Electromagnetic induction device with magnetic particles between core segments

• US 5,204,653 A
• Filed: 01/22/1991
• Issued: 04/20/1993
• Est. Priority Date: 01/22/1990
• Status: Expired due to Fees

• Current Assignee: Tabuchi Electric Company Limited
• Original Assignee: Tabuchi Electric Company Limited
• Inventors: Itoh, Tetsurou, Kuroda, Naoki, Saitoh, Susumu
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US07/643,949
• Time in Patent Office: 819 Days
• Field of Search: 336/83, 336/178, 336/210, 336/212, 336/165, 336/218, 336/219, 336/233, 335/281, 335/297
• US Class Current: 336/178
• CPC Class Codes: H01F 27/263 Fastening parts of the core together

Abstract

An electromagnetic induction device which comprises a split-type core assembly comprising at least one winding formed thereon and first and second core segments each having at least two joint faces spaced apart from each other, the first and second core segments are connected together with the joint faces of one of the first and second core segments held in contact with the joint faces of the other of the first and second core segments, and a finely divided ferromagnetic material is interposed between the joint faces of the respective first and second core segments. The ferromagnetic material used has an average particle size sufficient to form a magnetic fluid medium.

Claims

1. An electromagnetic induction device which comprises a split-type core assembly comprising at least one winding formed thereon and first and second core segments, each of said first and second core segments having at least two joint faces spaced apart from each other, said first and second core segments being connected together with said joint faces of one of the first and second core segments held in contact with said joint faces of the other of the first and second core segments, and a finely divided ferromagnetic material interposed between the joint faces of the respective first and second core segments, said ferromagnetic material having an average particle size less than 1 μ

m interposed to form a magnetic fluid medium.

2. The electromagnetic induction device as claimed in claim 1, further comprising a connecting means for firmly connecting the first and second core segments together.

5. The electromagnetic induction device as claimed in claim 1, wherein each of the joint faces of one of the first and second core segments has at least a surface portion lying generally parallel or diagonal to a magnetic circuit passing across the first and second core segments, and each of the joint faces of the other of the first and second core segments has a surface portion complemental in shape to that in each of the joint faces of such one of the first and second core segments.

6. The electromagnetic induction device as claimed in claim 5, wherein the first and second core segments are of identical shape.

21. The electromagnetic induction device of claim 1 wherein said average particle size is within the range of 20 to 300 Å

.

3. An electromagnetic induction device which comprises a split-type core assembly comprising at least one winding formed thereon and first and second core segments, each of said first and second core segments having at least two joint faces spaced apart from each other, said first and second core segments having at least two joint faces spaced apart from each other, said first and second core segments being connected together with said joint faces of one of the first and second core segments held in contact with said joint faces of the other of the first and second core segments;

a magnetic fluid medium including a ferromagnetic material having an average particle size less than 1 μ

m interposed between the joint faces of the respective first and second core segments; and

a sealing means for encompassing an outer perimeter of each of joints defined between the joint faces of the respective first and second core segments.

22. The electromagnetic induction device of claim 3 wherein said average particle size is within the range of 20 to 300 Å

.

4. An electromagnetic induction device which comprises a split-type core assembly comprising at least one winding formed thereon and first and second core segments, each of said first and second core segments having at least two joint faces spaced apart from each other, said first and second core segments being connected together with said joint faces of one of the first and second core segments held in contact with said joint faces of the other of the first and second core segments, and hardened deposits of an adhesive filler material interposed between the joint faces of the respective first and second core segments, said adhesive filler material comprising resinous material mixed with finely divided ferromagnetic particles having an average particle size of less than 1 μ

m to form a magnetic fluid medium.

23. The electromagnetic induction device of claim 4 wherein said average particle size is within the range of 20 to 300 Å

.

7. An electromagnetic induction device comprising:

an open-ended core having end portions opposite to each other;

at least one winding formed on the open-ended core;

a yoke having end portions opposite to each other, said yoke being mounted on the open-ended core with the opposite end portions of said yoke held parallel to and in abutting relationship with the opposite end portions of the open-ended core; and

deposits of finely divided ferromagnetic material an average particle size of less than 1 μ

m to form a magnetic fluid medium, said deposits being interposed between the opposite end portions of the open-ended core and the opposite end portions of the yoke, each of said deposit of the finely divided ferromagnetic material being formed so as to cover at least end faces of each of the open-ended core and the yoke.

8. The electromagnetic induction device as claimed in claim 7, wherein said finely divided ferromagnetic material is made of iron nitride.

24. The electromagnetic induction device of claim 7 wherein said average particle size is within the range of 20 to 300 Å

.

9. An electromagnetic induction device, comprising:

an electromagnetic assembly, including first and second segment means, each having a plurality of end faces, said first and second segment means being connected together at each of the plurality of end faces;

winding means, mounted on said electromagnetic assembly for generating a magnetic field; and

finely divided ferromagnetic particles applied between the plurality of end faces of the first and second segment means for electromagnetically bonding the first and second segment means together, said ferromagnetic particles having an average particle size less than 1 μ

m to form a magnetic fluid medium.

10. The electromagnetic induction device of claim 9, wherein said finely divided ferromagnetic particles are included in resin deposits for structurally bonding the first and second segment means together.

11. The electromagnetic induction device of claim 9, wherein said electromagnetic assembly is a split-type core assembly.

12. The electromagnetic induction device of claim 11, wherein said first and second segment means are of an "E"-shaped configuration.

13. The electromagnetic induction device of claim 9, wherein said finely divided ferromagnetic particles are dispersed in a dispersing agent to form the magnetic fluid medium, and further comprising sealing means applied at the connection of said first and second segment means for preventing evaporation of said dispersing agent.

14. The electromagnetic induction device of claim 10, wherein said resin deposits include additional ferromagnetic particles and a thermosetting resin, which is allowed to harden, thereby structurally bonding said first and second agent means together.

15. The electromagnetic induction device of claim 9, wherein a surface area connecting the plurality of end faces of the first and second segment means is maximized and wherein one surface of the plurality of end faces of the first and second segment is parallel or diagonal to a magnetic current passing through said first and second segment means.

16. The electromagnetic induction device of claim 15, wherein a first one of the plurality of end faces of said first and second segment means has a stepped surface portion and wherein a second one of the plurality of end faces of said first and second segment means is complemental in shape to the first one of the plurality of end faces of said first and second segment means.

17. The electromagnetic induction device of claim 15, wherein a first one of the plurality of end faces of said first and second segment means has a diagonal projection portion, a part of which is diagonal to a magnetic current passing through said first and second segment means and wherein a second one of the plurality of end faces of said first and second segment means are complemental in shape to the first one of the plurality of end faces of said first and second segment means.

18. The electromagnetic induction device of claim 15, wherein said finely divided ferromagnetic particles are iron nitride particles.

19. The electromagnetic induction device of claim 14, wherein said electromagnetic assembly is a yoke-mounted core assembly, said first segment means is an open-ended core, and said second segment means is a yoke.

20. The electromagnetic induction device of claim 9, further comprising:

clamping means for structurally binding the first and second segment means together; and

wherein said electromagnetic induction device is a yoke-mounted core assembly, said first segment means is an open-ended core, and said second segment means is a yoke.

25. The electromagnetic induction device of claim 9 wherein said average particle size is within the range of 20 to 300 Å

.