Stator core and motor

Abstract

The invention discloses a stator core and a motor, and relates to the technical field of motor parts, and the stator core is formed by stacking a plurality of stator punching sheets; the stator punching sheet comprises a stator yoke part and a plurality of stator tooth parts, the stator tooth parts are arranged on the inner side of the stator yoke part at intervals in the circumferential direction, and a stator groove is formed between every two adjacent stator tooth parts; wherein the stator yoke part and the stator tooth part are provided with slits extending along the radial direction of the stator punching sheet, and the slits start from the stator yoke part and end at the stator tooth part; and the slits of the adjacent stator punching sheets are partially or completely overlapped. According to the technical scheme, the breathing mode frequency is changed in a simple and reliable structural form, the exciting force frequency can be avoided, and therefore vibration and noise reduction is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor components, and particularly relates to a stator core and a motor. Background Art

[0002] As an important type of industrial product, motors are widely used in fields such as new energy vehicles and household appliances. When a motor operates, it often generates vibration noise, which affects the user experience.

[0003] For a cylindrical motor stator, due to its inherent structural characteristics, there is a vibration mode characterized by expansion and contraction, which is usually called the "breathing mode". When the breathing mode frequency is close to the exciting force frequency, resonance will occur, causing relatively large vibration noise.

[0004] In the related art, by providing slits in the stator yoke of a single stator section to completely disconnect it in the circumferential direction, and then offsetting and staggering different stator sections to form a whole, the breathing mode frequency can be changed to avoid the exciting force frequency, thereby achieving vibration reduction and noise reduction. However, this method requires offsetting and staggering different stator sections to form a whole during assembly. There are many types of stator laminations and the structure is complex, which is not conducive to manufacturing. Moreover, when multiple stator body sections are offset and staggered, under the action of external forces, the connection positions will bear shear forces in the axial normal plane, easily forming shear deformation and damage. Therefore, the load-bearing capacity of the connection positions is weak and the reliability is poor. Summary of the Invention

[0005] The main object of the present invention is to propose a stator core and a motor, aiming to change the breathing mode frequency in a simple and reliable structural form, be able to avoid the exciting force frequency, and thus achieve vibration reduction and noise reduction.

[0006] To achieve the above object, a stator core proposed by the present invention includes: the stator core is stacked by a plurality of stator laminations; the stator lamination includes a stator yoke and a plurality of stator teeth, and the plurality of stator teeth are circumferentially spaced apart and arranged inside the stator yoke, and a stator slot is formed between two adjacent stator teeth;

[0007] Wherein, the stator yoke and the stator teeth have slits extending radially along the stator lamination, the slits start from the stator yoke and terminate at the stator teeth; the slit portions of adjacent stator laminations partially or completely overlap.

[0008] In an embodiment, define the distance between the termination point of the slit and the inner side of the stator tooth as b, then it satisfies: b≥1mm.

[0009] In one embodiment, the distance between the termination point of the slit and the side edge of the stator tooth is defined as a, and it satisfies: a ≥ 0.5 mm.

[0010] In one embodiment, the distances between the termination point of the slit and the opposite side edges of the stator tooth are different.

[0011] In one embodiment, the width of the slit is defined as w, and it satisfies: 0.01 mm ≤ w ≤ 1 mm.

[0012] In one embodiment, the part of the stator tooth located on the left side of the slit is defined as the first connecting part, the part of the stator tooth located on the right side of the slit is defined as the second connecting part, and the part of the stator tooth located between the termination point of the slit and the inner side of the stator tooth is defined as the third connecting part;

[0013] One of the first connecting part, the second connecting part and the third connecting part is disconnected to form a first splicing part and a second splicing part, and the first splicing part and the second splicing part are spliced through a splicing structure.

[0014] In one embodiment, the splicing structure is a mortise and tenon structure, and one of the first splicing part and the second splicing part is provided with a tenon, and the other is provided with a mortise.

[0015] In one embodiment, a plurality of the slits are circumferentially and spacedly distributed between the stator yoke and the stator tooth.

[0016] To achieve the above object, the present invention further provides a motor, including:

[0017] A housing;

[0018] A stator, which is arranged in the housing and includes a stator winding and the stator core as described above, and the stator winding is wound around the stator slots of the stator core;

[0019] A rotor, which is arranged inside the stator.

[0020] The technical solution of the present invention is provided with slits extending radially along the stator laminations in the stator yoke and the stator teeth. The slits start from the stator yoke and terminate at the stator teeth, and the slit portions of adjacent stator laminations coincide partially or completely to form slits penetrating axially along the stator laminations. Since, under the condition that the overall shape, mass, material, etc. of the stator laminations remain unchanged, the breathing mode frequency of the ring structure mainly depends on the structural stiffness in the circumferential direction, that is, the change in the ring circumference under the action of a unit radial force. Therefore, when there are slits in the stator laminations, under the action of a unidirectional radial force, the deformation at the slit position is obviously greater than that without slits, and the slits can be widened or narrowed more easily, so that the change in the circumference of the stator laminations is greater. Therefore, the structural stiffness of the stator laminations in the circumferential direction is weaker and the breathing mode frequency is lower. So the design of the slits can achieve changing the breathing mode frequency and can avoid the exciting force frequency, thereby achieving vibration reduction and noise reduction.

[0021] In addition, since the slits start from the stator yoke and terminate at the stator teeth, that is, the slits are incompletely disconnected slits. When multiple stator laminations are stacked into a stator core, the slit positions of all stator laminations can be kept consistent so that the slit portions of adjacent stator laminations coincide partially or completely. The structure is simple and there is no need for offset or staggering. Therefore, the processing process of the stator core formed by stacking the stator laminations is also easier, and there will be no shear force in the axial normal plane in the overall stator core formed by stacking, and thus there will be no phenomenon of shear deformation and damage, and the load-bearing capacity is strong and the reliability is high.

[0022] Therefore, this solution can achieve changing the breathing mode frequency and avoiding the exciting force frequency in a simple and reliable structural form, thereby achieving vibration reduction and noise reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0024] Figure 1 FIG. [ID] is a schematic structural diagram of an embodiment of the stator lamination provided by the present invention;

[0025] Figure 2 FIG. [ID] is a partial structural diagram of an embodiment of the stator lamination provided by the present invention;

[0026] Figure 3 FIG. [ID] is a partial structural diagram of another embodiment of the stator lamination provided by the present invention;

[0027] Figure 4Partial structural schematic diagram of another embodiment of the stator punching sheet provided by the present invention before splicing;

[0028] Figure 5 Structural schematic diagram of an embodiment of the stator core provided by the present invention.

[0029] Explanation of the reference numerals in the drawings:

[0030]

[0031]

[0032] The realization of the object of the present invention, functional features and advantages will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0034] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0035] In addition, if there are descriptions such as "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution that satisfies both A and B at the same time. In addition, the technical solutions between the embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0036] As an important type of industrial product, motors are widely used in fields such as new energy vehicles and household appliances. When a motor operates, it often generates vibration and noise, affecting the user experience.

[0037] For a cylindrical motor stator, due to its inherent structural characteristics, there will be vibration modes characterized by expansion and contraction, which are usually called "breathing modes". When the breathing mode frequency is close to the exciting force frequency, resonance will occur, causing relatively large vibration noise.

[0038] In the related art, by providing slits in the stator yoke of a single stator section to completely disconnect in the circumferential direction, and then offsetting and interleaving different stator sections to form an integral body, the breathing mode frequency can be changed to avoid the exciting force frequency, thereby achieving vibration reduction and noise reduction. However, this method requires offsetting and interleaving different stator sections to form an integral body during assembly. There are many types of stator laminations and the structure is complex, which is not conducive to manufacturing. Moreover, when multiple stator body sections are offset and interleaved, under the action of external forces, the connection positions will bear shear forces in the axial normal plane, easily forming shear deformation and damage. Therefore, the load-bearing capacity of the connection positions is weak and the reliability is poor.

[0039] Based on the above problems, the present invention proposes a stator lamination 100, aiming to achieve changing the breathing mode frequency in a simple and reliable structural form, being able to avoid the exciting force frequency, thereby achieving vibration reduction and noise reduction.

[0040] Please refer to Figure 1 、 Figure 2 , in an embodiment of the present invention, the stator core 1000 is stacked by a plurality of stator laminations 100; the stator lamination 100 includes a stator yoke 10 and a plurality of stator teeth 20. The plurality of stator teeth 20 are circumferentially spaced apart and arranged on the inner side of the stator yoke 10. A stator slot 30 is formed between two adjacent stator teeth 20. Among them, the stator yoke 10 and the stator teeth 20 have a slit 11 extending radially along the stator lamination 100. The slit 11 starts from the stator yoke 10 and terminates at the stator teeth 20; the slits 11 of adjacent stator laminations 100 partially or completely overlap.

[0041] The technical solution of the present invention is provided with a slit 11 extending radially along the stator lamination 100 between the stator yoke portion 10 and the stator tooth portion 20. The slit 11 starts from the stator yoke portion 10 and terminates at the stator tooth portion 20, and the slit 11 portions of adjacent stator laminations 100 partially or completely overlap, so that a plurality of slits 11 form a gap 200 penetrating axially along the stator lamination 100. Since the breathing mode frequency of the ring structure mainly depends on the structural stiffness in the circumferential direction, that is, the change in the ring circumference under the action of a unit radial force, when the stator lamination 100 has a slit 11, under the action of a unidirectional radial force, the deformation at the slit 11 position is obviously larger than when there is no slit 11, and the slit 11 can be widened or narrowed more easily, so that the change in the circumference of the stator lamination 100 is larger. Therefore, the structural stiffness of the stator lamination 100 in the circumferential direction is weaker, and the breathing mode frequency is lower. Therefore, the design of the slit 11 can change the breathing mode frequency and avoid the exciting force frequency, thereby achieving vibration reduction and noise reduction.

[0042] In addition, since the slit 11 starts from the stator yoke portion 10 and terminates at the stator tooth portion 20, that is, the slit 11 is an incompletely disconnected slit 11. When a plurality of stator laminations 100 are stacked into a stator core 1000, the slit 11 positions of all stator laminations 100 can be kept consistent, so that the slit 11 portions of adjacent stator laminations 100 partially or completely overlap. The structure is simple and there is no need for offset or staggering. Therefore, the processing process of the stator core 1000 formed by stacking the stator laminations 100 is easier, and there will be no shear force in the axial normal plane in the overall stator core 1000 formed by stacking, and there will be no shear deformation and damage phenomenon, and the load-bearing capacity is strong and the reliability is high.

[0043] Therefore, this solution can change the breathing mode frequency in a simple and reliable structural form, avoid the exciting force frequency, and thus achieve vibration reduction and noise reduction.

[0044] In addition, compared with the method of extending the slit 11 to the stator slot 30, by designing an incompletely disconnected slit 11 and making the slit 11 extend radially inward from the outside of the stator yoke portion 10 to the stator tooth portion 20, that is, the termination point 21 of the slit 11 is located on the stator tooth portion 20, the radially extending length of the slit 11 can be designed to be longer, so that the breathing mode frequency can be reduced lower.

[0045] In this embodiment, the stator yoke portion 10 is designed in a circular ring shape.

[0046] It should be noted that for a permanent magnet synchronous motor, the radial electromagnetic force frequency that the motor can generate can range from 0 Hz to 20,000 Hz. The harmonic injection active noise reduction technology can reduce the radial electromagnetic force within a certain frequency range, generally not exceeding half of the controller switching frequency. For example, when the controller switching frequency is 10,000 Hz, the radial electromagnetic force within 5,000 Hz can be reduced to negligible through harmonic injection, so that the radial electromagnetic force generated by the motor is mainly above 5,000 Hz. However, the stator breathing mode frequency of a general motor is generally above 5,000 Hz. Therefore, through the design of the slit 11 in this solution, the breathing mode frequency can be reduced to within 5,000 Hz, that is, the main frequency of the radial electromagnetic force generated by the motor can be effectively avoided.

[0047] In the actual application process, among the multiple stator tooth parts 20 of the stator punching sheet 100, all the stator yoke parts 10 and stator tooth parts 20 can be provided with the slit 11, or some of the stator yoke parts 10 and some of the stator tooth parts 20 can be provided with the slit 11, or one of the stator yoke parts 10 and one of the stator tooth parts 20 can be provided with the slit 11.

[0048] Please refer to Figure 2 , in an embodiment of the present invention, the distance between the termination point 21 of the slit 11 and the inner side of the stator tooth part 20 is defined as b, and it satisfies: b≥1 mm.

[0049] With such a setting, when the distance between the termination point 21 of the slit 11 and the inner side of the stator tooth part 20 is too small, the position between the termination point 21 of the slit 11 and the inner side of the stator tooth part 20 is prone to breakage. Therefore, by controlling the distance between the termination point 21 of the slit 11 and the inner side of the stator tooth part 20 to be not less than 1 mm, the load-bearing capacity of the stator punching sheet 100 can be improved and the reliability can be enhanced.

[0050] As some examples, the distance b between the termination point 21 of the slit 11 and the inner side of the stator tooth part 20 can specifically be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, etc.

[0051] Please refer to Figure 2 , in an embodiment of the present invention, the distance between the termination point 21 of the slit 11 and the side edge of the stator tooth part 20 is defined as a, and it satisfies: a≥0.5 mm.

[0052] With such a setting, when the distance between the termination point 21 of the slit 11 and the side edge of the stator tooth portion 20 is too small, the position between the termination point 21 of the slit 11 and the side edge of the stator tooth portion 20 is also prone to breakage. Therefore, by controlling the distance between the termination point 21 of the slit 11 and the side edge of the stator tooth portion 20 to be not less than 0.5 mm, the bearing capacity of the stator punching sheet 100 can also be improved, and the reliability can be enhanced.

[0053] As some examples, the distance a between the termination point 21 of the slit 11 and the side edge of the stator tooth portion 20 can specifically be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, and so on.

[0054] It should be noted that by changing the distance a between the termination point 21 of the slit and the side edge of the stator tooth portion 20, as well as the distance b between the termination point 21 of the slit 11 and the inner side of the stator tooth portion 20, the breathing mode frequency of the stator can be changed, so that the breathing mode frequency can effectively avoid the excitation force frequency, thereby achieving vibration reduction.

[0055] Please refer to Figure 2 , in an embodiment of the present invention, the distances between the termination point 21 of the slit 11 and the opposite side edges of the stator tooth portion 20 are different.

[0056] With such a setting, the termination point 21 of the slit 11 can be offset toward one of the side edges of the stator tooth portion 20. Without changing the structural mass of the stator punching sheet 100 substantially, the structural stiffness of the stator punching sheet 100 can be further reduced, which can further reduce the breathing mode frequency.

[0057] Please refer to Figure 2 , in an embodiment of the present invention, the width of the slit 11 is defined as w, and it satisfies: 0.01 mm ≤ w ≤ 1 mm.

[0058] With such a setting, when the width of the slit 11 is too narrow, on the one hand, it is not convenient to process too narrow a slit 11 on the stator punching sheet 100, and on the other hand, the too narrow slit 11 is not easy to deform, resulting in the position of the slit 11 not being easy to become wider or narrower, so that the perimeter change amount of the stator punching sheet 100 is too small. Therefore, the structural stiffness of the stator punching sheet 100 in the circumferential direction cannot be reduced weak enough, and the breathing mode frequency cannot be reduced low enough; while when the width of the slit 11 is too large, it will cause an increase in local magnetic resistance, resulting in a reduction in motor performance and may also cause other NVH problems. Therefore, by controlling the width of the slit 11 between 0.01 mm and 1 mm, the breathing mode frequency can be reduced low enough while the motor performance will not be significantly reduced and other NVH problems will not be caused.

[0059] As some examples, the width w of the slit 11 may specifically be 0.01 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, and so on.

[0060] Please refer to Figure 3 , in an embodiment of the present invention, the part of the stator tooth portion 20 located on the left side of the slit 11 is defined as the first connection portion 22, the part of the stator tooth portion 20 located on the right side of the slit 11 is defined as the second connection portion 23, and the part of the stator tooth portion 20 located at the termination point 21 of the slit 11 and the inner side of the stator tooth portion 20 is defined as the third connection portion 24; one of the first connection portion 22, the second connection portion 23, and the third connection portion 24 is disconnected to form a first splicing portion 241 and a second splicing portion 242, and the first splicing portion 241 and the second splicing portion 242 are spliced through a splicing structure.

[0061] With such a setting, during actual processing, one of the first connection portion 22, the second connection portion 23, and the third connection portion 24 can be disconnected to form a first splicing portion 241 and a second splicing portion 242. In this way, multiple fan-shaped sub-punching sheets can be separately processed first, and then the first splicing portion 241 and the second splicing portion 242 are spliced into a complete stator punching sheet 100 using the splicing structure, which can make the processing and manufacturing easier.

[0062] During actual application, the splicing structure can be a mortise and tenon structure 25, or a structure with teeth mating with each other. Of course, the first splicing portion 241 and the second splicing portion 242 can also be spliced by means such as bonding and welding, as long as the splicing of the first splicing portion 241 and the second splicing portion 242 can be achieved.

[0063] Optionally, in an embodiment of the present invention, the splicing structure can be a mortise and tenon structure 25, and one of the first splicing portion 241 and the second splicing portion 242 is provided with a tenon 251, and the other is provided with a mortise 252.

[0064] With such a setting, during the splicing process, by inserting the tenon 251 into the mortise 252, the splicing between the first splicing portion 241 and the second splicing portion 242 can be achieved. Compared with splicing methods such as bonding and welding, the splicing of this solution using the mortise and tenon structure 25 has a stronger bearing capacity for external forces (such as torsion force, interference force, etc.) and higher reliability.

[0065] Please refer to Figure 1 , in an embodiment of the present invention, a plurality of slits 11 are circumferentially spaced between the stator yoke portion 10 and the stator tooth portion 20.

[0066] With such a setting, by circumferentially and spacedly distributing a plurality of slits 11 in the stator yoke 10 and the stator tooth portion 20, the change amount of the circumference of the stator punching 100 is made larger, so that the structural stiffness of the stator punching 100 in the circumferential direction is weaker and the breathing mode frequency is lower, thereby being able to better avoid the exciting force frequency and thus achieving vibration reduction and noise reduction.

[0067] The present invention also provides a motor, which includes a motor housing, a stator and a rotor. The stator includes a stator core 1000. The specific structure of the stator core 1000 refers to the above embodiments. Since this motor adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one. Among them, the stator is arranged in the motor housing and includes a stator winding and a stator core 1000. The stator winding is wound around the stator slots 30 of the stator core 1000; the rotor is arranged inside the stator.

[0068] The above is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention under the technical concept of the present invention, or direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A stator core, characterized in that, Comprising: The stator core is formed by stacking a plurality of stator laminations; the stator lamination includes a stator yoke portion and a plurality of stator tooth portions, and the plurality of stator tooth portions are circumferentially spaced and arranged inside the stator yoke portion, and a stator slot is formed between two adjacent stator tooth portions; Wherein, the stator yoke portion and the stator tooth portion have a slit extending radially along the stator lamination, and the slit starts from the stator yoke portion and terminates at the stator tooth portion; the slit portions of adjacent stator laminations coincide partially or completely.

2. The stator core according to claim 1, characterized in that Define the distance between the termination point of the slit and the inner side of the stator tooth portion as b, then it satisfies: b≥1mm.

3. The stator core according to claim 1, wherein, Define the distance between the termination point of the slit and the side edge of the stator tooth portion as a, then it satisfies: a≥0.5mm.

4. The stator core according to claim 3, wherein, The distances between the termination point of the slit and the opposite side edges of the stator tooth portion are different.

5. The stator core according to any one of claims 1 to 4, characterized in that, Define the width of the slit as w, then it satisfies: 0.01mm≤w≤1mm.

6. The stator core according to any one of claims 1 to 4, characterized in that Define the part of the stator tooth portion on the left side of the slit as the first connecting portion, the part of the stator tooth portion on the right side of the slit as the second connecting portion, and the part of the stator tooth portion between the termination point of the slit and the inner side of the stator tooth portion as the third connecting portion; One of the first connecting portion, the second connecting portion and the third connecting portion is disconnected to form a first splicing portion and a second splicing portion, and the first splicing portion and the second splicing portion are spliced through a splicing structure.

7. The stator core according to claim 6, characterized in that The splicing structure is a tenon and mortise structure, and one of the first splicing portion and the second splicing portion is provided with a tenon, and the other is provided with a mortise.

8. The stator core according to any one of claims 1 to 4, characterized in that, The stator yoke portion and the stator tooth portion are circumferentially spaced with a plurality of the slits.

9. A motor, characterized in that, Comprising: A housing; A stator, the stator is arranged inside the housing and includes a stator winding and a stator core as described in any one of claims 1 to 8, and the stator winding is wound around the stator slot of the stator core; A rotor, the rotor is arranged inside the stator.

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