Low-profile stepping motor with two coils arranged flush with each other horizontally

摘要

A low-profile stepping motor comprises: an upper twin-stator yoke plate composed of first and second upper stator yokes; a lower twin-stator yoke plate composed of first and second lower stator yokes; first and second coil units fixedly sandwiched between the upper and lower stator yoke plates so as to be arranged horizontally flush with each other; and a rotor assembly including a cylindrical magnet and disposed between the first and second coil units. In the stepping motor, one of the upper and lower twin-stator yoke plates is structured such that one half of its pole teeth partitioned in half by a predetermined datum line and open spaces each residing between two adjacent pole teeth of the other half are positioned symmetrically about the predetermined datum line, whereby the one twin-stator yoke plate can be used in common to the other twin-stator yoke plate.