| 摘要 |
PROBLEM TO BE SOLVED: To suppress stress concentration on a support part while suppressing a decrease in torque.SOLUTION: A first edge 51 is extended to the side of a core inner-periphery part 27 in such a manner that a support part 28 side end of a first inner surface 41a serves as a base point, and curved to become convex toward the side of a core outer-periphery part 26. A second edge 52 is curved to become convex toward the side of the core inner-periphery part 27, on the side of the core inner-periphery part 27 with respect to a second inner surface 41b, in such a manner that a core inner-periphery part 27 side end of a connection edge 53 serves as a base point P3. |
