Rotor stacks, rotor stack cores, rotors, electromechanical and vehicle

Abstract

The present invention relates to a rotor lamination (1) for a rotor (100) of an electric machine (111), the rotor lamination (1) comprising a plurality of through openings (2a-2f), each of which is provided for forming a magnet pocket (102) of a rotor lamination core (101), the rotor lamination (1) having a first long side (4) and a second long side (5) parallel to the first long side (4). In pairs of circumferentially adjacent through-openings (2a-2f) which are axially symmetrical with respect to the radial axis of symmetry (3), the ends (6, 7) of the long sides (4, 5) which face towards the axis of symmetry (3) are interconnected by an outer contour (8) of each through-opening (2a-2f) of each pair, said outer contour (8) extending from the first long side (4) in a direction away from both long sides (4, 5) and, along the direction of extension defined from the first long side (4) to the second long side (5), as far as the second long side (5), over an arcuate portion (12) curved towards the axis of symmetry (3).

Description

Technical Field

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[0001] The present invention relates to a rotor laminate for a rotor of an electric machine, comprising a plurality of passage openings, each of the plurality of passage openings being intended to form a magnet pocket of a rotor lamination core, having a first longitudinal side and a second longitudinal side parallel to the first longitudinal side, and for pairs of passage openings that are adjacent in the circumferential direction and symmetric with respect to a radial symmetry axis, the outer contours of the respective passage openings of each pair connect the ends facing the symmetry axis of the longitudinal sides to each other. <000000~5>

[0002] Furthermore, the present invention relates to a rotor lamination core for an electric machine, a rotor for an electric machine, an electric machine for a vehicle, and a vehicle.

Background Art

Prior Art Documents

Patent Documents

Patent Document 1

Summary of the Invention

[0006] Therefore, the present invention aims to identify a method for reducing mechanical stress in the regions of opposing outer contours of symmetrical magnetic pockets.

[0007] According to the present invention, this objective is achieved by a rotor laminate for an electromechanical rotor, comprising a number of passage openings, each of which is intended to form a magnet pocket of a rotor laminate core, having a first longitudinal side and a second longitudinal side parallel to the first longitudinal side, and for pairs of passage openings that are adjacent in the circumferential direction and axially symmetric with respect to the radial axis of symmetry, the outer contour of each passage opening in each pair connects the ends of the longitudinal side facing the axis of symmetry with respect to each other, and the outer contour extends from the first longitudinal side in a direction diverged from the two longitudinal sides, and extends beyond an arc-shaped portion curved toward the axis of symmetry to the second longitudinal side, along the direction of the spread defined from the first longitudinal side to the second longitudinal side.

[0008] Accordingly, the rotor laminate according to the present invention for an electromechanical rotor comprises a number of passage openings. Each of the passage openings is intended to form a magnet pocket of the rotor laminate core. Each of the passage openings has a first longitudinal side and a second longitudinal side parallel to the first longitudinal side. For pairs of passage openings that are adjacent in the circumferential direction and are axially symmetric with respect to the radial axis of symmetry, the outer contours of each passage opening in each pair connect the ends of the longitudinal sides that face the axis of symmetry. The outer contour extends from the first longitudinal side in a direction diverged from the two longitudinal sides. The outer contour extends beyond an arc-shaped portion curved toward the axis of symmetry along the direction of the spread defined from the first longitudinal side to the second longitudinal side.

[0009] The present invention is based on the knowledge that high mechanical stress is formed in such regions of the outer contour, where the notch effect increases as the radius decreases, so such regions produce a high notch effect because their radii are small. According to the present invention, since the outer contour first extends away from the longitudinal side and then extends back to the second longitudinal side beyond the arcuate portion, a larger value of the minimum radius of the arcuate portion can be achieved in the web region between the outer contours of each pair of passage openings.

[0010] Therefore, compared to conventional rotor laminates in which the outer contour does not initially extend in directions diverging from the two longitudinal sides, the local maximum of mechanical stress in the web region can be advantageously reduced. Assuming the same mechanical stress resistance capability of the rotor laminate, the rotor laminate can withstand higher volume forces, firstly, thanks to higher rotational speeds in particular, and secondly, higher surface forces, secondly, thanks to the use of stronger and heavier permanent magnets in particular. Alternatively, assuming the same surface forces and physical forces are generated, a more cost-effective material with lower stress resistance can be used. In this case, the above-described geometric shape of the outer contour can be adopted, taking into account the numerous known shapes and arrangements of magnet pockets.

[0011] The rotor laminate is typically formed from a soft magnetic material. The rotor laminate conveniently has a central cutout for fixing onto the shaft, particularly by press fitting. The web (or bridge, in other words) of the rotor laminate is typically formed between the outer contours of each pair of passage openings. The rotor laminate preferably has at least four, preferably at least six pairs, of passage openings arranged equidistant in the circumferential direction.

[0012] The distance between the vertical sides is generally less than the length of each vertical side. The ends of the vertical sides are typically located substantially on a straight line perpendicular to the vertical side. The permanent magnet preferably extends inward into the magnet pocket or passage opening in the direction of the axis of symmetry, up to the ends of the vertical sides. Thus, magnets with a rounded rectangular cross-section are typically used, and the vertical sides of the permanent magnet extend parallel to the vertical sides of the passage opening. The outer contour typically defines the boundaries of the air pockets within the magnet pocket. Additional air pockets can be formed at the ends of the vertical sides opposite to the outer contour.

[0013] In the rotor laminate according to the present invention, the arc-shaped portion has a first lower portion and a second lower portion, and it is preferable that the minimum radius of the first lower portion is larger than the minimum radius of the second lower portion. As a result, the maximum mechanical stress can be advantageously shifted to the region of the second lower portion having a smaller minimum radius.

[0014] It is preferable that the first lower portion is located in front of the second lower portion with respect to the direction of spread. This allows the outer contour to be guided in the direction of the second longitudinal edge, first along an arc portion having a larger minimum radius and therefore a smaller notch effect, to the point of the minimum distance between the outer contours of the pair of passage openings, and then along the second lower portion having a smaller minimum radius.

[0015] In principle, the lower parts can be elliptical or have some other arc-shaped configuration. However, it is particularly preferable if the first lower part is in the form of a circular arc, and / or the second lower part is in the form of a circular arc. In this case, the minimum radius of each lower part is a constant value of the radius of the corresponding lower part.

[0016] The second sub-part preferably directly adjacent to the first sub-part. The first sub-part preferably transitions smoothly into the second sub-part. The point of minimum distance between the outer contours of each pair of passage openings is preferably located within the second sub-part.

[0017] The rotor laminate according to the present invention can further be provided in which the outer contour has a straight portion between the end of the first longitudinal side and the arcuate portion. In order to achieve a desired increase in the size of the minimum radius of the arcuate portion, the outer contour can be guided in this manner to move away from the two longitudinal sides by a short distance.

[0018] In a particularly preferred development, a line extending along the first longitudinal side and a line extending along the linear portion intersect at a substantially right angle, and a projection of the angle extends along the first longitudinal side and the linear portion. Thanks to the substantially right-angled profile, firstly, when the angle is substantially greater than 90°, an undesirable reduction in the size of the air pocket can be prevented, and secondly, when the angle is substantially greater than 90°, the negative effects of the magnetic field line profile can be avoided. In particular, “substantially right-angled” is intended to be understood to mean an angle range of 85° to 95°, preferably 87° to 93°, and particularly preferably 89° to 91°. However, the angle is even more preferably 90° at most.

[0019] With regard to manufacturing, it is advantageous in principle if the transition between the first vertical side and the straight portion and / or the transition between the straight portion and the curved portion has a rounded configuration, particularly having a radius smaller than the minimum radius of the second lower portion.

[0020] According to a first preferred modification improvement of the rotor laminate according to the present invention, an arc-shaped portion terminates between two straight lines, the outer contour has a projection on the other side of the arc-shaped portion with respect to the direction of spreading, and the longitudinal side extends along the two straight lines, the projection preferably extending in a straight line. Such projections facilitate the positioning of permanent magnets within passage openings during manufacturing. The projections are configured to prevent movement of permanent magnets along the longitudinal side.

[0021] With regard to manufacturing, it can also be advantageously provided here that the transition between the arcuate portion and the protruding portion and / or the transition between the protruding portion and the second longitudinal side have a rounded configuration, particularly having a curve radius smaller than the second curve radius.

[0022] According to the alternative deformation improvement of the rotor laminate according to the present invention, the arcuate portion is provided to smoothly transition to the second longitudinal side, or to a transition portion of the outer contour that extends toward the second longitudinal side in a manner that is divergent from the two longitudinal sides. Thus, the arcuate portion can pass directly toward the second longitudinal side, or even beyond the straight line along which the second longitudinal side extends, and as a result, the minimum radius of the arcuate portion, and further increases, are possible. However, such a configuration of the outer contour generally requires that the permanent magnets inserted into the passage openings must be kept active when they are fixed in the magnet pockets.

[0023] In an advantageous development of the rotor laminate according to the present invention, the end of the first longitudinal side is located further inward radially than the end of the second longitudinal side. This has the effect that the outer contour initially extends radially inward in order to achieve a sufficient width of the web.

[0024] In the rotor stack according to the invention, it is provided in a preferred improvement that the pair of passage openings are arranged in a V-shape opening radially outward. Thus, the number of rotor poles corresponding to the number of pairs of passage openings can be advantageously formed in this way. The angle is typically less than 90°, preferably less than 75°, particularly preferably less than 65°, and / or greater than 20°, preferably greater than 45°, particularly preferably greater than 50°, where the protrusion of the angle extends along the symmetry axis and the first vertical side.

[0025] In a preferred development, the double V-arrangement of the permanent magnets is realized when for each pair the rotor stack has a further pair of passage openings arranged in an outwardly opening V-shape and axially symmetric with respect to the symmetry axis. The vertical sides of the further passage openings are typically shorter than the vertical sides of the passage openings. Furthermore, all the foregoing statements made with respect to the passage openings can be applied to the further passage openings.

[0026] Alternatively or additionally, the delta arrangement of the passage openings can be realized when for each pair the rotor stack has a further passage opening extending perpendicular to the symmetry axis.

[0027] In a preferred improvement, it is provided that the radially innermost point of the respective further passage opening is located further radially outward than the radially innermost point of the passage opening.

[0028] It is further possible to form each pair of passage openings from two passage openings directly adjacent in the circumferential direction, the center of the vertical sides being perpendicular radially. In this case, each pair of passage openings typically forms a magnet pocket for two adjacent rotor poles.

[0029] The object on which the present invention is based is further achieved by a rotor laminate core for an electromechanical device, comprising a plurality of rotor laminates according to the present invention, arranged in a manner that is stacked in layers in the axial direction. The rotor laminates are conveniently arranged such that magnet pockets form receiving spaces for permanent magnets, and the receiving spaces are continuous in the axial direction. The rotor laminates are typically electrically insulated from one another. It is even more preferable that the rotor laminates are connected to one another in a manner fixed in rotation, for example by integral joining, preferably by weld seams formed on the side surfaces of the rotor laminate core.

[0030] The objectives on which the present invention is based are further achieved by a rotor for an electromechanical device, comprising a rotor laminated core according to the present invention, wherein permanent magnets are arranged in magnet pockets. It is possible to place exactly one permanent magnet, or multiple permanent magnets arranged in an axially layered manner, in each magnet pocket. The permanent magnets are typically placed in the magnet pockets.

[0031] The object on which the present invention is based is further achieved by an electric machine for a vehicle comprising a stator and a rotor according to the present invention, wherein the rotor is rotatably mounted inside the stator. The electric machine according to the present invention may be an electric motor in particular. The electric machine according to the present invention is preferably a three-phase machine, in particular a permanently excited synchronous machine.

[0032] Furthermore, the objectives on which the present invention is based are achieved by a vehicle equipped with an electromechanism according to the present invention configured to drive the vehicle. Thus, the vehicle according to the present invention may be a battery-electric vehicle (BEV) or a hybrid vehicle.

[0033] Further advantages and details of the present invention can be found in the exemplary embodiments described below and based on the drawings, the latter of which are schematic diagrams. [Brief explanation of the drawing]

[0034] [Figure 1]This is a plan view of a first exemplary embodiment of a rotor laminate according to the present invention. [Figure 2] Figure 1 shows a detailed view of the sectors of the rotor stack. [Figure 3] Figure 1 is a detailed view of the outer contour of the passage opening in the rotor stack shown. [Figure 4] This is a detailed view of the outer contour according to a second exemplary embodiment of the rotor laminate according to the present invention. [Figure 5] This is a cross-sectional view of an exemplary embodiment of a rotor according to the present invention, which has an exemplary embodiment of the rotor laminated core according to the present invention. [Figure 6] This is a basic diagram of an exemplary embodiment of a vehicle according to the present invention, which has an exemplary embodiment of an electrical machine according to the present invention. [Modes for carrying out the invention]

[0035] Figures 1 and 2 show a plan view of a first exemplary embodiment of the rotor stack 1, and Figure 2 is a detailed view of a sector of the rotor stack 1.

[0036] The rotor laminate 1 is provided with a number of passage openings 2a to 2f, each of which is intended to form a magnet pocket of the rotor laminate core. In this exemplary embodiment, there are six pairs of passage openings 2a to 2f that are directly adjacent in the circumferential direction. The passage openings 2a to 2f forming each pair are axially symmetric with respect to each other with respect to the radial axis of symmetry 3.

[0037] In particular, as can be seen from Figure 2, which shows a typical passage opening 2a, each passage opening 2a to 2f has a first vertical side 4 and a second vertical side 5 parallel to the first vertical side. The first vertical side 4 has an end 6 facing the axis of symmetry 3, and the second vertical side 5 has an end 7 facing the axis of symmetry 3. The ends 6 and 7 are located on a straight line extending perpendicular to the vertical sides 4 and 5. The ends 6 and 7 are connected to each other by an outer contour 8, and as a result, a web 9 (see Figure 1) is formed between the outer contours 8 of each pair of passage openings 2a to 2f.

[0038] Figure 3 shows a detailed view of the outer contour 8 of the passage opening 2a shown in Figure 2.

[0039] As shown, the outer contour 8 extends from the end 6 of the first longitudinal side 4 in a direction diverged from the two longitudinal sides 4, 5, represented by the arrow 10, and beyond the arc-shaped portion 12, identified by the dashed boundary lines 11a, 11b, to the second longitudinal side 5 or its end 7. The direction of the outward spread of the outer contour 8 is defined here from the first longitudinal side 4 to the second longitudinal side 5.

[0040] The outer contour 8 first has a straight section 13 between the end 6 of the first vertical side 4 and the arc-shaped section 12. The straight section 13 extends along a straight line 14 that is perpendicular to the straight line 15, in a direction diverged from the two vertical sides 4 and 5 (see arrow 10), where the first vertical side 4 extends along the straight line 15. Here, the transition section is formed in a rounded manner between the first vertical side 4 and the straight section 13, and between the straight section 13 and the arc-shaped section 12.

[0041] The arc-shaped portion 12 has a first lower portion 16 and a second lower portion 17, the first lower portion 16 being located in front of the second lower portion 17 with respect to the direction of spread. The lower portions 16 and 17 are directly adjacent to each other, as defined by the boundary line 11c. Each of the lower portions 16 and 17 is in the form of an arc of a circle, with the radius of the first lower portion 16 being greater than the radius of the second lower portion 17. Here, the lower portions 16 and 17 smoothly transition toward each other at the boundary line 11c.

[0042] The outer contour 8 has a projecting portion 18 extending in a straight line on the other side of the arc-shaped portion 12. The projecting portion 18 is located between a straight line 15 and a straight line 19, where the second vertical side 5 extends along the straight line 19. The projecting portion 18 extends perpendicular to the straight line 19. The transition between the arc-shaped portion 12 and the projecting portion 18, and between the projecting portion 18 and the second vertical side 5, is formed with a rounded structure.

[0043] Referring to Figure 1, it can be seen that in the rotor stack 1, a pair of passage openings 2a to 2f are arranged in a V-shape that opens radially outward. In this case, the lines 15 and 19 (see Figure 3) enclose an angle of approximately 58° with the axis of symmetry 3, where the vertical sides 4 and 5 extend along these lines 15 and 19. For each pair of passage openings 2a to 2f, a further passage opening 21 is provided, which is arranged in a V-shape that opens outward and is axially symmetric with respect to the axis of symmetry 3. The further passage openings 21 are positioned further outward in the radial direction than the passage openings 2a to 2f, and in particular, the innermost point in the radial direction of the further passage opening 21 is located further outward in the radial direction than the innermost point in the radial direction of the passage openings 2a to 2f. Furthermore, the parallel vertical sides 22 of the further passage openings 21 are shorter than the vertical sides 4 and 5 of the passage openings 2a to 2f. In this way, a double V arrangement of passage openings 2a to 2f and 21 is realized.

[0044] Finally, Figure 1 also further shows a central cutout 23 of the rotor stack 1, through which a shaft can be passed. Here, the central cutout 23 is circular as an example. However, the central cutout 23 may also have a different shape, for example, having opposing parallel portions connected by opposing portions in the form of an arc of a circle.

[0045] Figure 4 shows a detailed view of the outer contour 8 according to a second exemplary embodiment of the rotor stack 1. Except as otherwise described below, all descriptions made relating to the first exemplary embodiment are applicable to the second exemplary embodiment. Components that are the same or have the same effect are given the same reference numerals here.

[0046] In a second exemplary embodiment, the outer contour 8 of the passage opening 2a does not have any protruding portions. The arcuate portion 12 or its second lower portion 17 smoothly transitions to the second longitudinal side 5. Such an outer contour 8 is advantageous, for example, when it is not necessary to prevent the permanent magnets from moving along the longitudinal side during the manufacturing of the rotor by any protruding portions, so that the permanent magnets are held in some other way.

[0047] In a further exemplary embodiment of the rotor stack, which otherwise corresponds to the second exemplary embodiment, the arcuate portion 12 extends beyond the straight line 19 in a direction divergent from the two longitudinal sides 4, 5 and further transitions to the second longitudinal side 5. In such exemplary embodiments, in particular, the centers of the longitudinal sides 4, 5 can be positioned perpendicular to the radial direction.

[0048] In other respects, according to a further exemplary embodiment of the rotor stack 1 corresponding to the first or second exemplary embodiment, for each pair of passage openings 2a to 2f, a further passage opening is provided in place of the V-shaped arrangement of further passage openings 21, the vertical side of which is perpendicular to the axis of symmetry 3. In this way, a delta arrangement of passage openings can be formed.

[0049] Figure 5 shows a cross-sectional view of an exemplary embodiment of a rotor 100 having an exemplary embodiment of the rotor laminated core 101 according to the present invention.

[0050] The rotor laminated core 101 is formed from a number of rotor laminates 1 according to a first exemplary embodiment, which are electrically insulated from one another and stacked in an axial layer. The passage openings 2a-2f, 21 of the rotor laminates 1 are, here coincidentally, one over the other, resulting in the formation of magnet pockets 102 that extend axially through the rotor laminated core 101. Here, for the sake of clarity, in Figure 5 only one passage opening 2a and one further passage opening 21 of the passage openings 2a-2f, 21 are given reference numerals. Here, each magnet pocket 102 comprises a receiving space 103 between longitudinal sides 4, 5 and an air pocket 104 oriented along the axis of symmetry 3, bounded by an outer contour 8. Further air pockets 105 are formed at the ends of longitudinal sides 4, 5 opposite to the air pockets 104. The rotor laminates 1 are joined together, for example, integrally, in a fixed manner of rotation, by laser welding, for example.

[0051] The rotor 100 further comprises a number of permanent magnets 106, which are arranged in magnet pockets 102 and penetrate the receiving spaces 103 of each magnet pocket 102. Here, a single permanent magnet 106, or a number of permanent magnets 106 arranged such that one is behind the others in the axial direction, can be placed in each magnet pocket 102. No permanent magnets are present in the air pockets 104, 105. The air pockets 104, 105, and the intermediate spaces between the permanent magnets and the vertical sides 4, 5 are filled with resin.

[0052] Furthermore, the rotor 100 includes a rotor shaft 107 that penetrates the central cutout portion 23 of the rotor stack 1. In this case, the rotor shaft 107 is, for example, a hollow shaft.

[0053] Further exemplary embodiments of the rotor 100 include a plurality of rotor stacks 1 according to further exemplary embodiments.

[0054] Figure 6 shows a schematic diagram of an exemplary embodiment of a vehicle 110 having an exemplary embodiment of an electrical machine 111.

[0055] The electromachine 111 comprises a stator 112 and a rotor 100 rotatably mounted inside the stator 112, according to one of the exemplary embodiments described above. The electromachine 111 is a permanently excited synchronous machine and is in the form of an electric motor. The electromachine 111 is configured to drive a vehicle 110, for example, a battery electric vehicle (BEV) or a hybrid vehicle.

Claims

1. A rotor laminate (1) for a rotor (100) of an electromechanism (111), comprising a plurality of passage openings (2a to 2f), each of which is intended to form a magnet pocket (102) of a rotor laminate core (101), having a first longitudinal side (4) and a second longitudinal side (5) parallel to the first longitudinal side (4), wherein for pairs of passage openings (2a to 2f) that are adjacent in the circumferential direction and axially symmetric with respect to a radial axis of symmetry (3), the outer contour (8) of each passage opening (2a to 2f) of each pair connects the ends (6, 7) of the longitudinal sides (4, 5) that face the axis of symmetry (3), The outer contour (8) extends from the first vertical side (4) toward the opposite side from the second vertical side (5), and includes an arc-shaped portion (12) that curves toward the axis of symmetry (3) along the direction from the first vertical side (4) to the second vertical side (5), up to the second vertical side (5). The arc-shaped portion (12) has a first lower portion (16) and a second lower portion (17), wherein the minimum radius of the first lower portion (16) is greater than the minimum radius of the second lower portion (17). The first lower portion (16) is located further away from the second vertical side (5) than the second lower portion (17), The minimum distance between the outer contours (8) of each pair of the passage openings (2a to 2f) is defined by the second lower portion (17). Rotor stack.

2. The first lower portion (16) is in the form of a circular arc, and / or the second lower portion (17) is in the form of a circular arc. The rotor laminate according to claim 1.

3. The outer contour (8) has a straight portion (13) between the end portion (6) of the first vertical side (4) and the arc-shaped portion (12). The rotor laminate according to claim 1 or 2.

4. The straight line (15) and the straight line (14) intersect at a substantially right angle, the first vertical side (4) extends along the straight line (15), and the straight line portion (13) extends along the straight line (14). The rotor laminate according to claim 3.

5. The arc-shaped portion (12) terminates between two straight lines (15, 19), the vertical sides (4, 5) extend along the two straight lines (15, 19), and the outer contour (8) has a projection (18) on the side of the vertical side (5) in the arc-shaped portion (12), the projection (18) extending in a straight line. The rotor laminate according to any one of claims 1 to 4.

6. The arc-shaped portion (12) includes a transition portion that smoothly transitions to the second vertical side (5), The rotor laminate according to any one of claims 1 to 4.

7. The end portion (6) of the first vertical side (4) is located further inward in the radial direction than the end portion (7) of the second vertical side (5), The rotor laminate according to any one of claims 1 to 6.

8. The pair of passage openings (2a to 2f) are arranged in a V-shape that opens outward in the radial direction. The rotor laminate according to any one of claims 1 to 7.

9. The rotor stacked body, -Each of the aforementioned pairs has a pair of further passage openings (21) that open outward and are arranged in a V-shape axially symmetric with respect to the axis of symmetry (3), The innermost point in the radial direction of the further passage opening (21) is located radially outward from the innermost point in the radial direction of the passage openings (2a to 2f). The rotor laminate according to claim 7.

10. A rotor laminated core (101) for an electromachine (111), comprising a plurality of rotor laminates (1) according to any one of claims 1 to 9, arranged in a manner that they are stacked in layers in the axial direction.

11. A rotor (100) for an electromechanical device (111), comprising the rotor stacked core (101) described in claim 10, wherein permanent magnets (106) are arranged in the magnet pockets (102).

12. An electric machine (111) for a vehicle (110), comprising a stator (112) and a rotor (100) according to claim 11, wherein the rotor (100) is rotatably mounted inside the stator (112).

13. A vehicle (110) comprising an electric machine (111) according to claim 12, configured to drive the vehicle (110).

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