Rotor for the electric machine

Patent metadata

Field	Value
Publication number	US-9231445-B2
Application number	US-201213982629-A
Country	US
Kind code	B2
Filing date	Feb 2, 2012
Priority date	Feb 3, 2011
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

A rotor ( 10 ) for a rotary electric machine has a plurality of magnetic poles ( 24 ) provided at intervals, in a circumferential direction, at the outer periphery of a rotor core ( 12 ). Each of the magnetic poles ( 24 ) has a first permanent magnet ( 26 ) buried in the center of the magnetic pole, and a pair of second permanent magnets ( 28 ) that are buried on both sides of the first permanent magnet ( 26 ) in the circumferential direction, and that are disposed such that a mutual spacing between the pair of the second permanent magnets ( 28 ) becomes narrower inward in the radial direction. A narrowest spacing between the pair of second permanent magnets ( 28 ) is set to be wider than a longitudinal-direction width of the first permanent magnet ( 26 ) in a magnetic path region ( 30 ) that is defined by the first permanent magnet ( 26 ) and the pair of second permanent magnets ( 28 ).

First claim

The invention claimed is:

1. A rotor for a rotary electric machine by comprising
a rotor core including a plurality of magnetic poles provided at intervals, in a circumferential direction of the rotor core, at an outer periphery of the rotor core, each of the magnetic poles having a first permanent magnet buried in the center of the magnetic pole, in the circumferential direction, and a pair of second permanent magnets that are buried on both sides of the first permanent magnet, in the circumferential direction, and that are disposed such that a mutual spacing between the pair of the second permanent magnets becomes narrower inward in a radial direction of the rotor core, wherein
the narrowest spacing between the pair of second permanent magnets is set to be wider than a width of the first permanent magnet in a direction perpendicular to the radial direction in a magnetic path region that is formed by being surrounded by the first permanent magnet and the pair of second permanent magnets, as viewed along an axial direction of the rotor core, wherein
each of the magnetic poles has a first magnetic flux suppression hole that is formed at a position opposite the first permanent magnet across the magnetic path region, between inner periphery-side end portions, in the radial direction, of the pair of second permanent magnets, the first permanent magnet, the second permanent magnets and the first magnetic flux suppression hole defining the first magnetic path region;
in each of the magnetic poles, a second magnetic path region is formed on an inner periphery side, in the radial direction, of the first magnetic path region with the first magnetic flux suppression hole interposed between the first magnetic path region and the second magnetic path region;
each of the magnetic poles further has a pair of third permanent magnets buried on both sides of the pair of second permanent magnets in the circumferential direction, and disposed such that a mutual spacing between the pair of third permanent magnets becomes narrower inward in the radial direction, and a second magnetic flux suppression hole formed opposite the first magnetic flux suppression hole across the second magnetic path region, between inner periphery-side end portions in the radial direction, of the pair of third permanent magnets; the second magnetic path region is defined by the second and third permanent magnets as well as the first and second magnetic flux suppression holes, on an inner periphery side, in the radial direction, of the first magnetic path region; and
in the second magnetic path region, the narrowest spacing between the pair of third permanent magnets is set to be equal to or greater than a width between edge portions, outward in the circumferential direction, of the pair of second permanent magnets, in a direction perpendicular to the radial direction.

2. The rotor for a rotary electric machine according to claim 1 , wherein
each of the first permanent magnet and the pair of second permanent magnets has a flat shape, and the direction perpendicular to the radial direction is a longitudinal direction of the first permanent magnet.

3. The rotor for a rotary electric machine according to claim 1 , wherein
a cross section, perpendicular to the axial direction of the rotor core, of each of the first permanent magnet and the pair of second permanent magnets, has an elongated rectangular shape.

4. The rotor for a rotary electric machine according to claim 1 , wherein
the first magnetic flux suppression hole has two first holes that communicate with inner periphery-side end portions of second magnet insertion holes into which the pair of second permanent magnets is respectively inserted, and a second hole that is formed between the first holes with bridge portions interposed between the second hole and the first holes; and
at least one of the first and second holes includes at least one of a void or a resin having lower relative permeability than that of a magnetic material that forms the rotor core.

5. The rotor for a rotary electric machine according to claim 1 , wherein
the second magnetic flux suppression hole has two third holes that communicate with inner periphery-side end portions of third magnet insertion holes into which the pair of third permanent magnets is respectively inserted, and a fourth hole that is formed between the third holes with bridge portions interposed between the fourth hole and the third holes; and
at least one of the third and fourth holes includes at least one of a void or a resin having lower relative permeability than that of a magnetic material that forms the rotor core.

6. The rotor for a rotary electric machine according to claim 1 , wherein
the first permanent magnet has two permanent magnets that are disposed close to each other forming a substantially V-shape that widens towards an outer periphery in the radial direction.

7. The rotor for a rotary electric machine according to claim 1 , wherein
each of the pair of second permanent magnets has two permanent magnets disposed close to each other so as to form a substantially V-shape that widens towards the first permanent magnet.

8. The rotor for a rotary electric machine according to claim 1 , wherein the pair of third permanent magnets have a flat shape.

9. The rotor for a rotary electric machine according to claim 1 , wherein a cross section, perpendicular to the axial direction of the rotor core, of each of the pair of third permanent magnets, has an elongated rectangular shape.

10. The rotor for a rotary electric machine according to claim 1 , wherein a longitudinal direction of each of the pair of third permanent magnets is disposed substantially along the radial direction.

11. The rotor for a rotary electric machine according to claim 1 , wherein
a radial direction position of the first permanent magnet, a position, in the radial direction, of outer periphery-side end portions of the pair of second permanent magnets in the radial direction, and a position, in the radial direction, of outer periphery-side end portions of the pair of third permanent magnets in the radial direction, are substantially identical to one another.

Assignees

• Sano Shinya
• Takeda Ken
• Inagaki Tomohiro
• Otake Shinichi
• Miyaji Tsuyoshi
• Watanabe Yuta
• Utaka Ryosuke
• Toyota Motor Co Ltd
• Aisin Aw Co
• Denso Corp

Inventors

• Sano Shinya
• Takeda Ken
• Inagaki Tomohiro
• Otake Shinichi
• Miyaji Tsuyoshi
• Watanabe Yuta
• Utaka Ryosuke

Classifications

• H02K1/27 Primary

  Rotor cores with permanent magnets · CPC title

• H02K1/2766 Primary

  having a flux concentration effect · CPC title