US 11,929,646 B2
Rotor for an electric machine
Paul David Flower, Buckinghamshire (GB); and Anthony Kelly, Buckinghamshire (GB)
Assigned to SAFRAN ELECTRICAL & POWER, Blagnac (FR)
Appl. No. 17/413,095
Filed by SAFRAN ELECTRICAL & POWER, Blagnac (FR)
PCT Filed Dec. 11, 2019, PCT No. PCT/EP2019/084700
§ 371(c)(1), (2) Date Jun. 11, 2021,
PCT Pub. No. WO2020/120599, PCT Pub. Date Jun. 18, 2020.
Claims priority of application No. 1820467 (GB), filed on Dec. 14, 2018.
Prior Publication US 2022/0014054 A1, Jan. 13, 2022
Int. Cl. H02K 1/24 (2006.01); B64D 27/24 (2006.01); H02K 1/02 (2006.01); H02K 15/02 (2006.01)
CPC H02K 1/246 (2013.01) [B64D 27/24 (2013.01); H02K 1/02 (2013.01); H02K 15/022 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An electric machine for an aircraft, comprising:
a stator; and
a rotor, rotatably journaled to rotate about a rotation axis within the stator, the rotor comprising:
a hollow tube forming a shaft portion;
a core pack portion, comprising a plurality of poles disposed around the shaft portion; and
a back iron portion, configured to provide a path for magnetic flux to flow between adjacent poles of the core pack portion, the back iron portion being at least partially formed by the shaft portion,
wherein the shaft portion comprises at least one shaft end which extends axially beyond the core pack portion, and wherein the shaft portion, the core pack portion and the back iron portion comprise a soft magnetic material, and
wherein an internal diameter of the shaft portion is reduced in a back iron region which is longitudinally aligned, along the rotation axis, with the core pack portion.