Rotor, motor, compressor and air conditioning equipment

By setting a dual fixing mechanism of limiting protrusions and abutment protrusions in the rotor core, the problem of axial movement of permanent magnets is solved, the stability and reliability of the motor are improved, noise and vibration are reduced, and the service life of the motor is extended.

CN223967713UActive Publication Date: 2026-03-03GUANGDONG MEIZHI COMPRESSOR
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2025-03-04
Publication Date
2026-03-03

AI Technical Summary

Technical Problem

In existing technologies, permanent magnets are prone to axial movement on the rotor, leading to increased friction, noise, and vibration in the internal components of the motor, which affects the motor's service life and reliability.

Method used

By setting a second lamination with a limiting protrusion in the rotor core and a first lamination with an abutting protrusion at one axial end, a double fixing mechanism is formed to restrict the axial movement of the permanent magnet.

Benefits of technology

It effectively prevents the permanent magnet from moving axially, improves the stability and reliability of the motor, reduces noise and vibration, and extends the service life of the motor.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses a rotor, motor, compressor and air conditioning equipment, relates to the motor technical field, a rotor core is provided with a plurality of magnet slots along the circumferential direction, the rotor core comprises a first punching sheet, a second punching sheet and a third punching sheet, the first punching sheet, the second punching sheet and the third punching sheet are laminated along the axial direction, permanent magnets are arranged in the magnet slots, the permanent magnets pass through the second punching sheet and the third punching sheet, the first punching sheet is arranged at the axial end part of the permanent magnet, the second punching sheet is arranged at the middle part of the rotor core, the minimum width in the circumferential direction in the accommodating area of the permanent magnet in the magnet groove of the second punching sheet is L2, the minimum width in the circumferential direction in the accommodating area of the permanent magnet in the magnet groove of the first punching sheet is L1, and the width in the circumferential direction of the magnet groove of the third punching sheet is W, w > d > L2 > = L1. According to the scheme, the permanent magnets are limited through the first punching sheets and the second punching sheets, so that the permanent magnets are fixed in the magnet grooves more stably, and the stability and reliability of the motor during operation are improved.
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Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a rotor, motor, compressor and air conditioning equipment. Background Technology

[0002] The rotor has magnet slots, and permanent magnets are placed in the magnet slots. To prevent the permanent magnets from moving axially, end plates are usually placed at both ends of the rotor to limit the movement of the permanent magnets, and then balance blocks are set to restrict the axial movement of the permanent magnets. If the end plates are eliminated, the product cost-effectiveness can be improved, but the permanent magnets will still have the problem of axial movement. Currently, there are also solutions that limit the movement of the magnets by setting two or more laminations in the rotor axial direction. However, the length of the iron core is generally greater than the length of the magnets, making it difficult to completely avoid the phenomenon of axial displacement of the magnets. The magnets will vibrate inside the iron core. This situation will not only increase the friction between the internal components of the motor and reduce the working efficiency, but may also cause unnecessary noise and vibration, seriously affecting the service life and reliability of the motor. Utility Model Content

[0003] The main purpose of this utility model is to propose a rotor, motor, compressor and air conditioning equipment, which aims to provide a solution to prevent the permanent magnet from axially displacing during operation. By limiting the permanent magnet with the first and second laminations, the permanent magnet is more firmly fixed in the magnet slot, which improves the stability and reliability of the motor during operation, prevents the magnet from moving axially, and makes the product quieter.

[0004] To achieve the above objectives, the rotor proposed in this utility model comprises:

[0005] Multiple permanent magnets, wherein the circumferential width of the permanent magnets is d; and

[0006] The rotor core has multiple magnet slots arranged circumferentially. The rotor core includes a first lamination, a second lamination, and a third lamination stacked axially. A permanent magnet is disposed in the magnet slots and passes through the second lamination and the third lamination. The first lamination is disposed at the axial end of the permanent magnet, and the second lamination is disposed in the middle of the rotor core. The minimum circumferential width of the magnet slot of the second lamination within the area for accommodating the permanent magnet is L2. The minimum circumferential width of the magnet slot of the first lamination within the area for accommodating the permanent magnet is L1. The circumferential width of the magnet slot of the third lamination is W, where W > d > L2 ≥ L1.

[0007] In one embodiment, the first lamination has an abutting protrusion in the magnet groove, which abuts against the end of the permanent magnet in the axial direction. The second lamination has a limiting protrusion protruding into the magnet groove, which extends circumferentially and abuts against the sidewall of the permanent magnet.

[0008] In one embodiment, the abutting protrusion and / or the limiting protrusion are disposed on the long side of the magnet groove in the radial direction.

[0009] In one embodiment, the abutting protrusions are provided in a plurality of staggered arrangement on the two opposite long sides of the rotor core in the radial direction of the magnet slot.

[0010] In one embodiment, the limiting protrusions are provided in a plurality of staggered arrangement on the two opposite long sides of the magnet groove in the radial direction.

[0011] In one implementation, 0.3*W≥L1.

[0012] In one embodiment, the axial height of the rotor core is T0, the total axial thickness of the plurality of first laminations is T1, and the total axial thickness of the plurality of second laminations is T2, satisfying the relationship: 0 < T1 < 0.3 * T0, 0 < T2 < 0.2 * T0.

[0013] In one embodiment, the plurality of magnet slots are arranged in multiple groups along the circumference, and each group is in the shape of a line, a V, a U, or a W.

[0014] In one embodiment, the second lamination is disposed at the lower end of the rotor core along the axial direction, and the limiting protrusion is used to abut against the end of the permanent magnet in the magnet slot, thereby restricting the permanent magnet in the magnet slot from detaching.

[0015] This utility model also proposes an electric motor, including the rotor described above.

[0016] This utility model also proposes a compressor, including the motor described above.

[0017] This utility model also proposes an air conditioning device, including a compressor or motor as described above.

[0018] This solution solves the problem of axial movement and vibration caused by insecure permanent magnet fixation in existing technologies by setting a second lamination with a limiting protrusion in the middle of the rotor core and a first lamination with an abutting protrusion at one axial end of the rotor core. Specifically, the limiting protrusion contacts and slightly presses the side of the permanent magnet, thereby initially fixing the permanent magnet in the axial direction; while the abutting protrusion is located at the axial end of the magnet slot, thus acting on the end face of the permanent magnet and further restricting any possible displacement of the permanent magnet in the axial direction. This dual fixing mechanism not only ensures the firmness of the magnet installation, but also significantly improves the stability and reliability of the motor during operation. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the structure of an embodiment of the rotor provided by this utility model;

[0021] Figure 2 This is a schematic diagram of the structure of one embodiment of the first lamination;

[0022] Figure 3 This is a schematic diagram of the structure of one embodiment of the second lamination;

[0023] Figure 4 This is a schematic diagram of the structure of one embodiment of the third lamination;

[0024] Figure 5 This is a schematic diagram of another embodiment of the first lamination;

[0025] Figure 6 This is a schematic diagram of another embodiment of the second lamination;

[0026] Figure 7 This is a diagram showing the difference in compressor noise between the infinite and finite protrusions of the second lamination.

[0027] Explanation of icon numbers:

[0028] 100. First punching; 110. Contacting the convex part;

[0029] 200. Second lamination; 210. Limiting protrusion;

[0030] 300, Third stamping;

[0031] 400. Magnetic slot;

[0032] 500. Permanent magnet.

[0033] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0035] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0036] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0037] The rotor has magnet slots, and permanent magnets are placed in the magnet slots. To prevent the permanent magnets from moving axially, end plates are usually placed at both ends of the rotor to limit the movement of the permanent magnets, and then balance blocks are set to restrict the axial movement of the permanent magnets. If the end plates are eliminated, the product cost-effectiveness can be improved, but the permanent magnets will still have the problem of axial movement. Currently, there are also solutions that limit the movement of the magnets by setting two or more laminations in the rotor axial direction. However, the length of the iron core is generally greater than the length of the magnets, making it difficult to completely avoid the phenomenon of axial displacement of the magnets. The magnets will vibrate inside the iron core. This situation will not only increase the friction between the internal components of the motor and reduce the working efficiency, but may also cause unnecessary noise and vibration, seriously affecting the service life and reliability of the motor.

[0038] This invention proposes a rotor designed to prevent axial displacement of permanent magnets during operation. By restricting the permanent magnets at their ends, the end plates at both ends of the motor can be removed, making the rotor simpler. At the same time, it can fix the magnets to prevent axial movement, resulting in better noise reduction of the product.

[0039] Please see Figures 1 to 5 In one embodiment of this utility model, the rotor core is provided with a plurality of magnet slots 400 along the circumferential direction. The circumferential width of the permanent magnet is d. The permanent magnet 500 is disposed in the magnet slots 400. The rotor core includes a first lamination 100, a second lamination 200 and a third lamination 300 stacked along the axial direction. The permanent magnet 500 passes through the second lamination 200 and the third lamination 300. The first lamination 100 is disposed at the axial end of the permanent magnet 500. The second lamination 200 is disposed in the middle of the rotor core 100. The minimum circumferential width of the magnet slot of the second lamination 200 is L2. The minimum circumferential width of the magnet slot of the first lamination 100 is L1. The circumferential width of the magnet slot of the third lamination 300 is W, where W > d > L2 ≥ L1.

[0040] The parameters are defined as follows:

[0041] d: Circumferential width of permanent magnet 500, i.e., the size of permanent magnet along the circumferential direction of rotor. Start / End: along the circumferential direction of permanent magnet, take the equivalent projection lines of the two end faces (axial end faces) of permanent magnet, and take the average value.

[0042] L1: The minimum circumferential width of the magnet slot 400 of the first lamination 100. Measurement start point: the outer edge of the slot on the first lamination. Measurement end point: the inner edge of the slot bottom (contact surface with the permanent magnet) on the first lamination. It refers to the circumferential dimension at the narrowest point of the magnet slot of the first lamination.

[0043] L2: The minimum circumferential width of the magnet slot 400 of the second lamination 200. Measurement start point: the outer edge of the slot on the second lamination. Measurement end point: the inner edge of the slot bottom on the second lamination (the contact surface with the permanent magnet). The second lamination is located in the middle of the rotor core, and the circumferential dimension of the narrowest part of its magnet slot must satisfy L2≥L1.

[0044] The minimum width of the magnet slot in the circumferential direction refers to the minimum radial dimension of the magnet slot projected along the direction perpendicular to the axis of the permanent magnet within the effective accommodating area of ​​the magnet slot (if the magnet slot is "V-shaped" or "trapezoidal", the minimum dimension is not the bottom of the V-shaped slot, but the minimum radial distance of the slot wall of the magnet slot within the magnet placement area). The starting point for measurement is a point on the slot wall of the magnet slot.

[0045] W: The circumferential width of the magnet slot 400 of the third lamination 300. The measurement start point is the edge of the slot on the outer edge of the third lamination (the non-permanent magnet side), and the measurement end point is the bottom edge of the slot on the inner edge of the third lamination (the side closer to the permanent magnet). The circumferential dimension of the magnet slot of the third lamination is a fixed value W (usually uniform, but there may be manufacturing errors, so the average value can be taken), and it satisfies W>d.

[0046] The first lamination 100 has an abutting protrusion 110 in the magnet groove 400, and the second lamination 200 has a limiting protrusion 210 protruding into the magnet groove 400. The limiting protrusion 210 extends circumferentially and abuts against the side wall of the permanent magnet 500. The abutting protrusion 110 is disposed at the axial end of the permanent magnet 500, and the abutting protrusion 110 forms an abutment against the end of the permanent magnet 500 in the axial direction.

[0047] The rotor core is a crucial component of the motor, featuring multiple magnet slots 400 circumferentially arranged to accommodate permanent magnets 500. The rotor core is formed by stacking multiple laminations, specifically, the first lamination 100, the second lamination 200, and the third lamination 300 are riveted together. The first lamination 100 is located at the end of the rotor core, ensuring that the end face of the magnet located within the magnet slot 400 is abutted by the abutting protrusion 110 within the magnet slot 400, thus enhancing the reliability of the permanent magnet 500's fixation. Furthermore, because the first lamination 100, the second lamination 200, and the third lamination 300 are riveted together, with the first lamination 100 abutting the end of the permanent magnet 500 and the limiting protrusion 210 of the second lamination 200 contacting the sidewall of the permanent magnet 500, the end plate can be eliminated, simplifying the rotor core structure. The first lamination 100 is located at one axial end of the rotor core, near either the side closest to the motor.

[0048] Combination Figure 2 and Figure 5 The second lamination 200 is located in the middle of the rotor core, specifically within a quarter-height range of the rotor core above and below the dividing line in the middle of the rotor core. The number of second laminations 200 is not limited, but at least one is required. If there are two or more, they can be stacked and then placed in the middle of the rotor core, or they can be spaced apart in the middle of the rotor core. For example, with six second laminations 200, in one configuration, the six second laminations 200 are stacked together and placed in the middle, that is, stacked between the cores formed by the third laminations 300. The first lamination 100 is located at the end, for example, at the bottom. Then, the rotor core, from bottom to top, consists of at least one first lamination 100, several third laminations 300, several second laminations 200, and several third laminations 300 (e.g., ...). Figure 1 In another scheme, the six second laminations 200 are divided into two groups of three stacked second laminations 200 groups, and a group of third laminations 300 is set between the two groups of second laminations 200; or the six second laminations 200 are divided into three groups of two stacked second laminations 200 groups, and the three groups of second laminations 200 are arranged at intervals along the axial direction of the rotor core.

[0049] Because the limiting protrusion 210 of the second lamination 200 is specifically located within the magnet groove 400. When the permanent magnet 500 is installed in the magnet groove 400, the limiting protrusion 210 contacts and slightly presses the permanent magnet 500, thereby effectively preventing the permanent magnet 500 from moving axially and increasing the stability of the permanent magnet 500. At the same time, the first lamination 100 is provided with an abutting protrusion 110, which is located at the axial end of the magnet groove 400 of the rotor core, thereby preventing the magnet from sliding out or detaching from one end of the magnet groove 400, thus enhancing the reliability of the entire magnet fixing system.

[0050] This solution solves the problem of axial movement and vibration caused by insecure fixing of the permanent magnet 500 in the prior art by setting a second lamination 200 with a limiting protrusion 210 in the middle of the rotor core and a first lamination 100 with an abutting protrusion 110 at one axial end of the rotor core. Specifically, the limiting protrusion 210 contacts and slightly presses the side of the permanent magnet 500, thereby initially fixing the permanent magnet 500 in the axial direction; while the abutting protrusion 110 is located at the axial end of the magnet groove 400, thereby acting on the end face of the permanent magnet 500, further restricting any possible displacement of the permanent magnet 500 in the axial direction. This dual fixing mechanism not only ensures the firmness of the magnet installation, but also significantly improves the stability and reliability of the motor during operation.

[0051] Reference Figures 2 to 5 Specifically, the abutting protrusion 110 and / or the limiting protrusion 210 are provided on the long side of the magnet groove 400 in the radial direction. The axial cross-section of the magnet groove 400 is rectangular, and the long side of the rectangle extends in the radial direction. The abutting protrusion 110 is provided on the long side. In one embodiment, the abutting protrusion 110 is provided on one long side, such as in the middle, or multiple protrusions are spaced apart on one long side. In another embodiment, the abutting protrusion 110 is provided on two opposite long sides, and the abutting protrusions 110 on the two long sides are opposite or staggered. Similarly, the limiting protrusion 210 can also be provided on the second lamination 200 in the same way as the abutting protrusion 110. Of course, the limiting protrusion 210 is also provided on the short side, or on both the long and short sides, to restrict the permanent magnet 500 in the magnet groove 400 from disengaging.

[0052] To ensure the installation of the permanent magnet 500 and to guarantee the fixing effect of the abutment protrusion 110 on the permanent magnet 500, the distance from the end of the abutment protrusion 110 to the other side of the magnet groove 400 is L1, and the distance from the end of the limiting protrusion 210 to the other side of the magnet groove 400 is L2, where L2 is greater than or equal to L1. By limiting L2, i.e., the distance from the limiting protrusion 210 to the other side of the magnet groove 400, appropriate pressure support is ensured in the central position of the magnet, avoiding excessive tightness or looseness. Appropriate contact pressure effectively prevents minute movements of the magnet during high-speed rotation, thereby reducing vibration.

[0053] The second lamination 200 can be the same as or different from the first lamination 100.

[0054] Specifically, the width of the magnet slot 400 in the circumferential direction of the rotor core is W, where W > L2 ≥ L1. Maintaining L2 greater than or equal to L1 makes the restriction of the magnets at both ends in the axial direction more reasonable. In particular, L1, as the outermost limiting point, has a smaller proportion relative to the width W of the magnet slot 400, ensuring that even in extreme cases, the magnets will not easily slip out or shift. By setting the width W of the magnet slot 400 to be greater than L2 (the distance from the end of the limiting protrusion 210 to the other side of the magnet slot 400), since L2 is greater than or equal to L1, it ensures that the magnets can be firmly fixed. The larger width W of the magnet slot 400 allows for some adjustment space when installing the magnets, reducing assembly difficulty caused by insufficient precision and improving assembly efficiency. L1 can also prevent the permanent magnets 500 within the magnet slot 400 from detaching.

[0055] Specifically, the width W of the magnet slot 400 and the limiting protrusion 210 satisfy the relationship: 0.3*W≥L2. By limiting 0.3*W≥L2, it is ensured that the limiting protrusion 210 does not get too close to the edge of the magnet slot 400, ensuring a reasonable assembly clearance. This makes it easier to insert the magnet into the magnet slot 400 and reduces assembly difficulty. At the same time, it allows for fine-tuning of the magnet to achieve the best positioning effect.

[0056] Reference Figure 1 Specifically, the axial height of the rotor core is T0, the total axial thickness of the first lamination 100 is T1, and the total axial thickness of the second lamination 200 is T2, satisfying the relationship: 0 < T1 < 0.3 * T0, 0 < T2 < 0.2 * T0.

[0057] T1 (Total Axial Thickness of the First Lamination): This refers to the overall thickness of the first lamination 100 along the rotor axis, which is composed of multiple stacked thin silicon steel sheets. For example, if the first lamination is made of 10 layers of silicon steel sheets, each with a thickness of 0.5mm, then T1 = 100 × 0.5mm = 50mm (theoretical value). Actual measurements may have an error of 0.2mm-1mm above or below the theoretical value (insufficient pressure can cause interlayer gaps).

[0058] T2 (Total Axial Thickness of the Second Lamination): The second lamination 200 is located in the middle of the rotor, and its total thickness after stacking is T2. The structure is similar to T1, but the thickness may differ depending on functional requirements.

[0059] Using a digital caliper or laser thickness gauge, place the first stacked lamination 100 vertically on the measuring platform. Measure the thickness at 3-5 evenly spaced points along the axial direction (avoiding edge warping errors). Take the average value as the actual value of T1.

[0060] First, 0 < T1 < 0.3 * T0, the first lamination 100 is at one end of the rotor core, and its proportion in the axial height of the entire rotor core is relatively small, but it is sufficient to provide the necessary support and fixing functions. That is, this ensures that the magnet can be effectively positioned and supported, while avoiding excessive increase in the overall weight or size of the rotor core, which helps to maintain the efficient operation of the motor.

[0061] 0 < T2 < 0.2 * T0, the fixing strength provided by the limiting protrusion 210 is sufficient to prevent the magnet from detaching. An appropriate T2 value can ensure that the magnet is firmly fixed while maintaining a good balance and operational stability of the rotor core.

[0062] Secondly, by limiting the specific ratio of T1 and T2, the amount of material used in manufacturing the stampings can be effectively reduced, thereby lowering production costs. Reasonable material use not only benefits economic efficiency but also meets environmental protection requirements.

[0063] In addition, multiple magnet slots 400 are arranged in multiple groups along the circumference, and each group is in the shape of a straight line, a V-shape, a U-shape, or a W-shape; for example, two magnet slots 400 form a group in a V-shape, and multiple groups are arranged in the circumference of the rotor core; or three magnet slots 400 form a group in a U-shape, and multiple groups are arranged in the circumference of the rotor core.

[0064] In summary, this solution solves the problem of axial movement caused by insecure magnet fixation, simplifies the assembly process, enhances the overall performance of the motor, and the stable 500 permanent magnet fixation can effectively reduce the noise and vibration generated during motor operation, extend the motor's service life, and improve the user experience.

[0065] This utility model also proposes an electric motor, which includes a rotor and a stator. The specific structure of the rotor is as described in the above embodiments. Since this electric motor adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here. The rotor includes a rotor rotatably disposed within the stator.

[0066] This utility model also proposes a compressor, including a housing and a motor arranged inside the housing. The motor adopts the rotor described above, and the specific structure of the rotor is as described in the above embodiment.

[0067] Reference Figure 7 , Figure 7 This is a graph showing the noise difference between the compressor with and without the limit protrusion 210 of the second lamination 200. The horizontal axis represents two different technical solutions, i.e., "without the limit protrusion 210" and "with the limit protrusion 210". The Y-axis represents the noise level in decibels (dB). The legend shows the two frequency markings: 500Hz is represented by a dark fill, and 630Hz by a light grid. As can be seen from the graph, at 500Hz: the noise level of the prior art without the limit protrusion 210 is 52dB. The noise level with the limit protrusion 210 is 49dB. This indicates that the noise level of this solution is 3dB lower than the prior art at 500Hz. At 630Hz, the noise level of the prior art without the limit protrusion 210 is 45dB. The noise level of this solution is 43dB. This indicates that the noise level of this solution is 2dB lower than the prior art at 630Hz. This solution achieves lower noise levels than existing technologies at both frequencies, demonstrating its advantage in reducing low-frequency noise.

[0068] This utility model also proposes an air conditioning device, including the above-mentioned compressor or motor, wherein the compressor or motor includes the above-mentioned rotor, and the specific structure of the rotor is as described in the above embodiments, and will not be repeated here.

[0069] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A rotor, characterized in that, include: Multiple permanent magnets, wherein the circumferential width of the permanent magnets is d; and The rotor core has multiple magnet slots arranged circumferentially. The rotor core includes a first lamination, a second lamination, and a third lamination stacked axially. A permanent magnet is disposed in the magnet slots and passes through the second lamination and the third lamination. The first lamination is disposed at the axial end of the permanent magnet, and the second lamination is disposed in the middle of the rotor core. The minimum circumferential width of the magnet slot of the second lamination within the area for accommodating the permanent magnet is L2. The minimum circumferential width of the magnet slot of the first lamination within the area for accommodating the permanent magnet is L1. The circumferential width of the magnet slot of the third lamination is W, where W > d > L2 ≥ L1.

2. The rotor as claimed in claim 1, characterized in that, The first lamination has an abutting protrusion in the magnet groove, which forms an abutment against the end of the permanent magnet in the axial direction. The second lamination has a limiting protrusion that protrudes into the magnet groove, which extends circumferentially and abuts against the side wall of the permanent magnet.

3. The rotor as described in claim 2, characterized in that, The abutting protrusion and / or the limiting protrusion are provided on the long side of the magnet groove in the radial direction.

4. The rotor as described in claim 2, characterized in that, The abutting protrusions are provided in multiple staggered positions on the two opposite long sides of the rotor core in the radial direction of the magnet slot; and / or, the limiting protrusions are provided in multiple staggered positions on the two opposite long sides of the magnet slot in the radial direction.

5. The rotor as claimed in claim 1, characterized in that, 0.3*W≥L2.

6. The rotor as claimed in claim 1, characterized in that, The axial height of the rotor is T0, the total axial thickness of the first lamination is T1, and the total axial thickness of the second lamination is T2, satisfying the relationship: 0 < T1 < 0.3 * T0, 0 < T2 < 0.2 * T0.

7. The rotor as claimed in claim 1, characterized in that, The multiple magnet slots are arranged in multiple groups along the circumference, and each group is in the shape of a straight line, a V-shape, a U-shape, or a W-shape.

8. The rotor as claimed in claim 2, characterized in that, The second lamination is located at the lower end of the rotor core along the axial direction. The limiting protrusion is used to abut against the end of the permanent magnet in the magnet slot, thereby preventing the permanent magnet in the magnet slot from detaching.

9. An electric motor, characterized in that, Includes a rotor as described in any one of claims 1 to 8.

10. A compressor, characterized in that, Includes the motor as described in claim 9.

11. An air conditioning device, characterized in that, Includes the compressor as described in claim 10.