US 12,107,470 B2
Rotary electric machine and in-vehicle motor system
Kazutami Tago, Tokyo (JP); Itsuki Shimura, Tokyo (JP); Junnosuke Nakatsugawa, Tokyo (JP); Wataru Yokoyama, Hitachinaka (JP); and Ippei Suzuki, Hitachinaka (JP)
Assigned to Hitachi Astemo, Ltd., Ibaraki (JP)
Appl. No. 17/786,626
Filed by Hitachi Astemo, Ltd., Hitachinaka (JP)
PCT Filed Dec. 15, 2020, PCT No. PCT/JP2020/046661
§ 371(c)(1), (2) Date Jun. 17, 2022,
PCT Pub. No. WO2021/145119, PCT Pub. Date Jul. 22, 2021.
Claims priority of application No. 2020-003747 (JP), filed on Jan. 14, 2020.
Prior Publication US 2023/0024138 A1, Jan. 26, 2023
Int. Cl. H02K 1/27 (2022.01); H02K 1/276 (2022.01); H02K 1/28 (2006.01); H02K 21/16 (2006.01); H02K 7/00 (2006.01)
CPC H02K 21/16 (2013.01) [H02K 1/276 (2013.01); H02K 7/006 (2013.01); H02K 2213/03 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A rotary electric machine comprising:
a stator around which a coil is wound; and
a rotor pivotally supported rotatably on an inner peripheral side of the stator, wherein the rotor includes
a core formed of a soft magnetic metal and
a magnet mounted on the core, and
the core includes
a magnet insertion hole into which the magnet is mounted,
a first magnet stopper portion provided on a q axis side of the magnet in the magnet insertion hole,
a magnet accommodation portion provided between the first magnet stopper portions on both sides of the magnet insertion hole,
a first space portion communicating with the magnet insertion hole,
a second space portion whose distance from the magnet is equal to or less than a thickness of the magnet, the second space portion formed on an inner peripheral side relative to the magnet,
a third space portion that has a convex shape on an inner peripheral side of a q axis of the magnet, and is formed between the second space portion and the magnet,
a bridge portion provided on an outer peripheral side of the first space portion, and
an umbrella-shaped core portion provided on an outer peripheral side of the magnet accommodation portion, wherein
when an intersection of a straight line parallel to a magnetic pole portion center line from a point closest to a magnetic pole portion center of the magnet stopper portion and an inner periphery of the umbrella-shaped core portion is defined as a point R,
a same point facing the point R of an adjacent magnetic pole is defined as a point R′, and
a point at which an angle formed by a q axis and a straight line connecting rotation centers and the first space portions is minimized is defined as a point Q,
a radial thickness of the umbrella-shaped core portion is smaller than rotation radius×(1−cos (magnetic pole pitch angle/2))×0.55+a width of a bridge portion,
C/(magnetic pole pitch angle/2) is approximately ⅔, where C is a central angle formed by a point R and a point R′ at which the magnet accommodation portions are adjacent to and face each other,
D/(magnetic pole pitch angle/2) is approximately 2/9, where D is an angle formed by a straight line connecting a point Q of the first space portion and a center and a straight line connecting the point R and a center,
a width of the bridge portion is substantially constant in a range within D/2 closer to the point R than the point Q, and
a q axis outer periphery of the magnet has a groove space portion that is open to an outer peripheral side of the core and is provided with a wide circumferential width of an outer peripheral side.