Motors, compressors and household appliances

Abstract

The present invention discloses a motor, a compressor and a household appliance. The motor includes a rotor and a stator. The rotor includes a rotor core and a plurality of permanent magnets. The permanent magnets are provided with a non-diffusion zone and a diffusion zone. The content of heavy rare earth elements in the diffusion zone is greater than that in the non-diffusion zone. The cross-sectional area of ​​the diffusion zone in the direction perpendicular to the rotor axis is S i mm 2 The stator includes a stator core, which is provided with stator teeth, stator slots and windings. The total number of turns of each phase of the winding in series is N, the slot width of the stator slot is b1mm, and the gap between the stator and the rotor is δmm; then: #imgabs0# where 0.01≤k i ≤0.95; c=0 or 1. The present invention improves the demagnetization resistance of the motor and reduces the cost by setting a diffusion zone and adjusting the motor structure. The present invention also provides a compressor and a household appliance including the motor.

Description

Technical Field

[0001] The present invention relates to the field of electrical appliances, and in particular to a motor, a compressor and a household appliance. Background Art

[0002] At present, domestic and foreign air-conditioning compressors basically use variable frequency motors, which generally use permanent magnet motors. The permanent magnet motor rotors use permanent magnet excitation. Due to the high power density characteristics of permanent magnet motors and the need to reduce costs, the anti-demagnetization ability of permanent magnets is weakened. When the magnets undergo irreversible demagnetization, the operating performance and reliability of the motor and compressor are affected, and the service life of the product is seriously affected.

[0003] Adding heavy rare earth elements like dysprosium and terbium to permanent magnets increases their remanence and coercivity. Coercivity directly reflects their resistance to demagnetization. When magnets are the same size and used in the same motor, magnets with low coercivity have poor rotor demagnetization resistance, resulting in a higher risk of rotor demagnetization and more pronounced demagnetization. As heavy rare earth element prices rise, the cost of permanent magnets and motors is skyrocketing. A more direct solution to this problem is to reduce the heavy rare earth element content in permanent magnets, but this also affects the remanence and coercivity of the permanent magnets, making it difficult to guarantee motor efficiency and operational reliability. Summary of the Invention

[0004] 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 reduces the cost of the motor while ensuring demagnetization reliability.

[0005] The present invention also provides a compressor using the motor.

[0006] The present invention also provides a household appliance using the motor or the compressor.

[0007] According to a first aspect of the present invention, an embodiment relates to a motor, comprising:

[0008] The rotor comprises a rotor core and a plurality of permanent magnets arranged on the rotor core, wherein the permanent magnets are provided with a non-diffusion zone and a diffusion zone, wherein the content of heavy rare earth elements in the diffusion zone is greater than the content of heavy rare earth elements in the non-diffusion zone, and the cross-sectional area of ​​the diffusion zone in the direction perpendicular to the axis of the rotor is S i mm 2 ;

[0009] A stator, the stator comprising a stator core disposed around the outside of the rotor, the stator core being provided with a plurality of stator teeth, with every two adjacent stator teeth forming a stator slot, the stator slots being provided with windings wound around the stator teeth, the total number of turns of the windings connected in series per phase being N, the slot width of the stator slot being b1 mm, and the gap between the stator and the rotor being δ mm;

[0010] The motor meets the following requirements:

[0011] Where, 0.01≤k i ≤0.95;

[0012] When the connection form of the windings on the stator teeth is a delta connection, c=1; when the connection form of the windings on the stator teeth is a star connection, c=0.

[0013] The motor according to the first embodiment of the present invention has at least the following beneficial effects:

[0014] Providing a diffusion zone with a higher concentration of heavy rare earth elements in a permanent magnet can improve the magnet's local resistance to demagnetization. It's easy to understand that a larger proportion of the diffusion zone in the permanent magnet, or a higher content of heavy rare earth elements in the diffusion zone, will improve the magnet's resistance to demagnetization, but this will also increase costs.

[0015] The present invention designs the structure of the motor according to the cross-sectional area S of the diffusion zone. i , the total number of turns N, slot width b1, and stator / rotor gap δ are matched and designed to satisfy the relationship of formula (1), which can take into account the anti-demagnetization and cost of the motor.

[0016] The dimensional parameters in the above formula have a key impact on the overall anti-demagnetization capability of the motor. Among them, the larger the total number of turns N, the smaller the stator / rotor gap δ, or the smaller the slot width b1, the worse the motor's anti-demagnetization capability. i The larger the value, the stronger the anti-demagnetization ability, but the amount of heavy rare earth elements increases and the cost is higher. Therefore, when the overall anti-demagnetization ability of the motor structure design is poor, the cross-sectional area S can be increased. i , to improve reliability; on the contrary, when the overall anti-demagnetization ability of the motor structure design is good, the cross-sectional area S can be i Smaller design.

[0017] Taking into account the impact of the above key parameters on the motor performance, when the above relationship is met, the demagnetization reliability of the motor can be guaranteed, the heavy rare earth element content of the permanent magnet can be reduced, or the anti-demagnetization performance can be significantly improved by setting a diffusion zone.

[0018] According to some embodiments of the first aspect of the present invention, k i Satisfies: 0.01≤k i ≤0.5.

[0019] According to some embodiments of the first aspect of the present invention, k i Satisfies: 0.05≤k i ≤0.2.

[0020] According to some embodiments of the first aspect of the present invention, k i Satisfies: 0.1≤k i ≤0.2.

[0021] According to some embodiments of the first aspect of the present invention, the cross-sectional area S of the diffusion region is i Meet: 1mm 2 ≤S i ≤40mm 2 .

[0022] According to some embodiments of the first aspect of the present invention, the cross-sectional area S of the diffusion region is i Meet: 1mm 2 ≤S i ≤20mm 2 .

[0023] According to some embodiments of the first aspect of the present invention, the cross-sectional area S of the diffusion region is i :5mm 2 ≤S i ≤15mm 2 , for example S i 、S i Is selected from 5mm 2 , 10mm 2 , 15mm 2 The same value or different values.

[0024] As the cross-sectional area increases, the permanent magnet's ability to resist demagnetization becomes stronger, but this also increases the cost. i The proportion is 2%-90%, further 2%-45%, and further 10%-25%, which can achieve better cost and anti-demagnetization performance overall.

[0025] According to some embodiments of the first aspect of the present invention, the number of the diffusion regions is one or more.

[0026] According to some embodiments of the first aspect of the present invention, there are multiple diffusion regions, which are combined to form a quadrangular, U-shaped or three-strip structure.

[0027] According to some embodiments of the first aspect of the present invention, the diffusion regions are distributed with equal cross sections or unequal cross sections in the length direction of the permanent magnet.

[0028] According to some embodiments of the first aspect of the present invention, an extension distance of the diffusion region in the length direction of the permanent magnet is equal to the length of the permanent magnet.

[0029] According to some embodiments of the first aspect of the present invention, an extension distance of the diffusion region in the length direction of the permanent magnet is smaller than the length of the permanent magnet.

[0030] When the cross-sectional area of ​​the diffusion zone is the same, the longer the extension distance, the better the demagnetization resistance and the higher the cost.

[0031] According to some embodiments of the first aspect of the present invention, an extension distance of the diffusion region in a thickness direction of the permanent magnet is equal to the thickness of the permanent magnet.

[0032] According to some embodiments of the first aspect of the present invention, an extension distance of the diffusion region in a thickness direction of the permanent magnet is smaller than a thickness of the permanent magnet.

[0033] According to some embodiments of the first aspect of the present invention, the diffusion region is located at an end portion of the permanent magnet along the width direction.

[0034] The risk of demagnetization is higher at the ends of the permanent magnet. Setting the diffusion zone at the ends along the width direction of the permanent magnet reduces the possibility of irreversible demagnetization.

[0035] According to some embodiments of the first aspect of the present invention, the diffusion region is located on a side of the permanent magnet close to the stator.

[0036] During the operation of the motor, the magnetic flux generated by the permanent magnet passes through the air gap (stator / rotor gap), the stator teeth, the stator yoke, and then returns to the stator teeth, the air gap, and the permanent magnet to form a completely closed magnetic line of force. The side close to the stator is closer to the outer edge of the rotor and is more prone to demagnetization. Setting the diffusion zone at the corresponding position is beneficial to improving the motor's anti-demagnetization ability.

[0037] According to some embodiments of the first aspect of the present invention, the mass percentage of heavy rare earth elements in the diffusion zone is 0.5%-2.0%.

[0038] According to some embodiments of the first aspect of the present invention, the mass percentage of heavy rare earth elements in the diffusion zone is 0.59%-2.0%.

[0039] According to some embodiments of the first aspect of the present invention, the heavy rare earth elements in the diffusion zone are evenly or unevenly distributed.

[0040] According to some embodiments of the first aspect of the present invention, the mass percentage of heavy rare earth elements in the non-diffusion zone is 0.0%-0.53%.

[0041] According to some embodiments of the first aspect of the present invention, the heavy rare earth element includes dysprosium and / or terbium.

[0042] According to some embodiments of the first aspect of the present invention, the difference in intrinsic coercivity between the diffusion region and the non-diffusion region is 50-200 kA / m.

[0043] According to some embodiments of the first aspect of the present invention, the difference in intrinsic coercivity between the diffusion region and the non-diffusion region is 80-160 kA / m.

[0044] According to some embodiments of the first aspect of the present invention, the diffusion region includes a first diffusion region and a second diffusion region, and the cross-sectional area of ​​the first diffusion region is S1 mm 2 , the cross-sectional area of ​​the second diffusion zone is S2mm 2 , and satisfy:

[0045] and

[0046] Among them, 0.01≤k1≤0.95; 0.01≤k2≤0.95. For further values ​​of k1 and k2, please refer to k i The relevant parameter value range of k1 and k2 can be the same or different.

[0047] The second diffusion zone on the permanent magnet improves the rotor's demagnetization resistance. Simultaneously, the presence of the second diffusion zone allows the cross-sectional area S1 of the first diffusion zone to be appropriately reduced. Furthermore, the first and second diffusion zones can have the same or different compositions and dimensions. This interaction further enhances the rotor's overall demagnetization resistance and reduces costs.

[0048] According to some embodiments of the first aspect of the present invention, the cross-sectional area of ​​the first diffusion region accounts for 2%-90% of the cross-sectional area of ​​the permanent magnet, and / or the cross-sectional area of ​​the second diffusion region accounts for 2%-90% of the cross-sectional area of ​​the permanent magnet. It should be noted that when both the first diffusion region and the second diffusion region meet this range, their sum is less than 100%.

[0049] According to some embodiments of the first aspect of the present invention, the cross-sectional area of ​​the first diffusion region accounts for 2%-45% of the cross-sectional area of ​​the permanent magnet, and / or the cross-sectional area of ​​the second diffusion region accounts for 2%-45% of the cross-sectional area of ​​the permanent magnet.

[0050] According to some embodiments of the first aspect of the present invention, the cross-sectional area of ​​the first diffusion region accounts for 10%-25% of the cross-sectional area of ​​the permanent magnet, and / or the cross-sectional area of ​​the second diffusion region accounts for 10%-25% of the cross-sectional area of ​​the permanent magnet, for example, the percentage is about 22.2%.

[0051] According to some embodiments of the first aspect of the present invention, the cross-sectional area of ​​the first diffusion region and the second diffusion region is S1 mm 2 、S2mm 2 Meet: 1mm2 ≤S1≤40mm 2 and / or 1mm 2 ≤S2≤40mm 2 .

[0052] According to some embodiments of the first aspect of the present invention, the cross-sectional area of ​​the first diffusion region and the second diffusion region is S1 mm 2 、S2mm 2 Meet: 1mm 2 ≤S1≤20mm 2 and / or 1mm 2 ≤S2≤20mm 2 .

[0053] According to some embodiments of the first aspect of the present invention, the cross-sectional area of ​​the first diffusion region and the second diffusion region is S1 mm 2 、S2mm 2 Meets: 5mm 2 ≤S1≤15mm 2 and / or 5mm 2 ≤S2≤15mm 2 For example, S1 and S2 are selected from 5mm 2 , 10mm 2 , 15mm 2 The same value or different values.

[0054] As the cross-sectional area increases, the permanent magnet's anti-demagnetization ability becomes stronger, but the cost will also increase. When the cross-sectional area accounts for 10%-25%, better cost and anti-demagnetization performance can be achieved overall. In addition, you can also refer to S i Design can be done with other value ranges.

[0055] According to some embodiments of the first aspect of the present invention, the first diffusion region is located at one end of the permanent magnet along the width direction, and the second diffusion region is located at the other end of the permanent magnet along the width direction.

[0056] According to some embodiments of the first aspect of the present invention, the mass percentage of the heavy rare earth element in the first diffusion region is 1.0%-2.0%.

[0057] According to some embodiments of the first aspect of the present invention, the mass percentage of heavy rare earth elements in the first diffusion region is 1.05%-2.0%.

[0058] According to some embodiments of the first aspect of the present invention, the cross-sectional areas of the first diffusion region and the second diffusion region are equal or different.

[0059] According to some embodiments of the first aspect of the present invention, a cross-sectional area of ​​the first diffusion region is greater than or equal to a cross-sectional area of ​​the second diffusion region.

[0060] According to some embodiments of the first aspect of the present invention, the content of the heavy rare earth element in the first diffusion region is equal to or different from the content of the heavy rare earth element in the second diffusion region.

[0061] According to some embodiments of the first aspect of the present invention, the content of heavy rare earth elements in the first diffusion region is greater than or equal to the content of heavy rare earth elements in the second diffusion region.

[0062] According to some embodiments of the first aspect of the present invention, the mass percentage of heavy rare earth elements in the second diffusion region is 0.5%-1.5%.

[0063] According to some embodiments of the first aspect of the present invention, the mass percentage of heavy rare earth elements in the second diffusion region is 0.59%-1.25%.

[0064] According to some embodiments of the first aspect of the present invention, there are two first diffusion regions, and the two first diffusion regions are respectively arranged at two ends of the permanent magnet along the length direction.

[0065] According to some embodiments of the first aspect of the present invention, there are multiple first diffusion regions, which are spaced apart along the length direction of the permanent magnet.

[0066] According to some embodiments of the first aspect of the present invention, there are two second diffusion regions, which are respectively disposed at two ends of the permanent magnet along the length direction.

[0067] According to some embodiments of the first aspect of the present invention, there are multiple second diffusion regions, which are spaced apart along the length direction of the permanent magnet.

[0068] According to some embodiments of the first aspect of the present invention, the diffusion region further includes a third diffusion region.

[0069] According to some embodiments of the first aspect of the present invention, the cross-sectional area of ​​the third diffusion region is S3mm 2 , then:

[0070]

[0071] Among them, 0.01≤k3≤0.95.

[0072] It is understood that the further value range of k3 and S3 can refer to k i and S i , which is not repeated here.

[0073] According to some embodiments of the first aspect of the present invention, the first diffusion region, the third diffusion region, and the second diffusion region are sequentially spaced apart along the width direction of the permanent magnet to form a three-strip structure.

[0074] According to some embodiments of the first aspect of the present invention, the first diffusion region and the second diffusion region are connected through the third diffusion region to form a U-shaped structure.

[0075] According to some embodiments of the first aspect of the present invention, the magnetization direction of the permanent magnet is radial magnetization or transverse magnetization. In practical applications, the magnetization directions of all permanent magnets are kept consistent.

[0076] According to some embodiments of the first aspect of the present invention, a plurality of groups of rotor slots are provided on the rotor core, and a plurality of the permanent magnets are respectively disposed in the plurality of groups of rotor slots.

[0077] One or more permanent magnets can be placed in a group of rotor slots, and all the permanent magnets in the same group of rotor slots form a magnetic pole. Generally, when a single magnetic pole is composed of multiple permanent magnets, it is more conducive to enhancing the motor's anti-demagnetization capability.

[0078] According to some embodiments of the first aspect of the present invention, each group of rotor slots is V-shaped, straight-shaped, W-shaped, or a combination thereof.

[0079] According to some embodiments of the first aspect of the present invention, each group of the rotor slots is V-shaped, and the opening of the V-shape faces the stator.

[0080] According to some embodiments of the first aspect of the present invention, each group of rotor slots utilizes a combination of a V-shaped and a straight-shaped configuration, with the V-shaped slot opening facing the stator and the straight-shaped slots being received within the V-shaped slot opening. This creates an enclosed magnetic pole, further improving demagnetization resistance.

[0081] According to some embodiments of the first aspect of the present invention, the number of groups of rotor slots is no less than 4.

[0082] According to some embodiments of the first aspect of the present invention, the number of groups of rotor slots is 4-10, for example, 6, 8 or 10.

[0083] According to some embodiments of the first aspect of the present invention, the number of pole pairs P of the rotor is ≥2.

[0084] According to some embodiments of the first aspect of the present invention, the number of pole pairs of the rotor is 2≤P≤5, for example, it can be 3, 4 or 5.

[0085] According to some embodiments of the first aspect of the present invention, the rotor core is formed by stacking a plurality of silicon steel sheets.

[0086] The laminated structure is adopted to reduce cutting scraps, improve the utilization rate of silicon steel materials, reduce eddy current loss, reduce temperature rise, and increase the service life of the motor.

[0087] According to some embodiments of the first aspect of the present invention, the stator core is an integral structure or a block structure.

[0088] Among them, the use of a block structure can reduce the waste of silicon steel plates, reduce eddy current losses, reduce temperature rise, and increase the service life of the motor.

[0089] According to some embodiments of the first aspect of the present invention, the stator core is a block-type structure, wherein the number of blocks is equal to the number of stator teeth.

[0090] According to some embodiments of the first aspect of the present invention, the number Q of the stator slots is ≥9, for example, 9 or 12.

[0091] According to some embodiments of the first aspect of the present invention, the winding is a distributed winding or a concentrated winding.

[0092] According to some embodiments of the first aspect of the present invention, the winding is a concentrated winding.

[0093] According to some embodiments of the first aspect of the present invention, the total number of turns N of each phase of the winding connected in series is: Wherein, Q is the number of stator slots, m is the number of phases, a is the number of parallel branches per phase of the concentrated winding, and N s is the number of turns of the concentrated winding on the stator teeth.

[0094] According to some embodiments of the first aspect of the present invention, the number of turns N of the concentrated winding on the stator teeth is s 50-140.

[0095] According to some embodiments of the first aspect of the present invention, the number a of branches connected in parallel per phase of the concentrated winding is 1 or 2.

[0096] According to some embodiments of the first aspect of the present invention, the winding is a single-layer winding or a multi-layer winding, wherein the multi-layer winding may be a double-layer winding.

[0097] According to some embodiments of the first aspect of the present invention, a gap between the stator and the rotor is 0.55-0.85 mm.

[0098] If the air gap is too large, the magnetic resistance will increase, the excitation current will increase, and the efficiency of the motor will be affected.

[0099] According to some embodiments of the first aspect of the present invention, the width of the stator slot is 2-4.5 mm.

[0100] The smaller the slot width, the worse the motor's overall anti-demagnetization ability. As the slot width increases, the eddy current loss in the rotor increases, affecting the motor's operating stability.

[0101] According to some embodiments of the first aspect of the present invention, the motor is a three-phase motor.

[0102] According to a second aspect of the present invention, an embodiment relates to a compressor, comprising the motor according to the first aspect.

[0103] The compressor according to the second embodiment of the present invention, because it uses the motor of the above embodiment, has at least all the advantages brought about by the technical solution of the above motor. For example, due to the reduced cost and good demagnetization resistance of the motor, the compressor using this motor also has cost and performance advantages.

[0104] According to a third aspect of the present invention, an embodiment relates to a household appliance, comprising the motor according to the first aspect or the compressor according to the second aspect.

[0105] The household appliance according to the third aspect of the present invention, because it utilizes the motor or compressor of the aforementioned embodiment, has at least all the beneficial effects provided by the technical solutions of the aforementioned motor or compressor. For example, because the motor is less expensive and has good demagnetization resistance, the household appliance utilizing this motor also has cost and performance advantages.

[0106] According to some embodiments of the third aspect of the present invention, the household appliance includes an air conditioner, a refrigerator, or a freezer.

[0107] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0108] Additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments with reference to the accompanying drawings, in which:

[0109] Figure 1 Schematic diagram of the structure of a motor according to an embodiment of the present invention;

[0110] Figure 2 Schematic diagram of the structure of a permanent magnet in one embodiment of the present invention;

[0111] Figure 3 Schematic diagram of the structure of a permanent magnet in one embodiment of the present invention;

[0112] Figure 4 for Figure 2 and Figure 3 AA section view;

[0113] Figure 5 Schematic diagram of the structure of a permanent magnet in one embodiment of the present invention;

[0114] Figure 6 Schematic diagram of the structure of a permanent magnet in one embodiment of the present invention;

[0115] Figure 7 Schematic diagram of the structure of a permanent magnet in one embodiment of the present invention;

[0116] Figure 8 Schematic diagram of the structure of a V-shaped magnetic pole in one embodiment of the present invention;

[0117] Figure 9 Schematic diagram of the structure of a W-shaped magnetic pole in one embodiment of the present invention;

[0118] Figure 10 This is a schematic structural diagram of a combined magnetic pole in an embodiment of the present invention;

[0119] Figure 11 A schematic structural diagram of a permanent magnet in one embodiment of the present invention;

[0120] Figure 12 Schematic diagram of the structure of the stator core in one embodiment of the present invention.

[0121] Reference numerals:

[0122] stator 100, stator teeth 110, stator slots 120, windings 130, yoke 140;

[0123] Rotor 200, rotor core 210, rotor slots 220, permanent magnets 230, first diffusion region 231, second diffusion region 232, and third diffusion region 233;

[0124] Air gap 300. DETAILED DESCRIPTION

[0125] 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.

[0126] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0127] In the description of the present invention, if there is a description of first, second, and third, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0128] In the description of the present invention, 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.

[0129] The embodiment of the first aspect of the present invention provides a motor, which reduces the cost of the motor and ensures demagnetization reliability through motor structural design. Therefore, it can be foreseen that the service life and efficiency of the motor can also be guaranteed.

[0130] like Figure 1 2 is a schematic diagram of the structure of the motor of this embodiment. The motor includes a rotor 200 and rotor 200. The rotor 200 includes a rotor core 210 and a plurality of permanent magnets 230 disposed on the rotor core 210. Typically, the plurality of permanent magnets 230 are centrally symmetrically distributed relative to the geometric center of the rotor 200 to ensure axial balance of the rotor 200. The permanent magnets 230 are composed of a diffusion region and a non-diffusion region. The content of heavy rare earth elements in the diffusion region is greater than that in the non-diffusion region. By providing a diffusion region with a higher content of heavy rare earth elements, the demagnetization resistance of the permanent magnets 230 in the corresponding region is improved. The stator 100 includes a stator core disposed outside the rotor 200. The stator core is provided with a plurality of stator teeth 110. Each pair of adjacent stator teeth 110 forms a stator slot 120. The stator slot 120 is embedded with a winding 130 wound around the stator tooth 110. Typically, the windings 130 are arranged in a delta connection or a star connection.

[0131] The motor meets the following requirements: Where S1 is the cross-sectional area of ​​the diffusion zone perpendicular to the axis of the rotor 200, in mm 2 ; N is the total number of turns of each phase of the winding 130 connected in series; b1 is the slot width of the stator slot 120, unit: mm; δ is the gap between the stator 100 and the rotor 200, that is, the air gap 300, unit: mm; when the connection form of the winding 130 on the stator tooth 110 is a triangle connection, c=1; when the connection form of the winding 130 on the stator tooth 110 is a star connection, c=0.

[0132] It's easy to understand that a larger proportion of the diffusion region in the permanent magnet 230, or a higher content of heavy rare earth elements, improves demagnetization resistance, but also increases cost. Furthermore, increasing the volume of the permanent magnet 230, for example by increasing its thickness, can also reduce demagnetization, but this also increases cost. Therefore, there's a need to address the difficult trade-off between motor cost and performance.

[0133] In this embodiment, the motor is structurally designed according to the cross-sectional area S of the diffusion zone. i, the total number of turns N, slot width b1, and stator / rotor gap δ are matched and designed to meet the following requirements: It can take into account both the anti-demagnetization performance and cost of the motor.

[0134] The size parameters in the formula have a key impact on the overall anti-demagnetization capability of the motor, among which:

[0135] (1) The larger the total number of turns N, the worse the motor's anti-demagnetization ability;

[0136] (2) When the air gap δ is small, the anti-demagnetization ability is poor; when the air gap δ is large, the magnetic resistance is large, the excitation current increases, and the efficiency of the motor is affected;

[0137] (3) When the slot width b1 is small, the motor's anti-demagnetization ability is poor; when the slot width b1 is large, the eddy current loss is large, affecting the motor's operating stability;

[0138] (4) Cross-sectional area S of the diffusion zone i The larger the value, the stronger the anti-demagnetization ability, but the amount of heavy rare earth elements increases and the cost is higher. When the overall anti-demagnetization ability of the motor structure design is poor, the cross-sectional area S can be increased. i , to improve reliability; on the contrary, when the overall anti-demagnetization ability of the motor structure design is good, the cross-sectional area S can be i Smaller design.

[0139] Considering the impact of the above parameters on motor performance, using the above relationship to constrain the relevant structures of the stator and rotor can ensure demagnetization reliability, reduce the heavy rare earth element content of the permanent magnet, or achieve a significant improvement in anti-demagnetization performance by setting a diffusion zone.

[0140] In the above formula, the reference values ​​of relevant parameters are as follows:

[0141] The slot width b1 of the stator slot is 2-4.5 mm.

[0142] Air gap δ: 0.55-0.85mm.

[0143] The total number of turns N of each phase of the winding connected in series: Where Q is the number of stator slots, m is the number of phases, and a is the number of parallel branches per phase of the concentrated winding.

[0144] For a common three-phase motor, the number of phases m=3.

[0145] Number of turns N of concentrated winding on stator teeth s =50-140.

[0146] The number of branches connected in parallel per phase of the concentrated winding is a=1 or 2.

[0147] The number of stator slots Q≧9, and may be 9 or 12, for example.

[0148] k i It is 0.01-0.5, further 0.05-0.2, and further 0.1-0.2.

[0149] It is easy to understand that as the cross-sectional area S of the diffusion zone i The increase in the demagnetization resistance of the permanent magnet 230 is stronger, but the cost will also increase. When the above formula is satisfied, the cross-sectional area of ​​all or part of the diffusion zone is controlled to be 2%-90% of the cross-sectional area of ​​the permanent magnet 230, which is more effective. However, in order to obtain a better cost-effectiveness, the more suitable percentage range is 2%-45%, especially when it reaches 10%-25%, the effect is optimal. In accordance with this, for the motor of the compressor for general household appliances, the cross-sectional area S can be designed to be i The range is 1mm 2 -40mm 2 , further 1-20mm 2 , further to 5-15mm 2 , for example, it can be about 5mm 2 , 10mm 2 , 15mm 2 .

[0150] It is understood that the diffusion zone is usually made using a conventional high-temperature diffusion method, and the relevant technology is well known in the art. The general process is as follows: a heavy rare earth element formula liquid is coated on the surface of the permanent magnet 230 (for example, the length and width of the permanent magnet 230 in this embodiment), and then subjected to high-temperature treatment to allow the heavy rare earth elements to diffuse and penetrate into the interior of the permanent magnet 230, thereby increasing the intrinsic coercive force of the coated area. Generally, the penetration area of ​​the heavy rare earth elements in the coating area can be adjusted by changing the diffusion temperature, diffusion time, etc. At the same time, different suppliers, different formulas or different production process parameters may also affect the uniformity of the heavy rare earth element distribution in the coating area. Among them, when the heavy rare earth element doping amount and its penetration area are not much different, the uniformity of the heavy rare earth element distribution has little effect on the performance of the motor. That is, corresponding to this embodiment, the heavy rare earth elements in the diffusion zone can be evenly distributed or unevenly distributed throughout the diffusion zone.

[0151] As an embodiment, the heavy rare earth elements in the diffusion region include dysprosium and / or terbium. The present invention does not specifically limit the type and composition of heavy rare earth elements; other heavy rare earth elements other than dysprosium and terbium that can enhance coercivity may also be used. Doping may be either single doping or mixed doping.

[0152] A more suitable solution is to form a diffusion region on the permanent magnet 230 so that the intrinsic coercivity of the diffusion region is higher than that of the non-diffused region, reaching a range of 50-200 kA / m, and further reaching 70-150 kA / m. To this end, the mass percentage of heavy rare earth elements in the diffusion region can be controlled within a range of 0.59% to 2.0%.

[0153] As an implementation method, refer to Figure 1 The diffusion area includes a first diffusion area 231 and a second diffusion area 232. The cross-sectional area of ​​the first diffusion area 231 is S1 mm. 2 The cross-sectional area of ​​the second diffusion region 232 is S2 mm 2 , and satisfy:

[0154] and

[0155] Among them, 0.01≤k1≤0.95; 0.01≤k2≤0.95.

[0156] It can be understood that the further values ​​of k1 and k2 can refer to k i The relevant parameter value range of k1 and k2 can be the same or different; similarly, the further values ​​of S1 and S2 can refer to S i The relevant parameter value ranges of S1 and S2 can be the same or different.

[0157] The two diffusion zones on permanent magnet 230 enhance the rotor's demagnetization resistance. Furthermore, the presence of the second diffusion zone 232 allows the cross-sectional area S1 of the first diffusion zone 231 to be appropriately reduced. The coordinated use of the first and second diffusion zones 231, 232, further enhances the rotor's overall demagnetization resistance and reduces costs.

[0158] In one embodiment, the content of heavy rare earth elements in the first diffusion region 231 is less than, equal to, or greater than the content of heavy rare earth elements in the second diffusion region 232. When the content of heavy rare earth elements in the first diffusion region 231 is greater than or equal to the content of heavy rare earth elements in the second diffusion region 232, the mass percentage of heavy rare earth elements in the first diffusion region 231 can be controlled to be 1.0%-2.0%, and the mass percentage of heavy rare earth elements in the second diffusion region 232 can be controlled to be 0.5%-1.5%. Furthermore, the mass percentage of heavy rare earth elements in the first diffusion region 231 can be controlled to be 1.05%-1.5%, and the mass percentage of heavy rare earth elements in the second diffusion region 232 can be controlled to be 0.59%-1.25%.

[0159] In one embodiment, reference Figure 1 and Figure 2In this embodiment, the first diffusion region 231 is located at one end of the permanent magnet 230 along the width direction, and the second diffusion region is located at the other end of the permanent magnet 230 along the width direction. The risk of demagnetization is higher at the ends of the permanent magnet 230. Placing the diffusion region at the ends along the width direction of the permanent magnet 230 reduces the possibility of irreversible demagnetization.

[0160] At the same time, both the first diffusion region 231 and the second diffusion region 232 are located on the side of the permanent magnet 230 closest to the stator. During motor operation, the magnetic flux generated by the permanent magnet 230 passes through the air gap, the stator teeth, the stator yoke, and then returns to the stator teeth, the air gap, and the permanent magnet 230, forming a closed magnetic field. The side closest to the stator is closer to the outer edge of the rotor and is more susceptible to demagnetization. Placing the diffusion region in this location helps improve the motor's resistance to demagnetization.

[0161] As an embodiment, the cross-sectional area of ​​the first diffusion region 231 is larger than the cross-sectional area of ​​the second diffusion region 232. In this case, the first diffusion region 231 can be set in an area on the permanent magnet 230 that is more susceptible to demagnetization, and by matching with the second diffusion region 232, the overall anti-demagnetization performance of the permanent magnet 230 can be balanced.

[0162] In one embodiment, reference Figure 1 and Figure 2 The first diffusion region 231 and the second diffusion region 232 extend a distance equal to the length of the permanent magnet 230 in the length direction of the permanent magnet 230. Meanwhile, the distance they extend in the thickness direction of the permanent magnet 230 is less than the thickness of the permanent magnet 230. In other words, the diffusion regions do not completely penetrate the entire thickness of the permanent magnet 230.

[0163] In another embodiment, reference Figure 2 、 Figure 4 The lengths of the first diffusion region 231 and the second diffusion region remain unchanged, but their extension distance in the thickness direction of the permanent magnet 230 is equal to the thickness of the permanent magnet 230. In other words, the diffusion region completely penetrates the permanent magnet 230. It should be noted that the diffusion regions can have uniform or unequal cross-sectional distributions. That is, the first diffusion region 231 and the second diffusion region can have different dimensional distributions in terms of the length, width, and thickness of the permanent magnet 230. Furthermore, the cross-sectional dimensions of different regions within the first diffusion region 231 or the second diffusion region can also vary.

[0164] In this embodiment, the first diffusion region 231 and the second diffusion region are both continuously distributed in strips on the long sides of the permanent magnet 230. Figure 3In another embodiment, there are two first diffusion regions 231, which are located at both ends of the same long side of the permanent magnet 230, that is, on the same side of the width direction of the permanent magnet 230. There are two second diffusion regions, which are located at both ends of the other long side of the plane where the length and width of the permanent magnet 230 are located. The first diffusion region 231 and the second diffusion region form a quadrangular structure on the plane where the length and width of the permanent magnet 230 are located. For this method, the cross-sectional view at the AA position is the same as Figure 4 The same as the strip-shaped continuous distribution, but with a discontinuous distribution along the length. Compared to the strip-shaped continuous distribution, this method uses less heavy rare earth elements and primarily strengthens the coercive force at the ends. It is more suitable for applications where the thickness of the permanent magnet 230 is small (less likely to expose the weak coercive force area in the middle of the permanent magnet 230).

[0165] although Figures 1 to 4 The figures all show the case where there are multiple diffusion regions, but there can also be only one diffusion region, that is, only one first diffusion region 231 or one second diffusion region is provided. Figure 5 As shown, a first diffusion region 231 is continuously distributed in a strip shape on one long side of the permanent magnet.

[0166] like Figure 6 As shown, in another embodiment, the diffusion region further includes a third diffusion region 233. The content of heavy rare earth elements in the third diffusion region 233 is greater than that in the non-diffusion region. In this embodiment, the first diffusion region 231 and the second diffusion region 232 are distributed in a long strip along each long side of the permanent magnet 230 and are connected by two third diffusion regions 233, forming a U-shaped structure in the direction of the length and width of the permanent magnet 230.

[0167] It can be understood that the cross-sectional area of ​​the third diffusion zone is S3mm 2, satisfy:

[0168] Among them, 0.01≤k3≤0.95. The further value range of k3 and S3 can refer to k i and S i , which is not repeated here.

[0169] like Figure 7 As shown, in another embodiment, the first diffusion region 231 and the second diffusion region 232 are distributed in strips on each long side of the permanent magnet 230, and the third diffusion region 233 is arranged in strips between the first diffusion region 231 and the second diffusion region 232, forming a three-strip structure.

[0170] Depending on the configuration of the diffusion region, the anti-demagnetization performance of the permanent magnet 230 may be different, and the application scenarios to which it is adapted may be different. Table 1 shows the following. Figure 2 、 Figures 5 to 7The characteristics of the diffusion zones of different configurations are shown to be different. In actual working conditions, several diffusion zones can be set and different arrangements of the diffusion zones can be selected as needed.

[0171] Table 1 Characteristics of different diffusion zone configurations

[0172]

[0173] In one embodiment, the rotor core 210 is provided with a plurality of groups of rotor slots 220, and a plurality of permanent magnets 230 are respectively disposed in each group of rotor slots 220. One or more permanent magnets 230 may be disposed in a group of rotor slots 220, and all permanent magnets 230 in the same group of rotor slots 220 constitute a magnetic pole. Generally, when a magnetic pole is composed of multiple permanent magnets 230, it is more conducive to enhancing the motor's anti-demagnetization capability.

[0174] Each set of rotor slots 220 may be as follows Figure 1 The straight shape shown can also be V-shaped ( Figure 8 )、W-shaped( Figure 9 , the first diffusion zone 231 and the second diffusion zone 232 are not shown) and other different configurations. Among them, multi-side slot structures such as V-shaped and W-shaped can accommodate more permanent magnets 230, which is beneficial to increase the amount of permanent magnets 230 and improve the demagnetization resistance of the motor. It should be noted that the V-shaped means that the rotor slot 220 is composed of two side slots arranged in a V shape, and the angle between the two side slots is: 0°<θ<180°, and further 90°<θ<180°. The W-shaped means that the rotor slot 220 is composed of four side slots arranged in a nearly W shape, and the four side slots form three V-shaped shapes with two common sides (the angle between the two side slots is θ, θ is as defined above), and the openings of two adjacent V-shaped slots are facing opposite directions.

[0175] In addition, the rotor slots 220 may also be a combination of different configurations, such as Figure 10 As shown, the rotor slots 220 are a combination of a V-shape (with the angle between the two slots being θ) and a straight line. The V-shaped opening faces the outside of the rotor 200, while the straight line is perpendicular to the line connecting the V-shaped tip (the intersection of the two slot axes) and the axis of the rotor 200 and is accommodated within the V-shaped opening. This arrangement creates an enclosed magnetic pole, further improving demagnetization resistance.

[0176] As an embodiment, the number of groups of rotor slots 220 is not less than 4, and correspondingly, the number of pole pairs of the rotor 200 (half of the number of magnetic poles) is not less than 2. For example, the number of groups of rotor slots 220 is 4-10, specifically 6, 8 or 10, and correspondingly, the number of pole pairs of the rotor 200 is 2-5, specifically 3, 4 or 5. Figure 1 As shown, the number of groups of rotor slots 220 is 6, and the number of pole pairs of rotor 200 is 3.

[0177] As an embodiment, the number Q of the stator slots 120 is ≥ 9, for example, it can be 9 or 12. Figure 1 As illustrated, the number of stator slots 120 is nine.

[0178] As an embodiment, the winding 130 is a distributed winding or a concentrated winding. For the concentrated winding, the number of turns N of the concentrated winding on each stator tooth 110 is set to s , then the total number of turns N of each phase of the winding 130 in series is: Wherein, Q is the number of stator slots 120, m is the number of phases, and a is the number of parallel branches of each phase of the concentrated winding. Furthermore, the number of turns N of the concentrated winding on each stator tooth 110 is s The number a of branches connected in parallel per phase is 1 or 2.

[0179] In addition, according to another classification method, the winding 130 is further divided into a single-layer winding or a multi-layer winding. Generally, for household compressor motors, single-layer windings or double-layer windings are mostly used.

[0180] As an embodiment, the rotor core is made of multiple silicon steel sheets stacked together. The laminated structure reduces the amount of cutting scraps, improves the utilization rate of silicon steel materials, and can also reduce eddy current loss, reduce temperature rise, and increase the service life of the motor. For similar purposes, the stator core can choose a block structure instead of an integral structure. The block structure of the stator core 100 is shown in FIG. Figure 12 , wherein each stator tooth 110 corresponds to a block, and two adjacent blocks form a stator slot 120.

[0181] According to some embodiments of the first aspect of the present invention, the stator core is a block-type structure, wherein the number of blocks is equal to the number of stator teeth.

[0182] The following uses a specific motor structure as an example for explanation. The relevant parameters of the motor are as follows. Except for the differences reflected in the motor parameters, the other structures of the motors are the same.

[0183] The permanent magnet 230 has a length * width * thickness = 54.5 mm * 18 mm * 2.5 mm, and is model 52SH.

[0184] The size of the first diffusion area 231 and the second diffusion area 232: length * width * depth = 54.5mm * 4mm * 2.5mm, S1 = S2 = 4mm * 2.5mm = 10mm 2 , the shapes of the two diffusion regions are as follows Figure 10 Indicated;

[0185] Mass percentage of heavy rare earth elements in the first diffusion region 231 (total amount of dysprosium and terbium): 1.05%-2.0%;

[0186] Mass percentage of heavy rare earth elements in the second diffusion zone 232 (total amount of dysprosium and terbium): 0.59%-1.25%;

[0187] Mass percentage of heavy rare earth elements in the non-diffusion zone (total amount of dysprosium and terbium): 0.0%-0.53%.

[0188] It should be noted that the content of heavy rare earth elements in the first diffusion region 231 , the second diffusion region 232 and the non-diffusion region can be reasonably selected according to the intrinsic coercivity in Table 2, and there is no technical difficulty.

[0189] The winding 130 is a concentrated winding, connected in a delta configuration, c = 1; the number of rotor slots 220 groups Q = 9; the number of phases m = 3; the number of turns of the concentrated winding on the stator teeth 110 N s =88, the total number of turns N of each phase of the winding 130 connected in series is 264; the air gap 300 is 0.6 mm; the slot width b1 of the stator slot 120 is 4.5 mm;

[0190] Calculation shows K1=k2=0.1138.

[0191] Furthermore, the motor's anti-demagnetization performance was tested. The test method is as follows:

[0192] The rotor 200 is magnetized and placed at room temperature to measure the initial magnetic flux φ0 of the rotor 200. After the initial magnetic flux is measured, the rotor 200 is placed in a constant temperature box for more than 4 hours, and the temperature of the constant temperature box is set at 13°C.

[0193] Connect the test DC motor to a DC power supply and set the demagnetization current according to the preset demagnetization current value. When ready, remove the rotor 200 from the constant temperature chamber, install the demagnetization test fixture, and rotate the rotor 200 one circle under the DC demagnetization current. After completion, place the rotor 200 at room temperature for more than 4 hours, and then measure the temperature of the rotor 200 and the magnetic flux φ1 after demagnetization.

[0194] The demagnetization rate is calculated according to the following formula: Demagnetization rate = (φ0-φ1) / φ0*100%.

[0195] Table 2 shows the performance comparison of the motors (motor 1 and motor 2) of this embodiment compared with a motor (existing motor) without the first diffusion region 231 and the second diffusion region 232 .

[0196] Table 2 Anti-demagnetization performance of different motors

[0197]

[0198]

[0199] As shown in Table 2, motor 1 significantly improves demagnetization resistance by providing first and second diffusion regions 231 and 232, each containing a higher content of heavy rare earth elements, within permanent magnet 230. Furthermore, while maintaining a comparable demagnetization rate, the heavy rare earth element content in permanent magnet 230 can be reduced compared to conventional motors, thereby reducing motor cost.

[0200] Thanks to the performance and cost advantages of the motor of the embodiment of the present invention, its application in household appliances such as air conditioners, refrigerators, and freezers can also achieve the effect of reducing costs and increasing efficiency.

[0201] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, 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 spirit of the present invention.

Claims

1. A motor, characterized in that include: The rotor comprises a rotor core and a plurality of permanent magnets arranged on the rotor core, wherein the permanent magnets are provided with a non-diffusion zone and a diffusion zone, wherein the content of heavy rare earth elements in the diffusion zone is greater than the content of heavy rare earth elements in the non-diffusion zone, and the cross-sectional area of ​​the diffusion zone in the direction perpendicular to the axis of the rotor is S i mm 2 ; A stator, the stator comprising a stator core disposed around the outside of the rotor, the stator core being provided with a plurality of stator teeth, with every two adjacent stator teeth forming a stator slot, the stator slots being provided with windings wound around the stator teeth, the total number of turns of the windings connected in series per phase being N, the slot width of the stator slot being b1 mm, and the gap between the stator and the rotor being δ mm; The motor meets the following requirements: Where, 0.01≤k i ≤0.95; when the connection form of the winding on the stator teeth is a delta connection, c=1; when the connection form of the winding on the stator teeth is a star connection, c=0.

2. The motor according to claim 1, characterized in that The number of the diffusion region is one or more.

3. The motor according to claim 1, characterized in that The diffusion regions are distributed with equal or unequal cross sections along the length direction of the permanent magnet.

4. The motor according to claim 1, characterized in that The diffusion region includes a first diffusion region and a second diffusion region, and the cross-sectional area of ​​the first diffusion region is S1 mm 2 , the cross-sectional area of ​​the second diffusion zone is S2 mm 2 , and satisfy: and Among them, 0.01≤k1≤0.95; 0.01≤k2≤0.

95.

5. The motor according to claim 4, characterized in that The cross-sectional area of ​​the first diffusion region accounts for 2%-90% of the cross-sectional area of ​​the permanent magnet, and / or the cross-sectional area of ​​the second diffusion region accounts for 2%-90% of the cross-sectional area of ​​the permanent magnet.

6. The motor according to claim 4, characterized in that The cross-sectional area of ​​the first diffusion region is S1 mm 2 , cross-sectional area of ​​the second diffusion zone S2 mm 2 Meet: 1mm 2 ≤S1≤40mm 2 and / or 1mm 2 ≤S2≤40mm 2 .

7. The motor according to any one of claims 4 to 6, characterized in that The diffusion region further includes a third diffusion region.

8. The motor according to claim 7, characterized in that The first diffusion region, the third diffusion region, and the second diffusion region are sequentially spaced apart along the width direction of the permanent magnet to form a three-strip structure.

9. The motor according to claim 7, characterized in that The first diffusion region and the second diffusion region are connected through the third diffusion region to form a U-shaped structure.

10. The motor according to claim 1, characterized in that The rotor core is provided with a plurality of rotor slots, and a plurality of permanent magnets are respectively arranged in the plurality of rotor slots.

11. The motor according to claim 1, characterized in that Each group of rotor slots is in a V-shape, a straight-line shape, a W-shape or a combination thereof.

12. The motor according to claim 1, characterized in that The mass percentage of heavy rare earth elements in the diffusion zone is 0.59%-2.0%.

13. The motor according to claim 1, characterized in that The pole pair number P of the rotor is ≥2.

14. The motor according to claim 1, wherein The total number of turns N of each phase of the winding connected in series is Wherein, Q is the number of stator slots, m is the number of phases, a is the number of parallel branches per phase of the concentrated winding, and N s is the number of turns of the concentrated winding on the stator teeth, N s =50-140.

15. The motor according to claim 1, characterized in that The slot width b1 of the stator slot is 2-4.5 mm, and / or the gap δ between the stator and the rotor is 0.55-0.85 mm.

16. A compressor, characterized in that The motor comprises the motor according to any one of claims 1 to 15.

17. A household appliance, characterized in that The method comprises the motor according to any one of claims 1 to 15 or the compressor according to claim 16.

18. The household appliance according to claim 17, characterized in that The household appliances include air conditioners, refrigerators or freezers.

Images