Motor rotor and motor

Abstract

The utility model provides a motor rotor and a motor, an iron core unit (10) forms a plurality of inner side grooves (11), each inner side groove (11) comprises an inner side first groove (111), an inner side second groove (112) and an inner side third groove (113), the inner side third groove (113) is communicated with the inner side first groove (111) and the inner side second groove (112) and forms a semi-ring shape with an opening facing the outer peripheral side of the iron core unit (10), and the inner side first groove (111) is communicated with the inner side second groove (112). The portion, surrounded by the inner third groove (113), of the iron core unit (10) forms a middle connecting portion (15), the middle connecting portion (15) comprises a radial column portion (151) and a root portion (152), the inner third groove (113) comprises first areas (I) located on the two sides of the radial column portion (151), the closer to the radial inner side, the larger the width of the first areas (I) in the circumferential direction is, and the closer to the radial outer side, the larger the width of the first areas (I) in the circumferential direction is. Each first area (I) is filled with a non-magnetic first filling body (F1). The motor rotor and the motor according to the utility model can still have great structural strength and reliability at a high rotating speed.

Description

[0001] Citation of Related Applications

[0002] This application claims the priority of the PCT application with the title "Motor Rotor and Method for Manufacturing a Motor Rotor" and application number PCT / CN2023 / 141276, filed with the World Intellectual Property Organization on December 22, 2023. The entire content of the above prior application is incorporated herein by reference. Technical Field

[0003] This application relates to the field of motors, and more particularly to a motor rotor and a motor. Background Art

[0004] For high-speed permanent magnet motors, such as the drive motors of new energy vehicles, the rotor of the motor needs to withstand a very large centrifugal force at high speeds, which poses high requirements for the mechanical strength of the rotor core.

[0005] The applicant has previously proposed an improved motor rotor in the PCT application with application number PCT / CN2023 / 141276. By providing a semi-circular inner third groove and an intermediate connecting portion with magnetic isolation and connection functions between a pair of grooves of the rotor core, the structural strength of the rotor core is increased. And, in this application, a scheme of arranging a metal filling material in the inner third groove is provided, which can further enhance the structural strength of the rotor.

[0006] However, in experiments and simulations, the applicant found that at high speeds, there is a risk of the above filling material shifting in the inner third groove, so there is room for further improvement in this scheme. Summary of the Utility Model

[0007] The purpose of the present utility model is to overcome or at least mitigate the deficiencies of the above-mentioned prior art, and to provide a motor rotor and a motor.

[0008] According to a first aspect of the present application, there is provided a motor rotor, including at least one rotor sub-unit, the rotor sub-unit including a core sub-unit and a permanent magnet embedded in the core sub-unit,

[0009] In a cross-section of the core sub-unit perpendicular to the axial direction, the core sub-unit forms a plurality of inner grooves that are circumferentially symmetric. Each inner groove includes an inner first groove, an inner second groove, and an inner third groove. The inner first groove and the inner second groove are symmetrically formed as a V shape with respect to each other. The inner third groove communicates with the inner first groove and the inner second groove. The inner third groove is formed as a semi-circular shape with an opening facing the outer peripheral side of the core sub-unit.

[0010] The part of the iron core sub-unit surrounded by the inner third groove is formed into an intermediate connecting part, the intermediate connecting part includes a radial column part and a root part, the radial column part extends along the radial direction of the rotor lamination, and in the circumferential direction, the size of the root part is larger than that of the radial column part, wherein,

[0011] The inner third groove includes two first regions located on both sides of the radial column part. In the cross-section of the iron core sub-unit perpendicular to the axial direction, the first region is wedge-shaped, and the closer to the radial inner side, the larger the width of the first region in the circumferential direction.

[0012] Each of the first regions is filled with a non-magnetic first filler, and the hardness of the first filler is greater than that of the iron core sub-unit.

[0013] In at least one embodiment, the first region is completely filled with the first filler, and the first filler is in interference fit with the iron core sub-unit.

[0014] In at least one embodiment, at least two symmetric first fillers are provided in each inner third groove, and the two first fillers are spaced apart in the circumferential direction of the motor rotor.

[0015] In at least one embodiment, a third sheet-shaped first filler is further provided in the radially inner region of each inner third groove located at the root part.

[0016] In at least one embodiment, the inner third groove further includes two second regions, two third regions and two fourth regions.

[0017] The second region, the third region and the fourth region are connected in sequence to form a C shape. The second region is located on the radially outer side of the root part, the third region is located on both sides of the root part in the circumferential direction, and the fourth region is located on the radially inner side of the root part.

[0018] Each first filler occupies the first region and the second region, or

[0019] Each first filler occupies the first region, the second region and the third region, or

[0020] Each first filler occupies the first region, the second region, the third region and the fourth region.

[0021] In at least one embodiment, at least the outer layer of the first filler is an insulating structure.

[0022] In at least one embodiment, the motor rotor further includes a carbon fiber layer wound around the outer periphery of the rotor sub-unit.

[0023] In at least one embodiment, the iron core sub-unit includes a first part that is not integrally formed and a plurality of second parts. The plurality of second parts are disposed on the outer peripheral side of the first part, and the space between the first part and the second parts forms the inner groove. Each of the second parts includes a fan-shaped portion and an intermediate connecting portion located radially inside the fan-shaped portion.

[0024] In at least one embodiment, the motor rotor includes a plurality of rotor sub-units stacked axially, and the magnetic steels disposed in at least two adjacent rotor sub-units are not aligned circumferentially.

[0025] According to a second aspect of the present application, there is provided a motor including the motor rotor according to the first aspect of the present application.

[0026] The motor rotor and the motor according to the present invention can still have great structural strength and reliability at high speeds. Description of the Drawings

[0027] Figure 1 is a schematic diagram of a partial structure of a rotor sub-unit in a cross-section perpendicular to the axial direction according to the first embodiment of the present application (the filling material in the inner third groove is not shown).

[0028] Figure 2 is Figure 1 a schematic diagram after the inner third groove is filled with a first filling body.

[0029] Figure 3 is Figure 1 a partially enlarged schematic diagram.

[0030] Figure 4 is a schematic diagram of a partial structure of a rotor sub-unit in a cross-section perpendicular to the axial direction according to the second embodiment of the present application (the filling material in the inner third groove is not shown).

[0031] Figure 5 is a schematic diagram of a partial structure of a rotor sub-unit in a cross-section perpendicular to the axial direction according to the third embodiment of the present application.

[0032] Figure 6 is a schematic diagram of a partial structure of a rotor sub-unit in a cross-section perpendicular to the axial direction according to the fourth embodiment of the present application.

[0033] Figure 7 and Figure 8Schematic diagram of a partial structure of a rotor subunit according to two other possible embodiments of the present application in a cross-section perpendicular to the axial direction.

[0034] Description of reference numerals:

[0035] U Rotor subunit; F1 First filler; F11 First part of the first filler; F12 Second part of the first filler;

[0036] 10 Iron core subunit; 10a First part; 10b Second part;

[0037] 11 Inner groove; 111 First inner groove; 112 Second inner groove; 113 Third inner groove;

[0038] 15 Intermediate connecting part; 151 Radial column part; 152 Root part;

[0039] 20 Permanent magnet; 21 Inner permanent magnet; 211 First inner permanent magnet; 212 Second inner permanent magnet; 30 Carbon fiber layer. Detailed implementation manners

[0040] The following describes exemplary embodiments of the present application with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present invention, and are not used to exhaust all possible ways of the present application, nor to limit the scope of the present invention.

[0041] Unless otherwise specified, the radial, axial, and circumferential directions mentioned below are referenced with respect to the radial, axial, and circumferential directions of the rotor core.

[0042] First Embodiment

[0043] Refer to Figures 1 to 3 , and introduce the motor rotor according to the first embodiment of the present application. The motor rotor of this embodiment includes one rotor subunit U or a plurality of rotor subunits U stacked axially. Each rotor subunit U includes an iron core subunit 10 and a plurality of permanent magnets 20. The iron core subunit 10 can be formed by stacking a plurality of silicon steel sheets, or can be formed by pressing, for example, soft magnetic composite material (referred to as SMC).

[0044] In a cross-section perpendicular to the axial direction of the motor rotor, the iron core subunit 10 forms multiple groups (six groups in this embodiment) of grooves that are symmetric in the circumferential direction (or arrayed in the circumferential direction). In this embodiment, each group of grooves includes a group of inner grooves 11 and a group of outer grooves, and the inner grooves 11 are located on the inner circumferential side of the outer grooves. Both the inner grooves 11 and the outer grooves are substantially V-shaped. The inner grooves 11 are used to mount the inner permanent magnets 21, and the inner permanent magnets 21 include the inner first permanent magnets 211 and the inner second permanent magnets 212 arranged in a figure-eight shape.

[0045] Each inner groove 11 includes a connected first inner groove 111, a second inner groove 112, and a third inner groove 113. Among them, the third inner groove 113 is located between the first inner groove 111 and the second inner groove 112. The first inner magnet 211 is inserted into the first inner groove 111, and the second inner magnet 212 is inserted into the second inner groove 112.

[0046] The third inner groove 113 has a zigzag trend in the cross-section as shown in the figure, so that it forms a semi-circular ring in the cross-section, and the opening of the semi-circular ring faces the outer peripheral direction of the iron core. Specifically, the part of the iron core sub-unit 10 surrounded by the third inner groove 113 forms an intermediate connecting portion 15. The intermediate connecting portion 15 Figure 4 has a substantially inverted T-shaped structure in the shown cross-sectional view, and it includes a radial column portion 151 and a root portion 152. The intermediate connecting portion 15 is radially opposite to the middle region of the outer magnet or the outer groove located on its outer peripheral side.

[0047] The radial column portion 151 extends along the radial direction of the iron core sub-unit 10. At different positions in the radial direction, the width of the radial column portion 151 in the circumferential direction is substantially equal. Since the radial column portion 151 and the iron core portions on its circumferential two sides are separated by the third inner groove 113, magnetic isolation is achieved on the circumferential two sides of the radial column portion 151, so the radial column portion 151 can have a relatively large width in the circumferential direction. The width of the radial column portion 151 in the circumferential direction is, for example, 3 mm to 5 mm.

[0048] The root portion 152 is connected to the radially innermost end of the radial column portion 151. The root portion 152 is formed into a structure substantially perpendicular to the radial column portion 151. In the circumferential direction, the size of the root portion 152 is larger than that of the radial column portion 151.

[0049] Referring to Figure 3 , the third inner groove 113 includes two first regions I, two second regions II, two third regions III, two fourth regions IV, and one fifth region V. The first region I, the second region II, the third region III, and the fourth region IV are connected in sequence to form a C shape. The first region I is located on both sides in the circumferential direction of the radial column portion 151, the second region II is located radially outside the root portion 152, the third region III is located on both sides in the circumferential direction of the root portion 152, the fourth region IV is located radially inside the root portion 152, and the fifth region V connects the two fourth regions IV on both sides.

[0050] In this embodiment, two first fillers F1 are provided in the third inner groove 113, and each first filler F1 occupies one side of the first region I and the second region II.

[0051] The hardness of the material for making the first filling body F1 is greater than that of the material for making the iron core sub-unit 10, and the material for making the first filling body F1 is a non-magnetic (or has a very low magnetic permeability) material. The material for making the first filling body F1 includes, for example, stainless steel or ceramics. Preferably, the first filling body F1 is also insulating. The insulation can be achieved in two ways. On the one hand, all the materials for making the first filling body F1 are insulators; on the other hand, the main body of the first filling body F1 can be made of metal, and then an insulating material is sprayed or coated on the surface of the main body of the first filling body F1, or an insulating oxide layer is formed by a chemical reaction on the metal surface. The insulating property of the first filling body F1 can further reduce the eddy current loss in the rotor sub-unit U.

[0052] The formed first filling body F1 and the iron core sub-unit 10 are assembled together by, for example, a hot-fitting process or a cold-fitting process, so that the two form an interference fit. For example, the first filling body F1 is cooled and shrunk, and / or the iron core sub-unit 10 is heated and expanded, and then the first filling body F1 is inserted into the inner groove 11.

[0053] It should be understood that due to the deformation effects of the first filling body F1 and / or the iron core sub-unit 10 in the hot-fitting process or the cold-fitting process, the two first filling bodies F1 in each inner third groove 113 are separated in the fifth region V, otherwise it is difficult for the first filling body F1 to be inserted into the inner third groove 113.

[0054] In this application, the first region I is wedge-shaped in the cross-section perpendicular to the rotor axis. The closer to the radial inner side, the greater the circumferential width of the first region I. Since the first filling body F1 and the iron core sub-unit 10 have an interference fit, in the cross-section perpendicular to the rotor axis, the shape of the first filling body F1 is similar to or basically the same as that of the first region I and the second region II. Specifically, the first filling body F1 includes a first part F11 of the first filling body filled in the first region I and a second part F12 of the first filling body filled in the second region II. The first part F11 of the first filling body is wedge-shaped, and in the cross-section perpendicular to the rotor axis, the closer to the radial inner side, the greater the circumferential width of the first part F11 of the first filling body.

[0055] The wedge shape of the first region I with a larger inner and smaller outer size makes it difficult for the first filling body F1 to move radially outward after being subjected to centrifugal force, so that the first filling body F1 can be stably maintained in the initial position in the iron core sub-unit 10 without loosening or displacement.

[0056] The remaining space in the inner third groove 113 can be filled with a second filling body to increase the overall structural strength of the rotor. The second filling body is, for example, resin or reinforced engineering plastic.

[0057] The filling materials within the inner third groove 113, namely the first filling body F1 and the second filling body, on the one hand, are equivalent to a part of the magnetic isolation bridge and play a role in restricting magnetic leakage; on the other hand, the second filling body also acts as an adhesive, capable of connecting the intermediate connecting portion 15 to the first part 10a of the inner circumference of the iron core sub-unit 10 located on the periphery of the inner third groove 113.

[0058] Combined Figure 3 , it can be understood that the first part 10a of the inner circumference of the iron core sub-unit 10 is relatively complete, without slots, without magnetic steel being provided, and the centrifugal force it receives is also relatively small. Therefore, the structural strength of the first part 10a is relatively high. For the second part 10b of the outer circumference of the iron core sub-unit 10 (especially the part located on the outer peripheral side of the inner groove 11), the centrifugal force it receives is large, and this part is relatively separated from other parts of the iron core sub-unit 10 due to the existence of the inner groove 11. Therefore, it is a part with relatively weak structural strength. The intermediate connecting portion 15 can transmit force through the filling materials in the inner third groove 113, such that the intermediate connecting portion 15 together with the filling materials in the inner third groove 113 acts as a hook or anchor-like role, tightly connecting the first part 10a and the second part 10b together. Among them, the radial column portion 151 has a certain extension length in the radial direction, creating a bridge with a sufficient length to connect the two side regions; the root portion 152 forms a certain width in the circumferential direction. For example, the width of the root portion 152 is 9 mm to 15 mm, such that the connecting force borne by the root portion 152 is distributed at various circumferential positions, thereby enabling a more reliable connection between the first part 10a and the second part 10b.

[0059] This application does not limit the structure and connection method of the outer magnetic steel and the outer groove, nor does it limit the filling method of the remaining space in the outer groove.

[0060] Second Embodiment

[0061] Refer to Figure 4 To introduce the second embodiment of this application. The second embodiment is a variant of the first embodiment. For components with the same or similar structures or functions as those in the first embodiment, the same reference numerals are marked, and the specific descriptions of these components are omitted.

[0062] The main difference between the second embodiment and the first embodiment is as follows:

[0063] First, the iron core sub-unit 10 includes a first part 10a that is not integrally formed (or is separately arranged) and a plurality of (6 in this embodiment) second parts 10b. The second parts 10b are arranged around the first part 10a, or in other words, the second parts 10b are arranged on the outer peripheral side of the first part 10a, and the interval between the first part 10a and the second parts 10b forms the inner groove 11.

[0064] Second, a carbon fiber layer 30 is wound around the outer periphery of the whole formed by multiple rotor sub-units U.

[0065] By setting the iron core sub-unit 10 as the split first part 10a and second part 10b, the rotor can be made without a main magnetic isolation bridge (the position where the so-called main magnetic isolation bridge is located is occupied by the second filling area S2 introduced next), and the magnetic leakage phenomenon is greatly reduced.

[0066] The second filling area S2 is in the area of the inner groove 11 on the outer peripheral side of the inner magnetic steel 21. The second filling area S2 is filled with a non-magnetic material, such as resin or engineering plastic. This filling process is realized, for example, by means of a mold that surrounds the outer periphery of the iron core sub-unit 10 to connect the first part 10a and the second part 10b. The filling material in the second filling area S2 simultaneously plays the roles of helping to fix the magnetic steel, helping to bond the first part 10a and each second part 10b, and magnetic isolation. After the filling in the second filling area S2 is completed, the first part 10a, the second part 10b and the inner magnetic steel 21 form a relatively stable whole.

[0067] To strengthen the structural strength of the rotor, a carbon fiber layer 30 is wound around the outer periphery of the whole formed by multiple rotor sub-units U.

[0068] It should be noted that the single rotor sub-unit U provided in this application does not have the carbon fiber layer 30 before assembly. In the subsequent assembly process, one rotor sub-unit U or multiple rotor sub-units U can be selected and stacked as needed, and the carbon fiber layer 30 is coated on the outer periphery of the rotor sub-unit U to form the final rotor. In the case where multiple rotor sub-units U are stacked, the magnetic steels 20 of at least two rotor sub-units U can be made not to align in the circumferential direction, so that the rotor forms a skewed pole and weakens the harmonic influence of the rotor.

[0069] The manufacturing method of the rotor according to this embodiment includes the following steps:

[0070] Step 1, provide an iron core sub-unit 10 corresponding to each rotor sub-unit U. It should be understood that at this time, the first part 10a and the second part 10b of the iron core sub-unit 10 are not connected together.

[0071] Step 2, insert the magnetic steel and the first filler F1 into the iron core sub-unit 10. Insert the inner magnetic steel 21 into its corresponding inner first groove 111 and inner second groove 112, insert the outer magnetic steel into its corresponding outer groove, and insert the first filler F1 into its corresponding inner third groove 113. Preferably, the magnetic steel 20 and the first filler F1 are respectively bonded to the iron core sub-unit 10 by adding an adhesive. Since the iron core sub-unit 10 is of a split design, it can be understood that during the assembly process, the application operation of the adhesive is very easy to achieve.

[0072] Step 3, form the rotor sub-unit U. Pour a non-magnetic filling material into the second filling area S2, and pour the second filler into the inner third groove 113, so that a rotor sub-unit U formed by a plurality of partial splicing parts forms a firm whole. Optionally, the gaps between the inner grooves of the iron core sub-unit 10 can all be filled with a non-magnetic filling material.

[0073] Step 4, form the rotor. Stack a plurality of rotor sub-units U together, and then sleuth the carbon fiber layer 30 on the outside of the rotor sub-unit U to form the rotor. Preferably, the magnetic steels 20 of at least two rotor sub-units U are not aligned in the circumferential direction, so that the rotor forms a skewed pole to weaken the harmonic influence of the rotor.

[0074] Third Embodiment

[0075] Refer to Figure 5 Introduce the third embodiment of the present application. The third embodiment is a variant of the first embodiment.

[0076] The main difference between this embodiment and the first embodiment is that: in this embodiment, three first fillers F1 are provided in the inner third groove 113. The additional first filler F1 is arranged on the outer peripheral side of the middle connecting portion 15, because this area is a relatively critical area for the first part 10a to transfer the extrusion force to the second part 10b. Adding the first filler F1 can further increase the structural strength of the rotor. At the same time, referring to Figure 3 the definition of each area in the inner third groove 113, the first filler F1 in this embodiment is arranged in the first area I, the second area II, the fourth area IV, and the fifth area V.

[0077] Fourth Embodiment

[0078] Refer to Figure 6 Introduce the fourth embodiment of the present application. The fourth embodiment is a variant of the first embodiment.

[0079] At the same time, referring to Figure 3, in this embodiment, the two first fillers F1 are only arranged in the two first regions I of the inner third groove 113, because this region is the most critical region for the first part 10a to transfer the extrusion force to the second part 10b. In this embodiment, the first fillers F1 are only arranged in the first region I, using the least amount of filling material to achieve the maximum effect of increasing the structural strength of the rotor.

[0080] It should be understood that the above embodiments and some of their aspects or features can be appropriately combined.

[0081] Of course, the present invention is not limited to the above embodiments, and those skilled in the art can make various modifications to the above embodiments of the present invention under the teaching of the present invention without departing from the scope of the present invention. For example, with reference to Figure 7 and Figure 3 , in some possible embodiments, each first filler F1 can completely fill the first region I, the second region II, and the third region III; or for another example, with reference to Figure 8 and Figure 3 , in some possible embodiments, each first filler F1 can completely fill the first region I, the second region II, the third region III, and the fourth region IV.

Claims

1. A motor rotor, comprising at least one rotor subunit (U), wherein the rotor subunit (U) comprises an iron core subunit (10) and a magnetic steel (20) embedded in the iron core subunit (10), On a cross section of the core subunit (10) perpendicular to the axial direction, the core subunit (10) forms a plurality of inner grooves (11) symmetrical in the circumferential direction, each of the inner grooves (11) comprising an inner first groove (111), an inner second groove (112) and an inner third groove (113), the inner first groove (111) and the inner second groove (112) being symmetrical with each other to form a V-shape, the inner third groove (113) connecting the inner first groove (111) and the inner second groove (112), and the inner third groove (113) being formed into a semi-ring shape with an opening toward the outer circumference of the core subunit (10), The portion of the core subunit (10) surrounded by the inner third groove (113) forms an intermediate connecting portion (15), the intermediate connecting portion (15) comprising a radial column portion (151) and a root portion (152), the radial column portion (151) extending in the radial direction of the core subunit (10), and in the circumferential direction, the size of the root portion (152) is larger than the size of the radial column portion (151), characterized in that: The inner third groove (113) comprises two first regions (I) located on both sides of the radial column (151); in a cross section of the core subunit (10) perpendicular to the axial direction, the first region (I) is wedge-shaped, and the closer to the radial inner side, the greater the width of the first region (I) in the circumferential direction. Each of the first regions (I) is filled with a first non-magnetic filling body (F1), and the hardness of the first filling body (F1) is greater than the hardness of the iron core subunit (10).

2. The motor rotor according to claim 1, characterized in that: The first area (I) is completely filled with the first filling body (F1), and the first filling body (F1) is interference fit with the iron core subunit (10).

3. The motor rotor according to claim 1, characterized in that: At least two symmetrical first filling bodies (F1) are arranged in each of the inner third grooves (113), and the two first filling bodies (F1) are arranged spaced apart in the circumferential direction of the motor rotor.

4. The motor rotor according to claim 3, characterized in that: A third sheet-shaped first filling body (F1) is also provided in each of the inner third grooves (113) in a radially inner region located at the root (152).

5. The motor rotor according to claim 1, characterized in that: The inner third groove (113) further includes two second areas (II), two third areas (III) and two fourth areas (IV). The second region (II), the third region (III) and the fourth region (IV) are sequentially connected to form a C-shape, the second region (II) is located radially outside the root (152), the third region (III) is located on both sides of the root (152) in the circumferential direction, and the fourth region (IV) is located radially inside the root (152). Each of the first filling bodies (F1) occupies the first region (I) and the second region (II), or Each of the first filling bodies (F1) occupies the first area (I), the second area (II) and the third area (III), or Each of the first filling bodies (F1) occupies the first region (I), the second region (II), the third region (III) and the fourth region (IV).

6. The motor rotor according to claim 1, characterized in that: At least the outer layer of the first filling body (F1) is an insulating structure.

7. The motor rotor according to claim 1, characterized in that: The motor rotor further comprises a carbon fiber layer (30), wherein the carbon fiber layer (30) is wound around the outer circumference of the rotor subunit (U).

8. The motor rotor according to claim 7, characterized in that: The core subunit (10) comprises a non-integrally formed first part (10a) and a plurality of second parts (10b), wherein the plurality of second parts (10b) are arranged on the outer peripheral side of the first part (10a), and the interval between the first part (10a) and the second part (10b) is formed as the inner groove (11), and each of the second parts (10b) comprises a fan-shaped sector portion and the intermediate connecting portion (15) located radially inward of the sector portion.

9. The motor rotor according to any one of claims 1 to 8, characterized in that: The motor rotor comprises a plurality of rotor subunits (U), the plurality of rotor subunits (U) are stacked in the axial direction, and the magnetic steels arranged in at least two adjacent rotor subunits (U) are not aligned in the circumferential direction.

10. A motor, characterized in that: The invention comprises a motor rotor according to any one of claims 1 to 9.

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