This paper describes a dynamic analysis of the rotor bearing system on rotary crushers and shredder which dispose of large sized discarded articles such as refrigerators, washing machines, bicycles and kitchen utensils. In the analytical model, the rotary share type shredder with knifes, the vertical type crusher with breakers and the horizontal type crusher with swing hammers are simplified to mass and spring system on the rotational vibration and on the bending vibration. In order to clear the relation between bearing vibration and rotor speed drop, simulation is carried out by using Runge-Kutta-Gill method. Calculation of results indicate that bearing vibration is related well to the rotor dynamic behavior similar to the rotor speed drop.
