US 12,456,891 B2
Field magneton
Yuki Takahashi, Kariya (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on Aug. 30, 2023, as Appl. No. 18/458,623.
Application 18/458,623 is a continuation of application No. PCT/JP2022/007723, filed on Feb. 24, 2022.
Claims priority of application No. 2021-032025 (JP), filed on Mar. 1, 2021.
Prior Publication US 2023/0412022 A1, Dec. 21, 2023
Int. Cl. H02K 1/27 (2022.01); H02K 1/278 (2022.01); H02K 21/14 (2006.01)
CPC H02K 1/278 (2013.01) [H02K 21/145 (2013.01); H02K 2213/03 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A field magneton constituting a rotating electric machine including an armature having an armature winding, and arranged radially facing the armature, comprising:
a magnet having a plurality of magnetic poles with alternating polarities in a circumferential direction, wherein
the magnet is oriented so that a direction of an axis of easy magnetization on a d-axis side, which is a magnetic pole center, is closer to a direction of the d-axis than the direction of the axis of easy magnetization on a q-axis side, which is a magnetic pole boundary,
in the magnet, a coefficient of linear expansion in the direction of the axis of easy magnetization is positive and the coefficient of linear expansion in the direction perpendicular to the axis of easy magnetization is negative, and an absolute value of the coefficient of linear expansion in the direction perpendicular to the axis of easy magnetization is larger than the absolute value of the coefficient of linear expansion in the direction of the axis of easy magnetization,
an amount of dimensional change in the circumferential direction per unit temperature change in a d-axis portion of the magnet is referred to as Fd,
an amount of dimensional change in the circumferential direction per unit temperature change in a q-axis portion of the magnet is referred to as Fq, and
a direction of the axis of easy magnetization on the d-axis side is closer to the direction of the d-axis side than the direction of the axis of easy magnetization on the q-axis side, and the magnet is oriented so as to satisfy Equation 1.
0.81≤|Fd/Fq|<1  (Equation 1).