Algorithm for investigation of impacts of rotors systems supported by radial active magnetic bearings

Abstract

The active magnetic bearings (AMBs) are consist of quite complicated and expensive electromechanical parts and due to this fact they are protected by the auxiliary bearings. If the rotor system design is made so that the clearance between the disc and the stationary part is smaller than between the auxiliary bearing and the shaft journal the contact between those two parts can occur due to the overloading of the rotor system. The influence of radial AMBs and of the impacts in rotor system is usually investigated separately. Eventually, the shaft is modelled as rigid or elastic but massless body. Due to this it is necessary to develop a procedure which makes possible to analyze their mutual behaviour on the rotor system discretized by the finite element method. The proposed procedure is verified on the test rotor system and the influence of Rayleigh coefficient of external damping and of vibration character during the impacts occurring between the disc and the stationary part is investigated by means of numerical simulations.