vibrations-excited-in-ring-shaped-spaces-1about 10 cmACDEGBFRotor vibrations can be caused by air vibrations in sealed ring-shaped spaces. Oil supply for theoil cushionOil cushion in a ring-shaped space sealed byO-ringsOuter bearing ringElastically suspended, Oil-damped bearing carrierSchematic diagram of an oil-damped, elastically suspended bearing= Bearing planesInfluence of TOBI labyrinth sealsAerodynamiccoupling with TOBI Flange hysteresis(flange friction)Shaft hysteresis(inner friction)Potential instability-promoting effects at the high-pressure rotorAlford's ForceAlford's ForceHPCHPTDamping in the bearing bracesInfluence of inlet pressureat the fan on the vibrationexcitement