US 11,936,239 B2
Bi-material permanent magnets for electric machines
Alireza Fatemi, Canton, MI (US); Anil K. Sachdev, Rochester Hills, MI (US); Jian Yao, Shanghai (CN); Anthony M. Coppola, Rochester Hills, MI (US); Thomas W. Nehl, Shelby Township, MI (US); and Chengwu Duan, Shanghai (CN)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Dec. 9, 2020, as Appl. No. 17/116,661.
Claims priority of application No. 202011346829.9 (CN), filed on Nov. 26, 2020.
Prior Publication US 2022/0166264 A1, May 26, 2022
Int. Cl. H02K 1/02 (2006.01); H01F 1/032 (2006.01); H01F 1/053 (2006.01); H01F 41/02 (2006.01); H02K 1/2793 (2022.01); H02K 1/32 (2006.01); H02K 15/03 (2006.01); H02K 21/24 (2006.01)
CPC H02K 1/02 (2013.01) [H01F 1/032 (2013.01); H01F 1/053 (2013.01); H01F 41/0253 (2013.01); H01F 41/0266 (2013.01); H02K 1/2793 (2013.01); H02K 1/32 (2013.01); H02K 15/03 (2013.01); H02K 21/24 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A rotor for an electric machine, comprising:
a rotor portion defining a plurality of slots; and
a plurality of bi-material permanent magnets each positioned in one of the plurality of slots, at least one bi-material permanent magnet including:
a core including a first magnetic material and defining one or more cooling channels formed in the first magnetic material; and
a shell portion located on the core and made of a second magnetic material,
wherein the one or more cooling channels extend within the bi-material permanent magnet from one side of the core to an opposite side of the core and are enclosed by the shell portion of the bi-material permanent magnet,
wherein the first magnetic material comprises a magnet material with an energy less than 20 Mega Gauss Oersteds (MGOe), and
wherein the second magnetic material comprises a magnet material with an energy greater than 30 MGOe.