High torque robot motor

Claim 1

An improved electric motor of the type having first and second stators having stator poles and a rotor mounted between them, the rotor and the stators each having opposing teeth, and electric coils wrapped about the stator poles for generating a magnetic flux therein and in the rotor which flux brings some segment of the rotor teeth into alignment with the opposed teeth of the magnetically energized stator poles, wherein the improvement comprises: opposed stator pole pieces on the first and second stators, with the stator teeth projecting from the pole pieces, the rotor teeth project from the surface of the rotor in opposition to the stator pole piece teeth and have the same angular pitch as the opposing stator teeth, and a plurality of coils, a single one of each of said coils encircling a separate one of the stator pole pieces, the coils of opposed pole pieces being connected together as a pair and a plurality of such pairs being connected together to form a single one of a plurality of phases, the coils of each phase being wound on stator pole pieces which as a group have pole piece teeth which are all simultaneously alignable with the opposing rotor teeth, the coils being connected and wound such that when a particular phase is energized, a magnetic flux is generated in each stator pole piece of such phase which flux has a magnetic polarity opposite to the magnetic polarity of the flux generated in the opposed pole piece and in the nearest stator pole piece of the same phase and also opposite to the magnetic polarity of the flux generated in the immediately adjacent pole piece during the preceding energized phase, whereby the rotor teeth align with the stator pole piece teeth of the energized phase and the magnetic flux generated travels only in stators between adjacent stator poles of the energized phase, only travels in the rotor transversely, and only travels through the rotor between opposed poles of the energized phase.