A motor and its application

Abstract

The present invention discloses a motor and its application. The motor includes a rotor and a stator surrounding the rotor; the rotor includes an iron core and a permanent magnet disposed on the iron core; the air gap width of the motor is δ; the number of magnetic poles in the rotor is 2P; the permanent magnet contains x% cerium by mass; the value of x ranges from 3 to 10; the thickness of the permanent magnet is h; the sum of the widths of the permanent magnets in each magnetic pole is w; and: x≤23*h‑25; 1+δ≤h≤1.4+δ; 2.5*x+15≤2P*h*w / 5≤4*x+37; h, w, and δ are all in units of mm. The motor provided by the present invention can reduce costs while ensuring its overall performance. The present invention also provides a compressor including the above motor and a temperature control device including the above compressor.

Description

Technical Field

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

[0002] Currently, air conditioning compressors generally use variable-frequency motors, which typically utilize permanent magnet motors. Permanent magnet motors use magnets to excite their rotors. Most permanent magnets used in motors are rare earth magnets, with common heavy rare earth elements such as praseodymium and neodymium. Due to their limited reserves, these rare earth elements have seen their prices rise, driving up the price of rare earth magnet materials and the cost of motors.

[0003] To address the aforementioned cost issues and waste of rare earth resources, one conventional solution is to replace elements such as praseodymium and neodymium in rare earth magnets with cerium, which is cheaper and more abundant. While this approach can alleviate cost pressures, it significantly affects the magnet's remanence and coercivity. Coercivity directly reflects its ability to resist demagnetization. When magnets are the same size and equipped with the same motor, magnets with low coercivity have poor rotor demagnetization resistance, resulting in more pronounced rotor demagnetization and a higher risk of demagnetization. Furthermore, this can lead to failure of the motor and related products, directly impacting product life and damaging the user experience.

[0004] Furthermore, as the power density of permanent magnet motors increases, the rotor magnets' resistance to demagnetization weakens. Irreversible demagnetization of the magnets can affect the performance and reliability of the motor and compressor, severely impacting the product's service life.

[0005] In summary, it is urgent to reduce the cost of magnets and motors while ensuring the reliable operation of the motor. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a motor that can reduce costs while ensuring the overall performance of the motor.

[0007] The present invention also provides a compressor comprising the motor.

[0008] The present invention also provides a temperature regulating device comprising the compressor.

[0009] According to an embodiment of a first aspect of the present invention, a motor is provided, comprising a rotor and a stator surrounding the rotor;

[0010] The rotor includes an iron core and a permanent magnet disposed on the iron core;

[0011] The air gap width of the motor is δ; the number of magnetic poles in the rotor is 2P;

[0012] The permanent magnet contains x% cerium by mass; the value of x% ranges from 3 to 10%;

[0013] The thickness of the permanent magnet is h; the sum of the widths of the permanent magnets in each pole is w;

[0014] and:

[0015] x≤23*h-25 (1);

[0016] 1+δ≤h≤1.4+δ (2);

[0017] 2.5*x+15≤2P*h*w / 5≤4*x+37 (3);

[0018] The units of h, w, and δ are all mm.

[0019] The control method according to the embodiment of the present invention has at least the following beneficial effects:

[0020] In motors using rare earth magnets, if other conditions remain unchanged, the cerium (Ce) content in the permanent magnet (the proportion of replacing heavy rare earths such as neodymium and praseodymium) is inversely correlated with the permanent magnet's remanence and intrinsic coercive force; the motor's air gap width, number of poles and anti-demagnetization ability are positively correlated; when the remanence and intrinsic coercive force are the same, the greater the thickness and length of the permanent magnet, the higher the overall efficiency and anti-demagnetization ability of the motor.

[0021] At the same time, the wider the air gap width, the better the running stability of the motor; the air gap width, the thickness and length of the permanent magnet are related to the final size of the motor; the number of rotor poles affects both the final size of the motor and its structural complexity.

[0022] After extensive experimental research and analysis, the inventors have statistically analyzed data such as thickness, width, number of rotor poles, and air gap width, and studied the relationship between changes in the Ce content in permanent magnets and motor performance. They found that when parameters such as x, h, and w satisfy the relationships of equations (1) to (3), the cost of the motor can be reduced while ensuring motor performance. In other words, by constraining the relative relationship between parameters such as the cerium content, thickness, width, number of rotor poles, and air gap width in the permanent magnets, and limiting the Ce content in the permanent magnets, the present invention achieves a motor with dimensions that meet usage requirements, performance such as energy efficiency and reliability that meet usage requirements, and the lowest possible cost. This balances the conflicting relationship between motor performance and cost. Furthermore, while reducing costs, it ensures that products associated with the above-mentioned motor can operate reliably over a long period of time, extending the product's service life.

[0023] According to some preferred embodiments of the present invention, the value range of x% is 3% to 6%.

[0024] According to some further preferred embodiments of the present invention, the value range of x% is 3% to 5%.

[0025] According to some embodiments of the present invention, cerium in the permanent magnet is uniformly distributed.

[0026] According to some embodiments of the present invention, cerium in the permanent magnet is distributed in a gradient.

[0027] Since the cerium content is inversely correlated with the anti-demagnetization performance of the resulting motor, limiting the cerium content within the above range can ensure the efficiency and anti-demagnetization performance of the resulting motor while reducing costs.

[0028] According to some embodiments of the present invention, the stator is provided with stator slots.

[0029] According to some embodiments of the present invention, the number of the stator slots on the stator is ≥12.

[0030] The number of stator slots is related to the overall design of the motor. Although 12 stator slots corresponding to 8 magnetic poles of the rotor is the more preferred technology at this stage, in fact the number of stator slots can be adjusted according to the actual design of the motor.

[0031] According to some embodiments of the present invention, the air gap width δ of the motor ranges from 0.3 to 0.8 mm; that is, the minimum gap between the stator and the rotor is from 0.3 to 0.8 mm.

[0032] According to some preferred embodiments of the present invention, the air gap width δ of the motor ranges from 0.4 to 0.6 mm.

[0033] According to some preferred embodiments of the present invention, the air gap width of the motor is δ=0.5 mm.

[0034] According to some embodiments of the present invention, the number of poles of the rotor is 2P≥6.

[0035] According to some embodiments of the present invention, the number of poles of the rotor is 2P≥8.

[0036] According to some embodiments of the present invention, the number of poles of the rotor is 2P≤12.

[0037] Preferably, the number of poles of the rotor is 6, 8, 10 or 12.

[0038] When the number of poles of the rotor is within the above range, even if the permanent magnet is doped with cerium, it will not affect the efficiency, anti-demagnetization and life of the motor.

[0039] According to some embodiments of the present invention, the thickness h of the permanent magnet ranges from 1.3 to 2.2 mm.

[0040] According to some preferred embodiments of the present invention, the thickness h of the permanent magnet ranges from 1.5 to 1.8 mm.

[0041] According to some preferred embodiments of the present invention, the thickness h of the permanent magnet ranges from approximately 1.6 mm to approximately 1.7 mm.

[0042] According to some embodiments of the present invention, in each magnetic pole, the sum of the widths of the permanent magnets is 15-22 mm.

[0043] According to some preferred embodiments of the present invention, in each magnetic pole, the sum of the widths of the permanent magnets is 16-19 mm.

[0044] According to some embodiments of the present invention, in each magnetic pole, the sum of the widths of the permanent magnets is approximately 16.4 mm, or 18.8 mm.

[0045] Therefore, the sum of the thickness and width matches the cerium content in the permanent magnet, which can effectively adjust the size and anti-demagnetization performance of the motor and ensure the life and efficiency of the motor.

[0046] According to some embodiments of the present invention, in the motor, the remanence of the permanent magnet is 1.25 to 1.35 T;

[0047] Preferably, the remanence of the permanent magnet is about 1.33T.

[0048] According to some embodiments of the present invention, the intrinsic coercive force of the permanent magnet is ≥1700 KA / m.

[0049] According to some preferred embodiments of the present invention, the intrinsic coercive force of the permanent magnet is between 1710 and 1750 kA / m.

[0050] According to some embodiments of the present invention, the permanent magnets are arranged on the iron core in a straight line.

[0051] When the permanent magnets are arranged in a straight line, each of the permanent magnets is a magnetic pole; therefore, the width of each of the permanent magnets is w.

[0052] According to some embodiments of the present invention, the permanent magnets are arranged in a V-shape on the iron core.

[0053] Among them, each "V-shape" is composed of two permanent magnets, and the opening of the "V-shape" can be facing the axis of the rotor core or the outside of the rotor core. There is no rigid limitation on this in this technical solution.

[0054] By arranging two permanent magnets in the same group in a V-shape, a hybrid magnetic circuit structure can be formed in the rotor. This hybrid magnetic circuit structure can improve the steady-state and dynamic performance of the rotor, helping to increase the power density and overload capacity of the motor. Furthermore, the hybrid magnetic circuit facilitates field-weakening speed expansion. Furthermore, it helps increase the coverage area of ​​the permanent magnets in the circumferential direction of the rotor core, thereby achieving the technical effect of improving the performance of the motor.

[0055] When the permanent magnets are arranged in a "V-shape", each "V-shape" is a magnetic pole, that is, two permanent magnets form a magnetic pole; therefore, the sum of the widths of the two permanent magnets forming the "V-shape" is w; further preferably, the width of each permanent magnet is w / 2.

[0056] Therefore, when the value of the number of poles 2P of the rotor is constant, the number of permanent magnets required for the "V-shaped" arrangement is twice the number of permanent magnets required for the "straight-line" arrangement.

[0057] According to some embodiments of the present invention, the iron core is provided with a magnet slot matching the permanent magnet.

[0058] "I-shaped" and "V-shaped" are the permanent magnet arrangements commonly used in this field. The present invention controls parameters so that the resulting technical solution can adapt to motors with the above two arrangements, has a wide range of applications, and is more conducive to commercial promotion.

[0059] According to some embodiments of the present invention, the magnet slot is in a straight line shape.

[0060] According to some embodiments of the present invention, the magnet slot is V-shaped.

[0061] Thus, the magnet slot can accommodate the permanent magnet and limit the permanent magnet, and further, the excitation effect of the permanent magnet can be better exerted.

[0062] According to some embodiments of the present invention, the motor further comprises a magnetic isolation bridge;

[0063] Preferably, the magnetic isolation bridges are provided at both ends of the permanent magnet in the width direction. This provides a magnetic isolation function, effectively reducing the possibility of magnetic circuit disorder and magnetic leakage problems within the rotor assembly. This optimizes the motor assembly structure and improves its practicality and reliability.

[0064] According to some embodiments of the present invention, the efficiency of the motor is ≥90% at 1800 rps.

[0065] According to some preferred embodiments of the present invention, the efficiency of the motor at 1800 rps is ≥ 90.1%, for example, approximately 90.2%.

[0066] According to some embodiments of the present invention, the efficiency of the motor is ≥92% at 3600 rps.

[0067] According to some preferred embodiments of the present invention, the efficiency of the motor at 3600 rps is ≥ 92.3%, for example, approximately 92.5%.

[0068] According to some embodiments of the present invention, the demagnetization rate of the motor at 130° C. / 24A is ≤3%.

[0069] According to some preferred embodiments of the present invention, the demagnetization rate of the motor at 130° C. / 24A is between 2% and 2.9%.

[0070] According to some preferred embodiments of the present invention, the demagnetization rate of the motor at 130° C. / 24A is approximately 2.23%, 2.86% or 2.78%.

[0071] According to an embodiment of the second aspect of the present invention, a compressor is provided, comprising the motor.

[0072] Since the compressor adopts all the technical solutions of the motor of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the motor of the above embodiment.

[0073] According to an embodiment of the third aspect of the present invention, a temperature regulating device is provided, which includes the compressor.

[0074] Since the temperature regulating device adopts all the technical solutions of the compressor of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the compressor of the above embodiment.

[0075] According to some embodiments of the present invention, the temperature regulating device includes at least one of a refrigerator and an air conditioner.

[0076] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which:

[0078] Figure 1 Schematic diagram of the structure of the motor provided by Example 1, Example 3 and Comparative Example 2 of the present invention;

[0079] Figure 2 yes Figure 1A partial enlarged view of

[0080] Figure 3 Schematic diagram of the dimensions of the motors provided in Example 1, Example 3 and Comparative Example 2 of the present invention;

[0081] Figure 4 Schematic diagram of the structure of the motor provided by Example 2 and Comparative Example 1 of the present invention;

[0082] Figure 5 yes Figure 4 A partial enlarged view of

[0083] Figure 6 Schematic diagram of the dimensions of the motors provided in Example 2 and Comparative Example 1 of the present invention.

[0084] Reference numerals:

[0085] Rotor 100;

[0086] Iron core 110, magnet slot 111;

[0087] Permanent magnet 120;

[0088] Stator 200 , stator slots 210 . DETAILED DESCRIPTION

[0089] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0090] In the description of the present invention, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0091] In the description of the present invention, it should be understood that descriptions involving orientation, such as the orientation or positional relationship indicated by up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0092] In the description of the present invention, it should be noted that, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0093] Unless otherwise specified, in the permanent magnet of the specific embodiment, in addition to cerium, the total content of praseodymium and neodymium is 25 wt %, the content of dysprosium is 1.5 wt %, the content of cobalt is 1.0 wt %, and the remaining elements are iron.

[0094] Example 1

[0095] This embodiment provides a motor, referring to Figures 1 to 3 As shown, specifically, the motor is composed of a rotor 100 and a stator 200 surrounding the rotor 100;

[0096] The stator 200 is provided with 12 stator slots 210 .

[0097] The rotor 100 includes an iron core 110 and a permanent magnet 120 disposed on the iron core 110;

[0098] The air gap width of the motor is δ; the number of magnetic poles in the rotor 100 is 2P;

[0099] The permanent magnet 120 contains x% by mass of cerium;

[0100] The thickness of the permanent magnet 120 is h; the sum of the widths of the permanent magnet 120 in each pole is w;

[0101] The parameters should satisfy the following formulas:

[0102] x≤23*h-25 (1);

[0103] 1+δ≤h≤1.4+δ (2);

[0104] 2.5*x+15≤2P*h*w / 5≤4*x+37 (3);

[0105] The units of h, w, and δ are all mm.

[0106] It is understandable that the permanent magnets 120 are arranged in a "V-shape", such as Figures 1 to 3 Thus, the width of each permanent magnet 120 is w / 2. The selected permanent magnet 120 is of model 42SH, with specific dimensions of 30 mm*8.4 mm*1.6 mm.

[0107] It is further understood that the iron core 110 is provided with a magnet slot 111 that matches the shape of the permanent magnet 120 .

[0108] It is further understood that, in order to reduce the harm caused by magnetic leakage, the motor can also be provided with magnetic isolation bridges ( Figure 1 and Figure 3 not shown).

[0109] Specifically, in this embodiment, the parameters of the motor are shown in Table 1.

[0110] Table 1 Parameters of the motor in Example 1

[0111] parameter h / mm w / mm δ / mm 2P x％ Example 1 1.6 8.4×2＝16.8 0.5 8 6％

[0112] Substituting the parameters in Table 1 into the formula yields:

[0113] 6≤23*1.6-25=11.8;

[0114] 1+0.5=1.5≤1.6≤1.4+0.5=1.9;

[0115] 2.5*6+15=30≤8*1.6*16.8 / 5=43.0008≤4*6+37=61.

[0116] That is, the parameters defined in this embodiment satisfy the requirements of formulas (1) to (3).

[0117] It should be noted that Figures 1 to 3 The number of poles and sizes shown are schematic and the specific values ​​cannot be read directly from the diagram.

[0118] Example 2

[0119] This embodiment provides a motor, referring to Figures 4-6 As shown, specifically, the motor is composed of a rotor 100 and a stator 200 surrounding the rotor 100;

[0120] The stator 200 is provided with 12 stator slots 210 .

[0121] The rotor 100 includes an iron core 110 and a permanent magnet 120 disposed on the iron core 110;

[0122] The air gap width of the motor is δ; the number of magnetic poles in the rotor 100 is 2P;

[0123] The permanent magnet 120 contains x% by mass of cerium;

[0124] The thickness of the permanent magnet 120 is h; the sum of the widths of the permanent magnet 120 in each pole is w;

[0125] The parameters should satisfy the following formulas:

[0126] x≤23*h-25 (1);

[0127] 1+δ≤h≤1.4+δ (2);

[0128] 2.5*x+15≤2P*h*w / 5≤4*x+37 (3);

[0129] The units of h, w, and δ are all mm.

[0130] It is understood that the permanent magnets 120 are arranged in a straight line; therefore, the width of each permanent magnet 120 is w. The selected permanent magnet 120 is model 42SH, with specific dimensions of 30 mm*18.8 mm*1.8 mm.

[0131] It is further understood that the iron core 110 is provided with a magnet slot 111 that matches the shape of the permanent magnet 120 .

[0132] It is further understood that, in order to reduce the harm caused by magnetic leakage, the above-mentioned motor may further be provided with magnetic isolation bridges (not shown in the figure) at both ends of the permanent magnet 120 in the width direction.

[0133] Specifically, in this embodiment, the parameters of the motor are shown in Table 2.

[0134] Table 2 Parameters of the motor in Example 2

[0135] parameter h / mm w / mm δ / mm 2P x％ Example 2 1.8 18.8 0.5 6 6％

[0136] Substituting the parameters in Table 2 into the formula yields:

[0137] 6≤23*1.8-25=16.4;

[0138] 1+0.5=1.5≤1.8≤1.4+0.5=1.9;

[0139] 2.5*6+15=30≤6*1.8*18.8 / 5=40.608≤4*6+37=61.

[0140] That is, the parameters defined in this embodiment satisfy the requirements of formulas (1) to (3).

[0141] It should be noted that Figures 4-6 The number of poles and sizes shown are schematic and the specific values ​​cannot be read directly from the diagram.

[0142] Example 3

[0143] This embodiment provides a motor, referring to Figures 1 to 3 As shown, specifically, the motor is composed of a rotor 100 and a stator 200 surrounding the rotor 100;

[0144] The stator 200 is provided with 12 stator slots 210 .

[0145] The rotor 100 includes an iron core 110 and a permanent magnet 120 disposed on the iron core 110;

[0146] The air gap width of the motor is δ; the number of magnetic poles in the rotor 100 is 2P;

[0147] The permanent magnet 120 contains x% by mass of cerium;

[0148] The thickness of the permanent magnet 120 is h; the sum of the widths of the permanent magnet 120 in each pole is w;

[0149] The parameters should satisfy the following formulas:

[0150] x≤23*h-25 (1);

[0151] 1+δ≤h≤1.4+δ (2);

[0152] 2.5*x+15≤2P*h*w / 5≤4*x+37 (3);

[0153] The units of h, w, and δ are all mm.

[0154] It is understandable that the permanent magnets 120 are arranged in a "V-shape", such as Figures 1 to 3 Thus, the width of each permanent magnet 120 is w / 2. The selected permanent magnet 120 is of model 42SH, with specific dimensions of 30 mm*8.4 mm*1.6 mm.

[0155] It is further understood that the iron core 110 is provided with a magnet slot 111 that matches the shape of the permanent magnet 120 .

[0156] It is further understood that, in order to reduce the harm caused by magnetic leakage, the above-mentioned motor may further be provided with magnetic isolation bridges (not shown in the figure) at both ends of the permanent magnet 120 in the width direction.

[0157] The motor parameters are slightly different, and the specific parameters are shown in Table 3:

[0158] Table 3 Parameters of the motor in Example 3

[0159] parameter h / mm w / mm δ / mm 2P x％ Example 3 1.6 8.4*2＝16.8 0.5 8 5％

[0160] Substituting the parameters in Table 3 into the formula yields:

[0161] 5≤23*1.6-25=11.8;

[0162] 1+0.5=1.5≤1.6≤1.4+0.5=1.9;

[0163] 2.5*5+15=27.5≤8*1.6*16.8 / 5=43.0008≤4*5+37=57.

[0164] That is, the parameters defined in this embodiment satisfy the requirements of formulas (1) to (3).

[0165] Comparative Example 1

[0166] This comparative example provides a motor, referring to Figures 4-6 As shown, specifically, the motor is composed of a rotor 100 and a stator 200 surrounding the rotor 100;

[0167] The stator 200 is provided with 12 stator slots 210 .

[0168] The rotor 100 includes an iron core 110 and a permanent magnet 120 disposed on the iron core 110;

[0169] The air gap width of the motor is δ; the number of magnetic poles in the rotor 100 is 2P;

[0170] The permanent magnet 120 contains x% by mass of cerium;

[0171] The thickness of the permanent magnet 120 is h; the sum of the widths of the permanent magnet 120 in each pole is w;

[0172] It is understood that the permanent magnets 120 are arranged in a straight line; therefore, the width of each permanent magnet 120 is w. The selected permanent magnet 120 is model 42SH, with specific dimensions of 30 mm*18.8 mm*1.8 mm.

[0173] It is further understood that the iron core 110 is provided with a magnet slot 111 that matches the shape of the permanent magnet 120 .

[0174] It is further understood that, in order to reduce the harm caused by magnetic leakage, the above-mentioned motor may further be provided with magnetic isolation bridges (not shown in the figure) at both ends of the permanent magnet 120 in the width direction.

[0175] Specifically, in this comparative example, the parameters of the motor are shown in Table 4.

[0176] Table 4 Parameters of the motor in Comparative Example 1

[0177] parameter h / mm w / mm δ / mm 2P x％ Comparative Example 1 1.3 17.4 0.5 6 5％

[0178] Substituting the parameters in Table 4 into formulas (1) to (3) yields:

[0179] 23*h-25=23*1.3-25=4.9<x=5, that is, the parameters in this comparative example do not meet the requirements of formula (1);

[0180] 1+δ=1+0.5=1.5>h=1.3, that is, the parameters in this comparative example do not meet the requirements of formula (2);

[0181] 2.5*x+15=2.5*5+15=27.5;

[0182] 2P*h*w / 5=6*1.3*17.4 / 5=22.439;

[0183] Therefore, in this comparative example, 2.5*x+15>2P*h*w / 5, which does not meet the requirement of formula (3).

[0184] Comparative Example 2

[0185] This comparative example provides a motor, referring to Figures 1 to 3 As shown, specifically, the motor is composed of a rotor 100 and a stator 200 surrounding the rotor;

[0186] The stator 200 is provided with 12 stator slots 210 .

[0187] The rotor 100 includes an iron core 110 and a permanent magnet 120 disposed on the iron core.

[0188] The air gap width of the motor is δ; the number of magnetic poles in the rotor 100 is 2P;

[0189] The permanent magnet 120 contains x% by mass of cerium;

[0190] The thickness of the permanent magnet 120 is h; the sum of the widths of the permanent magnet 120 in each pole is w;

[0191] It is understandable that the permanent magnets 120 are arranged in a "V-shape", such as Figures 1 to 3 Thus, the width of each permanent magnet 120 is w / 2. The selected permanent magnet 120 is of model 42SH, with specific dimensions of 30 mm*8.4 mm*1.6 mm.

[0192] It is further understood that the iron core 110 is provided with a magnet slot 111 that matches the shape of the permanent magnet 120 .

[0193] It is further understood that, in order to reduce the harm caused by magnetic leakage, the above-mentioned motor may further be provided with magnetic isolation bridges (not shown in the figure) at both ends of the permanent magnet 120 in the width direction.

[0194] In this comparative example, the specific parameters of the motor are shown in Table 5:

[0195] Table 5 Parameters of the motor in Comparative Example 2

[0196] parameter h / mm w / mm δ / mm 2P x％ Comparative Example 2 1.6 8.4×2＝16.8 0.5 8 11％

[0197] Substituting the parameters in Table 1 into the formula yields:

[0198] 11≤23*1.6-25=11.8;

[0199] 1+0.5=1.5≤1.6≤1.4+0.5=1.9;

[0200] 2.5*11+15=42.5≤8*1.6*16.8 / 5=43.0008≤4*11+37=81.

[0201] That is, the parameters defined in this comparative example satisfy the requirements of formulas (1) to (3).

[0202] However, the cerium content exceeds the required range of the present invention.

[0203] Test Case

[0204] This test example tests the performance of the motors provided by Examples 1 to 3 and Comparative Examples 1 to 2. The specific test conditions and test results are shown in Table 6.

[0205] Table 6 Performance of the motors provided by Examples 1 to 3 and Comparative Examples 1 to 2

[0206]

[0207] The results in Table 6 are all measured values. The intrinsic coercivity is related to the cerium content, the amount of other heavy rare earth elements used, and the magnet manufacturer's production process. Although the cerium content varies slightly in Examples 1-3 and Comparative Example 1, the intrinsic coercivity of the magnets used in this embodiment is consistently 1710 kA / m.

[0208] In Table 6, the comparison of the results of Example 1 and Example 3 shows that when the Ce content is within the range required by the present invention, the efficiency of the motor hardly changes. As the Ce content increases, the anti-demagnetization performance tends to decrease. However, the final anti-demagnetization performance is still relatively excellent, meeting the needs of industrial and daily use.

[0209] In Table 6, the comparison of the results of Examples 1 to 3 and Comparative Example 1 shows that although the Ce doping amount meets the range required by the present invention, the various parameters such as its thickness, width and air gap width do not meet the requirements of formulas (1) to (3), that is, the shape and setting position of the permanent magnet are not within the range required by the present invention. As a result, the efficiency and anti-demagnetization performance of the motor under various conditions are low, which does not meet the needs of actual production.

[0210] In Table 6, a comparison of the results of Examples 1 to 3 and Comparative Example 2 shows that, while other conditions are the same, the cerium doping level of the permanent magnets in Comparative Example 1 exceeds the range required by the present invention. Although the positional relationship and other factors satisfy the requirements of equations (1) to (3), the resulting motor has low energy efficiency and exhibits significant, uncontrollable demagnetization. In contrast, Example 1 does not exhibit the same issues.

[0211] Furthermore, based on current rare earth material prices, the price per gram of conventional 42SH grade NdPr magnets is 0.38 yuan / gram, while the price per gram of cerium-containing magnets (calculated at 5% cerium doping) is 0.279 yuan / gram. For example, in Example 2, each permanent magnet weighs approximately 3.1g, and a motor has 16 of these magnets. By replacing the conventional NdFeB magnets with Ce-doped permanent magnets, the material cost per motor can be reduced by approximately 5 yuan.

[0212] In summary, the motor provided by the present invention, by limiting the relationship between the shape of the permanent magnet, the air gap width between the stator and the rotor, and the number of magnetic poles in the motor, can replace the neodymium iron boron or praseodymium-containing permanent magnets in traditional technology with Ce-doped permanent magnets while ensuring the performance of the motor, thereby significantly reducing the cost of the motor.

[0213] It is further expected that as the cost of the motor decreases while maintaining performance, the cost of a compressor including the motor and a temperature regulating device including the compressor, such as a refrigerator or air conditioner, will decrease without compromising its performance.

[0214] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. A motor comprising a rotor and a stator surrounding the rotor, characterized in that: The rotor includes an iron core and a permanent magnet disposed on the iron core; The air gap width of the motor is δ; the number of magnetic poles in the rotor is 2P; The permanent magnet contains x% cerium by mass; the value of x% ranges from 3 to 10%; The thickness of the permanent magnet is h; the sum of the widths of the permanent magnets in each pole is w; and: x≤23*h-25 (1); 1+δ≤h≤1.4+δ (2); 2.5*x+15≤2P*h*w / 5≤4*x+37 (3); The units of h, w, and δ are all mm.

2. The motor according to claim 1, characterized in that The stator is provided with stator slots.

3. The motor according to claim 1, characterized in that The number of poles of the rotor is 2P≥6.

4. The motor according to claim 1, characterized in that The value range of the air gap width δ is 0.3-0.8 mm.

5. The motor according to claim 1, characterized in that The thickness h of the permanent magnet ranges from 1.3 to 2.2 mm.

6. The motor according to claim 1, characterized in that The sum of the widths w of the permanent magnets ranges from 15 to 22 mm.

7. The motor according to any one of claims 1 to 6, characterized in that: The permanent magnets are arranged on the iron core in a straight line.

8. The motor according to any one of claims 1 to 6, characterized in that: The permanent magnets are arranged in a V-shape on the iron core.

9. A compressor, characterized in that: The compressor comprises the motor according to any one of claims 1 to 8.

10. A temperature regulating device, characterized in that: The temperature regulating device includes the compressor according to claim 9.

11. The temperature regulating device according to claim 10, characterized in that The temperature regulating device includes at least one of a refrigerator and an air conditioner.

Images