Air core reactor for rolling stock

A reactor is equipped with a coil having unit coils. First spacers are disposed in at least one of spaces between the unit coils and in a space between one of the unit coils and a supporting frame. Second spacers are disposed between the first spacers. The supporting frames, the first spacers, and the second spacers are traversed by bolts and are fixed to the bolts. A space is defined between the bolt and a wall surface of a through hole formed in the first spacer and traversed by the bolt. A spacing distance between adjacent first spacers in the central axis direction of the coil is greater than a central-axis-direction thickness of the unit coil located between the adjacent first spacers, the central-axis-direction thickness of the unit coil being of when the coil is not energized.