Investigation of Dynamics of Damped Bearing-Rotor System of Centrifugal Milk Separator

Abstract

This paper analyses the dynamic behaviour of centrifugal milk separator's bearing-rotor system equipped with vibration absorbers. It is shown that rotational milk motion inside the separator causes a centrifugal force that increases dynamic unbalance of the rotor and has a negative effect on performance of the bearings. Mathematical simulation of bearing-rotor system has shown that the rotor rotates at frequency that is outside the resonant frequency region and the amplitude resonances are associated with the bearings and the components of step-up gear. Investigations of vibration transmissibility of vibration damping system have shown that the resonant frequencies are outside the rotor resonance interval and damping system suppresses the effect of separator with milk on rotor bearings and housing. However, it distorts results of diagnostic measurements. Experimental studies confirmed the last statement and showed that results of indirect (through the housing) vibration measurements cannot be used to diagnose the state of damped bearing-rotor system.

The annulling of the sudden appearance of an unbalance in rotary machines by using active magnetic bearings

“…They support rotating elements and have the task of ensuring relative movement and load transfer from moving elements to the machine construction, as well as ensuring the required accuracy between parts in relative movement [1]. Friction and mechanical vibrations are the main causes of problems that prevent bearings from performing their function effectively in machines [2][3][4][5]. Therefore, active magnetic bearings (AMB) are increasingly being used in applications for the support of rotating elements.…”