High-Speed Rotor Suspension Formed by Fully Floating Hydrodynamic Radial and Thrust Bearings

The hydrodynamic suspension of a 44,000-rpm gas turbine rotor is described with emphasis on interaction between the flexible rotor and its supports. Bearings with relatively large clearances are shown to allow continuous operation at the rotor first critical-speed of 22,000 rpm. The apparent absence of hydrodynamic system instabilities is attributed to the use of simple floating-sleeve bearings. A parametric study of the influence of bearing clearances upon vibrational excitation relief is presented together with test data collected on actual system hardware.