# US 2021/0241973 A1 · Laminated core, electric machine, transformer and method for producing a laminated core

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- Number: US 2021/0241973 A1
- Document ID: US20210241973A1
- Status: Published application
- Kind: A1
- Application number: 17/165,382
- Filed: 2021-02-02
- Published: 2021-08-05
- Earliest claimed: 2020-02-03
- Assignees: Vacuumschmelze GmbH & Co. KG
- Applicants: Vacuumschmelze GmbH & Co. KG
- Inventors: Frederic BÄCKER; Jens DIEHL; Dominik FACKELMANN
- Web page: https://patentgrep.com/patent/US20210241973A1

## CPC

- H01F 41/0233: {Manufacturing of magnetic circuits made from sheets (magnetic cores made from sheets H01F27/245; soft magnetic alloys in the form of sheets H01F1/16)}
- H02K 1/00: Details of the magnetic circuit (magnetic circuits for relays H01H50/16)
- H01F 1/14783: {with insulating coating}
- H01F 1/14791: {Fe-Si-Al based alloys, e.g. Sendust}
- H01F 1/15316: {based on Co (H01F1/15325 takes precedence)}
- H01F 3/02: made from sheets
- H01F 27/245: made from sheets, e.g. grain-oriented (H01F27/26 takes precedence)
- H01F 27/25: made from strips or ribbons (H01F27/26 takes precedence)
- H01F 41/0213: {Manufacturing of magnetic circuits made from strip(s) or ribbon(s) (magnetic cores made by winding a ribbon H01F27/25)}
- H02K 1/02: characterised by the magnetic material
- H02K 15/02: of stator or rotor bodies
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})

## Abstract

A laminated core comprising a plurality of lamination sheets made of a soft magnetic alloy is provided. The lamination sheets have a main surface and a thickness d. The main surfaces of the lamination sheets are stacked one on top of another in a direction of stacking. Adjacent lamination sheets are joined to one another by a plurality of substance-to-substance joints, the joints being filler-free and entirely surrounded by the main surfaces of the adjacent lamination sheets.

## Claims

### Claim 1

A laminated core, comprising:
a plurality of lamination sheets made of a soft magnetic alloy that each have a main surface and a thickness d, the main surfaces of the lamination sheets being stacked on top of another in a direction of stacking and adjacent lamination sheets being joined together by a plurality of substance-to-substance joints, the joints being filler-free and entirely surrounded by the main surfaces of the adjacent lamination sheets.

### Claim 2 (depends on 1)

A laminated core according to claim 1, wherein the joints are laterally entirely bordered by the crystalline material of the lamination sheets.

### Claim 3 (depends on 1)

A laminated core according to claim 1, wherein the joints are made of molten material of the soft magnetic alloy.

### Claim 4

(canceled)

### Claim 5

(canceled)

### Claim 6

(canceled)

### Claim 7 (depends on 1)

A laminated core according to claim 1, wherein the joints are distributed throughout the volume of the laminated core.

### Claim 8 (depends on 1)

A laminated core according to claim 1, wherein the joints are arranged in a plurality of planes of the laminated core and have a different lateral arrangement in the planes and/or are arranged one on top of another in the direction of stacking.

### Claim 9 (depends on 1)

A laminated core according to claim 1, wherein the joints in the plane of the main surface are punctiform, circular, elongated, corner-shaped, annular, curved, straight, X-shaped, Y-shaped, V-shaped or U-shaped.

### Claim 10

(canceled)

### Claim 11

(canceled)

### Claim 12

(canceled)

### Claim 13 (depends on 1)

A laminated core according to claim 1, wherein d≤0.5 mm.

### Claim 14 (depends on 1)

A laminated core according to claim 1, wherein the joints have a depth and the depth of at least one of the joints extends over a maximum of two or a maximum of three or at least three adjacent stacked lamination sheets.

### Claim 15

(canceled)

### Claim 16

(canceled)

### Claim 17 (depends on 1)

A laminated core according to claim 1, wherein together the joints have a total electrical contact surface of less than 10% of the boundary surface of the lamination sheets.

### Claim 18 (depends on 1)

A laminated core according to claim 1, wherein the lamination sheets are separated from a strip and each have a direction that is parallel to the direction of rolling of the strip, the lamination sheets have a thickness that varies over the area of the lamination sheet, and wherein the direction of the lamination sheets in the laminated core varies.

### Claim 19

(canceled)

### Claim 20 (depends on 1)

A laminated core according to claim 1, wherein the soft magnetic alloy is
an Fe—Si-based alloy comprising 2 to 4.5 wt % of at least one element from the group comprising Si and Al, the rest Fe and unavoidable impurities, or
a CoFe-based alloy comprising 35 to 55 wt % Co and up to 2.5 wt % V, the rest Fe and unavoidable impurities, or
a CoFe-based alloy comprising 45 wt %≤Co≤52% wt %, 45 wt %≤Fe≤52% wt %, 0.5 wt %≤V≤2.5% wt %, the rest Fe and unavoidable impurities, or
a CoFe-based alloy comprising 35 wt %≤Co≤55% wt %, 0 wt %≤Ni≤0.5% wt %, 0.5 wt %≤V≤2.5% wt %, the rest Fe and unavoidable impurities, or
a CoFe-based alloy comprising 35 wt %≤Co≤55% wt %, 0 wt %≤V≤2.5% wt %, 0 wt %≤(Ta+2Nb)≤1% wt %, 0 wt %≤Zr≤1.5% wt %, 0 wt %≤Ni≤5% wt %, 0 wt %≤C≤0.5% wt %, 0 wt %≤Cr≤1% wt %, 0 wt %≤Mn≤1% wt %, 0 wt %≤Si≤1% wt %, 0 wt %≤Al≤1% wt %, 0 wt %≤B≤0.01% wt %, the rest Fe and unavoidable impurities, or
a CoFe-based alloy comprising 5 to 25 wt % Co, 0.3 to 5.0 wt % V, the rest Fe and unavoidable impurities.

### Claim 21 (depends on 1)

A laminated core according to claim 1, wherein the soft magnetic alloy being a CoFe-based alloy consists essentially of
5% wt % ≤ Co ≤ 25% wt %
0.3% wt % ≤ V ≤ 5.0% wt %
0% wt % ≤ Cr ≤ 3.0% wt %
0% wt % ≤ Si ≤ 3.0% wt %
0% wt % ≤ Mn ≤ 3.0% wt %
0% wt % ≤ Al ≤ 3.0% wt %
0% wt % ≤ Ta ≤ 0.5% wt %
0% wt % ≤ Ni ≤ 0.5% wt %
0% wt % ≤ Mo ≤ 0.5% wt %
0% wt % ≤ Cu ≤ 0.2% wt %
0% wt % ≤ Nb ≤ 0.25% wt %
0% wt % ≤ Ti ≤ 0.05% wt %
0% wt % ≤ Ce ≤ 0.05% wt %
0% wt % ≤ Ca ≤ 0.05% wt %
0% wt % ≤ Mg ≤ 0.05% wt %
0% wt % ≤ C ≤ 0.02% wt %
0% wt % ≤ Zr ≤ 0.1% wt %
0% wt % ≤ O ≤ 0.025% wt %
0% wt % ≤ S ≤ 0.015% wt %
the rest iron, Cr+Si+Al+Mn being≤3.0% wt %, and up to 0.2 wt % other impurities.

### Claim 22 (depends on 21)

A laminated core according to claim 21, wherein
10 wt %≤Co≤20% wt %, or
0.5 wt %≤V≤4.0% wt %, or
0.1 wt %≤Cr≤2.0% wt %, or
0.1 wt %≤Si≤2.0% wt %, and/or
the sum formula being 0.1 wt %≤Cr+Si+Al+Mn≤1.5% wt %.

### Claim 23 (depends on 1)

An electric machine comprising a rotor and a stator or having an armature and a stator, the stator comprising a laminated core according to claim 1.

### Claim 24

(canceled)

### Claim 25 (depends on 1)

A transformer having a laminated core according to claim 1.

### Claim 26

(canceled)

### Claim 27

A method for producing a laminated core, comprising:
providing a plurality of lamination sheets made of a soft magnetic alloy and having a main surface and a thickness d,
stacking the main surface of a first lamination sheet on the main surface of a second lamination sheet in a direction of stacking,
substance-to-substance joining of the first and the second lamination sheets by means of a plurality of filler-free joints that are entirely surrounded by the main surfaces of the first and second lamination sheets.

### Claim 28 (depends on 27)

A method according to claim 27, wherein the first lamination sheet is substance-to-substance joined to the second lamination sheet by means of laser welding or laser spot welding to form a joint.

### Claim 29 (depends on 27)

A method according to claim 27, wherein a laser beam is directed in one or both of a lateral direction in order to position the joint on a first lamination sheet and a vertical direction.

### Claim 30

(canceled)

### Claim 31 (depends on 29)

A method according to claim 29, wherein the laser beam is directed at the main surface of the first lamination sheet so as to form a punctiform joint.

### Claim 32 (depends on 29)

A method according to claim 29, wherein the laser beam is directed over the main surface of the first lamination sheet so as to form an elongated joint with a longitudinal direction.

### Claim 33

(canceled)

### Claim 34

(canceled)

### Claim 35 (depends on 32)

A method according to claim 32, wherein the longitudinal direction is arranged parallel to the lines of the magnetic flow in this plane of the finished laminated core.

### Claim 36

(canceled)

### Claim 37

(canceled)

### Claim 38 (depends on 27)

A method according to claim 27, wherein the first lamination sheet and the second lamination sheet are aligned in relation to one another to form a lap joint or a parallel joint.

### Claim 39

(canceled)

### Claim 40 (depends on 27)

A method according to claim 27, wherein at least three lamination sheets are stacked one on top of another and joined to one another by means of a plurality of joints.

### Claim 41 (depends on 27)

A method according to claim 27, further comprising:
stacking at least one further lamination sheet on the second lamination sheet and then
substance-to-substance joining the further lamination sheet and the first lamination sheet by means of a plurality of filler-free joints that are entirely surrounded by the main surface of the further and the first lamination sheets.