Patent ID: 6714733
Filing Date: 2004-03-30
Classification: H02K

Abstract:
A step motor comprising:a rotor which is rotatably supported and which is comprised of a magnet having magnetic poles magnetized in four angular sections; a first stator which has a pair of counter poles disposed in opposed relation to the magnet and a coil wound around the first stator; a second stator which has another pair of counter poles disposed in opposed relation to the magnet and another coil wound around the second stator, the second stator being opposite to the first stator with respect to the rotor such that the counter poles of the first and second stators surround the rotor to stepwise rotate the rotor in response to electric pulses applied to the coils of the first and second stators; and a magnetic member having a pair of spaced apart interpoles positioned in a middle of the first and second stators in opposed relation to the rotor wherein, in a first stop state of the rotor, each of said interpoles attracts a different magnetic pole of the rotor, and in a second stop state of the rotor, both of said interpoles attract a same single magnetic pole of the rotor to stabilize a rest position of the rotor, which is held when the electric pulse is not applied to the coils.