Permanent magnet motor, compressor and refrigeration equipment

Abstract

The invention discloses a permanent magnet motor, a compressor and refrigeration equipment, and relates to the technical field of refrigeration equipment, 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 located on the two sides of the stator teeth, and the stator yoke is arranged on the rotor. 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 one 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 invention, the magnetic field intensity is balanced, the radial electromagnetic force is reduced, and the torque ripple is improved.

Description

Technical Field

[0001] This invention relates to the technical field of refrigeration equipment, and particularly to a permanent magnet motor, a compressor, and refrigeration equipment. Background Technology

[0002] As a crucial device for converting electrical energy into mechanical energy, the electric motor plays a key role in various fields such as compressors, refrigeration equipment, and household appliances. An electric motor mainly consists of a stator assembly and a rotor assembly. The rotating magnetic field generated by the current in the stator windings interacts with the rotor magnets in the rotor assembly, thereby producing rotational torque. However, during operation, existing electric motors are prone to torque pulsation, cogging torque, and other air gap unevenness, which can easily introduce harmonics, increasing radial electromagnetic force and consequently causing torque fluctuations and motor vibration. Summary of the Invention

[0003] The main objective of this invention is to provide a permanent magnet motor, compressor, and refrigeration equipment, which aims to balance the magnetic field strength, reduce radial electromagnetic force, and improve torque ripple.

[0004] To achieve the above objectives, the present invention proposes a permanent magnet motor comprising:

[0005] The stator includes a stator yoke, multiple stator teeth, and multiple tooth shoes. The stator teeth are spaced apart on the inner circumferential surface of the stator yoke. Each tooth is connected to one end of a stator tooth away from the stator yoke. Each stator tooth corresponds to two tooth shoes, and the two tooth shoes are located on opposite sides of the stator tooth. The maximum width between two tooth shoes corresponding to the same stator tooth is W.

[0006] The rotor includes a rotor core and a permanent magnet. The rotor core has magnet slots, and the permanent magnet is located within the magnet slots. The maximum outer radius of the rotor core is R1, and the number of magnetic poles of the rotor is P. The rotor core includes multiple rotor arc walls, each corresponding to a magnetic pole. Each rotor arc wall has multiple recesses, and the arc length of each rotor arc wall is V. The sum of the maximum opening widths of the plurality of recesses corresponding to a magnetic pole is L, where 0.35≤L / V≤0.4 and 1.85≤V / W≤2.15.

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

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

[0009] In one embodiment, the rotor core is provided with a shaft hole, the minimum radius of which is R2. The stator teeth and the stator yoke enclose a stator slot, the number of which is Q, 2.15.

[0010]

[0011] In one implementation,

[0012] In one embodiment, the number of recesses corresponding to the rotor arc wall is a, where 2 ≤ a ≤ 4.

[0013] In one embodiment, the width of the stator tooth is T, where 1.9 ≤ W / T ≤ 3.

[0014] In one embodiment, the stator teeth and the stator yoke enclose to form stator slots, and the number of stator slots is Q, where 15 ≤ Q ≤ 18.

[0015] In one implementation, 10 ≤ P ≤ 12.

[0016] In one embodiment, the stator teeth and the stator yoke enclose to form stator slots, the number of stator slots is Q, the number of phases of the motor is m, and 0 < Q / mP < 1.

[0017] In one embodiment, 8mm ≤ W ≤ 17mm.

[0018] In one embodiment, 23mm ≤ R1 ≤ 34mm.

[0019] In one embodiment, 3mm ≤ L ≤ 10mm.

[0020] In one embodiment, the width of the stator tooth is T, where 4mm ≤ T ≤ 11mm.

[0021] In one embodiment, the minimum inner radius of the stator is R2, where 24mm ≤ R2 ≤ 35mm.

[0022] The present invention also proposes a compressor comprising the permanent magnet motor described above.

[0023] The present invention also proposes a refrigeration device, including the compressor described above.

[0024] The permanent magnet motor in the technical solution of this invention includes a stator and a rotor. The stator includes a stator yoke, multiple stator teeth, and multiple tooth shoes. The multiple stator teeth are spaced apart 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. Each 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 has magnet slots, and the permanent magnet is located in the magnet slots. The maximum outer radius of the rotor core is R1, and the number of magnetic poles of the rotor is P. The rotor core includes multiple rotor arc walls, with one rotor arc wall corresponding to one magnetic pole. Each rotor arc wall has multiple recesses, and the arc length of the rotor arc wall is V. The sum of the maximum opening widths of multiple recesses corresponding to a magnetic pole is L, where 0.35≤L / V≤0.4 and 1.85≤V / W≤2.15. By setting recesses on the rotor arc wall, the air gap is modified and shaped, improving the distortion rate of the air gap magnetic flux density waveform and reducing harmonic introduction. Furthermore, by reasonably limiting the dimensions of the tooth shoe, rotor arc wall, and recesses, the air gap magnetic field distribution inside the motor is optimized, reducing the introduction of harmonics caused by uneven air gap due to torque pulsation, cogging torque, etc., thereby balancing the magnetic field strength, reducing the radial electromagnetic force, and improving torque fluctuation. Attached Figure Description

[0025] 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.

[0026] Figure 1 This is a schematic diagram of the structure of an embodiment of the stator in an electric motor provided by the present invention;

[0027] Figure 2 This is a schematic diagram of another embodiment of the stator in the motor provided by the present invention;

[0028] Figure 3 A schematic diagram of another embodiment of the stator in the electric motor provided by the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of a rotor in an electric motor according to an embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of another embodiment of the rotor in the electric motor provided by the present invention;

[0031] Figure 6 This is a schematic diagram of another embodiment of the rotor in the electric motor provided by the present invention;

[0032] Figure 7 This is a graph showing the variation of cogging torque with L / V in this invention;

[0033] Figure 8 This is a graph showing the variation of torque pulsation with V / W in this invention;

[0034] Figure 9 Torque pulsation in this invention The change graph;

[0035] Figure 10 This is a graph showing the variation of stator stiffness with W / T in this invention.

[0036] Explanation of icon numbers:

[0037] 11. Stator yoke; 12. Stator tooth; 13. Tooth shoe; 14. Stator slot; 21. Rotor core; 211. Magnet slot; 212. Recess; 22. Permanent magnet.

[0038] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] 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.

[0040] 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.

[0041] 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.

[0042] Reference Figures 1 to 6 This invention proposes a permanent magnet motor, comprising:

[0043] The stator includes a stator yoke 11, a plurality of stator teeth 12, and a plurality of toothed shoes 13. The stator teeth 12 are spaced apart on the inner circumferential surface of the stator yoke 11. Each toothed shoe 13 is connected to the end of a stator tooth 12 away from the stator yoke 11. One stator tooth 12 corresponds to two toothed shoes 13, and the two toothed shoes 13 are located on opposite sides of the stator tooth 12. The maximum width between the two toothed shoes 13 corresponding to the same stator tooth 12 is W.

[0044] The rotor includes a rotor core 21 and a permanent magnet 22. The rotor core 21 has magnet slots 211, and the permanent magnet 22 is located within the magnet slots 211. The maximum outer radius of the rotor core 21 is R1, and the number of magnetic poles of the rotor is P. The rotor core 21 includes multiple rotor arc walls, each corresponding to a magnetic pole. Each rotor arc wall has multiple recesses 212, and the arc length of each rotor arc wall is V. The sum of the maximum opening widths of the plurality of recesses 212 corresponding to a magnetic pole is L, where 0.35≤L / V≤0.4 and 1.85≤V / W≤2.15.

[0045] The permanent magnet motor in the technical solution of this invention includes a stator and a rotor. The stator includes a stator yoke 11, multiple stator teeth 12, and multiple tooth shoes 13. The multiple stator teeth 12 are spaced apart on the inner circumferential surface of the stator yoke 11. The tooth shoes 13 are connected to the end of the stator teeth 12 away from the stator yoke 11. Each stator tooth 12 corresponds to two tooth shoes 13, and the two tooth shoes 13 are located on both sides of the stator teeth 12. The maximum width between the two tooth shoes 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 has 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 R1, and the number of magnetic poles of the rotor is P. The rotor core 21 includes multiple rotor arc walls, each rotor arc wall corresponding to one magnetic pole. Each rotor arc wall has multiple recesses 212, and the arc length of the rotor arc wall is V. The sum of the maximum opening widths of the multiple recesses 212 corresponding to a magnetic pole is L, where 0.35≤L / V≤0.4 and 1.85≤V / W≤2.15. By setting the recesses 212 on the rotor arc wall, the air gap is modified and shaped, improving the distortion rate of the air gap magnetic flux density waveform and reducing the introduction of harmonics. Furthermore, by reasonably limiting the dimensions of the tooth shoe 13, the rotor arc wall, and the recesses 212, the distribution of the air gap magnetic field inside the motor is optimized, reducing the introduction of harmonics caused by uneven air gap due to torque pulsation and cogging torque, thereby balancing the magnetic field strength, reducing the radial electromagnetic force, and improving torque fluctuation.

[0046] Where L is the sum of the maximum opening widths of the multiple recesses 212 corresponding to a magnetic pole. When there are two recesses 212, refer to... Figure 4 L = L1 + L2; when there are 4 recesses 212, refer to Figure 5 At this point, all four recesses 212 are located within the same magnetic pole, and L = L1 + L2 + L3 + L 4， . Reference Figure 6 At this point, the two end depressions of the four depressions are shared by two adjacent magnetic poles, so L = L1 / 2 + L2 + L3 + L4 / 2.

[0047] It should be noted that L / V represents the ratio of the opening width of the recess 212 to the total 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 the correction of the air gap magnetic flux density waveform, leading to an increase in the harmonic content induced in the air gap magnetic flux density waveform, and thus affecting torque pulsation. When L / V > 0.4, it means that the opening width of the recess 212 is too large. An excessively large recess 212 will lead to an increase in the magnetic bridge length of the rotor core 21, a decrease in mechanical strength, and a significant reduction in reliability under the action of centripetal force during high-speed rotation. Secondly, excessive arc cutting will affect the fundamental amplitude of the air gap magnetic flux density, thereby reducing the utilization rate of the permanent magnet. Therefore, setting 0.35 ≤ L / V ≤ 0.4 within a reasonable range can reduce the impact of cogging torque while ensuring motor performance.

[0048] Furthermore, V / W represents the relative magnitude of the arc length of a magnetic pole on the rotor core 21 and the width of the stator tooth 12. The motor torque is generated by the interaction between the magnetic field produced by the energized stator windings and the magnetic field produced by the rotor permanent magnets in the air gap between the stator and rotor. Therefore, the width of the stator tooth is crucial to torque ripple. If V / W < 1.85 or V / W > 2.15, the motor's magnetic circuit structure will be unreasonable, thus increasing torque ripple. Therefore, by maintaining 1.85 ≤ V / W ≤ 2.15, the motor's magnetic circuit structure is optimized, thereby reducing torque ripple. Figures 1 to 3 These are schematic diagrams of three different stator structures.

[0049] Further optimization resulted in 0.35 ≤ L / V ≤ 0.38. By further optimizing the L / V ratio, the distortion rate of the air gap magnetic flux density waveform was improved, harmonic introduction was reduced, and consequently, the influence of cogging torque was further reduced. Figure 7 Experimental data shows that when 0.35 ≤ L / V ≤ 0.4, the cogging torque is in a low range, but when 0.35 ≤ L / V ≤ 0.38, the cogging torque can be further reduced. This allows for further optimization of the motor's magnetic circuit structure.

[0050] Further optimization resulted in 1.85 ≤ V / W ≤ 2.05. By further optimizing the V / W ratio, the motor's magnetic circuit structure was further optimized, reducing radial electromagnetic force and consequently further reducing torque ripple. Figure 8 It can be seen that when 1.85≤V / W≤2.15, the torque ripple of the motor is in a low range. When 1.85≤V / W≤2.05, the torque ripple can be further reduced, thereby improving the efficiency of the motor.

[0051] In one embodiment, the rotor core 21 is provided with a shaft hole, the minimum radius of which is R2. The stator teeth 12 and the stator yoke 11 enclose and form stator slots 14, the number of which is Q. In this design, a toothed shoe 13 corresponds to a stator slot 14. WQ represents the total width of the toothed shoe 13 in the motor, and 2R2 represents the minimum distance from the center of the stator core inner contour. Increasing the ratio of the total width of the toothed shoe 13 to the stator inner diameter helps to reduce the stator slot width, thereby reducing torque pulsation. Currently, the stator winding process involves the winding machine's wire nozzle penetrating deep into the slot to perform winding. If WQ < 2.15, the toothed shoe ratio is too large, and the stator slot opening is too small, causing the winding nozzle to be unable to penetrate deeply, thus making manufacturing impossible. Therefore, by setting a reasonable ratio... The range of values ​​is determined to optimize the magnetic field distribution and electromagnetic force of the motor, thereby reducing the torque pulsation of the motor.

[0052] Further optimization, Through further optimization The range of values ​​for this parameter is determined to further optimize the magnetic field distribution and electromagnetic force of the motor, thereby further reducing torque ripple. (Refer to...) Figure 9 It can be seen that when At this time, the torque ripple of the motor is within a low range, and the fluctuation of torque ripple within this range is relatively small. However, when At this time, the increased rotor outer diameter leads to a decrease in the area of ​​stator slot 14, resulting in severe winding overheating and a significant temperature rise, which in turn reduces the winding's service life. Therefore, while reducing the impact of torque ripple, and considering the winding's temperature reliability margin, the dimensions of the stator and rotor are limited to... Within the range.

[0053] In one embodiment, the number of recesses 212 corresponding to one of the rotor arc walls is 'a', where 2 ≤ a ≤ 4. Understandably, if a > 4, it indicates that there are too many recesses 212 on the rotor arc wall corresponding to a magnetic pole. Too many recesses 212 lead to an abnormally complex magnetic flux path on the rotor arc wall, increasing magnetic reluctance, reducing magnet utilization, and requiring a larger current to generate the same torque, thus increasing energy consumption. If a < 2, it indicates that there are too few recesses 212 on the rotor arc wall corresponding to a magnetic pole. A small number of recesses 212 may not effectively optimize the magnetic flux distribution, resulting in uneven magnetic flux distribution on the rotor arc wall, which in turn increases torque ripple and electromagnetic noise, reducing the motor's operational stability. Therefore, setting 2 ≤ a ≤ 4 within a reasonable range optimizes the motor's magnetic field distribution, thereby reducing torque ripple and electromagnetic noise and improving motor efficiency.

[0054] Reference Figure 10 Furthermore, the width of the stator tooth 12 is T, where 1.9 ≤ W / T ≤ 3. When W / T > 3, it indicates that the width of the stator tooth 12 is too small. An excessively small tooth width makes the system more prone to deformation under external forces, thus reducing the rigidity of the stator and affecting the service life of the motor. Secondly, it can lead to magnetic circuit saturation in the stator tooth 12 section. Magnetic circuit saturation reduces the magnetic energy utilization rate of the motor, resulting in a decrease in the torque generated by the motor under the same current, thereby affecting the motor's performance. 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, failing to create a closed magnetic circuit structure. This significantly reduces the utilization rate of the permanent magnet, thus affecting the efficiency and cost of the motor.

[0055] Specifically, the stator teeth 12 and the stator yoke 11 enclose to form stator slots 14, the number of which is Q, 15 ≤ Q ≤ 18. It is understood that the number of stator slots 14 Q within this range provides a relatively balanced performance. It is neither too few to affect the motor's efficiency and torque, nor too many to significantly increase manufacturing costs. Moreover, limiting the number of stator slots 14 Q to between 15 and 18 helps to provide a more uniform magnetic field distribution, thereby reducing magnetic field non-uniformity and improving motor efficiency and performance. Secondly, limiting the number of stator slots 14 Q to between 15 and 18 makes the motor's magnetic field more uniform, reducing magnetic field fluctuations and thus reducing motor noise. It also helps to reduce motor vibration. Compared to motors with a higher number of slots, motors with 15 to 18 slots may have a manufacturing cost advantage because they do not require as many winding coils and insulation materials, reducing manufacturing difficulty and cost. Limiting the number of stator slots 14 Q to between 15 and 18 can improve the motor's efficiency and torque density. Although increasing the number of stator slots Q by 14 can further improve these performance parameters, relatively high efficiency and torque can already be achieved in the range of 15 to 18.

[0056] Specifically, 10 ≤ P ≤ 12. Motors with a pole number P between 10 and 12 achieve a better balance between torque and speed. Compared to motors with fewer poles, motors with a pole number P between 10 and 12 have higher torque and lower speed, making them suitable for applications requiring high torque and low speed. Furthermore, compared to motors with more poles, motors with a pole number P between 10 and 12 avoid the problems of increased motor size and rotor inertia caused by excessive poles, thus maintaining higher efficiency.

[0057] Preferably, the stator teeth 12 and the stator yoke 11 enclose to form stator slots 14, the number of stator slots 14 is Q, and the number of phases of the motor is m, 0 < Q / mP < 1. The number of slots per pole per phase is equal to the ratio of the number of stator slots 14 to the product of the number of pole pairs of the rotor and the number of phases of the motor, and the number of slots per pole per phase is kept to 0 < Q / mP < 1, thus forming a fractional-slot motor. Under the action of the fractional-slot motor, the cogging torque induced by the permanent magnet magnetic field of the rotor can be effectively reduced. Moreover, the fractional-slot motor can effectively increase the equivalent number of slots per pole per phase. This means that with 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 reduce the magnetic flux pulsation vibration per pole caused by the change in air gap permeability, thereby reducing the pulsation amplitude. This helps to improve the electromotive force waveform and reduce pulsation loss, thereby improving the operating efficiency and stability of the motor. Because fractional-slot motors achieve the same distributed performance as integer-slot windings with a large number of slots using fewer slots, they have a relatively smaller number of slots and better manufacturability. This helps reduce manufacturing costs and improve production efficiency. Furthermore, fractional-slot motors typically have better torque characteristics and lower torque ripple. This is because fractional-slot motors can optimize the magnetic field distribution and reduce harmonic components, thereby reducing torque ripple. This makes fractional-slot motors advantageous in applications requiring high-precision control and stable operation.

[0058] In one embodiment, 8mm ≤ W ≤ 17mm. When W > 17mm, the width of the toothed shoe 13 is too large, which increases leakage between the stator and rotor, thereby reducing the efficiency of the motor; at the same time, an excessively wide toothed shoe 13 will cause local stress concentration in the stator structure, increasing the risk of damage. If W < 8mm, the width of the toothed shoe 13 is too small, which leads to uneven magnetic flux distribution in the stator teeth 12, thereby increasing the torque pulsation and electromagnetic noise of the motor, and reducing the smoothness of motor operation.

[0059] In one embodiment, 23mm ≤ R1 ≤ 34mm. If R1 > 34mm, it indicates that the rotor's outer diameter is too large. An increased rotor outer diameter leads to an increase in the motor's moment of inertia. This increased moment of inertia means the motor needs to overcome greater inertial forces when changing its motion state (such as starting, stopping, or changing speed), resulting in a decrease in the motor's response speed. Simultaneously, an increased rotor outer diameter usually leads to a decrease in the magnetic flux density of the motor's core. A decrease in magnetic flux density weakens the magnetic coupling between the core and the copper wire, but at the same time, the increased core volume may increase the total iron loss. If R1 < 23mm, it indicates that the rotor's outer diameter is too small. A smaller rotor outer diameter reduces the motor's air gap area and magnetic flux, thereby reducing the motor's output torque. Furthermore, a small rotor outer diameter may restrict airflow inside the motor, affecting heat dissipation and causing the motor to overheat and reduce efficiency during operation. Therefore, the range of 23mm ≤ R1 ≤ 34mm is used to optimize the motor's torque output, reduce the core size, and thus improve the motor's efficiency.

[0060] In one embodiment, 3mm ≤ L ≤ 10mm. When L > 10mm, the recess 212 on the rotor arc wall is too large, leading to an abnormally complex magnetic flux path on the rotor arc wall. This increases magnetic reluctance, reduces magnetic flux efficiency, and requires a larger current to generate the same torque, thus increasing energy consumption. If L < 2, the recess 212 on the rotor arc wall corresponding to one magnetic pole is too small, failing to effectively optimize the magnetic flux distribution. This results in uneven magnetic flux distribution on the rotor arc wall, increasing torque ripple and electromagnetic noise, and reducing the motor's operational stability. Therefore, setting 3mm ≤ L ≤ 10mm within a reasonable range optimizes the motor's magnetic field distribution, thereby reducing torque ripple and electromagnetic noise and improving motor efficiency.

[0061] In one embodiment, the width of the stator tooth 12 is T, where 4mm ≤ T ≤ 11mm. If T > 11mm, it indicates that the width of the stator tooth 12 is too large, which will lead to an unreasonable magnetic flux distribution, resulting in excessively high current density in some areas and thus reducing motor efficiency. If T < 4mm, the magnetic circuit of the stator tooth 12 will become narrower, leading to an increase in magnetic flux density, which will saturate the stator core and reduce motor performance.

[0062] In one embodiment, the minimum inner radius of the stator is R2, where 24mm ≤ R2 ≤ 35mm. If R2 > 35mm, the inner diameter of the stator is too large. With the rotor size remaining constant, this excessively large stator inner diameter increases the air gap between the stator and rotor, thereby increasing magnetic leakage and reducing motor efficiency. If R2 < 24mm, the inner diameter of the stator is too small, which restricts the distribution and intensity of the magnetic field inside the motor, thus affecting the motor's output power.

[0063] The present invention also proposes a compressor, which includes a permanent magnet motor. The specific structure of the permanent magnet motor is as described in the above embodiments. Since the compressor in the technical solution of the present invention 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.

[0064] This invention also proposes a refrigeration device, which includes a compressor. The specific structure of the compressor is as described in the above embodiments. Refrigeration devices can be classified into compression refrigeration devices, absorption refrigeration devices, vapor jet refrigeration devices, heat pump refrigeration devices, and electric heating refrigeration devices, etc. Refrigeration devices mainly consist of a compressor, expansion valve, evaporator, condenser, accessories, and piping. Examples include refrigerators and air conditioners. Since the compressor in this invention adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here.

[0065] 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 permanent magnet motor, characterized in that, include: The stator includes a stator yoke, a plurality of stator teeth, and a plurality of toothed shoes. The plurality of stator teeth are spaced apart on the inner circumferential surface of the stator yoke. The toothed shoes are connected to the end of the stator teeth away from the stator yoke. One stator tooth corresponds to two toothed shoes, and the two toothed shoes are located on both sides of the stator tooth. The maximum width between the two toothed shoes corresponding to the same stator tooth is W. and The rotor includes a rotor core and a permanent magnet. The rotor core has magnet slots, and the permanent magnet is located within the magnet slots. The maximum outer radius of the rotor core is R1, and the number of magnetic poles of the rotor is P. The rotor core includes multiple rotor arc walls, each corresponding to a magnetic pole. Each rotor arc wall has multiple recesses, and the arc length of each rotor arc wall is V. The sum of the maximum opening widths of the plurality of recesses corresponding to a magnetic pole is L, where 0.35≤L / V≤0.4 and 1.85≤V / W≤2.

15.

2. The permanent magnet motor as described in claim 1, characterized in that, 0.35≤L / V≤0.

38.

3. The permanent magnet motor as described in claim 1, characterized in that, 1.85≤V / W≤2.

05.

4. The permanent magnet motor as described in claim 1, characterized in that, The rotor core has a shaft hole with a minimum radius of R2. The stator teeth and the stator yoke form stator slots, and the number of stator slots is Q.

5. The permanent magnet motor as described in claim 4, characterized in that, 6. The permanent magnet motor as described in claim 1, characterized in that, The number of recesses corresponding to the rotor arc wall is a, where 2≤a≤4.

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

8. The permanent magnet motor as described in claim 1, characterized in that, The stator teeth and the stator yoke enclose each other to form stator slots, and the number of stator slots is Q, where 15 ≤ Q ≤ 18.

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

11. The permanent magnet motor as described in claim 1, characterized in that, 8mm≤W≤17mm.

12. The permanent magnet motor as described in claim 1, characterized in that, 23mm≤R1≤34mm.

13. The permanent magnet motor as described in claim 1, characterized in that, 3mm≤L≤10mm.

14. The permanent magnet motor as described in claim 1, characterized in that, The width of the stator teeth is T, where 4mm ≤ T ≤ 11mm.

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

16. A compressor, characterized in that, Includes the permanent magnet motor as described in any one of claims 1 to 15.

17. A refrigeration device, characterized in that, Includes the compressor as described in claim 16.

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