Design of high temperature high speed electromagnetic axial thrust bearing

Abstract

The National Aeronautics and Space Administration (NASA) is researching the magnetic bearings to use it as a better alternative to conventional bearings. This research was to develop an axial thrust electromagnetic bearing for high performance jet engines. This electromagnetic bearing, rotating at high speed, must be able to handle a significant amount of axial thrust load in a high temperature environment. The primary struggle to design such a bearing was to overcome the centrifugal stresses developed in the rotor. In usual practice, the rotor is attached to the shaft by interference fit. This adds more stress on the rotor. Both types of stresses are maximum at the same spot on the inner radius of the rotor disk. It makes the situation worse. The thesis incorporates the finite element modeling of the rotor rotating at high speed with other boundary conditions on it. The rotor stress was modeled with and without interference fit. The interference fit was also varied. As a requirement of the grant, it was necessary to check two different rotors with different inner diameter. Engineering design handbook formulae were used to cross check the finite element analysis. A concept was developed to build a test rig to do performance analysis of the thrust bearing.