Rotor for electric machine and method for producing rotor for electric machine

Abstract

The invention relates to a rotor for an electric machine, comprising: a lamination stack formed from stacked electrical sheets with magnet slots arranged therein; a plurality of magnets, at least one of which is inserted into each of the magnet grooves; a plurality of free spaces each delimited by the magnets inserted into one of the magnet slots and the lamination stack; a first end plate which is arranged on the axial side of the laminated core and has at least one filling opening, in which at least one distributor structure is formed on the side facing the laminated core, and a distributor structure which is in fluid connection with the at least one filling opening and by means of which fluid can be conducted from the at least one filling opening to at least one of the free spaces, at least one fastening structure is provided in the first end plate on the side facing the lamination stack for each of the magnets, which fastening structure is in mechanical contact with the magnets and fastens the magnets in the magnet grooves. Relates to a method for manufacturing a motor rotor.

Description

Technical Field

[0001] The invention relates to a rotor for an electric machine and a method for producing a rotor for an electric machine. Background Art

[0002] The production of rotors for permanently excited synchronous machines (permanenterregte Synchronmaschinen, sometimes called permanent magnet synchronous machines) often involves casting (Verguss, sometimes called potting) the magnets arranged in the lamination stack. By this process, the magnets can be securely fixed. In addition, such rotors typically include end disks or end plates at both end faces of the rotor, which have other functions, such as providing balancing weights. If there is a corresponding distributor structure in the disk, the casting material (Vergusssmasse, sometimes called potting material) can be guided from a small number of injection points per pole through the end disk into all magnet slots (Magnettaschen).

[0003] DE 10 2021 206 832 A1 discloses a rotor for an electric machine, comprising: a lamination stack formed of stacked electric sheets with magnet slots arranged therein; a plurality of magnets, at least one of which is inserted into each of the magnet slots; a plurality of free spaces, each of which is bounded by a magnet inserted into one of the magnet slots and the lamination stack; a first end plate arranged at an axial side of the lamination stack, with a first fill-in opening, through which a first free space in the free space is exposed; and a second end plate arranged at the opposite axial side of the lamination stack. Furthermore, an electric machine with a rotor, a vehicle with an electric machine and a method for producing a rotor are described.

[0004] Further rotors are known, for example, from US 2022 / 0 345 013 A1, EP 4 016 818 A1, EP 4 016 819 A1, DE 10 2021 206 833 A1, DE 10 2021 206 834 A1, DE 10 2021 206 836 A1, WO 2023 / 051608 A1 and WO 2023 / 051584 A1. Summary of the invention

[0005] The object of the present invention is to improve a rotor for an electric machine and a method for producing a rotor for an electric machine, in particular with regard to secure fixing of the magnets during casting.

[0006] This object is achieved according to the invention by a rotor and a method. Advantageous embodiments of the invention result from the invention.

[0007] In particular, a rotor for an electric motor is created, comprising: a lamination stack formed by stacked electric sheets, having magnet slots arranged therein; a plurality of magnets, at least one of which is inserted into each of the magnet slots; a plurality of free spaces, which are respectively limited by the magnet inserted into one of the magnet slots and the lamination stack; a first end plate arranged at the axial side of the lamination stack, having at least one filling opening, wherein at least one distributor structure is constructed in the first end plate on the side facing the lamination stack, the distributor structure is in fluid connection with the at least one filling opening and can guide fluid from the at least one filling opening to at least one of the free spaces by means of the distributor structure, and wherein at least one fixing structure is respectively provided for each of the magnets in the first end plate and / or on the side facing the lamination stack, the fixing structure is in mechanical contact with the magnet and fixes the magnet in the magnet slot.

[0008] In addition, a method for manufacturing a rotor for an electric motor is provided in particular, wherein a lamination stack is formed by stacked electric laminations, magnet slots are arranged in the lamination stack, at least one magnet is inserted into each of the magnet slots, a free space is retained which is bounded by the magnet inserted into one of the magnet slots and the lamination stack, a first end plate with at least one filling opening is arranged on an axial side of the lamination stack, at least one distributor structure is constructed in the first end plate on the side facing the lamination stack, the distributor structure is in fluid connection with the at least one filling opening and can guide fluid from the at least one filling opening to at least one of the free spaces by means of the distributor structure, and at least one fixing structure is provided for each of the magnets on the side facing the lamination stack, the fixing structure is brought into mechanical contact with the magnet and fixes the magnet in the magnet slot, the magnet inserted into the magnet slot is cast through the at least one filling opening with casting material introduced into the free space via the at least one distributor structure.

[0009] The rotor and the method make it possible to securely hold the magnets arranged in the magnet slots in place in the magnet slots during the casting process. Slippage caused by the casting material can thereby be prevented. In particular, the effect that the support surface of the magnets at the first end plate is reduced due to the cavity of the at least one distributor structure in conventional types of construction can be counteracted. The at least one fixing structure counteracts this and allows the magnets to be securely fixed in the magnet slots. By securely fixing the magnets during the casting process, the magnets continue to remain in the set position. A reduction in the effectiveness of the magnets caused by slippage and the accompanying reduction in torque can thereby be avoided.

[0010] In addition to the first end plate, in particular a second end plate can be provided on the opposite axial side of the laminated core. The second end plate can be designed like the first end plate, so that the magnets are also fixed or to be fixed on the opposite axial side.

[0011] The first end plate and / or—if present—the second end plate are designed in particular as round balancing weights or balancing disks.

[0012] It may be provided that at least a part of the distributor structure is alternatively designed and / or used for the passage of a coolant for cooling the rotor.

[0013] In one embodiment, it is provided that the at least one fixing structure is formed in and / or at the at least one distributor structure. As a result, the magnet can be fixed at the position where the casting material is introduced and distributed and where there is the greatest risk of position changes. The at least one fixing structure can, for example, include at least one projection, lug and / or element extending and / or protruding within the at least one distributor structure.

[0014] In one embodiment, it is provided that the at least one fastening structure is formed as part of the at least one distributor structure. In particular, the production of the first end plate can be simplified or will be simplified because the at least one fastening structure can be formed in the casting mold as part of the at least one distributor structure.

[0015] In one embodiment, it is provided that the at least one fixing structure is designed as part of an edge that circumscribes the at least one distributor structure. In particular, the circumscribed edge can have at least one fixing element that projects into the cavity of the at least one distributor structure. In particular, it can be provided that the at least one fixing structure has fixing elements that are arranged and / or configured in the edge region of the distributor structure and are in mechanical contact with a side section of the magnet on the end face side facing the first end plate.

[0016] In one embodiment, it is provided that the at least one distributor structure and the at least one fixed structure have a structure and / or a mutual arrangement that is optimized for flow and distribution with respect to the fluid flowing into the at least one distributor structure through the at least one filling opening. It is thereby possible to prevent, in particular, the fluid flowing in through the filling opening from being obstructed in terms of flow by the fixed structure. A structure that is optimized for flow and distribution should here in particular mean that the fluid flowing in through the inflow opening can reach a target area (in particular free space) on a direct and / or shortest path within the distributor structure, that is to say that in particular within the distribution structure, no forced reversal is made on the path from the filling opening to the target area. For example, it can be provided that, by arranging (multiple) fixed structures at the edge of the at least one distributor structure and / or extending from the edge, a flow behind the (multiple) fixed structure(s) and / or a flow completely around the (multiple) fixed structure(s) is avoided.

[0017] In one embodiment, it is provided that the at least one fixing structure ends in height with a flat surface of the side of the first end plate facing the laminated core. This simplifies the production of the first end plate in particular, since no structures extending beyond the flat surface need to be created.

[0018] In one embodiment, it is provided that the at least one fixing structure has a projection beyond the flat surface of the side of the first end plate facing the laminated core. As a result, the magnet can be pressed into the magnet slot, so that the magnet can be designed to be smaller than the magnet slot. As a result, the position of the magnet can be better preset.

[0019] In one embodiment, it is provided that the at least one fixing structure is constructed in such a way that the contact surface between the at least one fixing structure and the magnet is minimized or maximized. In the case of minimization, the casting process can also be extended to the surface of the magnet at the end face side facing the first end plate. In the case of maximization, on the other hand, in particular the entire surface at the end face side facing the first end plate can be used for fixing, whereby the fixing can be designed more reliably. One extreme is a point-shaped contact surface, which has the advantage that the magnet can also be cast over a large area at its end face side. The other extreme is that the at least one fixing structure is in complete contact with the end face side of the magnet.

[0020] In one embodiment, it is provided that the first end plate has at least one engagement element on the side facing the laminated core, which engages in an opening provided for the purpose of angular orientation of the laminated core. As a result, the first end plate can be arranged on the laminated core in a simple manner in a predetermined angular orientation. This can particularly simplify and speed up the arrangement steps during the manufacture of the rotor.

[0021] In one embodiment, it is provided that at least one of the magnets arranged at the axial side of the laminated core has a projection which protrudes from the laminated core, wherein the first end plate has a corresponding recess into which the projection of the at least one magnet engages and thereby determines the angular position of the first end plate relative to the laminated core. As a result, the first end plate can be arranged at the laminated core in a simple manner in a predetermined angular orientation. As a result, the arrangement step during the manufacture of the rotor can be particularly simplified and accelerated. This embodiment can also be used in combination with the embodiments described above.

[0022] Furthermore, in particular an electric machine is provided, which comprises at least one rotor according to one of the described embodiments. Also provided is a vehicle, in particular an electric vehicle or a hybrid vehicle, which comprises at least one rotor and / or an electric machine according to one of the described embodiments.

[0023] Further features of the embodiment of the method are derived from the description of the embodiment of the rotor. The advantages of the method are the same as in the embodiment of the rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be explained in detail below with reference to the accompanying drawings according to preferred embodiments.

[0025] Figure 1 A schematic diagram for explaining one embodiment of a rotor is shown (a view with a first end plate);

[0026] Figure 2 A schematic diagram for illustrating this embodiment of the rotor is shown (view without the first end plate);

[0027] Figure 3a , 3b A schematic diagram of a first end plate for illustrating one embodiment of a rotor is shown;

[0028] Figure 4a , 4b Shown to illustrate the Figure 3a and 3b A schematic diagram of an embodiment of a rotor shown in FIG.

[0029] Figure 5a , 5b A schematic diagram of a first end plate is shown for illustrating another embodiment of a rotor;

[0030] Figure 6a , 6b A schematic diagram is shown for illustrating the further embodiment of the rotor;

[0031] Figure 7 shows a schematic diagram for illustrating a further embodiment of a rotor;

[0032] Figure 8 A schematic diagram is shown for illustrating a further embodiment of a rotor;

[0033] Fig. 9 A schematic flow chart is shown to illustrate an embodiment of the method. DETAILED DESCRIPTION

[0034] Figure 1 , 2 , 3a, 3b, 4a and 4b show schematic diagrams for explaining an embodiment of the rotor 1. The rotor 1 comprises a lamination stack 3 formed by stacked electric sheets 2 (not all of which are provided with their own reference numerals for the sake of clarity) with magnet slots 4 arranged therein (not all of which are provided with their own reference numerals for the sake of clarity). A magnet 5 is inserted into each of the magnet slots 4 (not all of which are provided with their own reference numerals for the sake of clarity). The rotor 1 has a plurality of free spaces 6, which are respectively bounded by a magnet 5 inserted into one of the magnet slots 4 and the lamination stack 3.

[0035] A first end plate 8 with a plurality of fill-in openings 9 is arranged on the axial side 7 of the core stack 3. At least one distributor structure 11 ( Figure 3b and 4b ), which is in fluid connection with the at least one filling opening 9 and by means of which the fluid can be guided from the at least one filling opening 9 to at least one of the free spaces 6. In the illustrated embodiment, the distributor structure 11 has in particular a triangular shape, wherein the respective filling opening 9 is constructed at a (in particular rounded) corner of the triangle pointing toward the center of the first end plate 8 and the other two (in particular rounded) corners of the triangle point outward or coincide with the periphery of the first end plate 8. The sides of the triangle connecting the two corners are rounded and follow the annular periphery of the first end plate 8. In particular, the distributor structure 11 forms a recess in the first end plate 8 on the side facing the lamination stack 3. The fluid is guided from the filling opening 9 to the free space 6 by the distributor structure 11 and can thereby contribute to the filling of the free space 6.

[0036] In the first end plate 8, at the side 10 facing the laminated core 3, there is provided for each of the magnets 5 (not all of them are provided with their own reference numerals for the sake of clarity), which fixing structure is in mechanical contact with the magnet 5 and fixes the magnet 5 in the magnet slot 4. In particular, it is provided that the (at least one) fixing structure 12 is constructed in and / or at one of the at least one distributor structure 11. In the illustrated embodiment, two fixing structures 12 are constructed in each distributor structure 11, which are arranged in particular at the center of two sub-triangles, which are produced by bisecting the triangular distributor structure 11 at an axis of symmetry extending through the fill-in opening 9. With respect to the recessed portion of the distributor structure 11, the respective fixing structure 12 in particular forms a projection or a bulge, the poles of which end at the same height with the flat upper side of the first end plate 8. As can be seen in particular in Figure 4b As can be seen in FIG. 1 , the fixing structures 12 push the magnets 5 into the magnet grooves 4 of the laminated core 3 in the axial direction and thereby prevent the magnets 5 from moving during the pouring of the free space 6. The magnets 5 can therefore not slide during the pouring but remain fixed in their respective positions. In this embodiment, it is particularly provided that each of the two fixing structures 12 is formed as part of the distributor structure 11.

[0037] Figure 5a , 5b , 6a and 6b show further embodiments 1 for illustrating the rotor (see also Figure 1 and 2). The rotor 1 is designed substantially as in the embodiment described above. The same reference numerals represent the same features and terms. In this embodiment, it is particularly provided that each of the two fixing structures 12 is constructed as a part of the distributor structure 11.

[0038] Furthermore, it is particularly provided that the at least one fixing structure 12 is constructed as part of an edge 13 that surrounds the at least one distributor structure 11. In the illustrated embodiment, the triangular shape of the distributor structure 11 has two tongue-shaped, in particular V-shaped protrusions 14 at the curved sides placed at the periphery of the first end plate 8, which extend into the distributor structure 11 and in particular limit the distributor structure 11 in the direction of the periphery. The tongue-shaped, in particular V-shaped protrusions 14 respectively form fixing structures 12 that push the magnets 5 into the respective magnet slots 4 and fix them there. Alternatively, the shape of the protrusions 14 can also be U-shaped.

[0039] In particular, it can be provided that tongue-shaped, in particular V-shaped or U-shaped projections 14 are provided in a certain number and arranged in such a way that different variants of the laminated core can cooperate with the same (first) end plate 8. For example, it can be provided that the number of projections 14 is selected and the projections 14 are arranged at the circumferential edge of the distributor structure 11 in such a way that two magnets 5 can be used in one alternative or three magnets 5 and the associated magnet slots 4 can be used in another alternative for each of the distributor structures 11 in the laminated core 3. In this way, the (first) end plate 8 can be used more flexibly. In particular, then, for example, at least five projections 14 are arranged at the circumferential edge 13, wherein the projections 14 are then also arranged in particular at other (inwardly directed) sides of the triangle.

[0040] It can be provided that the at least one distributor structure 11 and the at least one fixing structure 12 have a structure and / or a mutual arrangement that is optimized for flow and distribution with respect to the fluid flowing through the at least one filling opening 9 into the at least one distributor structure 11. This can be achieved in particular Figure 5b The distributor structure 11 is optimized in such a way that the fluid is mainly directed to the two outer corners of the triangle, without being able to flow in the same direction as, for example, in the Figure 3b In the embodiment shown in FIG. 1 , it is possible to flow behind the fixing structure 12 or around the fixing structure 12 .

[0041] It can be provided that the at least one fixing structure 12 ends in height with a flat surface of the side 10 of the first end plate 8 facing the laminated core 3. This corresponds to Figure 4b and 6b The embodiment shown in FIG.

[0042] It can be provided that the at least one fixing structure 12 has a projection beyond the planar surface of the side 10 of the first end plate 8 facing the laminated core 3 .

[0043] It can be provided that the at least one fastening structure 12 is designed in such a way that the contact surface between the at least one fastening structure 12 and the magnet 5 is minimized or maximized. The two extremes are then point-shaped contact surfaces and full-surface contact surfaces.

[0044] It can be provided that the first end plate 8 has at least one engagement element 15 on the side 10 facing the laminated core 3, which engages in an opening 16 provided for this purpose in the laminated core 3 for angular orientation. Figure 7 Shown in.

[0045] It can be provided that at least one of the magnets 5 arranged on the axial side 7 of the laminated core 3 has a projection 17 which protrudes from the laminated core 3, wherein the first end plate 8 has a corresponding recess 18, into which the projection 17 of the at least one magnet 5 engages and thereby determines the angular position of the first end plate 8 relative to the laminated core 3. This embodiment is schematically shown in Figure 8 Shown in.

[0046] It can also be provided that the two embodiments described last above are combined with one another.

[0047] In all embodiments, it is provided in particular that a second end plate 19 ( Figure 1 ). The second end plate 19 is designed in particular like the first end plate 8 .

[0048] Fig. 9 A schematic flow chart is shown for illustrating one specific embodiment of a method for producing a rotor for an electric machine.

[0049] In measure 100, a laminated core is formed from stacked electric laminations, in which magnet slots are arranged. The magnet slots are previously introduced into the electric laminations, for example by punching them in.

[0050] In measure 101 , at least one magnet is inserted into each of the magnet slots, wherein a free space remains which is delimited by the magnet inserted into the magnet slot and the laminated core. The free space is in particular designed as part of the magnet slot.

[0051] In measure 102, a first end plate with at least one filling opening is arranged at an axial side of the lamination stack, wherein at least one distributor structure is constructed in the first end plate on the side facing the lamination stack, the distributor structure is in fluid connection with the at least one filling opening and can guide the fluid from the at least one filling opening to at least one of the free spaces by means of the distributor structure, and wherein at least one fixing structure is respectively provided for each of the magnets on the side facing the lamination stack in the first end plate, the fixing structure is brought into mechanical contact with the magnet and fixes the magnet in the magnet slot. In particular, a plurality of distributor structures with at least one filling opening and at least one fixing structure are provided for each of the magnets. The distributor structure and the fixing structure can be constructed, for example, during the manufacture of the first end plate, for example in a casting process. Alternatively, the fixing structure and the distributor structure can also be milled out.

[0052] In particular, measure 102 is implemented in the same way for the second end plate on the side of the laminated core opposite the axial side.

[0053] The magnet inserted into the magnet slot is cast through the at least one filling opening in measure 103 with the casting material introduced into the free space via the at least one distributor structure. The fixing structure ensures that the magnet remains in place during casting.

[0054] Other embodiments have been described above with respect to the rotor.

[0055] Reference Numbers List

[0056] 1 Rotor

[0057] 2. Electric sheet

[0058] 3 lamination pack

[0059] 4 Magnet slots

[0060] 5 Magnets

[0061] 6 Free Space

[0062] 7 Axial side

[0063] 8 First end plate

[0064] 9 Fill in the opening

[0065] 10 Side facing the lamination stack

[0066] 11 Allocator Structure

[0067] 12 Fixed structure

[0068] 13 Surrounding Edges

[0069] 14 Protrusion

[0070] 15 Jointing elements

[0071] 16 Opening

[0072] 17 Protrusion

[0073] 18 Blank space

[0074] 19 Second end plate

[0075] 20 Opposite axial side

[0076] 100-103 Methods of action

Claims

1. A rotor (1) for an electric motor, comprising: A lamination stack (3) formed of stacked electric sheets (2) with magnet slots (4) arranged therein, a plurality of magnets (5), at least one of which is inserted into each of the magnet slots (4), a plurality of free spaces (6) which are respectively bounded by the magnet (5) inserted into one of the magnet slots (4) and the lamination stack (3), a first end plate (8) arranged at an axial side (7) of the lamination stack (3) and having at least one filling opening (9), wherein at least one distributor structure (11) is formed in the first end plate (8) on the side (10) facing the laminated core (3), the distributor structure being in fluid connection with the at least one filling opening (9) and by means of which fluid can be conducted from the at least one filling opening (9) to at least one of the free spaces (6), and At least one fixing structure (12) is provided for each of the magnets (5) in the first end plate (8) and / or on the side (10) facing the lamination stack (3), the fixing structure being in mechanical contact with the magnet (5) and fixing the magnet (5) in the magnet slot (4).

2. The rotor (1) according to claim 1, characterized in that The at least one fastening structure (12) is formed in and / or on the at least one distributor structure (11).

3. The rotor (1) according to claim 1 or 2, characterized in that The at least one fixing structure (12) is configured as a part of the at least one distributor structure (11).

4. A rotor (1) according to any one of the preceding claims, characterised in that The at least one fixing structure (12) is configured as part of a rim (13) surrounding the at least one distributor structure (11).

5. A rotor (1) according to any one of the preceding claims, characterised in that The at least one distributor structure (11) and the at least one fixing structure (12) have a structure and / or a mutual arrangement which is flow- and distribution-optimized with respect to a fluid flowing through the at least one filling opening (9) into the at least one distributor structure (11).

6. A rotor (1) according to any one of the preceding claims, characterised in that The at least one fixing structure (12) ends in height with a flat surface of the side (10) of the first end plate (8) facing the laminated core (3).

7. A rotor (1) according to any one of the preceding claims, characterised in that The at least one fixing structure (12) has a protrusion beyond a flat surface of a side (10) of the first end plate (8) facing the lamination stack (3).

8. A rotor (1) according to any one of the preceding claims, characterised in that The at least one fixing structure (12) is designed in such a way that a contact surface between the at least one fixing structure (12) and the magnet (5) is minimized or maximized.

9. A rotor (1) according to any one of the preceding claims, characterised in that The first end plate (8) has at least one engagement element (15) on the side (10) facing the laminated core (3), which engages for angular alignment into an opening (16) of the laminated core (3) provided for this purpose.

10. A method for producing a rotor (1) for an electric machine, A lamination stack (3) is formed by stacked electric sheets (2), and a magnet slot (4) is arranged in the lamination stack. wherein at least one magnet (5) is inserted into each of the magnet slots (4), wherein a free space (6) is retained which is bounded by the magnet (5) inserted into one of the magnet slots (4) and the lamination stack (3), respectively, wherein a first end plate (8) with at least one filling opening (9) is arranged on an axial side (7) of the lamination stack (3), wherein at least one distributor structure (11) is constructed in the first end plate (8) on the side (10) facing the lamination stack (3), the distributor structure being in fluid connection with the at least one filling opening (9) and by means of which fluid can be conducted from the at least one filling opening (9) to at least one of the free spaces (6), and wherein at least one fixing structure (12) is provided for each of the magnets (5) on the side (10) facing the lamination stack (3), the fixing structure being brought into mechanical contact with the magnet (5) and fixing the magnet (5) in the magnet slot (4), The magnet (5) inserted into the magnet slot (4) is cast through the at least one filling opening (9) with a casting material introduced into the free space (6) via the at least one distributor structure (11).

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