Abstract
The rotational vibration by the unbalanced electromagnetic pull force in the rotor eccentricity of the universal motor is studied. In this paper, developed test equipment is described. The natural frequency of rotor system is 200Hz. And, the displacement of the rotor in the resonance was designed to be a parallel mode. The vibration of the rotor in being eccentric for non-pole direction of the stator or pole direction was examined. The effect of the unbalanced electromagnetic pull force of the universal motor for the pole direction is large. And, it is remarkable effect of AC than the direct current.
