Rotordynamics of 120$\thinspace$000 r/min 15 kW Ultra High Speed Motor

Abstract

This paper introduces a rotor with shrink fit and analyzes its rotordynamics by 3-D FEA. An ultra high speed motor prototype is manufactured for fuel cells at the rating of 15 kW, 120000 r/min. First, the stability of the rotor structure with shrink fit is evaluated in non-loading and loading condition (120 000 r/min, 210degC). And then the 3-D rotordynamics analysis and Campbell diagram considering shrink fit are examined for the critical speed of rotor. The analysis shows that the critical speed of the rotor is higher when the rotor is shrink fitted than when the rotor is not shrink fitted. The analysis also shows the increase of shaft stiffness when the rotor is shrink fitted.