| 摘要 |
The present invention is provided with a core back obtained by layering a plurality of strip-shaped core back piece groups obtained by connecting a plurality of arcuate core back pieces (1a, 1b, 1c, 1d, 1e, 1f), and a plurality of teeth that are obtained by layering a plurality of tooth pieces (2a, 2b, 2c, 2d, 2e), are disposed on the radial inside of the annularly formed core back groups, and are made to extend toward the center of the core back. Groove sections (1a1, 1b1, 1c1, 1d1, 1e1, 1f1) shaped so as to respectively fit with the end sections of the plurality of tooth pieces (2a, 2b, 2c, 2d, 2e, 2f) are formed in the respective concave surfaces of the plurality of core back pieces (1a, 1b, 1c, 1d, 1e, 1f). |
