Method for producing a laminated core of an electrical machine

Patent metadata

Field	Value
Publication number	US-2025047180-A1
Application number	US-202218717699-A
Country	US
Kind code	A1
Filing date	Nov 14, 2022
Priority date	Dec 8, 2021
Publication date	Feb 6, 2025
Grant date	—

Abstract

A method for producing a laminated core ( 1 ) of an electrical machine, comprising the steps of a) providing foil laminations ( 4 ) each comprising a carrier foil ( 6 ) made of aluminum and a natural or produced aluminum oxide layer ( 7 ) and each being coated with a first foil coating ( 10 ) made of a first powder mixture on at least one side ( 11, 12 ) at flux barrier surfaces ( 8 ), wherein the first powder mixture comprises an austenite stabilizer, aluminum oxide, and an adhesive agent, b) providing sheet metal laminations ( 5 ) of the laminated core ( 1 ), c) alternately stacking sheet metal laminations ( 5 ) and foil laminations ( 4 ), wherein the foil laminations ( 4 ) are oriented relative to the sheet metal laminations ( 5 ) such that the flux barrier surfaces ( 8 ) of the respective foil lamination ( 4 ) come into direct contact with the respective sheet metal lamination ( 5 ) at specified flux barrier locations ( 9 ) of the respective sheet metal lamination ( 5 ); d) heating the stack of sheet metal laminations ( 5 ) and foil laminations ( 4 ) such that
the austenite stabilizer is diffused from the first foil coating ( 10 ) of the foil laminations ( 4 ) at the respective flux barrier locations ( 9 ) into the metal of the respective contacted sheet metal lamination ( 5 ), thereby forming a flux barrier ( 15 ) the aluminum is diffused from the carrier foils ( 6 ) of the foil laminations ( 4 ) into the metal of the respective adjacent sheet metal lamination ( 5 ), thereby dissolving the carrier foil.

First claim

1 . A method for producing a laminated core ( 1 ) of an electrical machine comprising the steps of:
a) providing foil laminations ( 4 ), each comprising a carrier foil ( 6 ) made of aluminum and a natural or produced aluminum oxide layer ( 7 ) and each being coated with a first foil coating ( 10 ) made of a first powder mixture on at least one side ( 11 , 12 ) at flux barrier surfaces ( 8 ), wherein the first powder mixture comprises an austenite stabilizer, b) providing sheet metal laminations ( 5 ) of the laminated core ( 1 ), c) alternately stacking sheet metal laminations ( 5 ) and foil laminations ( 4 ), wherein the foil laminations ( 4 ) are oriented relative to the sheet metal laminations ( 5 ) such that the flux barrier surfaces ( 8 ) of the respective foil lamination ( 4 ) come into direct contact with the respective sheet metal lamination ( 5 ) at specified flux barrier locations ( 9 ) of the respective sheet metal lamination ( 5 ); d) heating, of the stack of sheet metal laminations ( 5 ) and foil laminations ( 4 ) such that the austenite stabilizer is diffused from the first foil coating ( 10 ) of the foil laminations ( 4 ) at the respective flux barrier locations ( 9 ) into the metal of the respective contacted sheet metal lamination ( 5 ), thereby forming a flux barrier ( 15 ) the aluminum is diffused from the carrier foils ( 6 ) of the foil laminations ( 4 ) into the metal of the respective adjacent sheet metal lamination ( 5 ), thereby dissolving the carrier foil ( 6 ).

2 . The method according to claim 1 , wherein the first powder mixture additionally comprises an electrically insulating insulator compound and/or an alloy material.

3 . The method according to claim 1 , wherein in step 1a) the foil laminations ( 4 ) are in each case additionally coated on insulation surfaces ( 16 ) with at least one second foil coating ( 20 ) made of a second powder mixture on the coated side ( 11 , 12 ), wherein the second powder mixture has, in each case, an electrically insulating insulator compound, and an adhesive agent.

4 . The method according to claim 2 , wherein the heating in step 1d) is carried out such that the insulator compound, from the first and/or second foil coating ( 20 ) of the foil laminations ( 4 ) and/or from the aluminum oxide layer ( 7 ), remains between the sheet metal laminations ( 5 ) after heating, in each case forming an insulating layer ( 32 ) between adjacent sheet metal laminations ( 5 ), wherein the respective insulating layer ( 32 ) is formed in the region of the insulating surfaces ( 16 ) and in the region of the flux barrier surfaces ( 8 ) or the flux barriers ( 15 ).

5 . The method according to claim 1 , wherein the adhesive agent is provided for adhering the first or second powder mixture to the carrier foil ( 6 ) of the respective foil lamination ( 4 ) and is a paste and/or a polysaccharide.

6 . The method according to claim 1 , wherein the shape and/or surface of the foil laminations ( 4 ) correspond to the shape and/or surface of the sheet metal laminations ( 5 ).

7 . The method according to claim 1 , wherein the first powder mixture comprises a further substance which is suitable for forming a eutectic, with a melting temperature <1300° C., with the austenite stabilizer.

8 . The method according to claim 7 , wherein the eutectoid former promotes the formation of austenite from the liquid phase down to low temperatures such that the austenite is also present at room temperature, and is based on copper and/or zinc and/or carbon and/or nitrogen.

9 . The method according to claim 1 , wherein, in order to decompose the adhesive agent of the first and/or second foil coating ( 10 , 20 ), a further heat treatment of the sheet metal lamination ( 5 ) with the coated foil laminations ( 4 ) arranged therebetween is carried out in a range from about 150° C. to about 500° C. in a hydrogen-containing atmosphere for about one to about two hours, preceding the heat treatment.

10 . The method according to claim 1 , wherein the first powder mixture comprises manganese and/or nickel and/or cobalt.

11 . The method according to claim 1 , wherein the first powder mixtures comprises aluminum oxide.

12 . The method according to claim 1 , wherein the first powder mixture comprises an adhesive agent.

13 . The method according to claim 1 , wherein the sheet metal laminations ( 5 ) are uninsulated.

14 . The method according to claim 1 , wherein the heating is heat treatment.

15 . The method of claim 2 , wherein the first powder mixture comprises aluminum oxide or silicon oxide (SiO2).

16 . The method of claim 2 , wherein the alloy material is silicon.

17 . The method of claim 3 , wherein the electrically insulating insulator compound is aluminum oxide or silicon oxide (SiO2).

18 . The method of claim 5 , wherein the adhesive agent is xanthan.

19 . The method of claim 5 , wherein the adhesive agent is amylopectin.

20 . The method of claim 7 , wherein the further substance is tin.

Assignees

• Bosch Gmbh Robert

Inventors

• Koehne Martin

Classifications

• H02K1/276

  Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] · CPC title

• B32B15/016

  all layers being formed of aluminium or aluminium alloys · CPC title

• C23C28/36

  including layers graded in composition or physical properties · CPC title

• C23C28/322

  only coatings of metal elements only · CPC title

• C23C10/34

  Embedding in a powder mixture, i.e. pack cementation · CPC title