US Patent 10128700 Rotary electric machine armature core

A core segment linked body is configured by linking a plurality of core segments by inserting first shafts of first core segments into first slots of core segments near a first longitudinal end thereof, and inserting second shafts of core segments near the first longitudinal end thereof into second slots of the first core segments, the linked core segments are expandable and contractible between an expanded position in which an interval between the magnetic pole tooth is expanded and a contracted position in which the interval is reduced by the first shafts being guided by the first slots and the second shafts being guided by the second slots, and central axes of the first shafts and the second shafts are: offset in a longitudinal direction of the back yoke in the expanded position; and positioned collinearly in a direction of lamination in the contracted position.