Bonded magnet, bonded magnet component, and bonded magnet production method

Patent metadata

Field	Value
Publication number	US-9583244-B2
Application number	US-201514867714-A
Country	US
Kind code	B2
Filing date	Sep 28, 2015
Priority date	Sep 30, 2014
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

A bonded magnet is provided which includes first and second components. The first and second components have first and second non-action surfaces, and first and second action surfaces that intersect the first and second non-action surfaces, respectively. First and second flux groups curve inside the first and second components from the first and second non-action surfaces to the first and second action surfaces, respectively. The areas of the first and second non-action surfaces are greater than the first and second action surfaces, respectively. The flux densities on the first and second action surfaces are higher than the first and second non-action surfaces, respectively. The pole on the first non-action surface is opposite to the second non-action surface. The first and second non-action surfaces are coupled to each other. The first flux groups continuously extend from one to another.

First claim

What is claimed is:

1. A bonded magnet comprising:
a first bonded magnet component having
a first surface,
a second surface that is connected to said first surface through a connection portion, and
a fifth surface that is connected to said second surface through a connection portion, and is connected to said first surface through a connection portion,
the first bonded magnet component having a substantially sector exterior shape, which is defined by said first, fifth and second surfaces as viewed in section, and has a predetermined central angle which is formed by said first and fifth surfaces,

a first magnetic flux group extending from said first surface to said second surface, and
a third magnetic flux group extending from said fifth surface to said second surface; and

a second bonded magnet component having
a third surface,
a fourth surface that is connected to said third surface through a connection portion, and
a sixth surface that is connected to said fourth surface through a connection portion, and is connected to said third surface through a connection portion,
the second bonded magnet component having a substantially sector exterior shape, which is defined by said third, sixth and fourth surfaces as viewed in section, and has a predetermined central angle which is formed by said third and sixth surfaces,
a second magnetic flux group extending from said fourth surface to said third surface, and
a fourth magnetic flux group extending from said fourth surface to said sixth surface,
wherein the magnetic flux density on said second surface is higher than the magnetic flux density on said first surface, and
the magnetic flux density on said fourth surface is higher than the magnetic flux density on said third surface,
wherein the magnetic pole on said first surface is opposite to the magnetic pole on said third surface,
wherein said first and third surfaces are coupled to each other so that the first and second magnetic flux groups continuously extend from one to another, and
the exposed magnetic pole on said second surface is opposite to the exposed magnetic pole on said fourth surface,
wherein the ratio A/B of a length A as the radius of the sector of said first bonded magnet component to a length B of a part of the arc of the sector that is magnetized satisfies
0.3184 n≦A/B<− 0.04 n 3 +1.47 n 2 −14.03 n+ 43

where n is the total number of poles of the bonded magnet,
in the case where the total number of poles of the bonded magnet is not greater than 12 and central angle Θ 0 ≧30°, or
0.3184 n ≦( A/B )

in the case where the total number of poles of the bonded magnet is greater than 12 and central angle Θ 0 <30°.

2. The bonded magnet according to claim 1 , wherein the area of said first surface is greater than the area of said second surface, and the area of said third surface is greater than the area of said fourth surface.

3. The bonded magnet according to claim 1 , wherein the sum of the areas of said first and fifth surfaces is greater than the area of said second surface, and the sum of the areas of said third and sixth surfaces is greater than the area of said fourth surface.

4. The bonded magnet according to claim 1 , wherein the angle that is formed by said first and second surfaces is not greater than 90°.

5. A bonded magnet comprising:
a first bonded magnet component having
a first surface, and
a second surface that is connected to said first surface through a connection portion,
the first bonded magnet component having a first magnetic flux group that extends from said first surface to said second surface; and

a second bonded magnet component having
a third surface, and
a fourth surface that is connected to said third surface through a connection portion,
the second bonded magnet component having a second magnetic flux group that extends from said fourth surface to said third surface,
wherein the area of said first surface is greater than the area of said second surface, and the magnetic flux density on said second surface is higher than the magnetic flux density on said first surface,
wherein the area of said third surface is greater than the area of said fourth surface, and the magnetic flux density on said fourth surface is higher than the magnetic flux density on said third surface,
wherein the magnetic pole on said first surface is opposite to the magnetic pole on said third surface,
wherein said first and third surfaces are coupled to each other so that the first and second magnetic flux group continuously extend from one to another, and
wherein the exposed magnetic pole on said second surface is opposite to the exposed magnetic pole on said fourth surface,
wherein said first bonded magnet component has an exterior flat shape,
wherein said first surface is the main surface of the flat shape, and said second surface is the side surface that extends in the thickness direction of the flat shape, and
wherein the magnetic lines of flux bend symmetrically inside the first bonded magnet component from said first surface to the both second-surface sides as viewed in section.

6. The bonded magnet according to claim 5 , wherein said second bonded magnet component has an exterior flat shape,
wherein said third surface is the main surface of the flat shape, and said fourth surface is the side surface that extends in the thickness direction of the flat shape, and
wherein the magnetic lines of flux bend symmetrically inside the second bonded magnet component from the fourth-surface sides to said third surface as viewed in section.

7. The bonded magnet according to claim 1 , wherein the distribution of the magnetic lines of flux in said first bonded component is generally the reflection of the distribution of the magnetic lines of flux in said second bonded component.

8. The bonded magnet according to claim 1 , wherein the joint surfaces of said first and second bonded components are adhered to each other.

9. The bonded magnet according to claim 1 , wherein said second surface is an action surface, and the magnetic flux does not outgo through the surface of said first bonded magnet component that is opposed to said second surface.

10. The bonded magnet according to claim 1 , wherein at least one of the connection portion between said first surface and said second surface, the connection portion between said first surface and said fifth surface, the connection portion between said third surface and said fourth surface, and the connection portion between said third surface and said sixth surface has the same straight line as a part of the radius of the sector shape as viewed in section.

11. The bonded magnet according to claim 1 , wherein at least one of the connection portion between said first surface and said second surface, the connection portion between said first surface and said fifth surface, the connection portion between said third surface and said fourth surface, and the connection portion between said third surface and said sixth surface is recessed as viewed in section.

Assignees

• Nichia Corp

Inventors

• Yoshida Rie
• Kume Michiya
• Ihara Kohei
• Ichimori Taku

Classifications

• H01F7/021 Primary

  Construction of PM (H01F7/0278 takes precedence; PM compositions H01F1/032) · CPC title

• H01F41/0273

  Imparting anisotropy (methods and devices for magnetising permanent magnets H01F13/003) · CPC title

• H02K15/03

  having permanent magnets · CPC title

• H02K1/06

  characterised by the shape, form or construction · CPC title

• H01F41/0266 Primary

  Moulding; Pressing (H01F41/0273 takes precedence; hard magnetic particles H01F1/06, H01F1/11) · CPC title