US 12,231,003 B2
Magnetic circuit with more than one magnet type
Bruno P. Lequesne, Menomonee Falls, WI (US)
Assigned to Niron Magnetics, Inc., Minneapolis, MN (US)
Filed by Niron Magnetics, Inc., Minneapolis, MN (US)
Filed on Mar. 22, 2022, as Appl. No. 17/701,047.
Prior Publication US 2023/0307970 A1, Sep. 28, 2023
Int. Cl. H02K 1/27 (2022.01); H02K 1/02 (2006.01); H02K 1/276 (2022.01)
CPC H02K 1/2766 (2013.01) [H02K 1/02 (2013.01)] 24 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
a first magnet with a first remanence value and a first coercivity value, the first magnet having a first cross-sectional area substantially normal to a direction of magnetization of the first magnet;
a second magnet positioned in series with the first magnet, the second magnet with a second remanence value and a second coercivity value that is less than the first coercivity value, the second magnet having a second cross-sectional area substantially normal to a direction of magnetization of the second magnet; and
an electric machine including a stator and a rotor separated from the stator by a gap between the stator and the rotor;
wherein the first magnet and the second magnet are positioned in series in only one of the stator or the rotor, and the first magnet is positioned closer to the gap than is the second magnet;
wherein a ratio of the first cross-sectional area to the second cross-sectional area is equal to or greater than a ratio of the second remanence value to the first remanence value.