Field magneton of rotary electric machine

A field magneton of a rotary electric machine, comprising:

• a plurality of magnets arranged annularly in a prescribed array and around an axis of the rotary electric machine;
• and
• a yoke provided along one of an inner peripheral surface and an outer peripheral surface of each of the magnets,
• wherein the yoke includes:
• a cylindrical main body extending in an axial direction from a first end surface of each of the magnets in the axial direction to a second end surface thereof in the axial direction;
• and
• an annular flange extending from the main body in a radial direction and including an abutting surface configured to abut against the first end surface of each of the magnets in the axial direction, and
• the abutting surface is provided with both of an annular circumferential groove and a plurality of radial grooves, the circumferential groove being formed at an intermediate position separated away from a base edge and a tip edge of the abutting surface in the radial direction, the plurality of radial grooves being formed at prescribed intervals in a circumferential direction of the abutting surface and extending from the base edge to the tip edge.