| 摘要 |
PROBLEM TO BE SOLVED: To prevent jointing parts which are adjacent to each other in a circumferential direction from being brought into contact with each other. SOLUTION: In a jointing part 25, in which a coil protruding part 4c of a lower layer coil 4 is jointed with the coil protruding part 5c of an upper layer coil 5 by means of arc weld, its outer periphery position 25a in a diametrical direction is the maximum on the axial end surface 5d of the upper layer coil end part 5b (that is, diametrical outer periphery end 25a of the jointing part 25 is formed on the axial end surface 5d of the upper layer coil end part 5b). A diametrical inner periphery end 25b is positioned further on the inner periphery side in a diametrical direction than a diametrical inner periphery end surface 4d of the lower layer coil protruding part 4c. A width 25W in the circumferential direction of the jointing part 25 is formed, so as to be wider than the width 5W in the circumferential direction of the upper layer coil protruding part 5c as a result of molten base material which expanded in the circumferetial direction. This arc weld is conducted, while the electrode of a welding torch is being oscillated to lower layer coil protruding part 4c side and upper-layer coil protruding part 5c side with the jointed boundary part of both the coil-protruding parts 4c, 5c and centers. |
