Why do the phases of a motor spin the rotor?

[kolleamm]

Assuming we have a 3 phase motor I've always wondered why is it that the rotor spins rather than just being compleltly pulled towards the direction of the phase or the electromagnet? What causes that angular movement?

 

[zoki85]

Assuming we have a 3 phase motor I've always wondered why is it that the rotor spins rather than just being compleltly pulled towards the direction of the phase or the electromagnet? What causes that angular movement?

Rotating magnetic field

 

[anorlunda]

This is a question that is best answered with animations. There are many designs of DC motors and AC motors. The video below animates one of them.