Permanent magnet motor, compressor and refrigeration equipment

Abstract

The invention provides a permanent magnet motor, a compressor and refrigeration equipment. Wherein the distance between the front ends of a pair of gap parts in the same pole of the permanent magnet motor is bs, the circumferential width of the parallel part of the tooth part is bt, the circumferential width of the front end part of the tooth part is bfe, and (bt + bfe) / 2 < = bs < = 0.98 * bfe. According to the scheme, the situation that the magnetic flux blocking effect on the permanent magnet is too large due to the fact that the bs distance is too small can be avoided, and it is guaranteed that the magnetic flux of the permanent magnet smoothly flows to the stator; and the counter electromotive force harmonic distortion rate and the cogging torque (peak-to-peak value) of the permanent magnet motor can be reduced by modulating the ratio relation of bs, bt and bfe, and the generation of torque ripple in the operation process of the permanent magnet motor is improved, so that the operation of the permanent magnet motor is more stable, the generation of noise of the permanent magnet motor is inhibited, and the stability of the compressor with the permanent magnet motor is improved. The noise of the compressor is reduced, and the comfort degree of a user using the refrigeration equipment with the compressor is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration equipment, and in particular to a permanent magnet motor, a compressor and a refrigeration equipment. Background Art

[0002] In recent years, motor technology, especially permanent magnet synchronous motor technology, has developed rapidly. The motor body structure design has become increasingly novel, and the motor torque density and power density have become increasingly larger. How to improve the motor torque density has become an important issue in reducing motor costs and improving motor competitiveness.

[0003] When designing permanent magnet motor laminations, it is necessary to comprehensively consider the size of the inner diameter and outer diameter of the second core, the ratio between the inner diameter and the outer diameter, the slot type and size of the magnet mounting slot, the winding method, the magnet material, brand, form, and dosage, etc., in order to achieve the best performance requirements. Among them, the design of the magnet mounting slot has a great relationship with the back electromotive force, back electromotive force harmonic distortion rate, and cogging torque of the motor. The design of different magnet mounting slots corresponding to different rotors can improve the motor back electromotive force, reduce the back electromotive force harmonic distortion rate and cogging torque, and thus improve the generation of torque pulsation.

[0004] Improving the torque pulsation during the operation of the permanent magnet motor can make the permanent magnet motor run more smoothly and suppress the noise of the permanent magnet motor, thereby improving the stability of the compressor with the permanent magnet motor and reducing the noise of the compressor. Compressor noise plays a key role in the noise of refrigeration equipment. Reducing the noise of the compressor can improve the comfort of users using refrigeration equipment. However, the current permanent magnet motor is not able to improve the torque pulsation during its operation, so the noise of the compressor and refrigeration equipment is high, affecting the user experience. Summary of the invention

[0005] An object of the present invention is to make the distance bs between the front ends of a pair of gap portions in the same pole greater than or equal to the circumferential width bt of the parallel portion of the tooth portion, thereby ensuring that the magnetic flux of the permanent magnet flows smoothly to the stator.

[0006] A further object of the present invention is to reduce the back electromotive force harmonic distortion rate and cogging torque of the permanent magnet motor, improve the generation of torque pulsation during the operation of the permanent magnet motor, thereby making the permanent magnet motor run more smoothly and suppressing the generation of permanent magnet motor noise.

[0007] In particular, the present invention provides a permanent magnet motor, comprising: a stator and a rotor, wherein the rotor is arranged inside the stator with a preset gap and rotates together with the rotating shaft,

[0008] The stator includes: a first core and a concentrated winding coil, wherein the first core has: a ring-shaped yoke, a plurality of teeth protruding radially inward from the yoke, and a plurality of slots formed between adjacent teeth, and the coil is directly wound on the teeth.

[0009] The rotor includes: a second core and a plurality of permanent magnets, wherein the second core has: a plurality of magnet mounting grooves arranged along a circumferential direction centered on the axis of the second core, the permanent magnets are buried in the magnet mounting grooves and magnetize N poles and S poles alternately, and

[0010] A plurality of pairs of gap portions are arranged along the circumferential direction and toward the center line of the magnetic pole from both ends of the magnet mounting slot, the distance between the front ends of a pair of gap portions in the same pole is bs, the tooth portion has a parallel portion that is roughly parallel from the outer diameter side to the inner diameter side, and the circumferential width of the parallel portion is bt, where bt≤bs.

[0011] Optionally, the tooth portion further has a front end portion that expands circumferentially from both sides of one end of the parallel portion approaching the inner diameter side, and the circumferential width of the front end portion is bfe, wherein (bt+bfe) / 2≤bs≤0.98*bfe.

[0012] Optionally, the magnet mounting groove is in a straight line shape or a V-shape protruding toward the axis of the second core.

[0013] Optionally, the magnet mounting groove is symmetrical with respect to the center line of the magnetic pole; and a pair of gap portions in the same pole are symmetrical with respect to the center line of the magnetic pole.

[0014] Optionally, the plurality of teeth are arranged at equal intervals along the circumferential direction.

[0015] Optionally, the coil is provided with a concentrated winding of a three-phase Y connection or a delta connection formed by directly winding a preset number of turns on the tooth portion.

[0016] Optionally, the number of the magnet mounting slots is 6 or 8.

[0017] Optionally, the first core and the second core are each formed by laminating a plurality of thin plates made of magnetic steel plates;

[0018] The permanent magnets are a plurality of flat plate-shaped rare earth permanent magnets mainly composed of neodymium, iron, and boron, magnetized in an alternating manner with N poles and S poles.

[0019] According to another aspect of the present invention, a compressor is provided, comprising any one of the permanent magnet motors described above.

[0020] According to yet another aspect of the present invention, there is provided a refrigeration device comprising the above-mentioned compressor.

[0021] The permanent magnet motor of the present invention comprises: a stator and a rotor, wherein the rotor is arranged inside the stator with a preset gap and rotates together with the rotating shaft, the stator comprises: a first iron core and a coil of concentrated winding, wherein the first iron core comprises: a yoke in an annular shape, a plurality of teeth protruding radially inward from the yoke, and a plurality of slots formed between adjacent teeth, the coil being directly wound on the teeth, and the rotor comprises: a second iron core and a plurality of permanent magnets, wherein the second iron core comprises: a plurality of A magnet mounting groove, in which a permanent magnet is buried, and the N pole and the S pole are magnetized alternately, and a plurality of pairs of gap portions are arranged from both ends of the magnet mounting groove along the circumferential direction and in the direction toward the center line of the magnetic pole, the distance between the front ends of a pair of gap portions in the same pole is bs, and the tooth portion has a parallel portion that is roughly parallel from the outer diameter side to the inner diameter side, and the circumferential width of the parallel portion is bt, wherein bt≤bs, which can avoid the bs distance being too small so that the magnetic flux blocking effect on the permanent magnet is too large, thereby ensuring that the magnetic flux of the permanent magnet flows smoothly to the stator.

[0022] Furthermore, in the permanent magnet motor of the present invention, the tooth portion also has a front end portion that expands circumferentially from both sides of one end of the parallel portion approaching the inner diameter side, and the circumferential width of the front end portion is bfe, wherein (bt+bfe) / 2≤bs≤0.98*bfe. By modulating the ratio of the distance bs between the front ends of a pair of gap portions in the same pole, the circumferential width bt of the parallel portion of the tooth portion 10, and the circumferential width bfe of the front end portion of the tooth portion, the harmonic distortion rate of the back electromotive force and the tooth slot torque (peak-to-peak value) of the permanent magnet motor can be effectively reduced, the generation of torque pulsation during the operation of the permanent magnet motor can be improved, the operation of the permanent magnet motor can be made more stable, and the generation of noise from the permanent magnet motor can be suppressed, thereby improving the stability of the compressor having the above-mentioned permanent magnet motor, reducing the noise of the compressor, and improving the comfort of users using refrigeration equipment having the above-mentioned compressor.

[0023] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0025] Figure 1 is an overall cross-sectional view of a permanent magnet motor having a V-shaped magnet mounting groove according to an embodiment of the present invention;

[0026] Figure 2is a partial cross-sectional view of a permanent magnet motor having a V-shaped magnet mounting groove according to an embodiment of the present invention;

[0027] Figure 3 is an overall cross-sectional view of a permanent magnet motor having a magnet mounting groove in a straight line shape according to an embodiment of the present invention;

[0028] Figure 4 It is a partial cross-sectional view of a permanent magnet motor having a magnet mounting groove in a straight line shape according to an embodiment of the present invention;

[0029] Figure 5 is a curve diagram of the back electromotive force of a permanent magnet motor according to an embodiment of the present invention as the distance bs changes;

[0030] Figure 6 3 is a graph showing the back electromotive force harmonic distortion rate and the cogging torque (peak-to-peak value) of the permanent magnet motor according to one embodiment of the present invention as the distance bs changes. DETAILED DESCRIPTION

[0031] The present embodiment provides a permanent magnet motor, which can avoid the bs distance being too small, which will cause excessive blocking effect on the magnetic flux of the permanent magnet, and ensure that the magnetic flux of the permanent magnet flows smoothly to the stator, by modulating the ratio of the distance bs between the front ends of a pair of gap portions in the same pole, the circumferential width bt of the parallel portion of the tooth portion 10, and the circumferential width bfe of the front end portion of the tooth portion. It can also effectively reduce the harmonic distortion rate of the back electromotive force and the tooth slot torque (peak-to-peak value) of the permanent magnet motor, improve the generation of torque pulsation during the operation of the permanent magnet motor, make the permanent magnet motor run more smoothly, and suppress the generation of noise from the permanent magnet motor, thereby improving the stability of the compressor with the above-mentioned permanent magnet motor, reducing the noise of the compressor, and improving the comfort of users using the refrigeration equipment with the above-mentioned compressor.

[0032] Figure 1 is an overall cross-sectional view of a permanent magnet motor having a magnet mounting groove 7 in a V shape according to an embodiment of the present invention, Figure 2 1 is a partial cross-sectional view of a permanent magnet motor according to an embodiment of the present invention, in which the magnet mounting groove 7 is V-shaped. Figure 3 1 is an overall cross-sectional view of a permanent magnet motor according to an embodiment of the present invention, in which the magnet mounting slot 7 is in a straight line shape. Figure 4 FIG. 1 is a partial cross-sectional view of a permanent magnet motor having a magnet mounting groove 7 in a straight line shape according to an embodiment of the present invention. Figures 1 to 4 As shown, the permanent magnet motor of this embodiment may generally include: a stator 1 and a rotor 2 .

[0033] The rotor 2 is arranged inside the stator 1 with a preset gap and rotates with the rotating shaft. Specifically, a rotating shaft (not shown in the figure) that rotates relative to the stator 1 can be arranged on the axis of the stator 1. Then the cylindrical rotor 2 can be fixed to the rotating shaft. The preset gap between the stator 1 and the rotor 2 can be an air gap of about 0.3 mm to 1 mm, and the rotor 2 can become a structure that rotates around the rotating shaft, and the rotating shaft is also rotating.

[0034] It should be noted that the “axial direction” mentioned in this article refers to the rotation axis direction of the rotor 2 , the “radial direction” refers to the radial direction of the rotor 2 , and the “circumferential direction” refers to the circumferential direction of the rotor 2 . Figure 1 The cross-sectional view of the permanent magnet motor of this embodiment shown is a cross-sectional view in a direction perpendicular to the rotation axis. Figure 2 , Figure 3 , Figure 4 The cross-sectional view of the permanent magnet motor is also a cross-sectional view in a direction perpendicular to the rotation axis. In addition, the permanent magnet motor of this embodiment can operate as a permanent magnet motor.

[0035] In a specific embodiment, the stator 1 may include: a first core 3 and a concentrated winding coil 5, wherein the first core 3 has: a ring-shaped yoke 9, a plurality of teeth 10 protruding radially inward from the yoke 9, and a plurality of slots 13 formed between adjacent teeth 10, and the coil 5 is directly wound on the teeth 10. In a preferred embodiment, the coil 5 is provided with a three-phase Y-connection or delta-connection concentrated winding formed by directly winding a preset number of turns on the teeth 10.

[0036] like Figure 1 and Figure 3 As shown, the first core 3 of the stator 1 may be cylindrical. In a preferred embodiment, the first core 3 may be formed by stacking a plurality of thin plates composed of magnetic steel plates. The magnetic steel plates may be silicon steel plates. The tooth portion 10 may have a parallel portion 11 that is substantially parallel from the outer diameter side to the inner diameter side. In addition, the tooth portion 10 may also have front end portions 12a, 12b that expand circumferentially from both sides of one end of the parallel portion 11 approaching the inner diameter side. In a preferred embodiment, a plurality of tooth portions 10 are arranged at equal intervals in the circumferential direction.

[0037] In a specific embodiment, the rotor 2 may include: a second core 4 and a plurality of permanent magnets 6, wherein the second core 4 has: a plurality of magnet mounting grooves 7 arranged along a circumferential direction centered on the axis 14 of the second core 4, and the permanent magnets 6 are buried in the magnet mounting grooves 7 and alternately magnetize the N pole and the S pole. Figure 1 and Figure 3As shown, the second core 4 of the rotor 2 may be cylindrical. In a preferred embodiment, the second core 4 may be formed by laminating a plurality of thin plates composed of magnetic steel plates. The magnetic steel plates may be silicon steel plates. The permanent magnet 6 may be a plurality of flat plate-shaped rare earth permanent magnets mainly composed of neodymium, iron, and boron, which are magnetized in an alternating manner of N poles and S poles.

[0038] like Figure 1 and Figure 2 As shown, the magnet mounting groove 7 may be V-shaped and protrude toward the axis 14 of the second core 4. Figure 3 and Figure 4 As shown, the magnet installation slot 7 of the permanent magnet motor can also be in a straight line shape. Figure 1 , Figure 2 and Figure 3 , Figure 4 Except for the difference in the shape of the magnet mounting groove 7, the structures of other parts of the permanent magnet motor can be the same.

[0039] It should be emphasized that multiple pairs of gaps 8a, 8b are provided along the circumferential direction from both ends of the magnet mounting slot 7 and in the direction toward the magnetic pole center line OO', and the distance between the front ends of a pair of gaps 8a, 8b in the same pole is bs. The front ends of the gaps 8a, 8b specifically refer to the ends of the gaps 8a, 8b close to the magnetic pole center line OO'.

[0040] In a specific embodiment, the magnet installation slot 7 is symmetrical with respect to the pole center line OO', which can ensure that the magnetic field distribution of the rotor 2 of the permanent magnet motor is symmetrical and uniform, so that the permanent magnet motor runs smoothly. In addition, a pair of gaps 8a and 8b in the same pole are symmetrical with respect to the pole center line OO', which can further ensure that the magnetic field distribution of the rotor 2 of the permanent magnet motor is symmetrical and uniform, so that the permanent magnet motor runs smoothly. In addition, in a specific embodiment, the number of magnet installation slots 7 is 6 or 8, which can make it simple and convenient to control the permanent magnet motor. For example, Figure 1 and Figure 3 The number of magnet mounting grooves 7 shown is eight.

[0041] As mentioned above, the tooth portion 10 has a parallel portion 11 that is substantially parallel from the outer diameter side to the inner diameter side. The circumferential width of the parallel portion 11 is bt. In this embodiment, bt≤bs. Figure 5 is a graph showing the back electromotive force of a permanent magnet motor according to an embodiment of the present invention as the distance bs changes. Figure 5As shown, as the distance bs increases, the smaller the circumferential width of the gaps 8a and 8b along the second core 4, the smaller the effect of blocking the magnetic flux of the permanent magnet 6, and the larger the amplitude of the back electromotive force. Therefore, in order to avoid the bs distance being too small so that the magnetic flux blocking effect on the permanent magnet 6 is too large, this embodiment limits the minimum value of the distance bs, and sets bt≤bs, which can ensure that the magnetic flux of the permanent magnet 6 can flow smoothly to the stator 1.

[0042] The principle of generating back electromotive force is based on the law of electromagnetic induction. When current flows in a conductor, a magnetic field is generated, and the changing magnetic field generates an electromotive force in the conductor. The direction of this electromotive force is opposite to the direction of the original current, so it is called back electromotive force. For example, in an electric motor, when coil 5 rotates in a magnetic field, it cuts the magnetic flux lines and generates an induced electromotive force. The direction of this electromotive force is opposite to the direction of the current that makes coil 5 rotate, which plays a role in weakening the electromotive force of the power supply.

[0043] The direction of the back electromotive force is opposite to that of the power supply electromotive force, which will offset part of the power supply electromotive force, reduce the current in the circuit, and thus hinder the rotation of the coil 5, but will not cause the coil 5 to rotate in the opposite direction. Therefore, the back electromotive force plays an important role in motor control, and it is necessary to limit the back electromotive force to overcome the harm of the back electromotive force, and also limit the maximum value of the distance bs.

[0044] As mentioned above, the tooth portion 10 also has front end portions 12a and 12b that expand circumferentially from both sides of one end of the parallel portion 11 approaching the inner diameter side. The circumferential width of the front end portions 12a and 12b is bfe. In fact, the circumferential width of the front end portions 12a and 12b is bfe, which refers to the maximum distance between the two tooth tops at the front end of the tooth portion 10 that can be measured. In a preferred embodiment, the distance bs between the front ends of a pair of gap portions 8a and 8b in the same pole is greater than or equal to the circumferential width bt of the parallel portion 11 of the tooth portion 10, and is less than or equal to 0.98 times the circumferential width bfe of the front end portions 12a and 12b of the tooth portion 10. That is, bt≤bs≤0.98*bfe.

[0045] In a specific embodiment, the circumferential width of the parallel portion 11 of the tooth portion 10 is bt=6.9mm, the circumferential width of the front end portions 12a, 12b of the tooth portion 10 is bfe=13mm, and the distance bs between the front ends of a pair of gap portions 8a, 8b in the same pole is 11mm. That is, bt=6.9mm≤bs=11mm≤0.98*bfe=0.98*13mm=12.74mm. It should be noted that the specific values ​​of bt, bs, and bfe mentioned above are only for illustrative purposes and are not intended to limit the present invention. In other embodiments, other values ​​can be set according to actual conditions, but bt≤bs≤0.98*bfe must be satisfied.

[0046] Figure 6 is a graph showing the back electromotive force harmonic distortion rate and cogging torque (peak-to-peak value) of a permanent magnet motor according to an embodiment of the present invention as the distance bs changes. It should be noted that: Figure 6 The solid line curve in refracts the trend of the harmonic distortion rate of the back electromotive force of the permanent magnet motor as the distance bs changes, and the dotted line curve refracts the trend of the cogging torque (peak-to-peak value) of the permanent magnet motor as the distance bs changes.

[0047] The harmonic distortion rate of back electromotive force refers to the ratio of the harmonic component in the back electromotive force to the fundamental component. Back electromotive force is an important physical quantity in the motor, representing the electromagnetic force between the motor rotor 2 and the stator 1. The magnitude of this force depends on the design of the motor, the position of the rotor 2 and the current of the stator 1. Since this force is variable, the back electromotive force is also variable, so the harmonic distortion rate of the back electromotive force reflects the content of the harmonic component in the back electromotive force. The cogging torque is the torque generated by the interaction between the permanent magnet 6 and the first core 3 of the stator 1 when the winding coil 5 of the permanent magnet motor is not energized. It is caused by the tangential component of the interaction force between the permanent magnet 6 and the tooth portion 10.

[0048] Too high harmonic distortion rate of back electromotive force will cause the following harm to the motor and the power grid: high-order harmonics will increase the loss of the motor and reduce efficiency; may cause overvoltage; affect the communication quality and normal operation of the equipment; affect the starting and running performance of the motor. The cogging torque will cause the motor to vibrate and make noise, and the speed will fluctuate, so that the motor cannot run smoothly, affecting the performance of the motor. In variable speed drive, when the torque pulsation frequency is consistent with the mechanical resonance frequency of stator 1 or rotor 2, the vibration and noise generated by the cogging torque will be amplified. The existence of cogging torque also affects the low-speed performance of the motor in the speed control system and the high-precision positioning in the position control system. Therefore, it is necessary to reasonably adjust the harmonic distortion rate of back electromotive force and the cogging torque.

[0049] like Figure 6 As shown in the figure, as the distance bs increases, the back-electromotive force harmonic distortion of the permanent magnet motor first decreases sharply, reaches a trough, and then increases sharply. Therefore, it can be seen that the distance bs has a more obvious modulation effect on the back-electromotive force harmonic distortion rate of the permanent magnet motor. By modulating the amplitude of the distance bs, the back-electromotive force harmonic distortion rate of the permanent magnet motor can be effectively adjusted.

[0050] In addition, if Figure 6As shown in the figure, the cogging torque (peak-to-peak value) of the permanent magnet motor decreases sharply to the first trough as the distance bs increases, then increases slowly to the peak, then decreases slowly to the second trough, and then increases sharply. A comprehensive comparison of the curves of the back-EMF harmonic distortion rate and the cogging torque (peak-to-peak value) of the permanent magnet motor as the distance bs changes shows that, overall, both the back-EMF harmonic distortion rate and the cogging torque (peak-to-peak value) increase first and then decrease as the distance bs increases, and the waveform overlap is high.

[0051] In this way, by modulating the amplitude of the distance bs, the back electromotive force harmonic distortion rate and the cogging torque (peak-to-peak value) of the permanent magnet motor can be effectively adjusted, thereby achieving the effect of simultaneously reducing the back electromotive force harmonic distortion rate and the cogging torque (peak-to-peak value) of the permanent magnet motor, which is also the purpose of setting bt≤bs≤0.98*bfe in this embodiment.

[0052] In a more preferred embodiment, in order to achieve a better modulation effect, the modulation range of the distance bs can be further reduced to (bt+bfe) / 2≤bs≤0.98*bfe. In this way, if the circumferential width bt of the parallel portion 11 of the tooth portion 10 is 6.9 mm, the circumferential width bfe of the front end portions 12a, 12b of the tooth portion 10 is 13 mm, and the distance bs between the front ends of a pair of gap portions 8a, 8b in the same pole is 11 mm, (bt+bfe) / 2=9.95 mm≤bs=11 mm≤0.98*bfe=0.98*13 mm=12.74 mm can be achieved, thereby obtaining a smaller amplitude of the back electromotive force harmonic distortion rate and the cogging torque (peak-to-peak value).

[0053] It should be noted that the specific values ​​of bt, bs, and bfe are only given as examples and are not intended to limit the present invention. In other embodiments, other values ​​may be set according to actual conditions, but (bt+bfe) / 2≤bs≤0.98*bfe must be satisfied.

[0054] By modulating the ratio of the distance bs between the front ends of the gap portions 8a and 8b in the same pole, the circumferential width bt of the parallel portion 11 of the tooth portion 10, and the circumferential width bfe of the front ends 12a and 12b of the tooth portion 10, the generation of torque pulsation during the operation of the permanent magnet motor can be effectively improved, making the operation of the permanent magnet motor more stable, suppressing the generation of permanent magnet motor noise, thereby improving the stability of the compressor having the above-mentioned permanent magnet motor, reducing the noise of the compressor, and improving the comfort of users using refrigeration equipment having the above-mentioned compressor.

[0055] In summary, the permanent magnet motor of this embodiment includes: a stator 1 and a rotor 2, wherein the rotor 2 is arranged inside the stator 1 with a preset gap and rotates together with the rotating shaft, the stator 1 includes: a first core 3 and a concentrated winding coil 5, wherein the first core 3 has: a ring-shaped yoke 9, a plurality of teeth 10 protruding radially inward from the yoke 9, and a plurality of slots 13 formed between adjacent teeth 10, and the coil 5 is directly wound on the teeth 10, and the rotor 2 includes: a second core 4 and a plurality of permanent magnets 6, wherein the second core 4 has: A plurality of magnet mounting grooves 7 are provided, wherein the permanent magnet 6 is buried in the magnet mounting grooves 7 and magnetized alternately with the N pole and the S pole, and a plurality of pairs of gap portions 8a, 8b are provided from both ends of the magnet mounting grooves 7 along the circumferential direction and in the direction of the magnetic pole center line OO', wherein the distance between the front ends of a pair of gap portions 8a, 8b in the same pole is bs, and the tooth portion 10 has a parallel portion 11 which is substantially parallel from the outer diameter side to the inner diameter side, and the circumferential width of the parallel portion 11 is bt, wherein bt≤bs, thereby avoiding the bs distance being too small so as to cause excessive blocking effect on the magnetic flux of the permanent magnet 6, thereby ensuring that the magnetic flux of the permanent magnet 6 flows smoothly to the stator 1.

[0056] Furthermore, in the permanent magnet motor of this embodiment, the tooth portion 10 also has front end portions 12a and 12b that expand circumferentially from both sides of one end of the parallel portion 11 approaching the inner diameter side, and the circumferential width of the front end portions 12a and 12b is bfe, wherein (bt+bfe) / 2≤bs≤0.98*bfe. By modulating the ratio of the distance bs between the front ends of a pair of gap portions 8a and 8b in the same pole, the circumferential width bt of the parallel portion 11 of the tooth portion 10, and the circumferential width bfe of the front end portions 12a and 12b of the tooth portion 10, the harmonic distortion rate of the back electromotive force and the tooth slot torque (peak-to-peak value) of the permanent magnet motor can be effectively reduced, the generation of torque pulsation during the operation of the permanent magnet motor can be improved, the operation of the permanent magnet motor can be made more stable, the generation of noise of the permanent magnet motor can be suppressed, thereby improving the stability of the compressor having the above-mentioned permanent magnet motor, reducing the noise of the compressor, and improving the comfort of users using refrigeration equipment having the above-mentioned compressor.

[0057] This embodiment also provides a compressor, including a permanent magnet motor of any of the above embodiments. The types of compressor motors are generally divided into two types: induction motors and permanent magnet motors. Induction motors are motors that work on the principle of electromagnetic induction. Their main features are stable speed, large output torque, and suitability for situations where load changes are large. Permanent magnet motors are motors that work using magnetic fields. Their main features are high efficiency, fast start-up, small size, light weight, etc. The compressor of this embodiment uses a permanent magnet motor to take advantage of its high efficiency, fast start-up, etc.

[0058] In addition, the compressor of this embodiment adopts the permanent magnet motor of any of the above-mentioned embodiments, that is, the permanent magnet motor of the compressor of this embodiment, the distance between the front ends of a pair of gap portions 8a and 8b in the same pole is bs, the circumferential width of the parallel portion 11 of the tooth portion 10 is bt, and the circumferential width of the front end portions 12a and 12b is bfe, wherein (bt+bfe) / 2≤bs≤0.98*bfe.

[0059] In this way, it is possible to avoid the bs distance being too small, which would result in excessive blocking effect on the magnetic flux of the permanent magnet 6, and ensure that the magnetic flux of the permanent magnet 6 flows smoothly to the stator 1; and it is also possible to reduce the harmonic distortion rate of the back electromotive force and the tooth slot torque (peak-to-peak value) of the permanent magnet motor by modulating the ratio of the distance bs between the front ends of a pair of gaps 8a and 8b in the same pole, the circumferential width bt of the parallel portion 11 of the tooth portion 10, and the circumferential width bfe of the front end portions 12a and 12b of the tooth portion 10, improve the generation of torque pulsation during the operation of the permanent magnet motor, make the permanent magnet motor run more smoothly, and suppress the generation of noise of the permanent magnet motor. Furthermore, the stability of the compressor having the above-mentioned permanent magnet motor in this embodiment can also be effectively improved, and the noise of the compressor is reduced.

[0060] This embodiment also provides a refrigeration device, including the above-mentioned compressor with a permanent magnet motor. The noise of the compressor plays a key role in the noise of the refrigeration device. By reducing the noise of the compressor, the noise of the refrigeration device can be effectively reduced, the comfort of the user using the refrigeration device with the above-mentioned compressor can be improved, and the user experience can be improved.

[0061] Those skilled in the art should understand that, unless otherwise specified, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "clockwise", "counterclockwise", etc. in the embodiments of the present invention used to indicate orientation or positional relationships are merely for the convenience of describing and understanding the technical solutions of the present invention, and do not indicate or imply that the referred device or component must have a specific orientation, and therefore should not be understood as limiting the present invention.

[0062] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first", "second", etc. may explicitly or implicitly include at least one of the features, that is, include one or more of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. When a feature "includes or contains" one or some of the features it covers, unless otherwise specifically described, this indicates that other features are not excluded and may further include other features.

[0063] Unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. A person skilled in the art should be able to understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0064] In addition, in the description of this embodiment, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. That is, in the description of this embodiment, the first feature being "above", "above", and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below", or "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0065] In the description of the present embodiment, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0066] At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

1. A permanent magnet motor, characterized in that: include: A stator and a rotor, wherein the rotor is arranged inside the stator with a preset gap and rotates together with the rotating shaft, The stator comprises: a first core and a concentrated winding coil, wherein the first core has: a ring-shaped yoke, a plurality of teeth protruding radially inward from the yoke, and a plurality of slots formed between adjacent teeth, and the coil is directly wound on the teeth. The rotor comprises: a second iron core and a plurality of permanent magnets, wherein the second iron core has: a plurality of magnet mounting grooves arranged in a circumferential direction with the axis of the second iron core as the center, the permanent magnets are buried in the magnet mounting grooves and are alternately magnetized with N poles and S poles, and A plurality of pairs of gap portions are arranged from both ends of the magnet mounting groove along the circumferential direction and in the direction toward the center line of the magnetic pole, the distance between the front ends of a pair of the gap portions in the same pole is bs, the tooth portion has a parallel portion that is roughly parallel from the outer diameter side to the inner diameter side, the circumferential width of the parallel portion is bt, wherein bt≤bs.

2. The permanent magnet motor according to claim 1, characterized in that: The tooth portion further comprises a front end portion which expands circumferentially from both sides of one end of the parallel portion approaching the inner diameter side, and the circumferential width of the front end portion is bfe, wherein (bt+bfe) / 2≤bs≤0.98*bfe.

3. The permanent magnet motor according to claim 1, characterized in that: The magnet installation groove is in a straight line shape or a V-shape protruding toward the axis of the second iron core.

4. The permanent magnet motor according to claim 1, characterized in that: The magnet mounting groove is symmetrical with respect to the magnetic pole center line; A pair of the gap portions in the same pole are symmetrical with respect to the magnetic pole center line.

5. The permanent magnet motor according to claim 1, characterized in that: The plurality of teeth are arranged at equal intervals along the circumferential direction.

6. The permanent magnet motor according to claim 1, characterized in that: The coil is provided with a three-phase Y-connected or delta-connected concentrated winding formed by directly winding a preset number of turns on the tooth portion.

7. The permanent magnet motor according to claim 1, characterized in that: The number of the magnet mounting slots is 6 or 8.

8. The permanent magnet motor according to claim 1, characterized in that: The first core and the second core are each formed by laminating a plurality of thin plates made of magnetic steel plates; The permanent magnets are a plurality of flat plate-shaped rare earth permanent magnets mainly composed of neodymium, iron, and boron and magnetized in an alternating manner with N poles and S poles.

9. A compressor, characterized in that: It comprises a permanent magnet motor according to any one of claims 1 to 8.

10. A refrigeration device, characterized in that: Comprising a compressor according to claim 9.

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