Stator core, permanent magnet synchronous motor, compressor and air conditioner

Abstract

The invention provides a stator core, a permanent magnet synchronous motor, a compressor and an air conditioner, and the stator core comprises a stator yoke ring, and the radial inner circumferential wall of the stator yoke ring is uniformly provided with a plurality of stator teeth at intervals in the circumferential direction. Each stator tooth comprises a tooth boot and a connecting column connected between the tooth boot and the stator yoke ring, and a stator slot is formed between two adjacent stator teeth; extending lines, facing one side of the circumferential wall of the radial inner ring, of the side walls of two circumferential tooth shoes close to each other of two adjacent stator teeth divide the stator groove into a middle winding groove in the middle and side winding grooves located in the two circumferential sides of the middle winding groove, the groove area of the middle winding groove is S1, and the groove area of the side winding grooves is S2. The groove area of each side winding groove is S2, and S1 / S2 is larger than 0 and smaller than or equal to 0.537. The invention can avoid the reduction of the effective slot area S2 of the stator, the reduction of the number of windings and the reduction of the counter electromotive force of the motor caused by the overlarge area S1 of the middle winding slot in the stator core.

Description

Technical Field

[0001] The invention belongs to the technical field of air conditioning, and in particular relates to a stator core, a permanent magnet synchronous motor, a compressor and an air conditioner. Background Art

[0002] With the decline in the cost of rare earth magnet materials, rare earth permanent magnet synchronous motors are becoming more and more widely used. Rare earth magnet materials have larger residual magnetism than ferrite magnet materials, and generally have obvious advantages when operating under severe working conditions. Under severe working conditions, motors need to have a certain load capacity.

[0003] The number of turns and stator slot area of ​​the existing rare earth motor technical solution are not designed reasonably. The motor stator slot area is small. When the motor winding wire diameter remains unchanged, the number of winding turns must decrease, resulting in a decrease in the motor back electromotive force. When the motor output power is the same, the required input current becomes larger, the motor load capacity decreases, and the motor copper loss increases; when the motor stator slot area is large, the motor tooth width decreases and the tooth magnetic density increases for the same stator core outer diameter. When the tooth magnetic density is greater than the core working magnetic density range, the motor iron loss increases, the motor efficiency decreases, and the motor performance decreases. In order to increase the effective value of the motor back electromotive force and thus improve the motor performance, the present invention is proposed. Summary of the invention

[0004] Therefore, the present invention provides a stator core, a permanent magnet synchronous motor, a compressor and an air conditioner, which can solve the technical problems in the prior art that the slot area of ​​the motor stator in the motor is unreasonable, resulting in a low effective value of the motor back electromotive force, low motor load capacity and low motor performance.

[0005] In order to solve the above problems, the present invention provides a stator core, including a stator yoke ring, a plurality of stator teeth are evenly spaced along the circumferential direction of the radial inner circumferential wall of the stator yoke ring, each of the stator teeth includes a tooth shoe and a connecting column connected between the tooth shoe and the stator yoke ring, a stator slot is formed between two adjacent stator teeth, and two circumferential tooth shoe side walls of the tooth shoes of the two adjacent stator teeth are respectively extended toward one side of the radial inner circumferential wall to divide the stator slot into a central middle winding slot and side winding slots on both sides of the middle winding slot in the circumferential direction, the slot area of ​​the middle winding slot is S1, the slot area of ​​the side winding slot is S2, 0<S1 / S2≤0.537.

[0006] In some embodiments, S1 / S2≥0.444; and / or, the radial cross-sectional area of ​​the connecting column is S3, 0.684≤S2 / S3≤0.91.

[0007] In some embodiments, the outer diameter of the stator yoke ring is r, the inner diameter of the stator yoke ring is r2, the radial inner diameter of the tooth shoe is r1, the radial outer diameter of the tooth shoe is r3, the radial inner ring and radial outer ring of the stator yoke ring, and the radial inner wall and radial outer wall of the tooth shoe are concentric, and r1<r3<r2<r; and / or, 49mm≤r≤52mm.

[0008] In some embodiments, 0.56≤r1 / r≤0.58.

[0009] In some embodiments, 6.5 mm ≤ r - r2 ≤ 0.5*(r2 - r3) ≤ 7 mm.

[0010] The present invention also provides a permanent magnet synchronous motor, comprising a motor stator, wherein the motor stator comprises the above-mentioned stator core.

[0011] In some embodiments, the motor stator further includes a stator winding wound on the stator teeth, and a wire diameter of the stator winding is φ, 0.68 mm ≤ Φ ≤ 0.73 mm.

[0012] In some embodiments, the permanent magnet synchronous motor also includes a motor rotor, on which a plurality of magnetic poles are formed along the circumference of the motor rotor, and a radially magnetized permanent magnet is provided under each magnetic pole, and the total length of the magnetic poles of the permanent magnet is L, 0.19≤L / S3≤0.22.

[0013] In some embodiments, the material of the permanent magnet is rare earth.

[0014] The present invention also provides a compressor, comprising the above-mentioned permanent magnet synchronous motor.

[0015] The present invention also provides an air conditioner, comprising the above-mentioned compressor.

[0016] The stator core, permanent magnet synchronous motor, compressor and air conditioner provided by the present invention have the following beneficial effects:

[0017] Optimizing and limiting S1 / S2 can prevent the middle winding slot area S1 in the stator core from being too large, which will lead to a decrease in the stator effective slot area S2, a decrease in the number of winding turns, and a decrease in the motor back EMF, that is, the back EMF of the motor using it will not be too low but at a relatively high level, the motor loss is small, and the motor efficiency and performance are both high. When S1 / S2 is greater than 0.537, the motor back EMF will be too small, which will lead to an increase in motor current, an increase in copper loss, and thus an increase in total motor loss, and a decrease in motor efficiency and performance; prevent the middle winding slot area S1 from being too small, the winding machine width is greater than the boot distance, and the stator cannot be wound by the winding machine, which increases the difficulty of winding the winding and reduces the motor trial production efficiency;

[0018] Reasonably distribute the radial cross-sectional area S3 of the connecting column and the effective slot area to improve the utilization rate of the stator core, avoid the phenomenon that the effective slot area is too large, resulting in a reduction in the connecting column area, a decrease in the width or length of the connecting column, which leads to an increase in the local magnetic flux density (i.e., the tooth magnetic flux density), and increases the motor loss, or a reduction in the effective slot area, resulting in an excessive decrease in the number of turns of the motor winding and the back electromotive force;

[0019] The tooth length is proportional to the stator core slot area, so that the yoke and shoe radius and the stator outer diameter meet this relationship, ensuring a certain slot area size, avoiding the slot area being too small due to unreasonable yoke and yoke radius size, and reducing the back EMF, while not causing the stator core magnetic flux density to increase and the motor loss to increase;

[0020] Avoid the decrease in the number of winding turns when the wire diameter is large, which leads to a decrease in the motor back EMF, and the increase in resistance when the winding wire diameter is small, which leads to an increase in motor loss. Balance the motor loss and optimize the motor performance.

[0021] The tooth area S3 is adjusted according to the rotor magnetic steel length, so that the magnetic flux density values ​​of the stator teeth at different magnetic steel lengths are kept within the working magnetic flux density range of the core material, thereby reducing the stator core loss;

[0022] According to the technical solution of the present invention, the stator core slot area and the tooth area are reasonably allocated. Under the same slot filling rate, the winding wire diameter of the optimized motor solution is reduced by 12.5%, the number of turns is increased by 35%, and the final back electromotive force is increased by about 31.1%; after the tooth area S3 is optimized according to the rotor magnetic steel length, the tooth area S3 is increased by 20.79% compared with the stator core tooth magnetic density, which is reduced by about 8.1%; after the stator core slot area and the tooth area are optimized, the total motor loss is reduced by 5.83% compared with the stator core, and accordingly, the motor efficiency is increased by about 0.38% compared with before optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0024] Figure 1 Schematic diagram of the internal structure of the permanent magnet synchronous motor according to an embodiment of the present invention (axial cross section);

[0025] Figure 2 yes Figure 1 A schematic structural diagram of another embodiment of the motor rotor in the figure, wherein the permanent magnet is in a straight line shape;

[0026] Figure 3 yes Figure 1A schematic structural diagram of another embodiment of the motor rotor in the figure, wherein the permanent magnet is a V-shaped structure formed by two straight-line permanent magnets with different magnetic pole lengths;

[0027] Figure 4 The stator core of the embodiment of the present invention is applied to the corresponding permanent magnet synchronous motor. When other conditions remain unchanged, the change curve of the motor output back electromotive force as S1 / S2 changes. It can be obtained from the figure that when S1 / S2 is less than 0.444, the boot width is less than 2.6 mm, and when S1 / S2 is greater than 0.537, the effective value of the back electromotive force is significantly reduced and is less than 42 V (when the S1 / S2 ratio is greater than 0.537 in the figure, the peak value is less than 60 V, and the effective value = peak value / 1.414);

[0028] Figure 5 The stator core of the embodiment of the present invention is applied to the corresponding permanent magnet synchronous motor. When other conditions remain unchanged, the change curve of the motor output back electromotive force as S2 / S3 changes. It can be obtained from the figure that S2 / S3 is less than 0.684, and the effective value of the back electromotive force is significantly reduced and is less than 42V (when the S2 / S3 ratio is less than 0.684, the peak value is less than 60V, and the effective value = peak value / 1.414);

[0029] Figure 6 The stator core of the embodiment of the present invention is applied to the corresponding permanent magnet synchronous motor. When other conditions remain unchanged, the change curve of the motor tooth magnetic density is obtained as S2 / S3 changes. It can be obtained from the figure that S2 / S3 is greater than 0.91, the tooth magnetic density value is 1.51, and the magnetic density range of the stator core for normal operation is 1.1T-1.5T. When it exceeds 1.5T, the magnetic density is too large, which increases the motor loss.

[0030] Figure 7 It is a schematic diagram of the magnetic lines of force flowing in the stator yoke ring and stator teeth;

[0031] Figure 8 The stator core of the embodiment of the present invention is applied to the corresponding permanent magnet synchronous motor. When other conditions remain unchanged, the change curve of the motor tooth magnetic density with the change of L / S3 shows that the permanent magnet length L is theoretically the larger the better. The larger L is, the better the excitation capacity of the motor is, and the back electromotive force is also improved to a certain extent. When L / S3 is less than 0.19, the tooth magnetic density is less than 1.1T, which is less than the normal working magnetic density range of the stator core (1T-1.5T), reducing the utilization rate of the stator core; but when L / S3 is greater than 0.22, the tooth magnetic density is greater than 1.5T, the stator core loss increases, the motor efficiency is reduced, and the motor performance is affected;

[0032] Fig. 9 A comparison diagram of the back electromotive force of a synchronous permanent magnet motor using the technical solution of the present application (the patent curve in the figure) and not using the technical solution of the present application (the curve before optimization in the figure);

[0033] Fig.10 A comparison diagram of the motor load capacity of a synchronous permanent magnet motor using the technical solution of the present application (the patent curve in the figure) and a synchronous permanent magnet motor not using the technical solution of the present application (the curve before optimization in the figure);

[0034] Fig.11 A motor efficiency comparison diagram of a synchronous permanent magnet motor using the technical solution of the present application (the patent curve in the figure) and a synchronous permanent magnet motor not using the technical solution of the present application (the curve before optimization in the figure);

[0035] Fig.12 A schematic diagram of magnetic flux distribution on a stator core of a motor that does not adopt the technical solution of the present application;

[0036] Fig.13 The figure is a schematic diagram of the magnetic flux distribution on the stator core of a motor adopting the technical solution of the present application.

[0037] The accompanying drawings are marked as follows:

[0038] 1. Motor stator; 11. Stator yoke ring; 121. Tooth shoe; 122. Connecting column; 13. Stator slot; 2. Motor rotor; 21. Permanent magnet. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0041] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90° or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0042] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0043] See also Figure 1 and Fig.13 As shown, according to an embodiment of the present invention, a stator core is provided, comprising a stator yoke ring 11, wherein a plurality of stator teeth (not labeled in the figure) are evenly spaced along the circumferential direction on the radial inner circumferential wall of the stator yoke ring 11, wherein each of the stator teeth comprises a tooth shoe 121 and a connecting column 122 connected between the tooth shoe 121 and the stator yoke ring 11, and a stator slot 13 is formed between two adjacent stator teeth, wherein the tooth shoes 121 of the two adjacent stator teeth are close to each other in the circumferential direction. The extension lines of the tooth shoe side walls toward one side of the radial inner circumferential wall (i.e., from the inside to the outside along the radial direction of the stator core) divide the stator slot 13 into a central middle winding slot (not labeled in the figure) and side winding slots (not labeled in the figure) on both sides of the circumference of the middle winding slot. The slot area of ​​the middle winding slot is S1, and the slot area of ​​the side winding slot is S2 (i.e., the effective slot area). 0<S1 / S2≤0.537, and further, S1 / S2≥0.444. Specifically, after the stator winding is wound on each stator tooth of the stator core, the stator winding will be in the side winding slot, and there is a gap between the stator windings respectively wound on two adjacent stator teeth. The gap is the aforementioned middle winding slot, that is, the part where the stator winding does not exist in the middle winding slot.

[0044] In this technical solution, by optimizing and limiting S1 / S2, it is possible to avoid the middle winding slot area S1 in the stator core being too large, which leads to a reduction in the stator effective slot area S2, a reduction in the number of winding turns, and a decrease in the motor back EMF, that is, the back EMF of the motor using it will not be too low but at a relatively high level, the motor loss is small, and the motor efficiency and performance are both high. When S1 / S2 is greater than 0.537, see Figure 4 As shown, the motor back EMF will be too small, which will lead to an increase in motor current and copper loss, which will in turn lead to an increase in total motor loss and a decrease in motor efficiency and performance.

[0045] In a specific embodiment, the effective value range of the back electromotive force should be maintained at 42V-56V. When it is too high, the overall magnetic density of the stator and rotor cores increases and the loss increases. When it is too low, the load capacity decreases and the copper loss increases.

[0046] Specifically, P = U * I, where U is the motor back electromotive force, I is the winding current, and P is the motor input power. When the input power P provided to the motor by the power supply is constant, U decreases and I increases, and the motor copper loss Pcu = 3 * I 2 *R, when the current increases, the copper loss increases, and the total motor loss = iron loss + copper loss. The increase in loss leads to a decrease in motor efficiency and performance.

[0047] Furthermore, S1 / S2≥0.444. When S1 / S2 is lower than 0.444, the width (circumferential width) of the tooth shoe 121 will be too narrow (in a specific embodiment, lower than 2.6 mm), which is not conducive to the winding of the winding machine. It can be understood that the smaller the aforementioned S1 is in theory, the better, but it should be taken into account that the width of the corresponding tooth shoe 121 cannot be too narrow under the premise of the aforementioned ratio limitation. That is, to prevent the middle winding slot area S1 from being too small, the winding machine width is greater than the shoe distance, and the stator cannot be wound by the winding machine, which increases the difficulty of winding the winding and reduces the efficiency of motor trial production.

[0048] In some embodiments, the radial cross-sectional area of ​​the connecting column 122 is S3, 0.684≤S2 / S3≤0.91, so that the radial cross-sectional area S3 of the connecting column 122 and the effective slot area are reasonably distributed, the utilization rate of the stator core is improved, and the effective slot area is too large to cause the connecting column area to be reduced, the connecting column width or length is reduced to increase the local magnetic flux density (that is, the tooth magnetic flux density), increase the motor loss, or the effective slot area is reduced to cause the number of motor winding turns and the back electromotive force to drop too much. For details, see Figure 5 As shown in the figure, when S2 / S3 is lower than 0.684, the motor back EMF is too low and the effective value is lower than 42V; see Figure 6As shown in the figure, when S2 / S3 exceeds 0.91, the tooth magnetic flux increases significantly, exceeding 1.5T, which exceeds the common working range of the stator core (1.1T-1.5T), which will cause a significant increase in motor losses.

[0049] In some embodiments, the outer diameter of the stator yoke ring 11 is r, the inner diameter of the stator yoke ring 11 is r2, the radial inner diameter of the tooth shoe 121 is r1, the radial outer diameter of the tooth shoe 121 is r3, the radial inner ring and radial outer ring of the stator yoke ring 11, and the radial inner wall and radial outer wall of the tooth shoe 121 are concentric, and r1<r3<r2<r; 49mm≤r≤52mm, further, 0.56≤r1 / r≤0.58.

[0050] The inner and outer diameters of the stator are restricted so that the overall size of the motor is within this range. When the inner and outer diameters of the stator core increase, the size and usage of the motor's stator and rotor core and magnetic steel increase under the same stator-rotor air gap. Since the cost of rare earth magnetic steel is relatively high, the cost of the motor increases to a certain extent. When the inner and outer diameters of the stator core decrease, the outer diameter of the rotor decreases, the usage of magnetic steel decreases, the excitation capacity of the motor decreases, the input current required to achieve the same output torque increases, the motor loss increases, and the efficiency decreases to a certain extent.

[0051] In some embodiments, 6.5 mm ≤ r-r2 ≤ 0.5*(r2-r3) ≤ 7 mm. Since the stator yoke ring 11 and the stator teeth are the main paths of the motor magnetic lines, such as Figure 7 As shown, under the same stator outer diameter and winding wire diameter, when the yoke radius r2 (that is, the inner diameter of the stator yoke ring 11 mentioned above is r2) increases, the yoke width (that is, the radial width of the stator yoke ring 11) decreases, the core magnetic flux increases, and the motor iron loss increases. When r2 decreases, the motor slot area decreases. Similarly, when the yoke radius is the same, r3 (that is, the radial outer diameter of the tooth boot 121 mentioned above is r3) increases, the stator core tooth length decreases, and the tooth length is proportional to the stator core slot area, so that the yoke and boot radius and the stator outer diameter satisfy this relationship, ensuring a certain slot area size, avoiding the slot area being too small due to unreasonable yoke and yoke radius size, and reducing the back electromotive force. At the same time, it will not cause the stator core magnetic flux to increase and the motor loss to increase.

[0052] According to an embodiment of the present invention, a permanent magnet synchronous motor is also provided, including a motor stator 1, wherein the motor stator 1 includes the above-mentioned stator core, and in some embodiments, the motor stator 1 also includes a stator winding (not shown in the figure, for reference) wound on the stator teeth, and the wire diameter of the stator winding is φ, 0.68mm≤Φ≤0.73mm. Specifically, the back electromotive force corresponding to different turns and wire diameters of the excitation winding (that is, the aforementioned stator winding) is different. According to the back electromotive force calculation formula F=4.44*f*Ψ*N*Kdp , where f is the motor operating frequency, Ψ is the motor flux value, N is the number of turns of the excitation winding, K dp is the winding distribution factor; when the effective slot area of ​​the motor is constant, the larger the winding wire diameter, the smaller the number of turns N, and the smaller the back electromotive force. Therefore, preferably, the wire diameter Φ of the excitation winding satisfies the relationship 0.68mm≤Φ≤0.73mm, so as to avoid the decrease in the number of winding turns when the wire diameter is large, resulting in a decrease in the motor back electromotive force, and the increase in resistance when the winding wire diameter is small, resulting in an increase in motor loss, so as to balance the motor loss and optimize the motor performance.

[0053] In some embodiments, the permanent magnet synchronous motor also includes a motor rotor 2, on which a plurality of magnetic poles are formed along the circumference of the motor rotor 2, and a radially magnetized permanent magnet 21 is provided under each magnetic pole. The permanent magnet 21 is preferably made of rare earth material so that the motor rotor can be smaller in size. The total pole length of the permanent magnet 21 is L, 0.19≤L / S3≤0.22. As the length of the radial magnetic steel (that is, the radially magnetized permanent magnet 21) increases, the motor excitation capacity increases, and the air gap magnetic density and the tooth magnetic density increase. Therefore, it is necessary to reduce the tooth magnetic density by increasing the tooth area S3. In this way, S3 and the total length L of each rotor pole magnetic steel satisfy the relationship of 0.19≤L / S3≤0.22. The tooth area S3 is adjusted according to the rotor magnetic steel length so that the magnetic density values ​​of the stator teeth at different magnetic steel lengths are maintained within the working magnetic density range of the core material, thereby reducing the stator core loss. Figure 8 It can be concluded that when L / S3 is less than 0.19, the tooth magnetic flux density is too small, less than 1.1 T, and when L / S3 is greater than 0.22, the tooth magnetic flux density is too large.

[0054] For details of the total length L of the magnetic poles, see Figure 2 and Figure 3 As shown in FIG. 1 , when there is only one radially magnetized permanent magnet 21 under each magnetic pole, as shown in FIG. Figure 2 As shown, it is arranged in a straight line, and L at this time is the magnetic pole length of the permanent magnet 21; and when there are multiple radially magnetized permanent magnets 21 under each magnetic pole, as shown in FIG. Figure 3 As shown, it is a V-shaped arrangement, in which the pole length of one permanent magnet 21 is L1, and the pole length of the other permanent magnet 21 is L2, and at this time L=L1+L2.

[0055] According to the technical solution of the present invention, the stator core slot area and the tooth area are reasonably allocated. Under the same slot filling rate, the winding wire diameter of the optimized motor solution is reduced by 12.5%, and the number of turns is increased by 35%. Fig. 9 As shown, the final back EMF increases by about 31.1%; combined with reference to Fig.12 and Fig.13As shown in FIG. 1 , after optimizing the tooth area S3 according to the rotor magnetic steel length, the tooth area S3 is increased by 20.79% and the magnetic flux density of the stator core tooth is reduced by about 8.1%. Fig. 9 and Fig.10 As shown, after optimizing the stator core slot area and tooth area, the total motor loss is reduced by 5.83%, and accordingly, the motor efficiency is increased by about 0.38% compared with before optimization.

[0056] According to an embodiment of the present invention, a compressor is further provided, comprising the above-mentioned permanent magnet synchronous motor.

[0057] According to an embodiment of the present invention, there is also provided an air conditioner, comprising the above-mentioned compressor.

[0058] It is easy for those skilled in the art to understand that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention. These improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A stator core, comprising a stator yoke ring (11), a plurality of stator teeth being evenly spaced along the circumferential direction of the stator yoke ring (11) on a radial inner circumferential wall thereof, each stator tooth comprising a tooth shoe (121) and a connecting column (122) connected between the tooth shoe (121) and the stator yoke ring (11), a stator slot (13) being formed between two adjacent stator teeth, characterized in that: The tooth shoes (121) respectively possessed by two adjacent stator teeth have two circumferential tooth shoe side walls close to each other, extending along a line toward one side of the radial inner circumferential wall to divide the stator slot (13) into a central middle winding slot and side winding slots on both circumferential sides of the middle winding slot, the slot area of ​​the middle winding slot is S1, the slot area of ​​the side winding slot is S2, and 0<S1 / S2≤0.

537.

2. The stator core according to claim 1, characterized in that: S1 / S2≥0.444; and / or, the radial cross-sectional area of ​​the connecting column (122) is S3, 0.684≤S2 / S3≤0.

91.

3. The stator core according to claim 2, characterized in that: The outer diameter of the stator yoke ring (11) is r, the inner diameter of the stator yoke ring (11) is r2, the radial inner diameter of the tooth shoe (121) is r1, the radial outer diameter of the tooth shoe (121) is r3, the radial inner ring and the radial outer ring of the stator yoke ring (11), the radial inner wall and the radial outer wall of the tooth shoe (121) are concentric, and r1<r3<r2<r; and / or, 49mm≤r≤52mm.

4. The stator core according to claim 3, characterized in that: 0.56≤r1 / r≤0.58; and / or, 6.5mm≤r-r2≤0.5*(r2-r3)≤7mm.

5. A permanent magnet synchronous motor, characterized in that: The invention comprises a motor stator (1), wherein the motor stator (1) comprises the stator core according to any one of claims 2 to 4.

6. The permanent magnet synchronous motor according to claim 5, characterized in that: The motor stator (1) further comprises a stator winding wound on the stator teeth, the wire diameter of the stator winding being φ, 0.68 mm ≤ Φ ≤ 0.73 mm.

7. The permanent magnet synchronous motor according to claim 5, characterized in that: It also comprises a motor rotor (2), on which a plurality of magnetic poles are formed and arranged along the circumference of the motor rotor (2), and a radially magnetized permanent magnet (21) is arranged under each magnetic pole, and the total magnetic pole length of the permanent magnet (21) is L, and 0.19≤L / S3≤0.

22.

8. The permanent magnet synchronous motor according to claim 7, characterized in that: The material of the permanent magnet (21) is rare earth.

9. A compressor, characterized in that: A permanent magnet synchronous motor comprising any one of claims 5 to 8.

10. An air conditioner, characterized in that: A compressor comprising the compressor described in any one of claim 9.

Images