Patent ID: 7518270
Filing Date: 2009-04-14
Classification: H02K

Abstract:
1. A stepper motor, comprising: a rotor having a plurality of equally spaced rotor teeth, the number of rotor teeth together with a specified number of phases defining a full step angle; and a stator with a plurality of stator poles wound with coils that can be driven in a series of phases so as to magnetically interact with the rotor, each stator pole having a specified number of stator teeth with an average stator tooth pitch different than a pitch of the equally spaced rotor teeth, wherein the stator teeth are organized into at least two groups of stator teeth with at least one of said groups displaced relative to another of said groups by a specified offset angle, wherein there is an even number of stator teeth on each stator pole and the stator teeth are organized into two groups, the specified offset angle being one-half of a full step angle.