Patent ID: 6885128

Claim:
A low-profile stepping motor comprising a first stator unit including: a first upper stator yoke having a plurality of pole teeth which are formed along its semicircular inner circumference, the first upper stator yoke having a hollow-cylindrical protrusion with a top lid; a first lower stator yoke having a plurality of pole teeth which are formed along its semicircular inner circumference and which mesh with the pole teeth of the first upper stator yoke, the first lower stator yoke having a hollow-cylindrical protrusion with a top lid, which opposes the protrusion of the first upper stator yoke thus configuring a pair of opposing protrusions; and a first coil unit fixedly sandwiched between the first upper and lower stator yokes, a second stator unit including: a second upper stator yoke formed as one piece integrally with the first upper stator yoke, and having a plurality of pole teeth which are formed along its semicircular inner circumference, the second upper stator yoke having a hollow-cylindrical protrusion with a top lid; a second lower stator yoke formed as one piece integrally with the first lower stator yoke, and having a plurality of pole teeth which are formed along its semicircular inner circumference and which mesh with the pole teeth of the second upper stator yoke, the second lower stator yoke having a hollow-cylindrical protrusion with a top lid, which opposes the protrusion of the second upper stator yoke thus configuring a pair of opposing protrusions; and a second coil unit fixedly sandwiched between the second upper and lower stator yokes and arranged horizontally flush with the first coil unit, and a rotor assembly rotatably disposed in a circular open space defined by the pole teeth of the first and second stator units.