0053] As a further improvement of the above technical solution, the number of pole pairs P of the permanent magnet is ≥2.

[0054] Specifically, by limiting the number of pole pairs of the permanent magnet to no less than 2, it is beneficial to improve the anti-demagnetization ability of the permanent magnet of the motor, meet the reliability requirements of the compressor, and thus improve the reliability of the compressor operation.

[0055] Preferably, the number of pole pairs of the permanent magnet is P=2-4.

[0056] As a further improvement of the above technical solution, the rotor core is formed by stacking multiple silicon steel sheets.

[0057] 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 the reliability of the rotor assembly.

[0058] A second aspect of the present invention provides a compressor.

[0059] Specifically, a compressor includes:

[0060] housing, and

[0061] As described in any technical solution of the first aspect of the present invention, the motor is arranged inside the housing.

[0062] The compressor provided by the present invention comprises a housing and the motor described in any one of the technical solutions of the first aspect, wherein the motor is disposed within the housing. Since the compressor includes the motor described in any one of the technical solutions, it has all the beneficial effects achievable by the motor. To avoid repetition, these are not further described here.

[0063] A third aspect of the present invention provides a refrigerator.

[0064] Specifically, a refrigerator includes:

[0065] The motor as described in any technical solution of the first aspect of the present invention; or

[0066] A compressor as described in the second aspect of the present invention.

[0067] The refrigerator provided by the present invention includes the motor described in any of the technical solutions of the first aspect or the compressor described in the second aspect. Since the refrigerator includes the motor or compressor of any of the technical solutions described above, it has all the beneficial effects achievable by the motor or compressor. To avoid repetition, these are not described here.

[0068] Compared with the prior art, the above technical solution of the present invention has at least the following technical effects or advantages:

[0069] (1) The present invention is based on the fact that the gap between the stator core and the rotor core is positively correlated with the anti-demagnetization performance of the motor, and the equivalent winding turns are negatively correlated with the anti-demagnetization performance of the motor. It is deduced and verified that by reasonably setting the number of coil turns N of the winding, the number of parallel winding branches a, the gap δ between the stator core and the rotor core, and 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 thickness direction of the permanent magnet 1max The relationship between the variable c and the variable c is made to satisfy the above formulas (1) and (2). This can improve the local anti-demagnetization ability of the permanent magnet while ensuring the demagnetization reliability and without increasing the volume of the permanent magnet, thereby improving the anti-demagnetization ability of the motor and reducing the production cost of the motor.

[0070] (2) The motor provided by the present invention has a demagnetization rate of the permanent magnet of up to 2.68% at 50A / 130°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 A schematic structural diagram of a motor according to an embodiment of the present invention;

[0072] Figure 2 A schematic diagram of the dimensions of a motor according to an embodiment of the present invention;

[0073] Figure 3This is a schematic structural diagram of a segmented stator core according to an embodiment of the present invention;

[0074] Figure 4 This is a schematic structural diagram of an integral stator core according to an embodiment of the present invention;

[0075] Figure 5 A schematic diagram of the number of parallel branches of a winding according to an embodiment of the present invention;

[0076] Figure 6 A schematic diagram of the number of parallel branches of a winding according to another embodiment of the present invention;

[0077] Figure 7 A schematic diagram of the structure and orientation of a V-shaped distribution of permanent magnets according to an embodiment of the present invention;

[0078] Figure 8 This is a schematic structural diagram of a W-shaped distribution of permanent magnets according to an embodiment of the present invention;

[0079] Figure 9 This is a schematic structural diagram of a combined distribution of permanent magnets according to an embodiment of the present invention;

[0080] Figure 10 This is a schematic structural diagram of a permanent magnet diffusion zone in a rotor assembly according to an embodiment of the present invention;

[0081] Figure 11 This is a schematic structural diagram of a U-shaped diffusion zone of a permanent magnet according to an embodiment of the present invention;

[0082] Figure 12 This is a schematic structural diagram of a quadrangular diffusion region of a permanent magnet according to an embodiment of the present invention;

[0083] Figure 13 This is a schematic structural diagram of three-strip diffusion regions of a permanent magnet according to an embodiment of the present invention;

[0084] Figure 14 This is a schematic structural diagram of a single diffusion zone of a permanent magnet according to an embodiment of the present invention.

[0085] In the accompanying drawings: 100-motor, 110-stator assembly, 111-stator core, 112-winding, 1111-protrusion, 120-rotor assembly, 121-rotor core, 122-permanent magnet, 1211-mounting slot, 1221-first diffusion region, 1222-second diffusion region, 1223-third diffusion region, 1224-non-diffusion region. DETAILED DESCRIPTION

[0086] 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.

[0087] 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.

[0088] 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.

[0089] Refer to the following Figure 1-14 A motor, a compressor, and a refrigerator according to some embodiments of the present invention are described.

[0090] Example 1

[0091] like Figure 1 As shown, according to the first aspect of the present invention, an embodiment proposes a motor 100, including a stator assembly 110 and a rotor assembly 120, wherein: the stator assembly 110 includes a stator core 111 and a winding 112, the stator core 111 is provided with a protrusion 1111, and the winding 112 is formed by a coil wrapped around the protrusion 1111, and the number of coil turns N of the winding 112 refers to the number of turns of the coil wrapped around the protrusion 1111; the rotor assembly 120 includes a rotor core 121 and a permanent magnet 122, the rotor core 121 is provided with a mounting groove 1211, and the permanent magnet 122 is arranged in the mounting groove 1211; the stator core 111 is arranged around the outside of the rotor core 121, and there is a gap between the stator core 111 and the rotor core 121.

[0092] Diffusion zones are provided on the planes defining the width and thickness of permanent magnet 122. These zones include a first diffusion zone 1221 and / or a second diffusion zone 1222. First diffusion zone 1221 is located on one side of the centerline of the width of permanent magnet 122, while second diffusion zone 1222 is located on the other side of the centerline. First diffusion zone 1221 and second diffusion zone 1222 are formed by coating the surface of permanent magnet 122 with a slurry containing rare earth elements during the manufacturing process to enhance the demagnetization resistance of permanent magnet 122. To meet different anti-demagnetic performance requirements, a slurry containing a rare earth element can be coated on one side of the width centerline of the permanent magnet 122 to form a first diffusion zone 1221; a slurry containing a rare earth element can be coated on the other side of the width centerline of the permanent magnet to form a second diffusion zone 1222; or a slurry containing a high anti-demagnetization performance can be coated on both sides of the width centerline of the permanent magnet 122 to form the first diffusion zone 1221 and the second diffusion zone 1222. In addition, the rare earth element content in the slurry can be controlled to meet different anti-demagnetization performance requirements.

[0093] Furthermore, both the first diffusion zone 1221 and the second diffusion zone 1222 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 substrate, they will penetrate and diffuse into the interior of the permanent magnet 122 substrate to form a diffusion zone, thereby improving the anti-demagnetization ability of the permanent magnet 122, and thereby improving the anti-demagnetization ability of the motor 100.

[0094] like Figure 2 As shown, the gap between the stator core 111 and the rotor core 121 is positively correlated with the anti-demagnetization performance of the motor 100, that is, as the gap between the stator core 111 and the rotor core 121 increases, the anti-demagnetization performance of the motor 100 also increases. On the premise of achieving the same anti-demagnetization performance, the area of the diffusion zone needs to be reduced; at the same time, the equivalent winding turns are negatively correlated with the anti-demagnetization performance of the motor 100, that is, as the equivalent winding turns increase, the anti-demagnetization performance of the motor 100 will decrease. On the premise of achieving the same anti-demagnetization performance, the area of the diffusion zone needs to be increased, and In addition, the area of the diffusion zone is related to the maximum length of each diffusion zone along the thickness direction and the width direction of the permanent magnet 122. Therefore, by reasonably setting the number of coil turns N of the winding, the number of parallel branches a of the winding 112, the gap δ between the stator core 111 and the rotor core 121, the maximum length L of the first diffusion zone 1121 along the width direction of the permanent magnet 122, 1max , the maximum length W of the first diffusion region 1121 along the thickness direction of the permanent magnet 122 1max , the maximum length L of the second diffusion region 1122 along the width direction of the permanent magnet 122 2max, the maximum length W of the second diffusion region 1122 along the thickness direction of the permanent magnet 122 2max and the variable c, and making them satisfy the operational relationship of the following formulas (1)-(2) or (1)-(4), it is possible to improve the local anti-demagnetization ability of the permanent magnet 122 while ensuring the demagnetization reliability and without increasing the volume of the permanent magnet 122, thereby improving the anti-demagnetization ability of the motor 100 and reducing the production cost of the motor 100.

[0095]

[0096]

[0097] In the above formula: 0.2≤k1≤12.5, 0.2≤k2≤12.5, 0.2≤k3≤6, 0.2≤k4≤6; the variable c is selected from 0 or 1, wherein: when the winding 112 is delta-connected (delta connection), the variable c is 0; when the winding 112 is star-connected (star connection), c is 1.

[0098] like Figure 3 As shown, further, the stator core 111 is a block-type structure, which is convenient for replacement and maintenance, and is more flexible and convenient during use.

[0099] like Figure 4 As shown, further, the stator core 111 is an integral structure, which is convenient for overall installation and disassembly, and is beneficial to improving the reliability of the operation of the motor 100.

[0100] like Figure 5 As shown, further, when the three-phase star-connected winding 112 is used, c is 1, and the number a of parallel branches of the winding 112 is 3.

[0101] like Figure 6 As shown, further, when the three-phase delta-connected winding 112 is connected, c is 0, and the number a of parallel branches of the winding 112 is 1.

[0102] like Figure 7-9 As shown, further, the shape of the mounting groove 1211 is V-shaped, W-shaped, or a combination of V-shaped and straight-shaped. The different structures of the mounting groove 1211 can meet the requirements of different distribution structures of the permanent magnet 122, thereby expanding the range of use of the product. Therefore, different shapes of mounting grooves 1211 can be provided according to different needs, and the shapes of the mounting grooves 1211 can be the same or different.

[0103] like Figure 7 As shown, the mounting groove 1211 is V-shaped, and the V-shaped distribution of the permanent magnets 122 is beneficial for further enhancing the anti-demagnetization capability of the motor 100 .

[0104] like Figure 8As shown, the shape of the mounting groove 1211 is W-shaped, and the W-shaped mounting groove 1221 is composed of two groups of V-shaped mounting grooves 1221. The W-shaped distribution of permanent magnets 122 has a stronger anti-demagnetization ability for the motor 100 than a single group of V-shaped permanent magnets.

[0105] like Figure 9 As shown, the mounting groove 1211 is composed of a V-shaped and a straight-shaped configuration, which can integrate the structural features of the V-shaped and straight-shaped permanent magnet 122 distributions.

[0106] Example 2

[0107] like Figure 1 As shown, in one embodiment of the present invention, based on the above-mentioned embodiment 1, the rare earth elements further include at least one of dysprosium, terbium, praseodymium, neodymium, and cerium, and the rare earth elements are uniformly or non-uniformly distributed in the permanent magnet 122. These rare earth elements penetrate and diffuse into the permanent magnet 122. During the high-temperature treatment process, they can form intermetallic compounds with the transition metal elements in the permanent magnet 122. The strong exchange interaction between the transition metal elements makes the compound have a higher Curie temperature. The large magnetic moment of the transition metal atoms ensures that the compound has a high saturation magnetization. The localized 4f electrons of the rare earth elements can provide strong anisotropy. The combined effect of the two types of elements is conducive to improving the coercive force of the permanent magnet 122, thereby enhancing the anti-demagnetization ability of the permanent magnet 122, and further improving the anti-demagnetization ability of the motor 100.

[0108] The distribution of rare earth elements in the permanent magnet 122 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 122. When the demagnetization resistance requirements of the permanent magnet 122 are high, a slurry with a high rare earth element content needs to be coated on the permanent magnet 122. 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 122 are low, a slurry with a low rare earth element content can be coated on the permanent magnet 122. 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.

[0109] Example 3

[0110] like Figure 1 As shown, in one embodiment of the present invention, based on the above embodiment 1 or 2, further, the content of rare earth elements in the first diffusion region 1221 accounts for a mass percentage g1 of the permanent magnet 122 of 0.98%-2.1%.

[0111] In this embodiment, by controlling the mass percentage range of the rare earth elements in the first diffusion region 1221, the low-cost requirement of the motor 100 is met. The weight percentage of the rare earth elements in the first diffusion region 1221 needs to be greater than 0.98% to ensure that the first diffusion region 1221 has the minimum requirement to meet the coercive force of the permanent magnet 122, thereby ensuring that the first diffusion region 1221 can improve the demagnetization resistance of the entire permanent magnet 122. At the same time, it is specified that the weight percentage of the rare earth elements in the first diffusion region 1221 needs to be less than 2.1%. On the basis of ensuring that the first diffusion region 1221 has strong demagnetization resistance, the cost of the permanent magnet 122 can be reduced, thus meeting the low-cost requirement of the motor 100.

[0112] Furthermore, the content of the rare earth elements in the second diffusion region 1222 accounts for the mass percentage g2 of the permanent magnet 122, which is 0.98% - 2.1%. The mass percentage of the rare earth elements in the second diffusion region 1222 is the same as that in the first diffusion region 1221, and it can be used as a supplement to the first diffusion region 1221 or independently as a diffusion region. At the same time, the weight percentage of the rare earth elements in the second diffusion region 1222 needs to be greater than 0.98% to ensure that the second diffusion region 1222 has the minimum requirement to meet the coercive force of the permanent magnet 122, thereby ensuring that the second diffusion region 1222 can improve the demagnetization resistance of the entire permanent magnet 122. At the same time, it is specified that the weight percentage of the rare earth elements in the second diffusion region 1222 needs to be less than 2.1%. On the basis of ensuring that the second diffusion region 1222 has strong demagnetization resistance, the cost of the permanent magnet 122 can be reduced, thus meeting the low-cost requirement of the motor 100.

[0113] Furthermore, the permanent magnet 122 further includes a non-diffusion region 1224, and the content of the rare earth elements in the non-diffusion region 1224 accounts for the mass percentage g3 of the permanent magnet 122, and g3 < g1, g3 < g2. The non-diffusion region 1224 refers to the region in the permanent magnet 122 where the slurry containing rare earth elements does not penetrate or diffuse. The mass percentage of the rare earth elements in the non-diffusion region 1224 is less than that in the first diffusion region 1221 and the second diffusion region, that is, the coercive force of the two diffusion regions is greater than that of the non-diffusion region 1224. Therefore, the intensity of the coercive magnetic field that the first diffusion region 1221 and the second diffusion region 1222 can resist is greater than that of the non-diffusion region 1224. When the non-diffusion region 1224 faces the risk of demagnetization, it can maintain its magnetic induction intensity, thereby preventing the non-diffusion region 1224 from undergoing irreversible demagnetization, so as to improve the demagnetization resistance of the permanent magnet 122, extend the service life of the permanent magnet 122, and improve its reliability at the same time.

[0114] Such as Figure 10As shown, the permanent magnet 122 further includes a plurality of third diffusion regions 1223, and the weight of the rare earth element in each third diffusion region 1223 accounts for a percentage of the weight of the permanent magnet 122 of g. i , g i >g3. In addition to the first diffusion region 1221 and / or the second diffusion region 1222, the permanent magnet 122 may also include a plurality of third diffusion regions 1223, which can serve as a supplement to the first diffusion region 1221 and the second diffusion region 1222. Furthermore, the mass percentage of the rare earth element in each diffusion region is greater than that of the non-diffusion region 1224, i.e., the coercive force of the third diffusion region 1223 is greater than that of the non-diffusion region 1224. By providing third diffusion regions 1223 and non-diffusion regions 1224 with different mass percentages, third diffusion regions 1223 and non-diffusion regions 1224 with different demagnetization capabilities can be formed on each permanent magnet 122. This enhances the anti-demagnetization performance of the permanent magnet 122 through the gradient anti-demagnetization region, thereby reducing the occurrence of irreversible demagnetization in the permanent magnet 122.

[0115] like Figure 11-14 As shown, the first diffusion region 1221, the second diffusion region 1222, and the third diffusion region 1223 can be simultaneously disposed within the permanent magnet 122, or individually disposed within the permanent magnet 122. For a permanent magnet motor, in the plane of the width and thickness of the permanent magnet 122, the permanent magnet 122 is susceptible to demagnetization at both ends of the width and in the middle of the width. Furthermore, the permanent magnet 122 is also susceptible to demagnetization at both ends of the length. Therefore, disposing diffusion regions at locations where the permanent magnet 122 is susceptible to demagnetization can both improve demagnetization resistance and reduce costs.

[0116] like Figure 11 As shown, the permanent magnet 122 includes a first diffusion region 1221 , a second diffusion region 1222 and a third diffusion region 1223 , and the third diffusion region 1223 is disposed between the first diffusion region 1221 and the second diffusion region 1222 . The first diffusion region 1221 , the second diffusion region 1222 and the third diffusion region 1223 form a U-shape.

[0117] like Figure 12 As shown, the permanent magnet 122 includes a first diffusion region 1221 and a second diffusion region 1222 , and the first diffusion region 1221 and the second diffusion region 1222 are respectively disposed at four corners of the permanent magnet 122 .

[0118] like Figure 13 As shown, the permanent magnet 122 includes a first diffusion region 1221 , a second diffusion region 1222 and a third diffusion region 1223 , and the first diffusion region 1221 , the second diffusion region 1222 and the third diffusion region 1223 are respectively arranged in parallel on both sides and the middle of the permanent magnet 122 , forming three stripes.

[0119] like Figure 14 As shown, the permanent magnet 122 only includes the second diffusion region 1222 .

[0120] Example 4

[0121] like Figure 1 As shown, in one embodiment of the present invention, based on any one of the above embodiments 1 to 3, further, the value ranges of the parameters in each calculation formula arbitrarily meet one or more of the following: 40≤N≤200; 1≤a≤8; 0.35mm≤δ≤1mm; 1mm≤L 1max ≤20mm; 1mm≤L 2max ≤20mm; 1mm≤W 1max ≤4mm; 1mm≤W 2max ≤4mm.

[0122] In this embodiment, by defining the parameters in the formula, the number of coil turns N, the number of parallel winding branches a, the gap δ between the stator core 111 and the rotor core 121, the maximum length L of the first diffusion region 1221 along the width direction of the permanent magnet 122, 1max , the maximum length W of the first diffusion region 1221 along the thickness direction of the permanent magnet 122 1max , the maximum length L of the second diffusion region 1222 along the width direction of the permanent magnet 122 2max and the maximum length W of the second diffusion region 1222 along the thickness direction of the permanent magnet 122 2max The range of values is set so that it satisfies 0.2≤k1≤12.5, 0.2≤k2≤12.5, 0.2≤k3≤6, and 0.2≤k4≤6 in each formula, thereby improving the local anti-demagnetization ability of the permanent magnet 122 while ensuring demagnetization reliability and not increasing the volume of the permanent magnet 122, thereby improving the anti-demagnetization ability of the motor 100 and reducing the production cost of the motor 100.

[0123] Example 5

[0124] like Figure 1 As shown, in one embodiment of the present invention, based on any one of the above embodiments 1 to 4, further, the first diffusion region 1221 and the second diffusion region 1222 are distributed in the entire area or partially along the axial direction of the permanent magnet 122 .

[0125] In this embodiment, the first diffusion zone 1221 and the second diffusion zone 1222 can be distributed in the entire area or partially distributed along the axial direction of the permanent magnet 122, which means: the distribution of the first diffusion zone 1221 and the second diffusion zone 1222 along the length direction of the permanent magnet 122 can be distributed in the entire area or in a partial area, which mainly depends on the requirements of the permanent magnet 122 for anti-demagnetization performance. The partial area distribution is mainly to reduce the diffusion area, thereby reducing costs.

[0126] Furthermore, the rotor assembly 120 includes multiple permanent magnets 122, each having the same or different diffusion areas along the width and thickness cross-sections. By arranging multiple permanent magnets 122 on the rotor assembly 120, the rotor assembly 120's resistance to demagnetization can be enhanced, further reducing the likelihood of irreversible demagnetization. Furthermore, for a single permanent magnet 122, the diffusion areas along the width and thickness planes along different lengths of the permanent magnet 122 can be the same or different, as long as the overall resistance to demagnetization of the permanent magnet 122 is maintained.

[0127] Furthermore, the permanent magnets 122 are magnetized radially or in parallel. The magnetization direction of the permanent magnets 122 can be radial or parallel, as long as the magnetization direction of each permanent magnet 122 on the rotor assembly 120 is consistent, and the magnetization directions of the first diffusion region 1221, the second diffusion region 1222, the third diffusion region 1223, and the non-diffusion region 1224 in each permanent magnet 122 are consistent. When the non-diffusion region 1224 is demagnetized by an external magnetic field, the first diffusion region 1221, the second diffusion region 1222, and the third diffusion region 1223, which have stronger demagnetization resistance, can maintain their own magnetism. Thus, the non-diffusion region 1224 is magnetized by the first diffusion region 1221, the second diffusion region 1222, and the third diffusion region 1223, thereby preventing irreversible demagnetization of the permanent magnets 122.

[0128] Furthermore, the number of pole pairs P of the permanent magnet 122 is ≥ 2. By limiting the number of pole pairs of the permanent magnet 122 to not less than 2, the anti-demagnetization capability of the permanent magnet 122 of the motor 100 is improved, and the reliability required for the use of the compressor is met, thereby improving the reliability of the compressor operation.

[0129] Furthermore, the rotor core 121 is formed from a plurality of stacked silicon steel sheets. The use of a stacked process for processing the rotor core 121 helps reduce eddy current losses. During operation, the rotor core 121 is exposed to a changing magnetic field, and the induced current within it results in energy loss, known as eddy current loss. The rotor core 121 is formed from stacked silicon steel sheets, effectively reducing iron loss and improving the reliability of the rotor assembly 120.

[0130] Example 6

[0131] like Figure 1 As shown, according to the second aspect of the present invention, an embodiment proposes a compressor, comprising a shell and a motor 100 according to any technical solution of the first aspect mentioned above, wherein the motor 100 is arranged inside the shell. Since the compressor includes the motor 100 according to any technical solution mentioned above, it has all the beneficial effects that can be achieved by the motor 100.

[0132] Example 7

[0133] like Figure 1 As shown, according to the third aspect of the present invention, an embodiment proposes a refrigerator, including the motor 100 of any technical solution of the first aspect or the compressor of any technical solution of the second 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.

[0134] 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.

[0135] The following describes specific applications of some embodiments of the present invention and comparative motors based on the motors of embodiments 1-5 above.

[0136] Application Example 1

[0137] A motor 100 includes a stator assembly 110 and a rotor assembly 120, wherein: the stator assembly 110 includes a stator core 111 and a winding 112, the stator core 110 is provided with a protrusion 1111 for fixing the winding 112, the winding 112 is formed by a coil wrapped around the protrusion 1111, and the number of turns N of the winding 112 refers to the number of turns of the coil wrapped around the protrusion 1111; the rotor assembly 120 includes a rotor core 121 and a permanent magnet 122, the rotor core 121 is provided with a mounting groove 1211, the rotor core 121 is formed by a plurality of stacked silicon steel sheets, the permanent magnet 122 is disposed in the mounting groove 1211, the permanent magnet 122 is radially magnetized and has a pole pair number P of 2; the stator core 111 is arranged around the outside of the rotor core 121 to form a gap.

[0138] A permanent magnet with dimensions and a grade of 1.9×13×40 / 42SH was selected. A slurry containing the rare earth element neodymium was coated on both ends along its length and subjected to high-temperature treatment to form a first diffusion region 1221 and a second diffusion region 1222. The first diffusion region 1221 and the second diffusion region 1222 were evenly distributed throughout the axial direction of the permanent magnet 122, resulting in the permanent magnet 122 of this application example. The rare earth element neodymium in the first diffusion region 1221 accounted for 1.5% by weight, the rare earth element neodymium in the second diffusion region 1221 accounted for 1.5% by weight, and the non-diffusion region contained no rare earth element neodymium.

[0139] The number of turns of the winding 112 is N=112, the number of parallel branches of the winding 112 is a=1, the gap between the stator core 111 and the rotor core 121 is δ=0.5mm, and the maximum length L of the first diffusion region 1221 along the width direction of the permanent magnet 122 is 1max=3.5mm, the maximum length W of the first diffusion region 1221 along the thickness direction of the permanent magnet 122 1max =1.9mm, the maximum length L of the second diffusion region 1222 along the width direction of the permanent magnet 122 2max =3.5mm, the maximum length W of the second diffusion region 1222 along the thickness direction of the permanent magnet 122 2max Substituting 1.9 mm and c = 0 into formulas (1)-(4) yields: k1 = k2 = 1.18 mm, k3 = k4 = 0.87 mm.

[0140] Comparative Example 1

[0141] A motor 100 includes a stator assembly 110 and a rotor assembly 120, wherein: the stator assembly 110 includes a stator core 111 and a winding 112, the stator core 110 is provided with a protrusion 1111 for fixing the winding 112, the winding 112 is formed by a coil wrapped around the protrusion 1111, and the number of turns N of the winding 112 refers to the number of turns of the coil wrapped around the protrusion 1111; the rotor assembly 120 includes a rotor core 121 and a permanent magnet 122, the rotor core 121 is provided with a mounting groove 1211, the rotor core 121 is formed by a plurality of stacked silicon steel sheets, the permanent magnet 122 is disposed in the mounting groove 1211, the permanent magnet 122 is radially magnetized and has a pole pair number P of 2; the stator core 111 is arranged around the outside of the rotor core 121 to form a gap.

[0142] The difference between the permanent magnets of 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, but the permanent magnet is not coated with any slurry containing rare earth elements, that is, it does not contain a diffusion zone, and the motor parameters do not satisfy the operational relationship of formulas (1)-(4) of the present invention.

[0143] Performance Testing

[0144] 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:

[0145] First, the rotor assembly 120 that is magnetized and saturated is placed at room temperature, and the magnetic flux of the rotor assembly 120 is measured. Then, after testing the initial magnetic flux, the rotor assembly 120 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 assembly 120 is taken out of the constant temperature box, and the demagnetization test fixture is installed. Under the DC demagnetization current, the rotor assembly rotates one circle; after completion, the rotor assembly 120 is placed at room temperature for more than 4 hours, and then the temperature of the rotor assembly 120 and the magnetic flux after demagnetization are measured.

[0146] Calculate the demagnetization rate, the calculation formula is as follows: (calculation time Need to use Same temperature):

[0147]

[0148] in: is the magnetic flux of the rotor assembly 120 at the beginning of the demagnetization test; is the magnetic flux of the rotor assembly 120 after the demagnetization test at the i-th demagnetization current value. The test results are shown in Table 1:

[0149] Table 1: Performance comparison table of application example 1 and comparative example 1

[0150] performance Demagnetization rate at 130℃ / 50A (%) Intrinsic coercivity Application Example 1 2.68 1920KA / m Comparative Example 1 3.81 2070KA / m

[0151] As can be seen from 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 can reach 2.68% at 50A / 130°C, which is 29.66% lower than that of ordinary motors, greatly reducing the production cost of the motor.

[0152] In addition, through a large number of experiments, it is found that when the parameters of the motor are the number of coil turns N, the number of parallel branches of the winding 112 a, the gap δ between the stator core 111 and the rotor core 121, and the maximum length L of the first diffusion region 1121 along the width direction of the permanent magnet 122, 1max , the maximum length W of the first diffusion region 1121 along the thickness direction of the permanent magnet 122 1max , the maximum length L of the second diffusion region 1122 along the width direction of the permanent magnet 122 2max , the maximum length W of the second diffusion region 1122 along the thickness direction of the permanent magnet 122 2max When the relationship between k1 and variable c does not satisfy the operational relationship of the above formulas (1)-(4), it is not conducive to reducing the cost of the motor. Specifically, when k1 is less than 0.2mm, k2 is less than 0.2mm, k3 is less than 0.2mm, and k4 is less than 0.2mm, the demagnetization effect of the motor is not good. When k1 is greater than 12.5mm, k2 is greater than 12.5mm, k3 is greater than 6mm, and k4 is greater than 6mm, the demagnetization effect of the motor is similar to that of Example 1, but the cost is much higher than that of Example 1. Therefore, the cost-effectiveness of the motor is not high, and the cost is increased.

[0153] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0154] 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.

[0155] 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 motor, characterized in that: include: A stator assembly (110) comprises a stator core (111) and a winding (112), wherein the stator core (111) is provided with a protrusion (1111), and a coil surrounds the protrusion (1111) to form the winding (112); A rotor assembly (120) comprises a rotor core (121) and a permanent magnet (122), wherein the rotor core (121) is provided with a mounting groove (1211), the permanent magnet (122) is arranged in the mounting groove (1211), the stator core (111) is arranged around the outside of the rotor core (121), and a gap is provided between the stator core (111) and the rotor core (121), and a diffusion region is provided on a plane where the width and thickness of the permanent magnet (122) are located, and the diffusion region comprises: A first diffusion region (1221) is provided on one side of a width center line of the permanent magnet (122); and / or A second diffusion region (1222) is arranged on the other side of the width center line of the permanent magnet (122); The first diffusion region (1221) and the second diffusion region (1222) both contain rare earth elements; Wherein: the number of coil turns N of the winding (112), the number a of parallel branches of the winding (112), the gap δ between the stator core (111) and the rotor core (121), the maximum length L of the first diffusion region (1221) along the width direction of the permanent magnet (122), 1max , the maximum length W of the first diffusion region (1221) along the thickness direction of the permanent magnet (122) 1max and variable c satisfy the following formulas (1) and (2): In the above formula: 0.2≤k1≤12.5, 0.2≤k3≤6; c=0 when the winding is connected in delta, c=1 when the winding is connected in star.

2. The motor according to claim 1, characterized in that The maximum length L of the second diffusion region (1222) along the width direction of the permanent magnet (122) 2max , the maximum length W of the second diffusion region (1222) along the thickness direction of the permanent magnet (122) 2max The following formulas (3) and (4) are satisfied: In the above formula: 0.2≤k2≤12.5, 0.2≤k4≤6; c=0 when the winding is connected in delta, c=1 when the winding is connected in star.

3. The motor according to claim 1 or 2, characterized in that The rare earth element includes at least one of dysprosium, terbium, praseodymium, neodymium and cerium.

4. The motor according to claim 1 or 2, characterized in that The rare earth element is uniformly or non-uniformly distributed in the diffusion zone.

5. The motor according to claim 1 or 2, characterized in that The content of the rare earth element in the first diffusion region (1221) accounts for a mass percentage g1 of 0.98%-2.1% of the permanent magnet (122).

6. The motor according to claim 5, characterized in that The content of the rare earth element in the second diffusion region (1222) accounts for a mass percentage g2 of 0.98%-2.1% of the permanent magnet (122).

7. The motor according to claim 6, characterized in that The permanent magnet (122) further includes a non-diffusion region (1224), wherein the content of the rare earth element in the non-diffusion region (1224) accounts for a mass percentage of g3 of the permanent magnet (122), and g3 <g1,g3<g2。 8. The motor according to claim 7, characterized in that The permanent magnet (122) further comprises a plurality of third diffusion regions (1223), wherein the third diffusion regions are arranged between the first diffusion region (1221) and the second diffusion region (1222), and the content of the rare earth element in each of the third diffusion regions (1223) accounts for a mass percentage of g of the permanent magnet (122). i , g i >g3.

9. The motor according to claim 1, characterized in that The first diffusion region (1221) and the second diffusion region (1222) are distributed in the entire region or partially along the axial direction of the permanent magnet (122).

10. The motor according to claim 1, characterized in that The rotor assembly (120) includes a plurality of permanent magnets (122), and the diffusion areas on cross sections of the permanent magnets (122) having different widths and thicknesses are the same or different.

11. The motor according to claim 1, characterized in that The permanent magnet (122) is magnetized radially or parallelly.

12. The motor according to claim 1, characterized in that The number of pole pairs P of the permanent magnet (122) is ≥2.

13. The motor according to claim 1, characterized in that The rotor core (121) is formed by stacking a plurality of silicon steel sheets.

14. A compressor, characterized in that: include: housing, and The motor according to any one of claims 1 to 13, wherein the motor is arranged inside the housing.

15. A refrigerator, characterized in that: include: The motor according to any one of claims 1 to 13; or The compressor of claim 14.

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