Rotor core, rotor assembly and motor having the same

Abstract

The present application provides a rotor core, a rotor assembly, and a motor having the same, comprising end punching sheets and stacked punching sheets, wherein the end punching sheets comprise a first set of ring punching sheets and at least two first tooth punching sheets, each of which is arranged on the outer peripheral side of the first set of ring punching sheets, and each of which is connected to the first set of ring punching sheets through a connecting structure; the stacked punching sheets comprise a second set of ring punching sheets and at least two second tooth punching sheets, each of which is arranged on the outer peripheral side of the second set of ring punching sheets; at least part of the second tooth punching sheets is not connected to the second set of ring punching sheets. According to the rotor core, the rotor assembly, and the motor having the same of the present application, magnetic steel leakage can be reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of electric motors, and in particular relates to a rotor core, a rotor assembly, and an electric motor having the same. Background Art

[0002] At present, in permanent magnet motors, in order to improve the performance of the motor, it is usually necessary to make the motor obtain better magnetic properties. Among the common structures, compared with the surface-mounted and built-in radial rotors, the built-in tangential rotor structure can effectively increase the flux area, increase the effective air gap flux, and thus improve the motor performance.

[0003] However, the built-in tangential rotor uses a connecting structure to connect each tooth punching and the shaft ring. Therefore, the inner part of the magnet will form leakage magnetic field through the connecting structure on both sides of the magnet. When each tooth punching is connected to the shaft ring through the connecting structure, the more connecting structures there are, the greater the leakage magnetic field of the magnet will be, and the lower the motor efficiency will be.

[0004] Therefore, how to provide a rotor core, a rotor assembly and a motor having the same that can reduce magnetic steel leakage has become an urgent problem that technicians in this field need to solve. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present application is to provide a rotor core, a rotor assembly and a motor having the same, which can reduce magnetic steel leakage.

[0006] In order to solve the above problems, the present application provides a rotor core, comprising:

[0007] The end punching sheet comprises a first set of ring punching sheets and at least two first tooth punching sheets, each of the first tooth punching sheets is arranged on the outer peripheral side of the first set of ring punching sheets, and each of the first tooth punching sheets is connected to the first set of ring punching sheets through a connecting structure;

[0008] and stacked punching sheets, the stacked punching sheets include a second set of ring punching sheets and at least two second tooth punching sheets, each of the second tooth punching sheets is arranged on the outer peripheral side of the second set of ring punching sheets; at least part of the second tooth punching sheets are not connected to the second set of ring punching sheets.

[0009] Furthermore, two adjacent first tooth punching sheets are not connected to each other; an injection molding groove is formed between the outer peripheral sides of the two adjacent first tooth punching sheets, and the injection molding groove is used to perform plastic coating and fixation on the first tooth punching sheets and the magnetic steel;

[0010] And / or, two adjacent second tooth punching sheets are not connected to each other; an injection molding groove is formed between the outer peripheral sides of two adjacent second tooth punching sheets, and the injection molding groove is used to encapsulate and fix the second tooth punching sheets and the magnetic steel.

[0011] Furthermore, the circumferential distance between two adjacent second tooth punching sheets is L1; the circumferential width of the injection molding groove is L2; ​​L2>L1; and / or, the outer diameter of the injection molding groove is D2; the outer diameter of the rotor core is D1; ​​wherein D2≤D1.

[0012] Furthermore, a first magnetic steel groove is formed between two adjacent first tooth punching sheets, and a first limiting structure is provided on the outer peripheral side of the first ring punching sheet. The first limiting structure corresponds to the number and position of the first magnetic steel grooves, and the first limiting structure is used to radially limit the magnetic steel in the corresponding first magnetic steel groove.

[0013] Furthermore, a second magnetic steel groove is formed between two adjacent second tooth punching sheets, and a second limiting structure is arranged on the outer peripheral side of the second ring punching sheet. The number of the second limiting structures is less than the number of the second magnetic steel grooves, and each second limiting structure corresponds to the position of one of the second magnetic steel grooves. The second limiting structure is used to radially limit the magnetic steel in the corresponding second magnetic steel groove.

[0014] Furthermore, the number of the second limiting structures is set to two, and the two second limiting structures are centrally symmetrical in the central direction of the central axis of the second set of ring punching sheets.

[0015] Furthermore, the second tooth punching sheets that are not connected to the second set of ring punching sheets are arranged in pairs, and each of the second tooth punching sheets is centrally symmetrically arranged in the central direction of the central axis of the second set of ring punching sheets.

[0016] Furthermore, the rotor core is formed by stacking end punches and stacking punches; the end punches are the first layer of punches in the stacking direction; the number of end punches is set to at least one; the number of stacking punches is set to multiple, and the multiple stacking punches are arranged in sequence in the stacking direction.

[0017] Furthermore, the plurality of stacked punching sheets are rotated in sequence by an angle of one magnetic pole in the stacking direction.

[0018] Further, each first tooth punching sheet is provided with a first positioning hole, a first injection hole and a first self-locking wedge; and / or each second tooth punching sheet is provided with a second positioning hole, a second injection hole and a second self-locking wedge.

[0019] According to another aspect of the present application, a rotor assembly is provided, including a rotor core, and the rotor core is the above-mentioned rotor core.

[0020] According to another aspect of the present application, a motor is provided, including a rotor assembly, which is the above-mentioned rotor assembly.

[0021] The rotor core, rotor assembly and motor provided by the present application are characterized in that at least part of the second tooth punching sheets are not connected to the second ring punching sheets, that is, the stacked punching sheets adopt a disconnected rotor core, which can effectively reduce the magnetic leakage of the magnetic steel caused by the connection structure; the end punching sheets punched first by the core, that is, the end surface adopts a fully connected bridge rotor punching sheet, which reduces the difficulty of stacking the tooth punching sheets with disconnected connection structures. The present application can reduce the magnetic leakage of the magnetic steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the end punching sheet of an embodiment of the present application;

[0023] Figure 2 A schematic diagram of the connection structure of stacked punching sheets according to an embodiment of the present application;

[0024] Figure 3 A schematic diagram of the stacked structure of the rotor core of an embodiment of the present application;

[0025] Figure 4 A schematic diagram of the structure of the rotor structure of an embodiment of the present application;

[0026] Figure 5 This is a schematic diagram of the structure of the rotor according to an embodiment of the present application.

[0027] The reference numerals are:

[0028] 1. End punching sheet; 11. First set of ring punching sheets; 12. First tooth punching sheet; 121. First positioning hole; 122. First injection hole; 123. First self-locking wedge; 13. First magnetic steel groove; 14. First limiting structure; 2. Stacking punching sheets; 21. Second set of ring punching sheets; 22. Second tooth punching sheet; 221. Second positioning hole; 222. Second injection hole; 223. Second self-locking wedge; 23. Second magnetic steel groove; 24. Second limiting structure; 3. Connection structure; 4. Shaft hole; 5. Plastic encapsulation material; 6. Injection groove; 7. Magnetic steel. DETAILED DESCRIPTION

[0029] See also Figure 1-5As shown, a rotor core includes an end punching sheet 1 and a stacked punching sheet 2. The end punching sheet 1 includes a first set of ring punching sheets 11 and at least two first tooth punching sheets 12. Each first tooth punching sheet 12 is arranged on the outer peripheral side of the first set of ring punching sheets 11, and each first tooth punching sheet 12 is connected to the first set of ring punching sheets 11 through a connecting structure 3; the stacked punching sheet 2 includes a second set of ring punching sheets 21 and at least two second tooth punching sheets 22. Each second tooth punching sheet 22 is arranged on the outer peripheral side of the second set of ring punching sheets 21; at least part of the second tooth punching sheets 22 are not connected to the second set of ring punching sheets 21. The present application uses at least part of the second tooth punching sheet 22 to be disconnected from the second ring punching sheet 21, that is, the stacked punching sheet 2 adopts a continuous rotor core, which can effectively reduce the magnetic leakage of the magnetic steel 7 caused by the connection structure 3; the end punching sheet 1 that is punched first in the core, that is, the end face adopts a fully connected bridge rotor punching sheet, which reduces the difficulty of stacking the tooth punching sheet with a disconnected connection structure 3; that is, each first tooth punching sheet 12 in the end punching sheet 1 is connected to the first ring punching sheet 11 through the connection structure 3, which can reduce the difficulty of stacking the tooth punching sheets in the stacked punching sheet 2. It can effectively solve the problem of large magnetic leakage of the magnetic steel 7 at the connection part of the built-in tangential rotor core; and solve the problem of difficulty in producing stacked iron cores of tooth punching sheets with disconnected connections. The fully connected bridge punching sheet refers to its "internal magnetic isolation bridge connection structure 3" that connects all the "sector-shaped tooth punching sheets" of the outer ring and the "rotating shaft ring" of the inner ring into one. The characteristic of the continuous rotor punching is that only part of it has the "internal magnetic bridge connection structure 3" to connect the "sector-shaped tooth punching" of the outer ring and the "rotating shaft collar" of the inner ring into one, and the remaining part is disconnected. The rotor core also has an axial hole 4.

[0030] The present application also discloses some embodiments, in which two adjacent first tooth punching sheets 12 are not connected to each other; an injection molding groove 6 is formed between the outer circumferences of the two adjacent first tooth punching sheets 12, and the injection molding groove 6 is used to encapsulate and fix the first tooth punching sheets 12 and the magnetic steel 7;

[0031] The present application also discloses some embodiments, in which two adjacent second tooth punching sheets 22 are not connected to each other; an injection molding groove 6 is formed between the outer peripheral sides of two adjacent second tooth punching sheets 22, and the injection molding groove 6 is used to encapsulate and fix the second tooth punching sheets 22 and the magnetic steel 7.

[0032] The present application also discloses some embodiments, wherein the circumferential distance L1 between two adjacent second tooth punching sheets 22; the circumferential width of the injection molding groove 6 is L2; ​​L2>L1; and / or, the outer diameter of the injection molding groove 6 is D2; the outer diameter of the rotor core is D1; ​​wherein D2≤D1. The injection molding through hole connects the plastic coating on both end surfaces of the plastic coating rotor, which can enhance the axial bonding strength of the plastic coating rotor; the circumferential width dimension L2 of the injection molding groove 6 is greater than the disconnection dimension L1 of the outer magnetic isolation bridge, and the magnetic steel 7 and the tooth core can be plastic coated and fixed on the outer circumference to enhance the radial bonding strength of the plastic coating rotor. Generally, the outer diameter D2 of the injection molding groove 6 needs to be less than or equal to the outer diameter D1 of the rotor core to prevent the plastic coating from rubbing against the inner diameter of the stator when the motor is running. The present application solves the problem of low bonding strength of plastic coating when plastic coating the built-in tangential rotor; and solves the problem of low bonding strength of plastic coating of the tooth core of the built-in tangential rotor. The rotor core is provided with injection molding holes to enhance the bonding strength of the plastic coating; at the same time, the plastic coating plays a role in strengthening the fixation of the magnetic steel 7 and the tooth core on the circumferential side of the rotor. The outer diameter D2 of the injection molding groove 6 refers to the distance between the central axis of the rotor core and the outer peripheral wall of the injection molding groove 6; the outer diameter D1 of the rotor core refers to the distance between the central axis of the rotor core and the outer peripheral wall of the rotor core, that is, the injection molding groove 6 protrudes to the periphery, which can prevent the plastic coating from rubbing against the inner diameter of the stator when the motor is running. The circumferential distance L1 between two adjacent second tooth punchings 22 refers to the spacing distance L1 between two adjacent second tooth punchings 22 in the circumferential direction; the circumferential width dimension L2 of the injection molding groove 6 refers to the extension length of the injection molding groove 6 in the circumferential direction.

[0033] The present application also discloses some embodiments in which two adjacent first tooth punching sheets 12 are not connected to each other, that is, the outer circumference and the inner circumference of two adjacent first tooth punching sheets 12 are isolated from each other and are not connected, which can further reduce magnetic leakage.

[0034] The present application also discloses some embodiments in which two adjacent second tooth punching sheets 22 are not connected to each other, that is, the outer circumference and the inner circumference of two adjacent second tooth punching sheets 22 are isolated from each other and are not connected, which can further reduce magnetic leakage.

[0035] The present application also discloses some embodiments, in which a first magnetic steel groove 13 is formed between two adjacent first tooth punching sheets 12, and a first limiting structure 14 is provided on the outer peripheral side of the first ring punching sheet 11. The first limiting structure 14 corresponds to the number and position of the first magnetic steel grooves 13, and the first limiting structure 14 is used to radially limit the magnetic steel 7 in the corresponding first magnetic steel groove 13.

[0036] The present application also discloses some embodiments, in which a second magnetic steel slot 23 is formed between two adjacent second tooth punching sheets 22, and a second limiting structure 24 is provided on the outer peripheral side of the second ring punching sheet 21, the number of the second limiting structures 24 is less than the number of the second magnetic steel slots 23, each second limiting structure 24 corresponds to the position of one of the second magnetic steel slots 23, and the second limiting structure 24 is used to limit the magnetic steel 7 in the corresponding second magnetic steel slot 23 in the radial direction. The protruding structure of the rotor core positioning magnetic steel 7 is also partially disconnected to improve the magnetization saturation of the magnetic steel 7; the problem of low magnetization saturation of the built-in tangential rotor core magnetic steel 7 is solved.

[0037] The present application also discloses some embodiments, in which the number of the second limiting structures 24 is set to two, and the two second limiting structures 24 are centrally symmetrical in the central direction of the central axis of the second set of ring punches 21 .

[0038] The present application also discloses some embodiments, in which the second tooth punching sheets 22 which are not connected to the second ring punching sheets 21 are arranged in pairs, and each pair of second tooth punching sheets 22 are arranged symmetrically around the central axis direction of the second ring punching sheets 21. That is, the outer magnetic isolation bridge of the continuous-disconnection rotor punching sheet is a fully disconnected structure; at least one pair of the inner magnetic isolation bridges is a connected structure 3 and at least one pair is a disconnected structure, so as to reduce the magnetic leakage inside the magnetic steel 7.

[0039] The present application also discloses some embodiments, wherein the rotor core is formed by stacking end punching sheets 1 and stacked punching sheets 2; the end punching sheets 1 are the first layer of punching sheets in the stacking direction; the number of end punching sheets 1 is set to be at least one; the number of stacked punching sheets 2 is set to be multiple, and multiple stacked punching sheets 2 are arranged in sequence in the stacking direction. The shaft collar has at least one pair of magnetic steel 7 positioning protrusions and at least one pair of magnetic steel 7 positioning protrusions are removed to improve the magnetization saturation of the magnetic steel 7; the inner magnetic bridge connection structure 3 and the magnetic steel 7 positioning protrusion structure are centrally symmetrically distributed to avoid stress asymmetry during mold stamping and cutting. Each tooth punching sheet of the outer ring has a circular self-locking wedge, a positioning through hole and an injection molding through hole. Compared with the continuous-break rotor punching sheet and the continuous-bridge rotor punching sheet, only the structure of the inner magnetic bridge and the magnetic steel 7 positioning protrusion is different, which can be achieved by adding inserts to the same pair of molds without the need to open an additional punching press mold.

[0040] The present application also discloses some embodiments, in which a plurality of stacked punching sheets 2 are rotated one magnetic pole angle in the stacking direction in sequence. When the continuous-disconnected rotor punching sheets are punched and stacked, two adjacent layers are rotated one magnetic pole angle in the same direction to ensure that the disconnected connection parts and the positioning protrusions of the magnetic steel 7 are evenly distributed in the circumference, avoiding asymmetry of the rotor magnetic circuit and affecting performance parameters such as motor noise.

[0041] The present application also discloses some embodiments, each first tooth punching sheet 12 is provided with a first positioning hole 121, a first injection hole 122 and a first self-locking wedge 123. The present application also discloses some embodiments, each second tooth punching sheet 22 is provided with a second positioning hole 221, a second injection hole 222 and a second self-locking wedge 223. The first self-locking wedge 123 and the second self-locking wedge 223 are both circular self-locking wedges; the positioning hole is a positioning through hole, and the injection hole is an injection through hole.

[0042] The rotor core is provided with injection holes and positioning holes. When the rotor is overmolded, the overmolded plastic penetrates and fills the injection holes, connecting the overmolded plastic on both end surfaces as a whole, thereby enhancing the bonding strength of the overmolded plastic. The overmolded plastic is on the circumferential side of the rotor, and the magnetic steel 7 and the tooth core are overmolded and fixed at the same time. The outer magnetic isolation bridge of the stacked punching sheet 2 and the end punching sheet 1 is a fully disconnected structure, that is, the outer circumferential sides of the two adjacent tooth punching sheets are disconnected and not connected; the inner magnetic isolation bridge is a fully connected structure 3, that is, the inner circumferential sides of the two adjacent tooth punching sheets are partially or completely connected to the sleeve punching sheet. The rotor punching sheet is a whole. There are circular self-locking wedges, positioning through holes and injection through holes on each tooth punching sheet of the outer ring. The function of the circular self-locking wedge is to connect the tooth punching sheets as a whole through stacking; the positioning through hole can reduce the mass of the rotor core, and can be used for positioning during subsequent overmolding and magnetization; the injection through hole is used for subsequent filling of plastic sealing material 5 to increase the connection strength of the entire overmolded rotor. Between two adjacent tooth punchings, a magnetic steel 7 positioning protrusion structure is provided on the shaft collar for positioning the magnetic steel 7 when it is inserted into the rotor core. Self-locking wedges and through holes are evenly distributed on the rotor punchings, and the number and shape can be adjusted according to actual use and production needs.

[0043] When punching the rotor core of the present application, at least one bridge punching sheet will be punched out first, and the overall frame will be fixed on the end face of the entire core. After the bridge punching sheets are punched and laminated, the laminated continuous and discontinuous punching sheets will be punched out on the basis of the bridge punching sheets. In order to reduce the rotor magnetic leakage as much as possible, the number of discontinuous punching sheets will be greater than or equal to the number of bridge punching sheets. After the punching sheets are stacked into the rotor core, they are fixed on the injection mold through the positioning holes of the tooth punching sheets, the magnetic steel 7 is inserted into the corresponding magnetic steel groove, and then the plastic encapsulation material 5 is used for injection molding. The injection molding groove 6 and the injection molding hole reserved on the core will be filled with the plastic encapsulation material 5, and the magnetic steel 7 and the rotor core will be connected as a whole to form the final plastic-coated rotor.

[0044] According to an embodiment of the present application, a rotor assembly is provided, including a rotor core, and the rotor core is the above-mentioned rotor core.

[0045] According to an embodiment of the present application, a motor is provided, including a rotor assembly, and the rotor assembly is the above-mentioned rotor assembly.

[0046] It is easy for those skilled in the art to understand that the above-mentioned advantageous methods can be freely combined and superimposed without conflict.

[0047] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. 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 application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A rotor core, It is characterized in that include: An end punch (1), the end punch (1) comprising a first ring punch (11) and at least two first tooth punches (12), each of the first tooth punches (12) being arranged on the outer peripheral side of the first ring punch (11), and each of the first tooth punches (12) being connected to the first ring punch (11) via a connecting structure (3); and a stacked punching sheet (2), the stacked punching sheet (2) comprising a second ring punching sheet (21) and at least two second tooth punching sheets (22), each of the second tooth punching sheets (22) being arranged on the outer peripheral side of the second ring punching sheet (21); at least part of the second tooth punching sheets (22) being not connected to the second ring punching sheet (21), and at least two of the second tooth punching sheets (22) being connected to the second ring punching sheet (21) via the connecting structure (3); The second tooth punching sheets (22) connected to the second ring punching sheet (21) via the connecting structure (3) are arranged in pairs, and each pair of the second tooth punching sheets (22) are arranged symmetrically in the central direction around the central axis of the second ring punching sheet (21); The rotor core is formed by laminating the end punching sheets (1) and the stacking punching sheets (2); the end punching sheets (1) are the first layer of punching sheets in the stacking direction; the number of the end punching sheets (1) is set to at least one; the number of the stacking punching sheets (2) is set to be multiple, and the multiple stacking punching sheets (2) are arranged in sequence in the stacking direction; The plurality of stacked punching sheets (2) are rotated in sequence by an angle of one magnetic pole in the stacking direction.

2. The rotor core according to claim 1, It is characterized in that Two adjacent first tooth punching sheets (12) are not connected to each other; an injection molding groove (6) is formed between the outer peripheral sides of the two adjacent first tooth punching sheets (12), and the injection molding groove (6) is used to encapsulate and fix the first tooth punching sheet (12) and the magnetic steel (7); And / or, two adjacent second tooth punching sheets (22) are not connected to each other; an injection molding groove (6) is formed between the outer peripheral sides of two adjacent second tooth punching sheets (22), and the injection molding groove (6) is used to encapsulate and fix the second tooth punching sheet (22) and the magnetic steel (7).

3. The rotor core according to claim 2, It is characterized in that The circumferential distance between two adjacent second tooth punching sheets (22) is L1; the circumferential width of the injection molding groove (6) is L2; ​​L2>L1; and / or, the outer diameter of the injection molding groove (6) is D2; the outer diameter of the rotor core is D1; ​​wherein D2≤D1.

4. The rotor core according to claim 1, It is characterized in that A first magnetic steel groove (13) is formed between two adjacent first tooth punching sheets (12), and a first limiting structure (14) is provided on the outer peripheral side of the first ring punching sheet (11). The number and position of the first limiting structures (14) correspond to those of the first magnetic steel grooves (13), and the first limiting structures (14) are used to radially limit the magnetic steel (7) in the corresponding first magnetic steel groove (13).

5. The rotor core according to claim 1, It is characterized in that A second magnetic steel groove (23) is formed between two adjacent second tooth punching sheets (22); a second limiting structure (24) is provided on the outer peripheral side of the second ring punching sheet (21); the number of the second limiting structures (24) is less than the number of the second magnetic steel grooves (23); each of the second limiting structures (24) corresponds to the position of one of the second magnetic steel grooves (23); and the second limiting structure (24) is used to radially limit the magnetic steel (7) in the corresponding second magnetic steel groove (23).

6. The rotor core according to claim 5, It is characterized in that The number of the second limiting structures (24) is set to two, and the two second limiting structures (24) are centrally symmetrical around the central axis direction of the second ring punch (21).

7. The rotor core according to claim 1, It is characterized in that The second tooth punching sheets (22) not connected to the second ring punching sheet (21) are arranged in pairs, and each pair of the second tooth punching sheets (22) are centrally symmetrically arranged in the central direction of the central axis of the second ring punching sheet (21).

8. The rotor core according to claim 1, It is characterized in that Each of the first tooth punching sheets (12) is provided with a first positioning hole (121), a first injection hole (122) and a first self-locking wedge (123); and / or each of the second tooth punching sheets (22) is provided with a second positioning hole (221), a second injection hole (222) and a second self-locking wedge (223).

9. A rotor assembly comprising a rotor core, It is characterized in that The rotor core is the rotor core according to any one of claims 1 to 8.

10. An electric machine, comprising a rotor assembly, It is characterized in that The rotor assembly is the rotor assembly described in claim 9.

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