PURPOSE: To increase the mechanical strength of the upper wall section and lower wall section of a coil groove, and to improve the workability of coil winding by making the width of a groove opening section on the leading side of a slit section narrower than that on the trading side.
CONSTITUTION: Width 31b on the leading side of a coil groove 31 is made narrower than that 31a on the trading side. It is favorable that width 31a on the trading side is at least one and half times of width 31b on the leading side. Physical strength such as shock resistance can be increased remarkably by thickening upper and lower walls 2a, 2b on the leading side, and a magnetic field generated can be augmented because the number of coil superposition on the outside of width 31a on the trading side is made smaller than that on the inside even when a coil is multiplex-wound by widening the width of the width 31a on the trading side. Accordingly, strength at a trading section against external force such as a shock or the stress of multiplex-wound coil can be increased.
KUBO TSUYOSHI
HIGASHIHARA RYUZO
| JPS6424514U | 1989-02-09 |