Abstract: The motion equations of medium layers are established to study the motion laws of media in the interior of a vibration mill. Considering elastic force and damping force, the differential equations of the vibration mill are suggested to describe the dynamic characteristics of the body. The stress and deforming of the body are analyzed on simple harmonic exciting force. The research results indicate that media held a given frequency do rotary motion around the center of the grinding body in the proper vibration intensity, and form a steady circle motion locus in some regions but form a cascade of motion in other regions. The grinding body occurs a circular motion on the persistent exciting force, which makes up the deficiency of energy in center of the cylinder and changes the kinetic state of media, thereby obtains more efficient grinding effects and uniform grain size. The dynamic loading coefficient increases suddenly, and the amplitude of system is close to maximum when the exciting frequency approaches natural frequency of the system, which should be avoided in the structural design.

Key words: Dynamic analysis, Excited frequency, Powder processing, Vibration mill