| 摘要 |
PURPOSE:To increase frictional force between foil winding and a sheet-shaped insulating member, and to prevent displacement in the vertical direction by winding the whole foil winding in a barrel shape of which the outer circumferential surface of a central section expands. CONSTITUTION:The thickness of a cylindrical wound core 16 existing on the outer circumference of the leg section 1 of a core is thickened in the central section, and thinned toward upper and lower end sections. Metallic foil 2 and the sheet-shaped insulating members 3 are wound around the barrel-shaped wound core 16, and the foil winding is constituted. When the metallic foil 2 on the right side intends to be displaced downward, strong tensile force equal to force required for stretching the metallic foil 2 only by pi.d is generated in a sheet because a point S on the metallic foil 2 shifts to S' and the circumferential length of the point S' is longer than that of the point S only by pi.d, and large frictional force is generated, and functions as force preventing displacement in the vertical direction. |
