Motor, compressor and refrigeration equipment

Abstract

The utility model discloses a motor, compressor and refrigeration equipment, relates to refrigeration equipment technical field, the motor comprises a stator and a rotor, the rotor comprises permanent magnets and a rotor iron core, the rotor iron core is provided with a plurality of magnet grooves at intervals along the circumferential direction, the permanent magnets comprise a first permanent magnet, a second permanent magnet and a third permanent magnet, the magnet grooves comprise the first magnet groove, the second magnet groove and the third magnet groove, the first magnet groove, the second magnet groove and the third magnet groove jointly form a U shape, and the first magnet groove and the third magnet groove are communicated through the second magnet groove. The first permanent magnet, the second permanent magnet and the third permanent magnet are arranged in the first magnet groove, the second magnet groove and the third magnet groove respectively, the number of pole pairs of the rotor is P, the total number of the permanent magnets is 3P, and 3P is larger than or equal to 18 and smaller than or equal to 30. According to the technical scheme provided by the utility model, the eddy-current loss in the permanent magnet is reduced, and the motor efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of refrigeration equipment, and particularly relates to an electric motor, a compressor and a refrigeration equipment. Background Art

[0002] With the rapid development of the economic level and the improvement of people's living standards, people's demand for high efficiency and low noise is increasing day by day. Therefore, it is necessary to reasonably optimize the air-conditioning compressor motor to effectively reduce losses and improve efficiency. Summary of the Utility Model

[0003] The main object of the utility model is to provide an electric motor, a compressor and a refrigeration equipment, aiming at reducing the eddy current loss in the permanent magnet and improving the efficiency of the electric motor.

[0004] To achieve the above object, the electric motor proposed by the utility model includes:

[0005] A stator; and

[0006] A rotor, the rotor includes a permanent magnet and a rotor core, the rotor core is provided with a plurality of magnet slots at intervals in the circumferential direction, the permanent magnet includes a first permanent magnet, a second permanent magnet and a third permanent magnet, the magnet slots include a first magnet slot, a second magnet slot and a third magnet slot, the first magnet slot, the second magnet slot and the third magnet slot together form a U shape, and the first magnet slot and the third magnet slot are connected through the second magnet slot, the first permanent magnet, the second permanent magnet and the third permanent magnet are respectively arranged in the first magnet slot, the second magnet slot and the third magnet slot, the number of pole pairs of the rotor is P, the total number of permanent magnets is 3P, and 18≤3P≤30.

[0007] In an embodiment, the widths of the first permanent magnet and the third permanent magnet are W 1 , and the width of the second permanent magnet is W 2 , and 0.735≤W 1 / W 2 ≤1.265.

[0008] In an embodiment, the width of the second permanent magnet is W 2 , and 2.116≤3P / W 2 ≤4.615.

[0009] In an embodiment, the minimum included angle between the second permanent magnet and the first permanent magnet or the third permanent magnet is θ, and 0.1125≤3P / θ≤0.1875.

[0010] In an embodiment, the width of the second permanent magnet is W 2, the minimum included angle between the second permanent magnet and the first permanent magnet or the third permanent magnet is θ, and the shortest distance between the midpoint on the outer side of the second permanent magnet and the outer peripheral surface of the rotor is s, 0.1 ≤ (π / P / θ)W 2 / s ≤ 0.2.

[0011] In one embodiment, the stator includes a stator yoke and stator teeth. The stator teeth are located inside the stator yoke, and a plurality of the stator teeth are arranged at intervals along the circumferential direction of the stator yoke. The rotor core is disposed within the plurality of stator teeth.

[0012] In one embodiment, the minimum inner diameter of the stator teeth is R 1 , and the maximum outer diameter of the stator yoke is R 2 , 30 ≤ 3P / (R 1 / R 2 ) ≤ 53.763.

[0013] In one embodiment, the number of the stator teeth is Z; Z / P = 3.

[0014] In one embodiment, the number of the stator teeth is Z, and the stator further includes a stator winding. The stator winding is wound around the stator teeth. The effective value of the line-to-line back electromotive force of the stator winding is U, the rotational speed of the motor is n, the maximum outer diameter of the stator yoke is R2, ke = U / n, 0.213 ≤ (ke / R2 / Z) × P ≤ 0.352.

[0015] In one embodiment, when Z = 9, 0.638 ≤ ke / R2 ≤ 0.933.

[0016] In one embodiment, when Z = 12, 0.679 ≤ ke / R2 ≤ 1.056.

[0017] In one embodiment, a plurality of air slots are provided on the rotor core, and the air slots are located between two adjacent permanent magnets.

[0018] In one embodiment, the air slots are arranged in a T shape, and the width of the air slots gradually increases in the direction close to the axis of the rotor core.

[0019] In one embodiment, a plurality of guide slots are provided on the rotor core, and the guide slots are arranged between the first magnet slot, the second magnet slot and the third magnet slot.

[0020] In one embodiment, the outer peripheral wall of the rotor core includes a plurality of arc segments; or the outer peripheral wall of the rotor core includes at least one arc segment and at least one straight segment.

[0021] The present utility model further provides a compressor, which includes the motor as described above.

[0022] The present utility model further provides a refrigeration device, which includes the compressor as described above.

[0023] The motor in the technical solution of the present utility model includes a stator and a rotor. The rotor includes a permanent magnet and a rotor core. The rotor core is provided with a plurality of magnet slots at intervals in the circumferential direction. The permanent magnet includes a first permanent magnet, a second permanent magnet, and a third permanent magnet. The magnet slots include a first magnet slot, a second magnet slot, and a third magnet slot. The first magnet slot, the second magnet slot, and the third magnet slot together form a U shape, and the first magnet slot and the third magnet slot are connected through the second magnet slot. The first permanent magnet, the second permanent magnet, and the third permanent magnet are respectively arranged in the first magnet slot, the second magnet slot, and the third magnet slot. By reasonably setting the first magnet slot, the second magnet slot, and the third magnet slot, the magnetic field distribution is optimized, the magnetic field is made more uniform, the magnetic leakage phenomenon is reduced, and thus the efficiency and performance of the motor are improved. At the same time, the connected magnet slots can also reduce the magnetic resistance, making the magnetic flux easier to pass through, and further improving the magnetic flux utilization rate of the motor. Further, the number of pole pairs of the rotor is P, and the total number of permanent magnets is 3P, where 18 ≤ 3P ≤ 30, thereby reasonably limiting the number of permanent magnets, and further increasing the magnetic field strength of the rotor. The technical solution of the present utility model optimizes the layout and arrangement of the permanent magnets, thereby increasing the magnetic flux density in the air gap, enhancing the magnetic energy utilization rate and performance of the motor, further improving the magnetic focusing effect of the motor, reducing the eddy current loss in the permanent magnets, and further improving the motor efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of an embodiment of the motor provided by the present utility model;

[0026] Figure 2 For Figure 1 It is a schematic structural diagram of the permanent magnet installed in the magnet slot of the rotor in

[0027] Figure 3 For Figure 1 It is a schematic structural diagram of the magnet slot of the rotor without the permanent magnet installed in

[0028] Figure 4Structural schematic diagram of an embodiment of the compressor provided by the present utility model;

[0029] Figure 5 Comparison diagram of eddy current loss and core loss between the motor provided by the present utility model and the existing motor;

[0030] Figure 6 Comparison diagram of the efficiency between the motor provided by the present utility model and the existing motor.

[0031] Explanation of the reference numerals in the drawings:

[0032] 1. Motor; 11. Stator yoke; 12. Stator teeth; 13. Rotor core; 131. First magnet slot; 132. Second magnet slot; 133. Third magnet slot; 135. Air slot; 136. Guide slot; 141. First permanent magnet; 142. Second permanent magnet; 143. Third permanent magnet.

[0033] The realization, functional features and advantages of the purpose of the present utility model will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

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

[0036] In addition, if the embodiments of the present utility model involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes Scenario A, or Scenario B, or the scenario where both A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0037] Referring to Figures 1 to 3 , the present utility model provides a motor 1, comprising:

[0038] a stator; and

[0039] a rotor, the rotor comprising a permanent magnet and a rotor core 13. The rotor core 13 is provided with a plurality of magnet slots at intervals in the circumferential direction. The permanent magnet comprises a first permanent magnet 141, a second permanent magnet 142, and a third permanent magnet 143. The magnet slots comprise a first magnet slot 131, a second magnet slot 132, and a third magnet slot 133. The first magnet slot 131, the second magnet slot 132, and the third magnet slot 133 together form a U shape, and the first magnet slot 131 and the third magnet slot 133 are connected through the second magnet slot 132. The first permanent magnet 141, the second permanent magnet 142, and the third permanent magnet 143 are respectively arranged in the first magnet slot 131, the second magnet slot 132, and the third magnet slot 133. The number of pole pairs of the rotor is P, the total number of permanent magnets is 3P, and 18 ≤ 3P ≤ 30.

[0040] In the technical solution of the present utility model, the motor 1 includes a stator and a rotor. The rotor includes a permanent magnet and a rotor core 13. The rotor core 13 is provided with a plurality of magnet slots at intervals in the circumferential direction. The permanent magnet includes a first permanent magnet 141, a second permanent magnet 142, and a third permanent magnet 143. The magnet slots include a first magnet slot 131, a second magnet slot 132, and a third magnet slot 133. The first magnet slot 131, the second magnet slot 132, and the third magnet slot 133 are arranged in a U shape, and the first magnet slot 131 and the third magnet slot 133 are connected through the second magnet slot 132. The first permanent magnet 141, the second permanent magnet 142, and the third permanent magnet 143 are respectively arranged in the first magnet slot 131, the second magnet slot 132, and the third magnet slot 133. By reasonably setting the first magnet slot 131, the second magnet slot 132, and the third magnet slot 133, the magnetic field distribution is optimized, the magnetic field is made more uniform, the magnetic leakage phenomenon is reduced, and thus the efficiency and performance of the motor 1 are improved. At the same time, the connected magnet slots can also reduce the magnetic resistance, making the magnetic flux easier to pass through, and further improving the magnetic flux utilization rate of the motor 1. Further, the number of pole pairs of the rotor is P, and the total number of permanent magnets is 3P, 18 ≤ 3P ≤ 30, thereby reasonably limiting the number of permanent magnets, and further increasing the magnetic field strength of the rotor. The technical solution of the present utility model improves the magnetic flux density in the air gap by optimizing the layout and arrangement of the permanent magnets, thereby enhancing the magnetic energy utilization rate and performance of the motor 1, further improving the magnetic flux concentration effect of the motor 1, reducing the eddy current loss in the permanent magnets, and further improving the efficiency of the motor 1.

[0041] Specifically, the widths of the first permanent magnet 141 and the third permanent magnet 143 are W 1 , and the width of the second permanent magnet 142 is W 2 , 0.735 ≤ W 1 / W 2 ≤ 1.265. Wherein, W 1 / W 2 represents the width ratio between the first permanent magnet 141 and the third permanent magnet 143 and the second permanent magnet 142. The first permanent magnet 141 and the third permanent magnet 143 are located on both sides of the second permanent magnet 142, that is, W 1 / W 2 represents the magnetic field distribution on the rotor. Therefore, 0.735 ≤ W 1 / W 2 ≤ 1.265, thereby reasonably setting the magnetic field distribution on the rotor, further increasing the torque density, reducing the magnetic resistance loss, and improving the heat dissipation performance.

[0042] Further, the width of the second permanent magnet 142 is W 2 , 2.116 ≤ 3P / W 2 ≤ 4.615. Wherein, 3P / W 2Indicates the distribution density of the permanent magnets on the rotor circumference; if 3P / W 2 > 4.615, it indicates that the density of the permanent magnets on the rotor is too high at this time; when the density of the permanent magnets is too high, it may cause magnetic saturation in some parts of the magnetic circuit, and magnetic saturation will limit the performance improvement of the motor 1; at the same time, the permanent magnets will generate a certain amount of heat during operation. If the density of the permanent magnets is too high, the heat inside the motor 1 will be more concentrated, thus increasing the difficulty of heat dissipation. If 3P / W 2 < 2.116, it indicates that the density of the permanent magnets on the rotor is too low at this time, resulting in insufficient magnetic field strength generated by the motor 1, and then the output power of the motor 1 is low, and thus it cannot meet the customer's requirements. Therefore, 2.116 ≤ 3P / W 2 ≤ 4.615, thus reasonably setting the layout of the permanent magnets, thereby increasing the magnetic flux density in the air gap, enhancing the magnetic energy utilization rate and performance of the motor 1, further improving the magnetic flux concentration effect of the motor 1, reducing the eddy current loss in the permanent magnets, and further improving the efficiency of the motor 1.

[0043] Specifically, the minimum included angle between the second permanent magnet 142 and the first permanent magnet 141 or the third permanent magnet 143 is θ, and 0.1125 ≤ 3P / θ ≤ 0.1875. Among them, 3P represents the total number of permanent magnets corresponding to one rotor, that is, the sum of the numbers of all the first permanent magnets 141, the second permanent magnets 142, and the third permanent magnets 143 corresponding to one rotor. 3P / θ represents the distribution density of the permanent magnets on the rotor; therefore, if 3P / θ > 0.1875, it indicates that the density of the permanent magnets on the rotor is too high at this time; when the density of the permanent magnets is too high, it may cause magnetic saturation in some parts of the magnetic circuit, and magnetic saturation will limit the performance improvement of the motor 1; at the same time, the permanent magnets will generate a certain amount of heat during operation. If the density of the permanent magnets is too high, the heat inside the motor 1 will be more concentrated, thus increasing the difficulty of heat dissipation. If 3P / θ < 0.1125, it indicates that the density of the permanent magnets on the rotor is too low at this time, resulting in insufficient magnetic field strength generated by the motor 1, and then the output power of the motor 1 is low, and thus it cannot meet the customer's requirements. Therefore, 0.1125 ≤ 3P / θ ≤ 0.1875, thus reasonably setting the layout of the permanent magnets, thereby increasing the magnetic flux density in the air gap, maximizing the back electromotive force of the motor 1; at the same time, it also enhances the magnetic energy utilization rate and performance of the motor 1, further improving the magnetic flux concentration effect of the motor 1, reducing the eddy current loss in the permanent magnets, and further improving the efficiency of the motor 1.

[0044] Specifically, the width of the second permanent magnet 142 is W 2, the minimum included angle between the second permanent magnet 142 and the first permanent magnet 141 or the third permanent magnet 143 is θ, and the shortest distance between the midpoint on the outer side of the second permanent magnet 142 and the outer peripheral surface of the rotor is s, 0.1 ≤ (π / P / θ)W 2 / s ≤ 0.2. Wherein, s represents the distance from the midpoint on the outer side of the rotor to the outer edge of the rotor, and (π / P / θ)W 2 / s represents the usage of permanent magnets at different pole numbers. If (π / P / θ)W 2 / s > 0.2, it indicates that the permanent magnet density on the rotor is too high at this time; when the permanent magnet density is too high, it may cause magnetic saturation in some parts of the magnetic circuit, and magnetic saturation will limit the improvement of the performance of the motor 1; at the same time, the permanent magnet will generate a certain amount of heat during operation. If the permanent magnet density is too high, the heat inside the motor 1 will be more concentrated, thus increasing the difficulty of heat dissipation. If (π / P / θ)W 2 / s < 0.1, it indicates that the permanent magnet density on the rotor is too low at this time, resulting in insufficient magnetic field strength generated by the motor 1, and further resulting in a low output power of the motor 1, which cannot meet the needs of customers.

[0045] In an embodiment, the stator includes a stator yoke 11 and stator teeth 12. The stator teeth 12 are located inside the stator yoke 11, and a plurality of the stator teeth 12 are arranged at intervals along the circumferential direction of the stator yoke 11. The rotor core 13 is arranged inside the plurality of stator teeth 12. That is, the rotor is arranged inside the stator, and the motor 1 is an inner-rotor motor 1.

[0046] In an embodiment, the minimum inner diameter of the stator is R 1 , and the maximum outer diameter of the stator is R 2 , 30 ≤ 3P / (R 1 / R 2 ) ≤ 53.763. Since the technical solution of this application is an inner-rotor motor 1, therefore, R 1 also represents the space in the stator for installing the rotor, and 3P / (R 1 / R 2 ) represents the number of permanent magnets in this installation space. If 3P / (R 1 / R 2 ) > 53.763, it indicates that the permanent magnet density on the rotor is too high at this time; when the permanent magnet density is too high, it may cause magnetic saturation in some parts of the magnetic circuit, and magnetic saturation will limit the improvement of the performance of the motor 1; at the same time, the permanent magnet will generate a certain amount of heat during operation. If the permanent magnet density is too high, the heat inside the motor 1 will be more concentrated, thus increasing the difficulty of heat dissipation. If 3P / (R 1 / R 2) < 30, it indicates that the density of the permanent magnets on the rotor is too small at this time, resulting in insufficient magnetic field strength generated by the motor 1, and further causing the output power of the motor 1 to be low, and thus unable to meet the customer's requirements. Therefore, 30 ≤ 3P / (R 1 / R 2 ) ≤ 53.763, thereby reasonably setting the layout of the permanent magnets, improving the magnetic flux density in the air gap, enhancing the magnetic energy utilization rate and performance of the motor 1, further improving the magnetic focusing effect of the motor 1, reducing the eddy current loss in the permanent magnets, and further increasing the efficiency of the motor 1.

[0047] In one embodiment, the number of the stator teeth 12 is Z; Z / P = 3. When Z / P = 3, the interaction between the stator and rotor magnetic fields reaches the best state at this time, thereby improving the torque output and efficiency of the motor 1; at the same time, the reasonable magnetic field distribution also makes the mechanical stress inside the motor 1 evenly distributed, and further reduces the generation of vibration and noise.

[0048] In another embodiment, the number of the stator teeth 12 is Z, the stator further includes a stator winding wound around the stator teeth 12, the effective value of the line-to-line back electromotive force of the stator winding is U, the rotational speed of the motor 1 is n, and the maximum outer diameter of the stator yoke 11 is R 2 , ke = U / n, 0.213 ≤ (ke / R 2 / Z) × P ≤ 0.352. (ke / R 2 / Z) × P represents the value range of the ke value under different rotor pole numbers; when 0.213 ≤ (ke / R 2 / Z) × P ≤ 0.352, the energy efficiency at the system end of the motor 1 can be improved. When (ke / R 2 / Z) × P < 0.213 or (ke / R 2 / Z) × P > 0.352, the energy efficiency at the system end of the motor 1 is low at this time, and further reduces the efficiency of the motor 1.

[0049] Furthermore, in one embodiment, when Z = 9, 0.638 ≤ ke / R 2 ≤ 0.933, ke / R 2 represents the value range of ke under different stator outer diameters. By further optimizing the range of the ke value, the energy efficiency at the system end of the motor 1 is further improved.

[0050] Furthermore, in one embodiment, when Z = 12, 0.679 ≤ ke / R 2 ≤ 1.056, ke / R 2 represents the value range of ke under different stator outer diameters. By further optimizing the range of the ke value, the energy efficiency at the system end of the motor 1 is further improved.

[0051] In one embodiment, a plurality of air grooves 135 are provided on the rotor core 13, and the air grooves 135 are located between two adjacent permanent magnets. The air grooves 135 can improve the magnetic field uniformity in the dense magnetic field region of the rotor, prevent the magnetic field intensity from being too high at local positions, thereby optimizing the magnetic circuit of the motor 1, making the distribution of magnetic force lines more reasonable, and thus improving the operating efficiency and stability of the motor 1. Further, opening axial air grooves 135 on the surface of the solid rotor can increase the effective area of the rotor surface, thereby reducing the rotor resistance and further improving the pull-in synchronization ability of the motor 1.

[0052] Further, the air groove 135 is arranged in a T shape, and the width of the air groove 135 gradually increases along the direction close to the axis of the rotor core 13. The T-shaped air groove 135 can more effectively guide the distribution of magnetic force lines, making the magnetic field on the rotor core 13 more uniform. This helps to reduce energy loss and electromagnetic noise caused by uneven magnetic field distribution. At the same time, a reasonable T-shaped groove design can increase the effective magnetic flux area of the rotor core 13, thereby improving the utilization rate of magnetic flux, enabling the motor 1 to generate a larger torque under the same current.

[0053] In one embodiment, a plurality of guiding grooves 136 are provided on the rotor core 13, and the guiding grooves 136 are arranged between the first magnet groove 131, the second magnet groove 132, and the third magnet groove 133. The design of the guiding grooves 136 helps to guide the path of magnetic force lines in the iron core, thereby optimizing the magnetic field distribution, further reducing magnetic leakage and magnetic resistance, improving the utilization efficiency of the magnetic field, and further enhancing the performance and efficiency of the motor 1.

[0054] In one embodiment, the outer peripheral wall of the rotor core 13 includes a plurality of arc segments; or the outer peripheral wall of the rotor core 13 includes at least one arc segment and at least one straight segment. By changing the geometric shape of the rotor outer peripheral wall, such as adopting a multi-pole arc or eccentric arc design or a straight segment design, etc., the distribution of the air gap magnetic flux density can be optimized, making the waveform approach a sine wave, reducing the harmonic content, thereby reducing torque ripple and improving the running smoothness of the motor 1.

[0055] Refer to Figure 5 and Figure 6 , Figure 5 which are the bar charts of the eddy current loss and iron core loss of the motor 1 in the technical solution of the present invention and the motor 1 in the prior art; Figure 6 which are the bar charts of the efficiency of the motor 1 in the technical solution of the present invention and the motor 1 in the prior art. From Figure 5 and Figure 6It can be seen that the eddy current loss and core loss of the motor 1 in this embodiment are significantly lower than those of the motor 1 in the prior art; at the same time, the efficiency of the motor 1 in this embodiment is significantly higher than that of the motor 1 in the prior art.

[0056] Referring to Figure 4 , the present utility model also provides a compressor, which includes a motor 1. The specific structure of the motor 1 refers to the above embodiment. Since the compressor in this solution adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, and will not be elaborated here one by one.

[0057] The present utility model also provides a refrigeration device, which includes a compressor. The specific structure of the compressor refers to the above embodiment. Since the compressor in this solution adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, and will not be elaborated here one by one.

[0058] The above are only exemplary embodiments of the present utility model, and do not limit the patent scope of the present utility model. Any equivalent structural transformation made under the technical concept of the present utility model by using the content of the specification and drawings of the present utility model, or direct / indirect application in other related technical fields is included in the patent protection scope of the present utility model.

Claims

1. A motor, characterized in that: include: stator; and A rotor, the rotor comprising a permanent magnet and a rotor core, the rotor core being provided with a plurality of magnet slots spaced apart in a circumferential direction, the permanent magnet comprising a first permanent magnet, a second permanent magnet and a third permanent magnet, the magnet slots comprising a first magnet slot, a second magnet slot and a third magnet slot, the first magnet slot, the second magnet slot and the third magnet slot together forming a U-shape, and the first magnet slot and the third magnet slot being connected through the second magnet slot, the first permanent magnet, the second permanent magnet and the third permanent magnet being respectively arranged in the first magnet slot, the second magnet slot and the third magnet slot, the number of pole pairs of the rotor being P, the total number of the permanent magnets being 3P, and 18≤3P≤30.

2. The motor according to claim 1, characterized in that The width of the first permanent magnet and the third permanent magnet is W1, the width of the second permanent magnet is W2, and 0.735≤W1 / W2≤1.

265.

3. The motor according to claim 1, characterized in that The width of the second permanent magnet is W2, 2.116≤3P / W2≤4.

615.

4. The motor according to claim 1, characterized in that The minimum angle between the second permanent magnet and the first permanent magnet or the third permanent magnet is θ, and 0.1125≤3P / θ≤0.1875.

5. The motor according to claim 1, characterized in that The width of the second permanent magnet is W2, the minimum angle between the second permanent magnet and the first permanent magnet or the third permanent magnet is θ, the shortest distance between the midpoint of the outward side of the second permanent magnet and the outer peripheral surface of the rotor is s, 0.1≤(π / P / θ)W2 / s≤0.

2.

6. The motor according to claim 1, characterized in that The stator includes a stator yoke and stator teeth. The stator teeth are located inside the stator yoke, and a plurality of the stator teeth are arranged at intervals along the circumferential direction of the stator yoke. The rotor core is arranged inside the plurality of the stator teeth.

7. The motor according to claim 6, characterized in that The minimum inner diameter of the stator teeth is R1, the maximum outer diameter of the stator yoke is R2, and 30≤3P / (R1 / R2)≤53.

763.

8. The motor according to claim 6, characterized in that The number of stator teeth is Z; Z / P=3.

9. The motor according to claim 6, characterized in that The number of stator teeth is Z, and the stator also includes a stator winding, which is wound around the stator teeth. The effective value of the line-to-line back electromotive force of the stator winding is U, the rotation speed of the motor is n, and the maximum outer diameter of the stator yoke is R2, ke=U / n, 0.213≤(ke / R2 / Z)×P≤0.

352.

10. The motor according to claim 9, characterized in that When Z=9, 0.638≤ke / R2≤0.

933.

11. The motor according to claim 9, characterized in that When Z=12, 0.679≤ke / R2≤1.

056.

12. The motor according to claim 1, characterized in that The rotor core is provided with a plurality of air slots, and the air slots are located between two adjacent permanent magnets.

13. The motor according to claim 12, characterized in that The air slot is arranged in a T-shape, and the width of the air slot is gradually increased along the direction close to the axis of the rotor core.

14. The motor according to claim 1, characterized in that The rotor core is provided with a plurality of guide grooves, and the guide grooves are provided between the first magnet groove, the second magnet groove and the third magnet groove.

15. The motor according to claim 1, characterized in that The outer peripheral wall of the rotor core includes a plurality of arc segments; or The outer peripheral wall of the rotor core includes at least one arc segment and at least one straight segment.

16. A compressor, characterized in that: Comprising a motor as claimed in any one of claims 1 to 15.

17. A refrigeration device, characterized in that: Comprising the compressor of claim 16.

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