Hey Monte......, its good to hear from you again.

I like to think of it as a dog chasing its own tail. By the time its mouth gets there, the tail has moved on - so it chases it again, -- ad infinitum.

In a three phase induction motor, each set of stator windings receives electrical energy 120 degrees out of phase from the next. As current (thus magnetism) peaks, it pulls its polar complement on the rotor towards it. But by the time it gets there, the energy peak is transferring on to the next phase winding, and so on and so on. As magnetic field strength fades in one coil, it is building up in the next. Due to the "vectored" nature of magnetic force (all force actually); the magnetic field rotates fairly smoothly around the stator, just as if it were a dogs tail, with the dogs mouth (rotor) close behind of course.

In a DC motor, the stator windings (sometimes called field windings) maintain their polarity. But on the rotor (or armature), winding are overlapped with each other. As each coil on the rotor winding just reaches for its tail (the stator winding) so to speak, the commutator switches out that coil and switches in the next; so that the dog is tricked into thinking it is still in the next coil back, and so just keeps on reaching for it tail. This just keeps on happening; and like most dogs, its too dumb to ever figure it out it has been tricked agian and again.

Not only that, but as each rotor coil passes the stator winding, current is reversed so that like magnetic poles are now repelling each other. So while one rotor coil is pushing away, the next is pulling towards.

Hope that paints a a good enough picture -- see ya.

OPB