Permanent magnet motor, compressor and refrigeration equipment

Abstract

The utility model discloses a permanent magnet motor, compressor and refrigeration equipment, and relates to refrigeration equipment technical field, the permanent magnet motor comprises a stator and a rotor, the stator comprises a stator yoke, a plurality of stator teeth and a plurality of tooth boots, the stator teeth are arranged corresponding to the two tooth boots, the two tooth boots are arranged on two sides of the stator tooth, and the stator yoke is arranged on the stator yoke. The maximum width between the two tooth boots corresponding to the same stator tooth is W. The rotor comprises a rotor iron core and permanent magnets, the rotor iron core is provided with magnet grooves, the permanent magnets are located in the magnet grooves, the maximum outer radius of the rotor iron core is R1, the number of magnetic poles of the rotor is P. The rotor iron core comprises a plurality of rotor arc walls, one rotor arc wall is provided with a plurality of concave parts, and the concave parts are arranged on the rotor arc walls. The arc length of the rotor arc wall is V, the sum of the maximum opening widths of the plurality of concave parts corresponding to the # imgabs0 # magnetic pole is L, L / V is larger than or equal to 0.35 and smaller than or equal to 0.4, and V / W is larger than or equal to 1.85 and smaller than or equal to 2.15. According to the technical scheme provided by the utility model, the magnetic field intensity is balanced, the radial electromagnetic force is reduced, and the torque ripple is improved.

Description

Technical Field

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

[0002] As an important device for converting electrical energy into mechanical energy, the motor plays a key role in many fields such as compressors, refrigeration equipment, and household appliances. The motor mainly consists of a stator assembly and a rotor assembly. A rotating magnetic field is generated by the current in the stator winding, and interacts with the rotor magnets in the rotor assembly to generate a rotating torque. However, in the operation process of the existing motor, uneven air gaps such as torque pulsation and cogging torque are likely to cause harmonic introduction, thereby increasing the radial electromagnetic force, and further causing torque fluctuation and motor vibration. Summary of the Utility Model

[0003] The main purpose of the utility model is to propose a permanent magnet motor, a compressor and a refrigeration equipment, aiming to balance the magnetic field intensity, reduce the radial electromagnetic force and improve the torque fluctuation.

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

[0005] A stator, the stator includes a stator yoke, a plurality of stator teeth and a plurality of tooth shoes. The plurality of stator teeth are spaced on the inner circumferential surface of the stator yoke. The tooth shoes are connected to the ends of the stator teeth away from the stator yoke. One stator tooth corresponds to two tooth shoes, and the two tooth shoes are located on both sides of the stator tooth. The maximum width between the two tooth shoes corresponding to the same stator tooth is W; and

[0006] A rotor, the rotor includes a rotor core and a permanent magnet. A magnet slot is provided on the rotor core, and the permanent magnet is located in the magnet slot. The maximum outer radius of the rotor core is R 1 , the number of magnetic poles of the rotor is P, the rotor core includes a plurality of rotor arc walls, one rotor arc wall corresponds to one magnetic pole, a plurality of recessed portions are provided on one rotor arc wall, the arc length of the rotor arc wall is V, The sum of the maximum opening widths of the plurality of recessed portions corresponding to one magnetic pole is L, 0.35 ≤ L / V ≤ 0.4, 1.85 ≤ V / W ≤ 2.15.

[0007] In an embodiment, 0.35 ≤ L / V ≤ 0.38.

[0008] In an embodiment, 1.85 ≤ V / W ≤ 2.05.

[0009] In an embodiment, a shaft hole is provided on the rotor core, and the minimum radius of the shaft hole is R 2, the stator teeth and the stator yoke enclose to form stator slots, and the number of the stator slots is Q,

[0010] In one embodiment,

[0011] In one embodiment, the number of recesses corresponding to one rotor arc wall is a, and 2 ≤ a ≤ 4.

[0012] In one embodiment, the width of the stator teeth is T, and 1.9 ≤ W / T ≤ 3.

[0013] In one embodiment, the stator teeth and the stator yoke enclose to form stator slots, the number of the stator slots is Q, and 15 ≤ Q ≤ 18.

[0014] In one embodiment, 10 ≤ P ≤ 12.

[0015] In one embodiment, the stator teeth and the stator yoke enclose to form stator slots, the number of the stator slots is Q, the number of phases of the motor is m, and 0 < Q / mP < 1.

[0016] In one embodiment, 8 mm ≤ W ≤ 17 mm.

[0017] In one embodiment, 23 mm ≤ R 1 ≤ 34 mm.

[0018] In one embodiment, 3 mm ≤ L ≤ 10 mm.

[0019] In one embodiment, the width of the stator teeth is T, and 4 mm ≤ T ≤ 11 mm.

[0020] In one embodiment, the minimum inner radius of the stator is R 2 , 24 mm ≤ R 2 ≤ 35 mm.

[0021] The present utility model further provides a compressor, including the permanent magnet motor as described above

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

[0023] The permanent magnet motor in the technical solution of the present utility model includes a stator and a rotor. The stator includes a stator yoke, a plurality of stator teeth, and a plurality of tooth shoes. The plurality of stator teeth are arranged at intervals on the inner circumferential surface of the stator yoke. The tooth shoes are connected to the ends of the stator teeth away from the stator yoke. One stator tooth corresponds to two tooth shoes, and the two tooth shoes are located on both sides of the stator tooth. The maximum width between the two tooth shoes corresponding to the same stator tooth is W. The rotor includes a rotor core and a permanent magnet. The rotor core is provided with magnet slots, and the permanent magnet is located in the magnet slots. The maximum outer radius of the rotor core is R 1 , the number of magnetic poles of the rotor is P. The rotor core includes a plurality of rotor arc walls. One rotor arc wall corresponds to one magnetic pole. A plurality of recessed portions are provided on one rotor arc wall. The arc length of the rotor arc wall is V, The sum of the maximum opening widths of the plurality of recessed portions corresponding to one magnetic pole is L, 0.35 ≤ L / V ≤ 0.4, 1.85 ≤ V / W ≤ 2.15. By providing recessed portions on the rotor arc wall, the air gap is modified and shaped, the distortion rate of the air gap magnetic density waveform is improved, and the introduction of harmonics is reduced. Further, by reasonably limiting the dimensions such as the widths of the tooth shoes, the rotor arc wall, and the recessed portions, the air gap magnetic field distribution inside the motor is optimized, the introduction of harmonics caused by uneven air gaps such as torque ripple and cogging torque is reduced, the magnetic field intensity is balanced, the radial electromagnetic force is reduced, and the torque ripple is improved. 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 use in 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, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

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

[0026] Figure 2 It is a schematic structural diagram of another embodiment of the stator in the motor provided by the present utility model;

[0027] Figure 3 It is a schematic structural diagram of yet another embodiment of the stator in the motor provided by the present utility model;

[0028] Figure 4 It is a schematic structural diagram of an embodiment of the rotor in the motor provided by the present utility model;

[0029] Figure 5 It is a schematic structural diagram of another embodiment of the rotor in the motor provided by the present utility model;

[0030] Figure 6Schematic diagram of another embodiment of the rotor in the motor provided by the present utility model;

[0031] Figure 7 Variation diagram of cogging torque with L / V in the present utility model;

[0032] Figure 8 Variation diagram of torque ripple with V / W in the present utility model;

[0033] Figure 9 Torque ripple in the present utility model with respect to Variation diagram;

[0034] Figure 10 Variation diagram of stator rigidity with W / T in the present utility model.

[0035] Explanation of reference numerals in the drawings:

[0036] 11. Stator yoke; 12. Stator teeth; 13. Tooth shoes; 14. Stator slots; 21. Rotor core; 211. Magnet slots; 212. Depressions; 22. Permanent magnets.

[0037] The realization of the purpose, functional characteristics and advantages of the present utility model will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0038] 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 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.

[0039] 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 components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0040] 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 fact that those of ordinary skill in the art can implement it. 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.

[0041] Referring to Figures 1 to 6 , the present utility model provides a permanent magnet motor, comprising:

[0042] A stator, the stator comprising a stator yoke 11, a plurality of stator teeth 12 and a plurality of tooth shoes 13. The plurality of stator teeth 12 are spaced on the inner circumferential surface of the stator yoke 11. The tooth shoes 13 are connected to one end of the stator teeth 12 away from the stator yoke 11. One stator tooth 12 is provided corresponding to two tooth shoes 13, and the two tooth shoes 13 are located on both sides of the stator tooth 12. The maximum width between the two tooth shoes 13 corresponding to the same stator tooth 12 is W; and

[0043] A rotor, the rotor comprising a rotor core 21 and a permanent magnet 22. A magnet slot 211 is provided on the rotor core 21. The permanent magnet 22 is located in the magnet slot 211. The maximum outer radius of the rotor core 21 is R 1 , the number of magnetic poles of the rotor is P. The rotor core 21 comprises a plurality of rotor arc walls. One rotor arc wall is provided corresponding to one magnetic pole. A plurality of recesses 212 are provided on one rotor arc wall. The arc length of the rotor arc wall is V, The sum of the maximum opening widths of the plurality of recesses 212 corresponding to one magnetic pole is L, 0.35 ≤ L / V ≤ 0.4, 1.85 ≤ V / W ≤ 2.15.

[0044] The permanent magnet motor in the technical solution of the present utility model includes a stator and a rotor. The stator includes a stator yoke 11, a plurality of stator teeth 12 and a plurality of tooth boots 13. The plurality of stator teeth 12 are arranged at intervals on the inner peripheral surface of the stator yoke 11. The tooth boots 13 are connected to one end of the stator teeth 12 away from the stator yoke 11. One stator tooth 12 corresponds to two tooth boots 13, and the two tooth boots 13 are located on both sides of the stator tooth 12. The maximum width between the two tooth boots 13 corresponding to the same stator tooth 12 is W. The rotor includes a rotor core 21 and a permanent magnet 22. The rotor core 21 is provided with a magnet slot 211, and the permanent magnet 22 is located in the magnet slot 211. The maximum outer radius of the rotor core 21 is R 1 , the number of poles of the rotor is P. The rotor core 21 includes a plurality of rotor arc walls. One rotor arc wall corresponds to one pole. A plurality of recesses 212 are provided on one rotor arc wall. The arc length of the rotor arc wall is V, The sum of the maximum opening widths of the plurality of recesses 212 corresponding to one pole is L, 0.35 ≤ L / V ≤ 0.4, 1.85 ≤ V / W ≤ 2.15. By providing the recesses 212 on the rotor arc wall, the air gap is modified and shaped, the distortion rate of the air gap magnetic density waveform is improved, and the introduction of harmonics is reduced; further, by reasonably limiting the widths of the tooth boots 13, the rotor arc wall and the recesses 212 and other dimensions, the air gap magnetic field distribution inside the motor is optimized, the introduction of harmonics caused by air gap unevenness such as torque ripple and cogging torque is reduced, and thus the magnetic field intensity is balanced, the radial electromagnetic force is reduced, and the torque ripple is improved.

[0045] Among them, L is the sum of the maximum opening widths of the plurality of recesses 212 corresponding to one pole. When there are two recesses 212, refer to Figure 4 , L = L 1 +L 2 ; when there are 4 recesses 212, refer to Figure 5 , at this time, all 4 recesses 212 are completely located within the same pole, L = L 1 +L 2 +L 3 +L 4， . Refer to Figure 6 , at this time, two of the four recesses at both ends are shared by two adjacent poles by half. Therefore, L = L 1 / 2 + L 2 +L 3 +L 4 / 2.

[0046] It should be noted that L / V represents the ratio of the opening width of the recess 212 to the entire arc length. When L / V < 0.35, it means that the opening width of the recess 212 is relatively small, which is not conducive to correcting the air-gap magnetic density waveform, resulting in an increase in the harmonic content introduced in the air-gap magnetic density waveform, and further affecting the torque ripple. When L / V > 0.4, it means that the opening width of the recess 212 is too large. The overly large recess 212 will increase the magnetic bridge length of the rotor core 21 and reduce the mechanical strength. Under the action of the centripetal force during high-speed rotation, the reliability is greatly reduced. Secondly, excessive arc cutting will affect the fundamental wave amplitude of the air-gap magnetic density, and thus reduce the utilization rate of the permanent magnet. Therefore, setting 0.35 ≤ L / V ≤ 0.4 within a reasonable range can reduce the influence of the cogging torque while ensuring the performance of the motor.

[0047] Furthermore, V / W represents the relative size of the arc length of one pole on the rotor core 21 to the width of the stator tooth 12 shoe. The torque of the motor is generated by the interaction between the magnetic field generated by the energized stator winding and the magnetic field generated by the rotor permanent magnet in the air gap between the stator and the rotor. Therefore, the width of the stator tooth shoe is also crucial for the influence of torque ripple. If V / W < 1.85 or V / W > 2.15, it will lead to an unreasonable magnetic circuit structure of the motor, and further increase the torque ripple. Therefore, by setting 1.85 ≤ V / W ≤ 2.15, the magnetic circuit structure of the motor can be optimized, and further the torque ripple can be reduced. Among them Figures 1 to 3 are schematic diagrams of three different shapes of stator structures.

[0048] Further optimized, 0.35 ≤ L / V ≤ 0.38. By further optimizing the size of L / V, the distortion rate of the air-gap magnetic density waveform is further improved, the introduction of harmonics is reduced, and further the influence of the cogging torque is reduced. From Figure 7 the experimental data, it can be seen that when 0.35 ≤ L / V ≤ 0.4, the cogging torque is in a relatively low range, but when 0.35 ≤ L / V ≤ 0.38, the effect of further reducing the cogging torque can be achieved. Furthermore, the magnetic circuit structure of the motor is further optimized.

[0049] Further optimized, 1.85 ≤ V / W ≤ 2.05. By further optimizing the size of V / W, the magnetic circuit structure of the motor is further optimized, the radial electromagnetic force is reduced, and further the torque ripple is reduced. From Figure 8 it can be seen that when 1.85 ≤ V / W ≤ 2.15, the torque ripple of the motor is in a relatively low range. When 1.85 ≤ V / W ≤ 2.05, the torque ripple can be further reduced, thereby improving the efficiency of the motor.

[0050] In an embodiment, a shaft hole is provided on the rotor core 21, and the minimum radius of the shaft hole is R 2, the stator teeth 12 and the stator yoke 11 enclose to form stator slots 14, and the number of the stator slots 14 is Q. Among them, a tooth boot 13 is arranged corresponding to a stator slot 14, WQ represents the total width of the tooth boots 13 in the motor, and 2R 2 represents the minimum distance from the inner contour of the stator core to the center of the circle. Increasing the ratio of the total width of the tooth boots 13 to the inner diameter of the stator is beneficial to reducing the slot opening width of the stator, and further reducing the torque ripple. The current stator winding process is to wind through the slot opening by the wire nozzle of the winding machine and penetrate to the bottom of the slot. If WQ < 2.15, the proportion of the tooth boots is too large and the stator slot opening is too small, which will cause the winding nozzle to not be able to penetrate, and thus the manufacturing cannot be realized. Therefore, by reasonably setting the value range, the magnetic field distribution and electromagnetic force action of the motor are optimized, thereby reducing the torque ripple of the motor.

[0051] Further optimized, by further optimizing the value range, the magnetic field distribution and electromagnetic force action of the motor are further optimized, and further reduce the torque ripple of the motor. Refer to Figure 9 It can be seen that when , the torque ripple of the motor is in a relatively low range at this time, and the change of the torque ripple in this range is relatively small. However, when , the outer diameter of the rotor increases, resulting in a decrease in the area of the stator slot 14, and further causing serious heating of the winding, a significant increase in temperature, and thus reducing the service life of the winding. Therefore, on the premise of reducing the influence of the torque ripple, taking into account the reliability margin of the winding temperature, the sizes of the stator and the rotor are limited to the range.

[0052] In an embodiment, the number of the recessed portions 212 corresponding to the arc wall of the rotor is a, and 2 ≤ a ≤ 4. It can be understood that if a > 4, it means that there are too many recessed portions 212 on the arc wall of the rotor corresponding to one magnetic pole. Too many recessed portions 212 will cause the magnetic flux path on the arc wall of the rotor to become extremely complex, thereby increasing the magnetic resistance, reducing the magnet utilization rate, and making the motor require a larger current to generate the same torque, thus increasing the energy consumption. If a < 2, it means that there are too few recessed portions 212 on the arc wall of the rotor corresponding to one magnetic pole. A small number of recessed portions 212 may not be able to effectively optimize the magnetic flux distribution, resulting in uneven magnetic flux distribution on the arc wall of the rotor, further increasing the torque ripple and electromagnetic noise of the motor, and reducing the running stability of the motor. Therefore, setting 2 ≤ a ≤ 4 within a reasonable range optimizes the magnetic field distribution of the motor, further reduces the torque ripple and electromagnetic noise of the motor, and improves the efficiency of the motor.

[0053] Refer to Figure 10, Further, the width of the stator tooth 12 is T, and 1.9 ≤ W / T ≤ 3. When W / T > 3, it indicates that the width of the stator tooth 12 is too small. Such a small tooth width makes the system more likely to deform when subjected to external forces, thus reducing the rigidity of the stator, and further affecting the service life of the motor. Secondly, it will cause the magnetic circuit in the stator tooth 12 to become saturated. Magnetic circuit saturation will reduce the magnetic energy utilization rate of the motor, causing the torque generated by the motor under the same current to decrease, thereby affecting the performance of the motor. When W / T < 1.9, the width of the stator tooth shoe 13 is too small, and the magnetic flux generated by the rotor cannot effectively enter the stator core, unable to generate a closed magnetic circuit structure, greatly reducing the utilization rate of the permanent magnet, and further affecting the efficiency and cost of the motor.

[0054] Specifically, the stator tooth 12 and the stator yoke 11 enclose to form a stator slot 14, and the number of stator slots 14 is Q, where 15 ≤ Q ≤ 18. It can be understood that the number of slots Q of the stator slots 14 within this range can provide relatively balanced performance. It is neither too few to affect the efficiency and torque of the motor, nor too many to cause a significant increase in manufacturing cost. Moreover, limiting the number of slots Q of the stator slots 14 between 15 and 18 helps to provide a more uniform magnetic field distribution, thereby reducing the magnetic field non-uniformity and improving the efficiency and performance of the motor. Secondly, limiting the number of slots Q of the stator slots 14 between 15 and 18 can make the magnetic field of the motor more uniform, reduce the magnetic field fluctuation, thereby reducing the noise of the motor. At the same time, it also helps to reduce the vibration of the motor. Compared with motors with a higher number of slots, motors with 15 to 18 slots may have an advantage in manufacturing cost because they do not require too many winding coils and insulating materials, reducing the manufacturing difficulty and cost. Limiting the number of slots Q of the stator slots 14 between 15 and 18 can improve the efficiency and torque density of the motor. Although increasing the number of slots Q of the stator slots 14 can further improve these performance parameters, relatively high efficiency and torque can already be achieved within the range of 15 to 18.

[0055] Specifically, 10 ≤ P ≤ 12. Motors with the number of poles P between 10 and 12 can achieve a better balance between torque and speed. Compared with motors with fewer poles, motors with the number of poles P between 10 and 12 have higher torque and lower speed, and are suitable for application scenarios that require high torque and lower speed. Compared with motors with more poles, motors with the number of poles P between 10 and 12 can avoid problems such as the increase in the motor body size and rotor inertia caused by too many poles, thus maintaining high efficiency.

[0056] Preferably, the stator teeth 12 and the stator yoke 11 enclose to form a stator slot 14, the number of the stator slots 14 is Q, the number of phases of the motor is m, and 0 < Q / mP < 1. The number of slots per pole per phase is equal to the ratio of the number of slots of the stator slot 14 to the product of the number of pole pairs of the rotor and the number of phases of the motor, and 0 < Q / mP < 1 is satisfied, so that a fractional-slot motor can be formed as a whole. Under the action of the fractional-slot motor, the cogging torque induced by the rotor permanent magnet magnetic field can be effectively weakened. Moreover, the fractional-slot motor can effectively increase the equivalent number of slots per pole per phase. This means that under the same number of slots, the fractional-slot motor can obtain better distribution performance, making the motor waveform closer to a sine wave. This helps to improve the efficiency and performance of the motor. Secondly, the fractional-slot motor can effectively weaken the per-pole magnetic flux pulsation caused by the change of the air-gap permeance, thereby reducing the pulsation amplitude. This helps to improve the electromotive force waveform and reduce the pulsation loss, and improve the operating efficiency and stability of the motor. Since the fractional-slot motor uses fewer slots to obtain the same distribution performance as an integer-slot winding with a large number of slots, its number of slots is relatively small, and it has good processability. This helps to reduce the manufacturing cost of the motor and improve the production efficiency. Furthermore, the torque characteristics of the fractional-slot motor are usually good, and the torque ripple is small. This is because the fractional-slot motor can optimize the magnetic field distribution, reduce the harmonic components, and thus reduce the torque ripple. This makes the fractional-slot motor have an advantage in occasions where high-precision control and stable operation are required.

[0057] In one embodiment, 8 mm ≤ W ≤ 17 mm. When W > 17 mm, the width of the tooth tip 13 is too large at this time, which will increase the leakage between the stator and the rotor, and thus reduce the efficiency of the motor; at the same time, the too-wide tooth tip 13 will cause local stress concentration in the stator structure, increasing the risk of damage. If W < 8 mm, the width of the tooth tip 13 is too small at this time, which will cause uneven magnetic flux distribution in the stator tooth 12 part, and thus increase the torque ripple and electromagnetic noise of the motor, reducing the running smoothness of the motor.

[0058] In one embodiment, 23 mm ≤ R 1 ≤ 34 mm. If R 1 > 34 mm, it means that the outer diameter of the rotor is too large. The increase in the outer diameter of the rotor will cause an increase in the moment of inertia of the motor. The increase in the moment of inertia means that the motor needs to overcome a greater inertial force when changing its motion state (such as starting, stopping, or changing the speed), which will lead to a decrease in the response speed of the motor; at the same time, the increase in the outer diameter of the rotor usually causes a decrease in the core magnetic flux density of the motor, and the decrease in the magnetic flux density will weaken the magnetic coupling between the core and the copper wire. However, at the same time, due to the increase in the core volume, the total iron loss may increase. If R 1<23mm, it indicates that the outer diameter of the rotor is too small. The reduction of the rotor outer diameter will decrease the air-gap area and magnetic flux of the motor, thereby reducing the output torque of the motor. At the same time, too small a rotor outer diameter may cause restricted air flow inside the motor, thus affecting the heat dissipation effect of the motor, causing the temperature of the motor to rise during operation and reducing the efficiency. Therefore, 23mm ≤ R 1 ≤ 34mm, thereby optimizing the torque output of the motor, reducing the iron core, and further improving the efficiency of the motor.

[0059] In one embodiment, 3mm ≤ L ≤ 10mm. When L > 10mm, at this time the recess 212 on the arc wall of the rotor is too large, which will cause the magnetic flux path on the arc wall of the rotor to become extremely complex, thereby increasing the magnetic resistance and reducing the magnetic flux efficiency, making the motor require a larger current to generate the same torque, thus increasing the energy consumption. If L < 2, it indicates that the recess 212 provided on the arc wall of the rotor corresponding to one magnetic pole is too small at this time, so that the magnetic flux distribution cannot be effectively optimized, which will lead to uneven magnetic flux distribution on the arc wall of the rotor, further increasing the torque ripple and electromagnetic noise of the motor and reducing the running stability of the motor. Therefore, setting 3mm ≤ L ≤ 10mm within a reasonable range optimizes the magnetic field distribution of the motor, thereby reducing the torque ripple and electromagnetic noise of the motor and improving the efficiency of the motor.

[0060] In one embodiment, the width of the stator tooth 12 is T, 4mm ≤ T ≤ 11mm. If T > 11mm, it indicates that the width of the stator tooth 12 is too large, which will cause unreasonable magnetic flux distribution, further resulting in too high current density in some areas and reducing the motor efficiency. If T < 4mm, the magnetic path of the stator tooth 12 will become narrower, resulting in an increase in magnetic flux density, further saturating the stator iron core and reducing the performance of the motor.

[0061] In one embodiment, the minimum inner radius of the stator is R 2 , 24mm ≤ R 2 ≤ 35mm. If R 2 > 35mm, at this time the inner diameter of the stator is too large. With the rotor size unchanged, the too large inner diameter of the stator will increase the air gap between the stator and the rotor, further increasing the magnetic leakage of the motor and reducing the efficiency of the motor. If R 2 < 24mm, at this time the inner diameter of the stator is too small, which will limit the magnetic field distribution and intensity inside the motor, thereby affecting the output power of the motor.

[0062] The present utility model also proposes a compressor, which includes a permanent magnet motor. The specific structure of the permanent magnet motor refers to the above embodiments. Since the compressor in the technical solution of the present utility model adopts all the technical solutions of the above all embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated one by one here.

[0063] The present utility model also provides a refrigeration device, which includes a compressor. For the specific structure of the compressor, reference may be made to the above-mentioned embodiments. Refrigeration devices can be classified into compression refrigeration devices, absorption refrigeration devices, steam jet refrigeration devices, heat pump refrigeration devices, electrothermal refrigeration devices, etc. The refrigeration device mainly consists of a compressor, an expansion valve, an evaporator, a condenser, and accessories and pipelines. Such as refrigerators, air conditioners, etc. Since the compressor in the technical solution of the present utility model adopts all the technical solutions of the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, and will not be elaborated herein one by one.

[0064] The above description is only an exemplary embodiment of the present utility model, and does 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 any direct / indirect application in other related technical fields is included in the patent protection scope of the present utility model.

Claims

1. A permanent magnet motor, characterized in that: include: A stator, the stator comprising a stator yoke, a plurality of stator teeth and a plurality of tooth shoes, the plurality of stator teeth being arranged at intervals on the inner circumference of the stator yoke, the tooth shoe being connected to one end of the stator tooth away from the stator yoke, two tooth shoes being arranged corresponding to one stator tooth, and the two tooth shoes being located on both sides of the stator tooth, and the maximum width between the two tooth shoes corresponding to the same stator tooth being W; and The rotor comprises a rotor core and a permanent magnet, wherein the rotor core is provided with a magnet slot, the permanent magnet is located in the magnet slot, the maximum outer radius of the rotor core is R1, the number of magnetic poles of the rotor is P, the rotor core comprises a plurality of rotor arc walls, one of the rotor arc walls is arranged corresponding to one magnetic pole, one of the rotor arc walls is provided with a plurality of recessed portions, the arc length of the rotor arc wall is V, The sum of the maximum opening widths of the plurality of recessed portions corresponding to one magnetic pole is L, 0.35≤L / V≤0.4, 1.85≤V / W≤2.

15.

2. The permanent magnet motor according to claim 1, characterized in that: 0.35≤L / V≤0.

38.

3. The permanent magnet motor according to claim 1, characterized in that: 1.85≤V / W≤2.

05.

4. The permanent magnet motor according to claim 1, characterized in that: The rotor core is provided with a shaft hole, the minimum radius of the shaft hole is R2, the stator teeth and the stator yoke are combined to form stator slots, the number of the stator slots is Q, 5. The permanent magnet motor according to claim 4, characterized in that:

6. The permanent magnet motor according to claim 1, characterized in that: The number of the recessed parts corresponding to the rotor arc wall is a, 2≤a≤4.

7. The permanent magnet motor according to claim 1, characterized in that: The width of the stator teeth is T, 1.9≤W / T≤3.

8. The permanent magnet motor according to claim 1, characterized in that: The stator teeth and the stator yoke are combined to form stator slots, and the number of the stator slots is Q, where 15≤Q≤18.

9. The permanent magnet motor according to claim 1, characterized in that: 10≤P≤12。 10. The permanent magnet motor according to claim 1, characterized in that: The stator teeth and the stator yoke are combined to form stator slots, the number of the stator slots is Q, the number of phases of the motor is m, and 0<Q / mP<1.

11. The permanent magnet motor according to claim 1, characterized in that: 8mm≤W≤17mm.

12. The permanent magnet motor according to claim 1, characterized in that: 23mm≤R1≤34mm.

13. The permanent magnet motor according to claim 1, characterized in that: 3mm≤L≤10mm.

14. The permanent magnet motor according to claim 1, characterized in that: The width of the stator teeth is T, 4mm≤T≤11mm.

15. The permanent magnet motor according to claim 1, characterized in that: The minimum inner radius of the stator is R2, 24mm≤R2≤35mm.

16. A compressor, characterized in that: Comprising a permanent magnet 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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