Staas & Halsey LLP
Method for driving stepping motor of multiphase hybrid type
 A multi-phase hybrid type stepping motor includes a rotor which is rotatably mounted on a rotary shaft. A rotor magnet is mounted to an axial center of the rotor and two rotor caps are mounted to both sides of the rotor magnet respectively. Each of said rotor caps has a plurality of rotor teeth of predetermined pitch disposed about a perimeter thereof. A stator encircles said rotor cap and includes a first plurality of magnetic poles and a second plurality of magnetic poles alternately disposed between said first plurality of magnetic poles. The first plurality of magnetic poles includes a first predetermined number of teeth disposed on an inward end thereof while the second plurality of magnetic poles has a second predetermined number of teeth disposed on an inward end thereof. The first and second predetermined number of teeth have the same pitch as the rotor teeth. Each of said second plurality of magnetic poles includes a second predetermined number of teeth greater than said first predetermined number of teeth. 
Minebea Co., Ltd.
H
H02K
inventional
Noriyuki Kenji
Yoshimura Yoshida