Patent ID: 11881341
Assignee: DENSO CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. A method of manufacturing a core sheet, the core sheet having an annular core back portion and a plurality of tooth portions extending from the annular core back portion toward a radial center thereof,
the method comprising steps of:
partially removing, from a grain-oriented magnetic steel sheet having an easy direction of magnetization in one in-plane direction and an insulation coating formed on its surface to apply tension in the easy direction of magnetization, the insulation coating on a region for forming a band-shaped core back portion which extends in a perpendicular direction to the easy direction of magnetization;
blanking out a sheet piece from the grain-oriented magnetic steel sheet, the sheet piece having a band-shaped core back portion present in the region for forming a band-shaped core back portion and a plurality of parallel tooth portions extending, from the band-shaped core back portion, parallel to the easy direction of magnetization; and
rolling the sheet piece, with the parallel tooth portions being on an inner side, into an annular shape, thereby obtaining the core sheet having the core back portion and the tooth portions.