Rotary electric machine and vehicle

Patent metadata

Field	Value
Publication number	US-2018183289-A1
Application number	US-201815903518-A
Country	US
Kind code	A1
Filing date	Feb 23, 2018
Priority date	Sep 16, 2016
Publication date	Jun 28, 2018
Grant date	—

Abstract

According to embodiments, an electric machine includes a shaft, a rotor core, and a plurality of permanent magnets. The shaft rotates about an axis thereof. The rotor core is fixed to the shaft. The plurality of permanent magnets are provided in the rotor core, and include at least a first permanent magnet and a second permanent magnet. The first permanent magnet has an intrinsic coercive force of 1200 [kA/m] or more. The second permanent magnet has an intrinsic coercive force of 800 [kA/m] or more, a residual magnetization substantially the same as or larger than that of the first permanent magnet, and a recoil permeability smaller than that of the first permanent magnet.

First claim

What is claimed is:

1 . A rotary electric machine comprising:
a shaft rotating about an axis thereof; a rotor core fixed to the shaft; and a plurality of permanent magnets provided in the rotor core, wherein the plurality of permanent magnets include at least: a first permanent magnet which has an intrinsic coercive force of 1200 [kA/m] or more; and a second permanent magnet which has an intrinsic coercive force of 800 [kA/m] or more, whose residual magnetization is substantially the same as or larger than that of the first permanent magnet, and whose recoil permeability is smaller than that of the first permanent magnet.

2 . The rotary electric machine according to claim 1 , wherein the first permanent magnet and the second permanent magnet are disposed to correspond to the same rotor magnetic pole.

3 . The rotary electric machine according to claim 1 , wherein the first permanent magnet and the second permanent magnet are magnetically disposed in parallel or in series.

4 . The rotary electric machine according to claim 1 , wherein a residual magnetization of the first permanent magnet and the second permanent magnet is 1.16 [T] or more.

5 . The rotary electric machine according to claim 1 , wherein a residual magnetization of the second permanent magnet is larger than a residual magnetization of the first permanent magnet.

6 . The rotary electric machine according to claim 1 , wherein:
a recoil permeability of the first permanent magnet is 1.1 or more; and a recoil permeability of the second permanent magnet is less than 1.1.

7 . The rotary electric machine according to claim 1 , wherein a composition formula of the first permanent magnet is RpFeqMrCutCo 100-p-q-r-s-t in which:
R is at least one element selected from rare earth elements; Fe is the element iron; M is at least one element selected from titanium, zirconium, and hafnium; Cu is the element copper; Co is the element cobalt; and p, q, r, s and t are numbers respectively satisfying 10.8≤p≤11.6, 25≤q≤40, 0.88≤r≤4.5, and 0.88≤t≤13.5 when each of p, q, r, s and t is expressed as an atomic composition percentage.

8 . The rotary electric machine according to claim 1 , wherein a composition formula of the second permanent magnet is RsTuBv in which:
R is at least one element selected from rare earth elements; T is formed of iron and at least one element selected from cobalt, nickel, copper, aluminum, zinc, silicon, gadolinium, and gallium; B is the element boron; and s and v are numbers respectively satisfying 10≤s≤25, 2≤q≤20, and u=100−s−v, when each of s and v is expressed as an atomic composition percentage.

9 . The rotary electric machine according to claim 1 , wherein the first permanent magnet is disposed on an outer circumferential side of the rotor core with respect to the second permanent magnet.

10 . A vehicle including the rotary electric machine according to claim 1 .

Assignees

• Toshiba Kk

Inventors

• Horiuchi Yosuke
• Sakurada Shinya
• Matsushita Makoto
• Takahashi Norio
• Hasebe Toshio
• Tokumasu Tadashi
• Okamoto Keiko

Classifications

• H02K21/028

  by modifying the magnetic circuit within the field or the armature, e.g. by using shunts, by adjusting the magnets position, by vectorial combination of field or armature sections · CPC title

• H02K1/2773 Primary

  consisting of tangentially magnetized radial magnets · CPC title

• H01F41/0293

  diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets · CPC title

• H01F1/057

  and IIIa elements, e.g. Nd2Fe14B · CPC title

• H02K2213/03

  Machines characterised by numerical values, ranges, mathematical expressions or similar information · CPC title