Stator of permanent magnet synchronous motor and permanent magnet synchronous motor

Abstract

The invention provides a stator of a permanent magnet synchronous motor and the permanent magnet synchronous motor, the stator of the permanent magnet synchronous motor comprises stator tooth parts and stator yoke parts, the stator tooth parts and the stator yoke parts are connected in the radial direction of the stator, the number of the stator tooth parts in the circumferential direction is N, the circumferential width of the parts, relatively close to the stator yoke parts, of the stator tooth parts is small, and the number of the stator tooth parts is N; the circumferential width of the part, relatively close to the inner circle of the stator, of the stator tooth part is large, the stator tooth part comprises a stator tooth body and a stator tooth boot which are connected in the radial direction, the circumferential width of the stator tooth boot is larger than that of the stator tooth body, and the stator tooth boot comprises a first tooth boot and a second tooth boot which are connected in the radial outward direction of the stator; the first tooth boot is located on the innermost side in the radial direction, and the circumferential width of the first tooth boot is larger than that of the second tooth boot, so that a stepped tooth part structure in the radial direction is formed. According to the invention, the cogging effect can be brought, the magnetic resistance distribution at each part of the magnetic circuit of the motor is improved, the magnetic flux trend is improved, and the counter potential harmonic of the motor is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a stator of a permanent magnet synchronous motor and a permanent magnet synchronous motor. Background Art

[0002] In recent years, with the development of permanent magnet material manufacturing technology and the rapid decline in costs, its excellent performance and low price have greatly promoted the development of permanent magnet motor technology. China's rich permanent magnet material resources have promoted China's permanent magnet motor technology research and development.

[0003] Permanent magnet motors generate main magnetic fields with permanent magnets. Compared with ordinary induction motors, permanent magnet synchronous motors do not require reactive excitation current, and the rotor resistance loss is zero in synchronous operation. Therefore, it has the characteristics of high power factor and high efficiency, and can usually be used to replace induction motors with lower power indexes. Its economic and social benefits are very significant, and it is widely used in all walks of life.

[0004] However, the permanent magnet material of the permanent magnet synchronous motor has a fixed brand and material, and its magnetic energy product remains unchanged. It is difficult to adjust the air gap magnetic field of the motor. At the same time, the tooth structure of the motor makes the harmonic content of the air gap magnetic density and back electromotive force larger, and the peak value of the electromagnetic force of the motor is large, which makes the motor torque pulsation and vibration noise larger.

[0005] Since the permanent magnet synchronous motor in the prior art has technical problems such as large back electromotive force harmonics, the present invention studies and designs a stator of a permanent magnet synchronous motor and a permanent magnet synchronous motor. Summary of the invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the defect of large back-electromotive force harmonics in the permanent magnet synchronous motor in the prior art, thereby providing a stator of a permanent magnet synchronous motor and a permanent magnet synchronous motor.

[0007] In order to solve the above problems, the present invention provides a stator of a permanent magnet synchronous motor, which comprises:

[0008] A stator tooth portion and a stator yoke portion, wherein the stator tooth portion is connected to the stator yoke portion in the radial direction of the stator, and there are N stator teeth portions in the circumferential direction, the circumferential width of the portion of the stator tooth portion relatively close to the stator yoke portion is small, and the circumferential width of the portion of the stator tooth portion relatively close to the inner circle of the stator is large, the stator tooth portion includes a stator tooth body and a stator tooth shoe connected in the radial direction, the circumferential width of the stator tooth shoe is greater than the circumferential width of the stator tooth body, and along the radial outward direction of the stator, the stator tooth shoe includes a first tooth shoe and a second tooth shoe connected, the first tooth shoe is located at the radial innermost side, and the circumferential width of the first tooth shoe is greater than the circumferential width of the second tooth shoe, so as to form a stepped tooth structure in the radial direction.

[0009] In some embodiments,

[0010] The angle occupied by the second tooth shoe on the stator circumference is smaller than the pole arc angle, wherein the pole arc angle is the angle formed by the lines connecting the two side edges of the permanent magnet under each pole opposite to the outer circle of the rotor and the center of the rotor, the pole arc angle is D, and the angle occupied by the second tooth shoe on the stator circumference is B, and the following relationship is satisfied between B and D: 0.4≤B / D≤0.6.

[0011] In some embodiments,

[0012] The stator tooth shoe comprises M tooth shoes with different circumferential widths arranged in a radial direction, wherein M≥2, and the circumferential widths of the stator tooth shoes increase sequentially along the radial inward direction of the stator.

[0013] In some embodiments,

[0014] The circumferential width of the stator tooth body is F, the circumferential width of the first tooth shoe is set to G1, the circumferential width of the second tooth shoe is set to G2, and G1, G2 and F satisfy the following relationship: (F+G1) / G2≤2.

[0015] In some embodiments,

[0016] The total radial height of the stator tooth shoe is smaller than the radial height of the stator tooth body, the radial height of the stator tooth body is set to I, the radial height of the first tooth shoe is set to H1, the radial height of the second tooth shoe is set to H2, and H1, H2 and I satisfy the following relationship: 2.6≤(H1+I) / H2≤5.2.

[0017] In some embodiments,

[0018] A stator slot is located between two adjacent stator teeth, and the circumferential width of the stator slot narrows in a step-by-step manner along the radial inward direction.

[0019] In some embodiments,

[0020] The radial inner circumferential surface of the stator tooth shoe is provided with a tooth shoe groove which is recessed in the radial outward direction, the stator tooth portion has a tooth center line extending in the radial direction, the stator tooth portion is symmetrically distributed relative to the tooth center line, and the tooth shoe groove is symmetrically distributed relative to the tooth center line, so that for the same stator tooth shoe, the radial width of the air gap between its radial inner circle and the outer circle of the rotor is not equal along the circumferential direction.

[0021] In some embodiments,

[0022] For the same stator tooth shoe, the radial depth of the tooth shoe groove opened on its radial inner circumferential surface gradually increases from one circumferential end to the tooth center line, and the radial depth is the largest at the tooth center line position. The radial depth of the tooth shoe groove at this position is J, and the radial width of the air gap formed by the radial inner circumferential surface of the stator tooth shoe and the outer circle of the rotor is K. The following relationship is satisfied between J and K: 0.2≤J / K≤0.6.

[0023] In some embodiments,

[0024] The tooth shoe groove has a preset length in the circumferential direction, and the angle between its two ends and the line connecting the center of the stator is E. The angle occupied by the second tooth shoe on the stator circumference is B, that is, the angle between the two circumferential ends of the second tooth shoe and the line connecting the center of the stator is B, and the following relationship is satisfied between E and B: 0.5≤E / B≤1.2.

[0025] In some embodiments,

[0026] The position where the stator tooth body is connected to the second tooth shoe is a first arc transition surface structure, and the position where the second tooth shoe is connected to the first tooth shoe is a second arc transition surface structure, so as to form an arc transition step tooth structure.

[0027] The present invention also provides a permanent magnet synchronous motor, which includes the aforementioned stator and rotor, wherein the rotor includes a rotor core, a permanent magnet slot is provided on the rotor core, a permanent magnet is arranged in the permanent magnet slot, a plurality of the permanent magnet slots are arranged at intervals along the circumferential direction of the rotor core, the permanent magnets are arranged in a one-to-one correspondence with the permanent magnet slots, and the stator is located on the outer periphery of the rotor.

[0028] The stator of a permanent magnet synchronous motor and the permanent magnet synchronous motor provided by the present invention have the following beneficial effects:

[0029] 1. The present invention forms a radially stepped tooth structure by providing a portion of the stator tooth portion close to the stator yoke portion with a smaller circumferential width, a portion of the stator tooth portion close to the inner circle of the stator with a larger circumferential width, a stator tooth shoe with a circumferential width greater than a stator tooth body, and along the radially outward direction of the stator, the stator tooth shoe includes a first tooth shoe and a second tooth shoe connected to each other, the first tooth shoe is located at the radially innermost side, and the circumferential width of the first tooth shoe is greater than the circumferential width of the second tooth shoe. The second tooth shoe forms a transition part connecting the first tooth shoe and the tooth body. The transition part is preferably made of silicon steel sheet material, which can increase the magnetic permeability of the tooth part, adjust the magnetic permeability of the stator slot and the corresponding part of the stator tooth part during the rotation of the motor, improve the air gap magnetic density waveform, reduce the back electromotive force harmonics of the motor, and reduce harmonic noise. That is, the present invention brings about the tooth slot effect by changing the structural characteristics of the stator tooth slot as mentioned above, which can improve the magnetic resistance distribution at various parts of the motor magnetic circuit, improve the direction of magnetic flux, reduce the back electromotive force harmonics of the motor, reduce the electromagnetic force peak of the motor, and reduce the electromagnetic vibration noise of the motor.

[0030] 2. The present invention also sets the angle occupied by the second tooth shoe on the stator circumference to B and the pole arc angle to D to satisfy the relationship: 0.4≤B / D≤0.6. The wider the pole arc, the greater the tooth magnetic density, the greater the difference in corresponding magnetic density between the tooth and the slot, the more obvious the tooth slot effect, and the greater the waveform distortion. Therefore, the present invention sets the second tooth shoe to have the above-mentioned corresponding relationship with the pole arc angle, which can further increase the tooth magnetic permeance, further effectively adjust the size of the magnetic permeance of the corresponding part of the stator slot and the stator tooth during the rotation of the motor, improve the air gap magnetic density waveform, reduce the back electromotive force harmonics of the motor, and reduce harmonic noise.

[0031] 3. The present invention also sets the tooth body width F, the width G1 of the first tooth shoe and the width G2 of the second tooth shoe to satisfy the following relationship: (F+G1) / G2≤2. The second tooth shoe serves as an intermediate transition connection part. The larger its width, the larger the magnetic permeability and the smaller the tooth slot effect. However, if the tooth shoe width is too large, the motor leakage will increase and the motor output torque will be reduced. Within this range, the motor output can be guaranteed while improving the air gap harmonics and reducing the electromagnetic noise caused by the harmonics.

[0032] 4. The present invention also sets the tooth body height I, the first tooth shoe height H1, and the second tooth shoe height H2 to satisfy the relationship: 2.6≤(H1+I) / H2≤5.2. Within this range, the tooth shoe height can be adjusted while ensuring low leakage flux, thereby increasing the tooth magnetic permeability, further improving the magnetic flux direction, reducing the air gap magnetic density harmonics, and reducing the peak electromagnetic force of the motor.

[0033] 5. The present invention also provides tooth shoe grooves on the radial inner circumference of the stator tooth shoe, the grooves are recessed toward the outer circle of the stator, and the grooves are symmetrical about the tooth center line, so that the air gap widths at various locations along the circumferential direction between the inner circle of the stator and the outer circle of the rotor are different, the air gap width formed by the tooth shoe grooves and the outer circle of the rotor is large, and the air gap width formed by the tooth shoe without grooves and the outer circle of the rotor is small. The magnetic resistance distribution of the air gap magnetic circuit when the center line of the magnetic pole corresponds to the center line of the tooth can be adjusted, the electromagnetic force and torque pulsation can be reduced, the electromagnetic noise of the motor operation can be reduced, and the user comfort can be improved.

[0034] 6. The present invention also satisfies the relationship between the tooth shoe groove depth J at the tooth centerline position and the air gap width K formed by the tooth shoe and the outer circle of the rotor: 0.2≤J / K≤0.6. If the groove depth is too large, the air gap magnetic resistance will be too large, reducing the motor output capacity. By setting J and K within this range (0.2≤J / K≤0.6), the air gap magnetic density waveform can be improved while ensuring the motor output capacity, the back electromotive force harmonics can be reduced, and the torque pulsation can be reduced.

[0035] 7. The present invention also satisfies the relationship between the angle E occupied by the stator tooth shoe groove on the circumference and the angle B occupied by the second tooth shoe on the stator circumference: 0.5≤E / B≤1.2. On the one hand, by setting a raised second tooth shoe, the magnetic permeance near the slot position is increased, and on the other hand, by setting a recessed tooth shoe groove, the magnetic permeance at the center line of the tooth can be reduced. Together, they improve the magnetic flux direction of the magnetic circuit, reduce the air gap magnetic density harmonics, reduce the electromagnetic force peak, and reduce the electromagnetic vibration of the motor.

[0036] 8. The present invention also adopts an arc transition at the connection position between the stator tooth body and the second tooth shoe, and an arc transition at the connection position between the second tooth shoe and the first tooth shoe, to form an arc transition stepped tooth structure, thereby reducing the stress of the stator teeth, reducing the deformation of the tooth shoe, and reducing the vibration noise of the motor caused by the deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a top view of the stator and rotor structure of the permanent magnet synchronous motor according to Embodiment 1 of the present invention;

[0038] Figure 2 yes Figure 1 A top view of the stator structure of the permanent magnet synchronous motor;

[0039] Figure 3 yes Figure 1 A top view of the rotor structure of a permanent magnet synchronous motor;

[0040] Figure 4 yes Figure 1 A partial enlarged view of the stator tooth structure of the stator in FIG. 1 (showing the partial size relationship);

[0041] Figure 5 yes Figure 1A partial enlarged view of the stator tooth structure of the stator in FIG. 1 (showing the partial size relationship);

[0042] Figure 6 is a top view of the stator and rotor structure of the permanent magnet synchronous motor according to Embodiment 2 of the present invention;

[0043] Figure 7 is a comparative bar graph of back-EMF harmonics of the permanent magnet synchronous motor of the present invention and the conventional motor (corresponding to the stepped tooth structure);

[0044] Figure 8 It is a comparative bar graph of back EMF harmonics of the permanent magnet synchronous motor of the present invention and the conventional motor (corresponding to the overall scheme of the novel motor of the present invention);

[0045] Fig. 9 It is a comparative bar graph of the electromagnetic force between the permanent magnet synchronous motor of the present invention and the conventional motor (corresponding to the overall scheme of the novel motor of the present invention);

[0046] Fig.10 It is a comparative bar graph of the noise of the permanent magnet synchronous motor of the present invention and the traditional motor (corresponding to the overall solution of the new motor of the present invention).

[0047] The reference numerals are:

[0048] 1. Stator tooth; 2. Stator yoke; 3. Stator inner circle; 4. Stator tooth body; 5. Stator tooth shoe; 6. First tooth shoe; 7. Second tooth shoe; 8. Stator slot; 9. Tooth shoe groove; 10. Tooth center line; 11. First arc transition surface; 12. Second arc transition surface; 13. Rotor core; 14. Permanent magnet slot; 15. Permanent magnet; 16. Slot; 100. Stator; 200. Rotor. DETAILED DESCRIPTION

[0049] 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.

[0050] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0051] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0052] 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.

[0053] 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" may include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0054] 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.

[0055] like Figure 1-10 As shown, the present invention provides a stator of a permanent magnet synchronous motor, which includes:

[0056] A stator tooth portion 1 and a stator yoke portion 2, wherein the stator tooth portion 1 is connected to the stator yoke portion 2 in the radial direction of the stator, and there are N stator tooth portions 1 in the circumferential direction. The circumferential width of the portion of the stator tooth portion 1 relatively close to the stator yoke portion 2 is small, and the circumferential width of the portion of the stator tooth portion 1 relatively close to the stator inner circle 3 (the stator inner circle is the radial inner circumference of the stator) is large. The stator tooth portion 1 includes a stator tooth body 4 and a stator tooth shoe 5 connected in the radial direction, the circumferential width of the stator tooth shoe 5 is greater than the circumferential width of the stator tooth body 4, and along the radial outward direction of the stator, the stator tooth shoe 5 includes a first tooth shoe 6 and a second tooth shoe 7 connected, the first tooth shoe 6 is located at the radial innermost side, and the circumferential width of the first tooth shoe 6 is greater than the circumferential width of the second tooth shoe 7, so as to form a stepped tooth structure in the radial direction.

[0057] The present invention has a smaller circumferential width of the portion of the stator tooth portion relatively close to the stator yoke portion, a larger circumferential width of the portion of the stator tooth portion relatively close to the inner circle of the stator, a circumferential width of the stator tooth shoe greater than the circumferential width of the stator tooth body, and along the radial outward direction of the stator, the stator tooth shoe includes a first tooth shoe and a second tooth shoe connected to each other, the first tooth shoe is located at the radial innermost side, and the circumferential width of the first tooth shoe is greater than the circumferential width of the second tooth shoe, so as to form a radial step tooth structure. The present invention forms a transition portion connecting the first tooth shoe and the tooth body by arranging the second tooth shoe, and the transition portion is preferably made of silicon steel sheet material, which can increase the tooth permeability, can adjust the permeability of the stator slot and the corresponding portion of the stator tooth portion during the rotation of the motor, improve the air gap magnetic density waveform, reduce the back electromotive force harmonics of the motor, and reduce harmonic noise. That is, the present invention brings about the tooth slot effect by changing the structural characteristics of the stator tooth slot as mentioned above, which can improve the magnetic resistance distribution at various parts of the motor magnetic circuit, improve the direction of the magnetic flux, and reduce the back electromotive force harmonics of the motor (such as Figure 7 ), reduce the peak value of the electromagnetic force of the motor and reduce the electromagnetic vibration noise of the motor.

[0058] In some embodiments,

[0059] The angle occupied by the second tooth shoe 7 on the stator circumference is smaller than the pole arc angle, wherein the pole arc angle is the angle formed by the two side edges of the permanent magnet under each pole opposite to the outer circle of the rotor and the lines connecting the center of the rotor circle, the pole arc angle is D, and the angle occupied by the second tooth shoe 7 on the stator circumference is B, and the following relationship is satisfied between B and D: 0.4≤B / D≤0.6.

[0060] The present invention also sets the angle B occupied by the second tooth shoe on the stator circumference and the pole arc angle D to satisfy the relationship: 0.4≤B / D≤0.6. The wider the pole arc, the greater the tooth magnetic density, the greater the difference in corresponding magnetic density between the tooth and the slot, the more obvious the tooth slot effect, and the greater the waveform distortion. Therefore, the present invention sets the second tooth shoe to have the above-mentioned corresponding relationship with the pole arc angle, which can further increase the tooth magnetic permeance, further effectively adjust the size of the magnetic permeance of the corresponding part of the stator slot and the stator tooth during the rotation of the motor, improve the air gap magnetic density waveform, reduce the back electromotive force harmonics of the motor, and reduce harmonic noise.

[0061] The stator tooth portion of the present invention comprises a tooth body and a tooth shoe, wherein the stator tooth shoe has at least two places with different widths, and the tooth shoe width increases successively from the yoke to the inner circle of the stator, forming a stepped tooth structure; the angle occupied by the second tooth shoe on the stator circumference is smaller than the pole arc angle, wherein the pole arc angle is the angle formed by the line connecting the edges of the two sides of the permanent magnet under each pole close to the outer circle of the rotor and the center of the circle, the angle occupied by the second tooth shoe on the stator circumference is B, the pole arc angle is D, and B and D should satisfy the following relationship: 0.4≤B / D≤0.6; the wider the pole arc, the greater the magnetic flux density of the tooth portion, the greater the difference in the corresponding magnetic flux density between the tooth portion and the slot portion, and the more obvious the slot effect, and the second tooth shoe corresponding to the pole arc angle is added to reduce the slot effect, improve the magnetic resistance distribution at various locations of the motor magnetic circuit, improve the direction of the magnetic flux, and reduce the back electromotive force harmonics of the motor (such as Figure 8 ), reduce the peak value of the electromagnetic force of the motor (such as Fig. 9 ), reduce the electromagnetic vibration noise of the motor.

[0062] In some embodiments,

[0063] The stator tooth shoe 5 includes M tooth shoes with different circumferential widths arranged in the radial direction, wherein M≥2, and the circumferential width of the stator tooth shoe 5 increases sequentially along the radial inward direction of the stator.

[0064] The present invention forms a specific stator slot type through such tooth structure design, the stator slot width is stepped transition toward the inner circle of the stator, and the width gradually narrows in multiple gradients, thereby reducing the slot effect caused by the stator slotting, especially near the air gap position, reducing back electromotive force harmonics, reducing the slot torque, and improving the smoothness of motor operation.

[0065] In some embodiments,

[0066] The circumferential width of the stator tooth body 4 is F, the circumferential width of the first tooth shoe 6 is set to G1, the circumferential width of the second tooth shoe 7 is set to G2, and G1, G2 and F satisfy the following relationship: (F+G1) / G2≤2.

[0067] The present invention also sets the tooth body width F, the width G1 of the first tooth shoe and the width G2 of the second tooth shoe to satisfy the following relationship: (F+G1) / G2≤2. The second tooth shoe serves as an intermediate transition connection part. The larger its width, the larger the magnetic permeability and the smaller the tooth slot effect. However, if the tooth shoe width is too large, the motor leakage will increase and the motor output torque will be reduced. Within this range, the motor output can be guaranteed while improving the air gap harmonics and reducing the electromagnetic noise caused by the harmonics.

[0068] In some embodiments,

[0069] The total radial height of the stator tooth shoe 5 is smaller than the radial height of the stator tooth body 4. The radial height of the stator tooth body 4 is set to I, the radial height of the first tooth shoe 6 is set to H1, and the radial height of the second tooth shoe 7 is set to H2. H1, H2 and I satisfy the following relationship: 2.6≤(H1+I) / H2≤5.2.

[0070] The present invention also sets the tooth body height I, the first tooth shoe height H1, and the second tooth shoe height H2 to satisfy the relationship: 2.6≤(H1+I) / H2≤5.2. Within this range, the tooth shoe height can be adjusted while ensuring low magnetic leakage, thereby increasing the tooth magnetic permeability, further improving the magnetic flux direction, reducing the air gap magnetic density harmonics, and reducing the peak value of the motor electromagnetic force (such as Fig. 9 ).

[0071] In some embodiments,

[0072] A stator slot 8 is provided between two adjacent stator teeth 1 , and the circumferential width of the stator slot 8 narrows in a step-wise manner along the radial inward direction.

[0073] In some embodiments,

[0074] The radial inner circumferential surface of the stator tooth shoe 5 is provided with a tooth shoe groove 9 which is recessed in the radial outward direction. The stator tooth portion 1 has a tooth center line 10 extending in the radial direction. The stator tooth portion 1 is symmetrically distributed relative to the tooth center line 10, and the tooth shoe groove 9 is symmetrically distributed relative to the tooth center line 10, so that for the same stator tooth shoe 5, the radial width of the air gap between its radial inner circle and the outer circle of the rotor is not equal along the circumferential direction.

[0075] The present invention also provides tooth shoe grooves on the radial inner circumference of the stator tooth shoe, the grooves are recessed toward the outer circle of the stator, and the grooves are symmetrical about the tooth center line, so that the air gap widths at various locations along the circumferential direction between the inner circle of the stator and the outer circle of the rotor are different, the air gap width formed by the tooth shoe grooves and the outer circle of the rotor is large, and the air gap width formed by the tooth shoe without grooves and the outer circle of the rotor is small, so that the magnetic resistance distribution of the air gap magnetic circuit when the center line of the magnetic pole corresponds to the center line of the tooth can be adjusted, the electromagnetic force and torque pulsation can be reduced, and the electromagnetic noise of the motor operation (such as Fig.10 ), improving user comfort.

[0076] In some embodiments,

[0077] For the same stator tooth shoe 5, the radial depth of the tooth shoe groove 9 opened on its radial inner circumferential surface gradually increases from one circumferential end to the tooth center line 10, and the radial depth is the largest at the position of the tooth center line 10. The radial depth of the tooth shoe groove 9 at this position is J, and the radial width of the air gap formed by the radial inner circumferential surface of the stator tooth shoe 5 and the outer circle of the rotor is K. The following relationship is satisfied between J and K: 0.2≤J / K≤0.6.

[0078] The present invention also satisfies the relationship between the tooth shoe groove depth J at the tooth centerline position and the air gap width K formed by the tooth shoe and the outer circle of the rotor: 0.2≤J / K≤0.6. If the groove depth is too large, the air gap magnetic resistance will be too large, reducing the motor output capacity. By setting J and K within this range (0.2≤J / K≤0.6), the air gap magnetic density waveform can be improved while ensuring the motor output capacity, the back electromotive force harmonics can be reduced, and the torque pulsation can be reduced.

[0079] In some embodiments,

[0080] The tooth shoe groove 9 has a preset length in the circumferential direction, and the angle between its two ends and the line connecting the center of the stator is E. The angle occupied by the second tooth shoe 7 on the stator circumference is B, that is, the angle between the two circumferential ends of the second tooth shoe 7 and the line connecting the center of the stator is B, and the following relationship is satisfied between E and B: 0.5≤E / B≤1.2.

[0081] The present invention also satisfies the relationship between the angle E occupied by the stator tooth shoe groove on the circumference and the angle B occupied by the second tooth shoe on the stator circumference: 0.5≤E / B≤1.2. On the one hand, by providing a raised second tooth shoe, the magnetic permeance near the slot position is increased, and on the other hand, by providing a recessed tooth shoe groove, the magnetic permeance at the tooth center line can be reduced. Together, the magnetic flux direction of the magnetic circuit is improved, the air gap magnetic density harmonics are reduced, the electromagnetic force peak is reduced, and the electromagnetic vibration of the motor (such as Fig.10 ).

[0082] In some embodiments,

[0083] The position where the stator tooth body 4 is connected to the second tooth shoe 7 is the structure of the first arc transition surface 11, and the position where the second tooth shoe 7 is connected to the first tooth shoe 6 is the structure of the second arc transition surface 12, so as to form a circular arc transition step tooth structure.

[0084] The present invention also adopts an arc transition at the connection position between the stator tooth body and the second tooth shoe, and an arc transition at the connection position between the second tooth shoe and the first tooth shoe, to form an arc transition stepped tooth structure, reduce the stress of the stator teeth, reduce the deformation of the tooth shoe, and reduce the vibration noise of the motor caused by the deformation.

[0085] The present invention also provides a permanent magnet synchronous motor, which includes the aforementioned stator 100 and rotor 200, wherein the rotor 200 includes a rotor core 13, a permanent magnet slot 14 is opened on the rotor core 13, and a permanent magnet 15 is arranged in the permanent magnet slot 14, a plurality of the permanent magnet slots 14 are arranged at intervals along the circumferential direction of the rotor core, the permanent magnets 15 are arranged one by one with the permanent magnet slots 14, and the stator 100 is located on the outer periphery of the rotor 200.

[0086] The present invention relates to a permanent magnet synchronous motor, which comprises a stator and a rotor of the permanent magnet synchronous motor, wherein the stator comprises a stator tooth portion, a stator yoke portion, and a winding, and the rotor comprises a rotor core, a permanent magnet slot provided on the rotor core, and a permanent magnet placed in the permanent magnet slot, wherein the permanent magnet is arranged on the rotor core along the circumference of the rotor core; wherein the stator tooth portion is connected to the stator yoke portion, the number of stator teeth is N, the width of the stator tooth portion close to the stator yoke portion is small, the width close to the inner circle of the stator is large, and the stator tooth portion includes a plurality of stator teeth, and the stator tooth portion includes a plurality of stator teeth, wherein ... The invention comprises a tooth body and a tooth shoe, wherein the width of the stator tooth shoe is greater than the width of the stator tooth body, the stator tooth shoe comprises a first tooth shoe, a second tooth shoe, a third tooth shoe, ... an Mth tooth shoe, and the stator tooth shoe has at least two different widths, and the tooth shoe width increases successively from the yoke to the inner circle of the stator, forming a stepped tooth structure; the tooth slot effect brought about by changing the structural characteristics of the stator tooth slots improves the magnetic resistance distribution at various parts of the motor magnetic circuit, improves the direction of the magnetic flux, reduces the back electromotive force harmonics of the motor, reduces the peak value of the electromagnetic force of the motor, and reduces the electromagnetic vibration noise of the motor.

[0087] The present invention can effectively solve the following technical problems:

[0088] 1. Solved the problem of large back-electromotive force harmonics of permanent magnet synchronous motor.

[0089] 2. Solve the problem of large motor cogging torque.

[0090] 3. Solve the problem of large electromagnetic force of the motor.

[0091] 4. Solve the problem of large motor vibration and noise.

[0092] 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 of a permanent magnet synchronous motor, characterized in that: include: A stator tooth portion (1) and a stator yoke portion (2), wherein the stator tooth portion (1) is connected to the stator yoke portion (2) in the radial direction of the stator, and there are N stator tooth portions (1) in the circumferential direction. The circumferential width of the portion of the stator tooth portion (1) relatively close to the stator yoke portion (2) is small, and the circumferential width of the portion of the stator tooth portion (1) relatively close to the stator inner circle (3) is large. The stator tooth portion (1) comprises a stator tooth body (4) and a stator tooth shoe (5) connected in the radial direction, the circumferential width of the stator tooth shoe (5) is greater than the circumferential width of the stator tooth body (4), and along the radial outward direction of the stator, the stator tooth shoe (5) comprises a first tooth shoe (6) and a second tooth shoe (7) connected, the first tooth shoe (6) being located at the radial innermost side, and the circumferential width of the first tooth shoe (6) is greater than the circumferential width of the second tooth shoe (7), so as to form a stepped tooth structure in the radial direction.

2. The stator of the permanent magnet synchronous motor according to claim 1, characterized in that: The angle occupied by the second tooth shoe (7) on the stator circumference is smaller than the pole arc angle, wherein the pole arc angle is the angle formed by the two side edges of the permanent magnet under each pole opposite to the outer circle of the rotor and the lines connecting the center of the rotor circle, the pole arc angle is D, and the angle occupied by the second tooth shoe (7) on the stator circumference is B, and the following relationship is satisfied between B and D: 0.4≤B / D≤0.

6.

3. The stator of the permanent magnet synchronous motor according to claim 1, characterized in that: The stator tooth shoe (5) comprises M tooth shoes with different circumferential widths arranged in a radial direction, wherein M≥2, and the circumferential width of the stator tooth shoe (5) increases sequentially along the radial inward direction of the stator.

4. The stator of the permanent magnet synchronous motor according to claim 1, characterized in that: The circumferential width of the stator tooth body (4) is F, the circumferential width of the first tooth shoe (6) is set to G1, the circumferential width of the second tooth shoe (7) is set to G2, and G1, G2 and F satisfy the following relationship: (F+G1) / G2≤2.

5. The stator of the permanent magnet synchronous motor according to claim 1, characterized in that: The total radial height of the stator tooth shoe (5) is less than the radial height of the stator tooth body (4), the radial height of the stator tooth body (4) is set to I, the radial height of the first tooth shoe (6) is set to H1, the radial height of the second tooth shoe (7) is set to H2, and H1, H2 and I satisfy the following relationship: 2.6≤(H1+I) / H2≤5.

2.

6. The stator of the permanent magnet synchronous motor according to claim 1, characterized in that: A stator slot (8) is provided between two adjacent stator teeth (1), and the circumferential width of the stator slot (8) narrows in a step-wise transition along the radially inward direction.

7. The stator of a permanent magnet synchronous motor according to any one of claims 1 to 6, characterized in that: The radial inner circumferential surface of the stator tooth shoe (5) is provided with a tooth shoe groove (9) which is recessed in the radial outward direction; the stator tooth portion (1) has a tooth center line (10) extending in the radial direction; the stator tooth portion (1) is symmetrically distributed relative to the tooth center line (10); and the tooth shoe groove (9) is symmetrically distributed relative to the tooth center line (10), so that for the same stator tooth shoe (5), the radial width of the air gap between its radial inner circle and the rotor outer circle is not equal along the circumferential direction.

8. The stator of the permanent magnet synchronous motor according to claim 7, characterized in that: For the same stator tooth shoe (5), the radial depth of the tooth shoe groove (9) opened on its radial inner circumferential surface gradually increases from one circumferential end to the tooth center line (10), and the radial depth is the largest at the position of the tooth center line (10). The radial depth of the tooth shoe groove (9) at this position is J, and the radial width of the air gap formed by the radial inner circumferential surface of the stator tooth shoe (5) and the outer circle of the rotor is K. The following relationship is satisfied between J and K: 0.2≤J / K≤0.

6.

9. The stator of the permanent magnet synchronous motor according to claim 7, characterized in that: The tooth shoe groove (9) has a preset length in the circumferential direction, and the angle between its two ends and the line connecting the center of the stator is E. The angle occupied by the second tooth shoe (7) on the circumference of the stator is B, that is, the angle between the two circumferential ends of the second tooth shoe (7) and the line connecting the center of the stator is B, and the following relationship is satisfied between E and B: 0.5≤E / B≤1.

2.

10. The stator of a permanent magnet synchronous motor according to any one of claims 1 to 9, characterized in that: The position where the stator tooth body (4) is connected to the second tooth shoe (7) is a structure of a first arc transition surface (11), and the position where the second tooth shoe (7) is connected to the first tooth shoe (6) is a structure of a second arc transition surface (12), so as to form a structure of an arc transition step tooth portion.

11. A permanent magnet synchronous motor, characterized in that: The invention comprises a stator (100) and a rotor (200) as described in any one of claims 1 to 10, wherein the rotor (200) comprises a rotor core (13), a permanent magnet slot (14) is provided on the rotor core (13), a permanent magnet (15) is arranged in the permanent magnet slot (14), a plurality of the permanent magnet slots (14) are arranged at intervals along the circumferential direction of the rotor core, the permanent magnets (15) are arranged in a one-to-one correspondence with the permanent magnet slots (14), and the stator (100) is located on the outer periphery of the rotor (200).

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