METHOD FOR PRODUCING A LAMINATION STACK FOR A ROTOR AND/OR A STATOR OF AN ELECTRIC MACHINE

Abstract

The invention relates to a method for producing a lamination stack for a rotor and/or a stator of an electric machine, wherein the lamination stack is produced of a stack of disk- or ring-shaped sheet metal laminations which are assembled of sub-segments that each have a radial outer edge, a radial inner edge and two lateral edges, wherein the sub-segments are stamped out of a sheet metal strip having a strip longitudinal direction that corresponds to a rolling direction of the sheet metal strip. In accordance with the invention provision is made in that for the purpose of stamping-out of the sheet metal strip first sub-segments are arranged in a first row and second sub-segments are arranged in a second row and stamped out, wherein the first row and the second row run in the strip longitudinal direction of the sheet metal strip and lie next to each other, in that the first sub-segments in the first row are aligned identically with respect to each other, wherein the radial outer edge and/or the radial inner edge run transversely to the longitudinal direction of the strip, and in that the second sub-segments in the second row are arranged identically with respect to each other, with radial outer edges and/or radial inner edges running transversely to the longitudinal direction of the strip, but diametrically opposed to the first sub-segments in the first row on the sheet metal strip.

Claims

1-11. (canceled)

12. A method for producing a lamination stack for a rotor and/or a stator of an electric machine, wherein the lamination stack comprises a stack of disk- or ring-shaped sheet metal laminations which are assembled of sub-segments that each have a radial outer edge, a radial inner edge and two lateral edges, wherein the sub-segments are stamped out of a sheet metal strip having a strip longitudinal direction that corresponds to a rolling direction of the sheet metal strip, the method comprising: arranging first sub-segments in a first row and arranging second sub-segments in a second row, wherein the first row and the second row are aligned in the strip longitudinal direction of the sheet metal strip and lie next to each other, wherein the first sub-segments in the first row are aligned identically with respect to each other, wherein the radial outer edge and/or the radial inner edge run transversely to the longitudinal direction of the strip, wherein the second sub-segments in the second row are arranged identically with respect to each other, with radial outer edges and/or radial inner edges running transversely to the longitudinal direction of the strip, but diametrically opposed to the first sub-segments in the first row on the sheet metal strip, wherein a circular arc section or a circular arc angle of the respective sub-segment ranges between 20° and 120°; and stamping out the sheet metal strip such that each sub-segment is stamped out with a groove on a first lateral edge and with a matching tongue on the opposite second lateral edge in order to form a tongue and groove joint to allow for assembling the sub-segments to a sheet metal lamination.

13. The method according to claim 12, wherein the first sub-segments and the second sub-segments are designed identically.

14. The method according to claim 12, wherein the sub-segments are designed as quarter circular arc segments.

15. The method according to claim 12, wherein the sub-segments have radially directed webs that are substantially aligned in the longitudinal direction of the strip.

16. The method according to claim 12, wherein for the purpose of the interlocking, the sub-segments are provided with form-locking elements perpendicular to the strip plane.

17. The method according to claim 12, wherein the stamping step is performed on a press with at least one stamping tool and/or at least one embossing tool.

18. The method according to claim 12, wherein a stator or rotor of an electric machine is formed, which is formed with a lamination stack, and wherein the lamination stack is produced with sub-segments.

19. The method according to claim 18, wherein a disk-shaped rotor or a ring-shaped stator is formed only of first sub-segments or only of second sub-segments.

20. The method according to claim 18, wherein a disk-shaped rotor or a ring-shaped stator is formed of first sub-segments and of second sub-segments.

21. The method according to claim 12, wherein an electric machine is formed with the stator and/or rotor.

Description

[0026] The invention is explained further hereinafter by way of preferred embodiments illustrated schematically in the drawings, wherein show:

[0027] FIG. 1 a perspective view of a stator constructed according to the invention;

[0028] FIG. 2 a perspective view of a rotor constructed according to the invention;

[0029] FIG. 3 a perspective view of the arrangement of sub-segments on a sheet metal strip according to the invention;

[0030] FIG. 4 an assembly of a stator ring of four sub-segments; and

[0031] FIG. 5 a plan view of an assembled stator ring.

[0032] In FIG. 1 a stator 10 produced according to the invention for an electric motor is illustrated, wherein the stator 10 is formed of a lamination stack 12 of a plurality of axially stacked ring-shaped sheet metal laminations 14.

[0033] In FIG. 2 a rotor 11 produced according to the invention is constructed of a lamination stack 12 of substantially disk-shaped sheet metal laminations 14. The construction of a stator 10 or a rotor 11 of a plurality of thin sheet metal laminations 14 improves the electromagnetic behavior of the electric motor or a corresponding electric generator and thus the efficiency of the respective electric machine.

[0034] To further improve the efficiency the individual sheet metal laminations 14 are divided into sub-segments 20 which are arranged in a manner according to the invention on a sheet metal strip 40 in at least two rows, namely a first row 41 and a second row 42, in the longitudinal direction of the sheet metal strip 40 and are thus stamped out. The invention is based on the finding that when rolling a sheet metal strip 40, especially when cold rolling it, a stretching and alignment of the grain structure arises in the metal material. According to a finding of the invention such a stretching and alignment of the grain structure can enhance the efficiency of an electric machine if this stretching is as uniform as possible in a radial direction in a stator 10 or rotor 11.

[0035] According to the invention such an alignment is achieved in that a ring shape is divided into several arched sub-segments that deviate only slightly from a straight line. In the first row 41 first sub-segments 20a are aligned one behind the other and identically in the longitudinal direction of the sheet metal strip 40. In doing so, a radial outer edge 22 and a radial inner edge 24, on which radially directed webs 28 are designed, run substantially transversely to the longitudinal direction of the sheet metal strip 40. At the same time, a groove 30 can be designed on a first lateral edge 26 of a sub-segment 20 and a projecting tongue 32 can be designed on a second lateral edge 26 of the same sub-segment 20. The approximately V-shaped groove 30 and the matching arrow-like designed tongue 32 are on the whole designed such that they can engage in a form-locking manner to establish a tongue-and-groove connection.

[0036] According to the invention a very good utilization of the material of the sheet metal strip 40 is realized in that in the second row 42 the second sub-segments 20b are arranged diametrically opposed to the first sub-segments 20a in the first row 41 on the sheet metal strip 40 and are stamped out of the latter. Despite the fact that the second sub-segments 20b are arranged by being rotated by 180° in the longitudinal direction of the sheet metal strip 40 a largely equally good alignment of the second sub-segments 20b in the longitudinal direction and thus also in the rolling direction of the sheet metal strip 40 is achieved as in the case of the first sub-segments 20a in the first row 41.

[0037] The first sub-segments 20a in the first row 41 and the second sub-segments 20b in the second row 42 are arranged next to each other such that the respective lateral edges 26 with the grooves 30 lie directly opposite so that, in a particularly material-saving way, no or only a minimal intermediate web remains in-between the two sub-segments 20a, 20b. The respective lateral edges 26 with the projecting tongues 32 are in each case directed outwards.

[0038] Following stamping-out of the sub-segments 20 the webs 28 on the respective inner edge 24 can still undergo thermal treatment, whereby an even finer grain structure can be adjusted in these material regions e.g. through solution annealing.

[0039] As illustrated in FIGS. 4 and 5, in this preferred embodiment the sub-segments 20 are designed as a quarter circular arc segment so that a total of four sub-segments 20 can be assembled to a ring of a stator 10. The sub-segments 20 are arranged with respect to each other in such a manner that the lateral groove 30 and the lateral tongue 32 of two adjacent sub-segments 20 lie opposite in each case. Through appropriate assembly a closed ring-shaped sheet metal lamination 14 can thus be formed for a stator 10. Before being assembled to a ring the individual sub-segments 20 can be stacked axially so that corresponding sheet metal stacks 12 can be assembled with each other to form a ring. Alternatively, a single ring-shaped lamination 14 can also be assembled initially, and subsequently a plurality of assembled sheet metal laminations 14 are stacked axially to the sheet metal stack 12 for a stator 10.

[0040] The procedure can be applied correspondingly to a rotor 11 which can also be assembled of several sub-segments 20.