A hybrid bearing concept for high-speed applications employing aerodynamic gas-bearings and a self-sensing active magnetic damper

Abstract

Successful application of ultra high-speed electrical drive systems in industrial products is currently limited by lacking high-speed bearing technologies permitting high reliability and long lifetime. Promising bearing technologies for high rotational speeds are contact-less bearing concepts such as active magnetic bearings or gas bearings. While magnetic bearings usually are major electromechanical systems with substantial complexity, gas bearings allow compact realizations with high load capacity and stiffness; however poor dynamic stability has been limiting their use at high rotational speeds. For a new hybrid bearing concept employing an aerodynamic gas bearing for load support, a small-sized self-sensing active magnetic damper is proposed allowing to effectively counteract the self-excited whirl instability of the gas bearing and therewith enabling high speed operation with a minimum of additional complexity and costs.