Rotor, electric machine and compressor

Abstract

The application discloses a rotor, a motor and a compressor, and relates to the technical field of motors, wherein the rotor comprises a rotor core and a permanent magnet, the rotor core comprises a core body, the core body comprises at least one first punching sheet and a plurality of second punching sheets which are stacked along an axial direction, the first punching sheet and the second punching sheet are each provided with a magnetic steel slot, a limiting protrusion is arranged on the slot wall of the magnetic steel slot of the first punching sheet, the shortest distance from the limiting protrusion to the slot wall opposite to the limiting protrusion is L, and the width of the magnetic steel slot is W; the permanent magnet is arranged in the magnetic steel slot, the thickness of the permanent magnet is T, and the following condition is met: 0 < L < 5 x (W-T). The technical scheme provided by the application can prevent the permanent magnet from vibrating when the rotor rotates, thereby being favorable for improving the noise level of the motor and the compressor.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a rotor, motor, and compressor. Background Technology

[0002] In modern motor systems, permanent magnet motors are widely used in electric vehicles, industrial drives, aerospace, and many other fields due to their numerous advantages such as high efficiency, energy saving, and high power density. The rotor of a permanent magnet motor typically uses permanent magnets to provide the magnetic field, and the stable installation of these permanent magnets is crucial to the motor's performance and reliability.

[0003] Currently, common methods for fixing permanent magnets in permanent magnet motor rotors include mechanical fixing and adhesive fixing. However, these traditional methods face the risk of permanent magnet vibration during actual operation. Summary of the Invention

[0004] The main objective of this invention is to provide a rotor, motor, and compressor designed to solve the problem of permanent magnet vibration.

[0005] To achieve the above objectives, the rotor proposed in this invention comprises:

[0006] A rotor core, comprising a core body, the core body including at least one first lamination and a plurality of second laminations stacked along the axial direction, wherein both the first and second laminations are provided with magnetic slots, the slot wall of the magnetic slot of the first lamination is provided with a limiting protrusion, the shortest distance from the limiting protrusion to the slot wall opposite the limiting protrusion is L, and the width of the magnetic slot is W; and

[0007] A permanent magnet is disposed in the magnetic steel groove, and the thickness of the permanent magnet is T, which satisfies: 0 < L < 5 × (WT).

[0008] In one embodiment, the difference between W and T satisfies: 0 < WT < 0.3 mm.

[0009] In one embodiment, the rotor core further includes a third lamination located at one end of the core body. The third lamination has a limiting groove corresponding to the magnet slot. A limiting rib is provided between the two slot walls that are arranged opposite each other in the width direction of the limiting groove. The limiting rib is used to limit the end of the permanent magnet.

[0010] In one embodiment, the width of the limiting rib is d1, and the width of the permanent magnet is d2, wherein d1 and d2 satisfy: d1 < d2.

[0011] In one embodiment, the width d1 of the limiting rib satisfies: 0.15mm < d1 < 5mm.

[0012] In one embodiment, the third lamination is located within the first 15 laminations of the rotor core from the end inwards.

[0013] In one embodiment, the first lamination is located between a plurality of second laminations.

[0014] In one embodiment, the height of the rotor core is t, and the total stack thickness of the third type of laminations is t1, where 0 < t1 < 0.2t.

[0015] In one embodiment, the height of the rotor core is t, and the total thickness of the first lamination is t2, where 0 < t2 < 0.2t.

[0016] In one embodiment, the magnetic groove is in the shape of a straight line, a V-shape, or a U-shape.

[0017] The present invention also proposes an electric motor comprising the rotor described above.

[0018] The present invention also proposes a compressor comprising the aforementioned motor.

[0019] The technical solution of this invention provides a limiting protrusion on the groove wall of the magnet slot in the first lamination. This protrusion presses against the permanent magnet, limiting its displacement and preventing vibration during rotor rotation, thereby improving the noise level of the motor and compressor. Secondly, this solution limits the shortest distance L from the limiting protrusion to the groove wall opposite it to 0 to 5 × (WT). This ensures that the limiting protrusion presses against the permanent magnet, preventing vibration during rotor rotation, while also preventing the limiting protrusion from excessively encroaching on the width of the magnet slot and interfering with the insertion of the permanent magnet into the slot. This makes the installation of the permanent magnet more efficient and labor-saving. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the structure of the first embodiment of the rotor provided by the present invention;

[0022] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0023] Figure 3 for Figure 1 A partial structural schematic diagram of the first lamination of the rotor provided;

[0024] Figure 4 for Figure 1 A partial structural schematic diagram of the second lamination of the rotor is provided;

[0025] Figure 5 A schematic diagram of the structure of the second embodiment of the rotor provided by the present invention;

[0026] Figure 6 for Figure 5 A partial structural schematic diagram of the third lamination of the rotor is provided;

[0027] Figure 7 for Figure 5 A schematic diagram of the axial stacking of the rotor core of the provided rotor;

[0028] Figure 8 A schematic diagram of the structure of the third embodiment of the rotor provided by the present invention;

[0029] Figure 9 A schematic diagram showing the relationship between the magnetic flux leakage rate and d1 of a motor with a rotor provided by the present invention.

[0030] Explanation of icon numbers:

[0031] 100. Rotor core; 110. Core body; 111. First lamination; 112. Second lamination; 113. Magnet slot; 114. Limiting protrusion; 120. Third lamination; 121. Limiting groove; 122. Limiting rib; 200. Permanent magnet.

[0032] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications 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 indications will also change accordingly.

[0035] Furthermore, if the embodiments of this invention 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. Thus, 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 invention.

[0036] In modern motor systems, permanent magnet motors are widely used in electric vehicles, industrial drives, aerospace, and many other fields due to their numerous advantages such as high efficiency, energy saving, and high power density. The rotor of a permanent magnet motor typically uses permanent magnets to provide the magnetic field, and the stable installation of these permanent magnets is crucial to the motor's performance and reliability.

[0037] Currently, common methods for fixing permanent magnets in permanent magnet motor rotors include mechanical fixing and adhesive fixing. However, these traditional methods face the risk of permanent magnet vibration during actual operation.

[0038] To address the problem of vibration in permanent magnets during rotor rotation, this invention proposes a rotor.

[0039] Please see Figures 1 to 4 In one embodiment of the present invention, the rotor includes a rotor core 100 and a permanent magnet 200. The rotor core 100 includes a core body 110, which includes at least one first lamination 111 and a plurality of second laminations 112 stacked along the axial direction. Both the first lamination 111 and the second laminations 112 are provided with magnetic slots 113. The slot wall of the magnetic slot 113 of the first lamination 111 is provided with a limiting protrusion 114. The shortest distance from the limiting protrusion 114 to the slot wall opposite to the limiting protrusion 114 is L, and the width of the magnetic slot 113 is W. The permanent magnet 200 is disposed in the magnetic slot 113, and the thickness of the permanent magnet 200 is T, satisfying: 0 < L < 5 × (WT).

[0040] The technical solution of this invention provides a limiting protrusion 114 on the groove wall of the magnet slot 113 of the first lamination 111. This allows the limiting protrusion 114 to press against the permanent magnet 200, thereby limiting the displacement of the permanent magnet 200 and preventing vibration of the permanent magnet 200 during rotor rotation, thus improving the noise level of the motor and compressor. Secondly, this solution limits the shortest distance L from the limiting protrusion 114 to the groove wall opposite to the limiting protrusion 114 to between 0 and 5 × (WT). This ensures that the limiting protrusion 114 presses against the permanent magnet 200, preventing vibration of the permanent magnet 200 during rotor rotation, while also preventing the limiting protrusion 114 from excessively encroaching on the width space of the magnet slot 113 and interfering with the insertion of the permanent magnet 200 into the magnet slot 113. This makes the installation of the permanent magnet 200 more efficient and labor-saving.

[0041] It should be noted that the first starting point is the most protruding point of the limiting protrusion 114. A perpendicular line is drawn from the first starting point to the groove wall opposite to the limiting protrusion 114. The intersection of this perpendicular line and the groove wall opposite to the limiting protrusion 114 is the first ending point. L represents the distance between the first starting point and the first ending point.

[0042] The magnetic steel trough 113 has a first trough side and a second trough side arranged opposite to each other along its own width direction. W represents the perpendicular distance between the first trough side and the second trough side. That is, taking the center point of the first trough side as the second starting point, the center point is the intersection of the four diagonals of the first trough side. A perpendicular line is drawn from the second starting point to the second trough side. The intersection of this perpendicular line and the second trough side is the second ending point. W represents the distance between the second starting point and the second ending point.

[0043] The permanent magnet 200 has a first side and a second side distributed along its thickness direction. T represents the perpendicular distance between the first and second sides. Specifically, taking the center point of the first side as the third starting point (the intersection of the four diagonals of the first side), and drawing a perpendicular line from the third starting point to the second side, the intersection of this perpendicular line and the second side is the third ending point. T represents the distance between the third starting point and the third ending point. After the permanent magnet 200 is installed in the magnetic groove 113, the thickness direction of the permanent magnet 200 is parallel to the width direction of the magnetic groove 113.

[0044] Furthermore, in this embodiment, the difference between W and T satisfies: 0 < WT < 0.3 mm. It can be understood that 0 < WT means there is a gap between the permanent magnet 200 and the magnetic steel groove 113, which facilitates the insertion of the permanent magnet 200 into the magnetic steel groove 113, making the installation of the permanent magnet 200 more efficient and labor-saving. Furthermore, setting WT < 0.3 mm means that the gap width between the permanent magnet 200 and the magnetic steel groove 113 is less than 0.3 mm, so that the gap between the permanent magnet 200 and the magnetic steel groove 113 is within a reasonable range. This facilitates the insertion of the permanent magnet 200 into the magnetic steel groove 113 while avoiding the gap between the permanent magnet 200 and the magnetic steel groove 113 being too large, thereby avoiding excessive magnetic flux attenuation in the magnetic steel groove 113.

[0045] It should be noted that "at least one" in this scheme refers to one or more, that is, it can be one, two, three, seven or ten. "Multiple" refers to two or more, that is, two, seven, eight or ten.

[0046] In this embodiment, the limiting protrusion 114 is provided on the wall of the magnet groove 113 of the first punch 111 in the width direction. Of course, this solution is not limited to this. In other embodiments, the limiting protrusion 114 may also be provided on the wall of the magnet groove 113 of the first punch 111 in the length direction.

[0047] Furthermore, in this embodiment, the limiting protrusion 114 is only provided on one of the groove walls of the magnet groove 113 of the first punch 111 in the width direction. In other embodiments, the limiting protrusion 114 can also be provided on both groove walls of the magnet groove 113 of the first punch 111 in the thickness direction, so that the limiting protrusion 114 can press against the permanent magnet 200 on both sides in the thickness direction of the permanent magnet 200.

[0048] Furthermore, in this embodiment, only one limiting protrusion 114 is provided on the magnet groove 113 of a first punch 111. Of course, this solution is not limited to this. Multiple limiting protrusions 114 can also be provided on a magnet groove 113, such as two or three limiting protrusions 114.

[0049] The limiting protrusion 114 has a guide slope on its side wall at least in the insertion direction. This can press against the permanent magnet 200 and guide the permanent magnet 200 into the magnet slot 113 of the first punch 111 when it is inserted, which makes the installation of the permanent magnet 200 easier.

[0050] Furthermore, in this embodiment, the outer peripheral surface of the limiting protrusion 114 is generally arc-shaped. This not only presses against the permanent magnet 200, but also guides the permanent magnet 200 into the magnetic groove 113 of the first lamination 111 when it is inserted, making the installation of the permanent magnet 200 easier. Secondly, it also makes the outer peripheral surface of the limiting protrusion 114 smoother, reducing wear on the permanent magnet 200. Of course, this solution is not limited to this. In other embodiments, the limiting protrusion 114 may only have a guiding slope or guiding arc surface on its sidewall in the insertion direction, while the sidewall that presses against the permanent magnet 200 is flat.

[0051] Reference Figure 5 , Figure 6 and Figure 8 Optionally, in this embodiment, the rotor core 100 further includes a third lamination 120 located at one end of the core body 110. The third lamination 120 has a limiting groove 121 corresponding to the magnet slot 113. A limiting rib 122 is provided between the two slot walls of the limiting groove 121 that are arranged opposite each other in the width direction. The limiting rib 122 is used to limit the end of the permanent magnet 200. It can be understood that the limiting rib 122 can restrict the axial displacement of the permanent magnet 200 and prevent the permanent magnet 200 from flying out of the magnet slot 113 axially. In this way, the end plates at both ends of the motor can be removed, making the rotor simpler. At the same time, it can also fix the permanent magnet 200 to prevent the permanent magnet 200 from moving axially, resulting in better noise reduction of the product. Of course, this solution is not limited to this. In other embodiments, the third lamination 120 may not be provided.

[0052] Specifically, the third lamination 120 is located at the end of the core body 110. This can be understood as follows: in this embodiment, the side of the third lamination 120 away from the core body 110 does not have other laminations. Of course, in other embodiments, the side of the third lamination 120 away from the core body 110 may also have other laminations, such as, but not limited to, the first lamination 111 and / or the second lamination 112.

[0053] Furthermore, the width of the limiting rib 122 is d1, and the width of the permanent magnet 200 is d2, wherein d1 and d2 satisfy: d1 < d2; this can reduce the attenuation of the magnetic energy of the permanent magnet 200.

[0054] It should be noted that the limiting rib 122 has a first rib surface and a second rib surface distributed along its own width direction. d1 represents the perpendicular distance from the first rib surface to the second rib surface. That is, taking the center point of the first rib surface as the fourth starting point, the center point is the intersection of the four diagonals of the first rib surface. A perpendicular line is drawn from the fourth starting point to the second rib surface. The intersection of this perpendicular line and the second rib surface is the fourth ending point. d1 represents the distance between the fourth starting point and the fourth ending point.

[0055] The permanent magnet 200 has a third side and a fourth side distributed along its width direction. d2 represents the perpendicular distance from the third side to the fourth side. That is, taking the center point of the third side as the fifth starting point (the intersection of the four diagonals of the third side), and drawing a perpendicular line from the fifth starting point to the fourth side, the intersection of this perpendicular line and the fourth side is the fifth ending point. d2 represents the distance between the fifth starting point and the fifth ending point. When the permanent magnet 200 is installed on the rotor core 100, the width direction of the limiting rib 122 is parallel to the width direction of the permanent magnet 200.

[0056] Furthermore, the width d1 of the limiting rib 122 satisfies: 0.15mm < d1 < 5mm; if the width d1 of the limiting rib 122 is less than 0.15mm, the strength of the limiting rib 122 is too small. If the width d1 of the limiting rib 122 is greater than 5mm, the magnetic energy attenuation of the permanent magnet 200 will be too large. This solution limits the width d1 of the limiting rib 122 to between 0.15mm and 5mm, which helps to ensure the strength of the limiting rib 122 while avoiding excessive attenuation of the magnetic energy of the permanent magnet 200.

[0057] Reference Figure 9 , Figure 9 A schematic diagram showing the relationship between the magnetic flux leakage rate and d1 of the motor using the rotor provided by this invention is shown below. Figure 9 It can be seen that as d1 increases, the magnetic flux leakage rate of the motor will increase. When d1 is greater than 5mm, the magnetic flux leakage rate of the motor increases significantly with the increase of d1. Moreover, when d1 < 5mm, the magnetic flux leakage rate of the motor is less than 2.5%. Therefore, it can be seen that limiting d1 to less than 5mm can avoid excessive attenuation of the magnetic energy of the permanent magnet 200.

[0058] Reference Figure 7 Optionally, the third lamination 120 is located within the first 15 laminations of the rotor core 100 from the end inwards. It should be noted that the third lamination 120 is located at the end of the core body 110, but other laminations can also be provided on the side of the third lamination 120 away from the core body 110. Other laminations include, but are not limited to, the first lamination 111 and / or the second lamination 112. For the entire rotor core 100, the third lamination 120 is located within the first 15 laminations of the rotor core 100 from the end inwards. Since the laminations at the end of the rotor core 100 after the third lamination 120 are not provided with permanent magnets 200, if the position of the third lamination 120 exceeds the first 15 laminations from the end inwards, it will lead to a waste of the rotor core 100 and increase the cost of the product.

[0059] Specifically, at least one third lamination 120 is provided. In this embodiment, when multiple third laminations 120 are provided, the multiple third laminations 120 are stacked together to form a whole. Of course, other laminations can also be stacked between multiple third laminations 120, such as, but not limited to, the first lamination 111 and / or the second lamination 112.

[0060] Furthermore, the first lamination 111 is positioned between the first lamination and the last lamination in the axial direction of the entire rotor core 100. This fixes the permanent magnet 200 in the middle part of the magnet slot 113, which helps to further increase the limiting effect of the permanent magnet 200 and reduce the probability of the permanent magnet 200 vibrating during operation.

[0061] Furthermore, the first lamination 111 is located between the plurality of second laminations 112. That is, the first lamination 111 is located in the middle position of the iron core body 110, so that the limiting protrusion 114 can limit the middle part of the permanent magnet 200 in the magnetic groove 113, which is conducive to further increasing the limiting effect of the permanent magnet 200 and reducing the probability of the permanent magnet 200 vibrating during operation.

[0062] Optionally, in this embodiment, multiple first laminations 111 and multiple second laminations are provided. During stacking, multiple first laminations 111 are stacked together to form a whole, and then stacked between multiple laminations 112. Of course, this solution is not limited to this. In other embodiments, multiple first laminations 111 can also be arranged in other ways between multiple second laminations 112. For example, but not limited to, two first laminations 111 are grouped together, and multiple groups of first laminations are provided, with multiple groups of first laminations spaced apart between the second laminations 112.

[0063] Furthermore, the height of the rotor core 100 is t, and the total stack thickness of the third type of lamination is t1, where 0 < t1 < 0.2t. It can be understood that if there are too many third laminations 120, it will lead to magnetic flux attenuation and leakage, resulting in a decrease in motor efficiency. This solution limits the total stack thickness of the third laminations 120 to less than 0.2t, which can reduce magnetic flux attenuation and leakage, thereby improving motor efficiency.

[0064] It should be noted that t represents the perpendicular distance between the two end faces of the rotor core 100 in the axial direction. That is, taking the center of one end face of the rotor core 100 as the sixth starting point and the center of the other end face as the sixth ending point, t represents the distance between the sixth starting point and the sixth ending point. t1 represents the total stacking height of the third lamination 120 in the axial direction. Specifically, when there are multiple third laminations 120, and these multiple third laminations 120 are stacked together, t1 represents the straight-line distance between the centers of the two opposite end faces of the two end laminations 120 located at the ends of the multiple third laminations 120. When there is only one third lamination 120, t1 represents the straight-line distance between the centers of the two end faces of the third lamination 120 distributed along the axial direction.

[0065] In one embodiment, the height of the rotor core 100 is t, and the total stack thickness of the first lamination 111 is t2, where 0 < t2 < 0.2t. It can be understood that the axial thickness of the first lamination 111 cannot be set too much, as too much thickness will have adverse effects on manufacturing, such as increasing the number of manufacturing steps, leading to difficulties in insertion, and slow manufacturing cycle. In this solution, the total stack thickness of the first lamination 111, t2, is limited to less than 0.2t. This ensures the manufacturing cycle while increasing the limiting effect of the permanent magnet 200, thereby reducing the noise of the motor and compressor.

[0066] It should be noted that t2 represents the total stacking height of the first lamination 111 in the axial direction. Specifically, when there are multiple first laminations 111 stacked together, t2 represents the straight-line distance between the centers of the two opposite end faces of the two end laminations 111 located at the ends of the multiple first laminations 111. When there is only one first lamination 111, t2 represents the straight-line distance between the centers of the two end faces of the first lamination 111 distributed along the axial direction.

[0067] Reference Figure 1 In one embodiment, the shape of the magnet groove 113 is straight, V-shaped or U-shaped; it is understood that the shape of the magnet groove 113 can be straight or other shapes composed of straight lines; for example, but not limited to straight lines forming a V-shape or U-shape, etc.

[0068] In this embodiment, the magnet slot 113 is V-shaped. This is because the V-shaped magnet slot 113 can effectively increase the power density of the motor. By optimizing the magnetic field distribution, the motor can output higher power within the same volume. The V-shaped design also reduces magnetic field leakage, improving motor efficiency and reducing energy loss. The V-shaped magnet slot 113 also helps enhance the motor's torque characteristics, increasing its starting torque and overload capacity.

[0069] In the second embodiment, the magnetic groove 113 is in a straight line shape because this type of magnetic groove 113 has a simple structure: the design of the straight magnetic groove 113 is simple and direct, easy to process and manufacture, and can reduce production costs and production cycle. Moreover, the straight magnetic groove 113 has good fixation: it can provide a better fixing effect, protect the permanent magnet 200 from collisions, and effectively resist centrifugal force, improving the stability of the permanent magnet 200. This shape of magnetic groove 113 is conducive to heat dissipation, improving the heat dissipation efficiency of the permanent magnet 200 and preventing the permanent magnet 200 from being damaged due to overheating.

[0070] In the third embodiment, the magnet slot 113 is U-shaped. This is because the U-shaped slot design can effectively reduce magnetic flux leakage and improve the efficiency and power factor of the motor. The U-shaped magnet slot 113 has a compact structure, making it suitable for applications with limited space, and can improve the performance of the motor without increasing its size.

[0071] The present invention also proposes an electric motor, which includes a rotor. The specific structure of the rotor is as described in the above embodiments. Since the present 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 described in detail here.

[0072] The present invention also proposes a compressor, which includes a motor. The specific structure of the motor is as described in the above embodiments. Since the compressor 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 described in detail here.

[0073] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A rotor, characterized in that, include: The rotor core includes a core body, which includes at least one first lamination and a plurality of second laminations stacked along the axial direction. Both the first lamination and the second laminations are provided with magnetic slots. The slot wall of the magnetic slot of the first lamination is provided with a limiting protrusion. The shortest distance from the limiting protrusion to the slot wall opposite to the limiting protrusion is L, and the width of the magnetic slot is W. and A permanent magnet is disposed in the magnetic steel groove, and the thickness of the permanent magnet is T, which satisfies: 0 < L < 5 × (WT).

2. The rotor as claimed in claim 1, characterized in that, The difference between W and T satisfies: 0 < WT < 0.3 mm.

3. The rotor as described in claim 1, characterized in that, The rotor core also includes a third lamination located at one end of the core body. The third lamination has a limiting groove corresponding to the magnet slot. A limiting rib is provided between the two slot walls that are arranged opposite each other along the width direction of the limiting groove. The limiting rib is used to limit the end of the permanent magnet.

4. The rotor as described in claim 3, characterized in that, The width of the limiting rib is d1, and the width of the permanent magnet is d2. The d1 and d2 satisfy: d1 < d2.

5. The rotor as described in claim 4, characterized in that, The width d1 of the limiting rib satisfies: 0.15mm < d1 < 5mm.

6. The rotor as claimed in claim 3, characterized in that, The third lamination is located within the first 15 laminations of the rotor core from the end inwards.

7. The rotor as claimed in claim 3, characterized in that, The first lamination is located between a plurality of second laminations.

8. The rotor as claimed in claim 3, characterized in that, The height of the rotor core is t, and the total stack thickness of the third type of laminations is t1, where 0 < t1 < 0.2t.

9. The rotor as claimed in any one of claims 1 to 8, characterized in that, The height of the rotor core is t, and the total thickness of the first lamination is t2, where 0 < t2 < 0.2t.

10. The rotor as claimed in any one of claims 1 to 8, characterized in that, The magnetic groove is in the shape of a straight line, a V-shape, or a U-shape.

11. An electric motor, characterized in that, Includes the rotor as described in any one of claims 1 to 10.

12. A compressor, characterized in that, Including the motor as described in claim 11.

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