A Novel Rolling Element Back-Up Bearing for a 9t Rotor Application

The paper outlines the development of a novel backup bearing unit which complements Siemens’ new magnetic bearings for an electric motor with a 9 t rotor. The back-up bearing utilizes rolling bearing elements. Principles for the rotor supported by the back-up bearings are derived and used to design the novel, so-called “Smiley” design. Dynamic simulations are presented predicting that the system fulfils the requirements. This is proven by comparison with experimental data.