Development of Crash Avoidance Technology for Turbo-molecular Pumps

In this study, the Crash Avoidance Technology (CAT) for Turbo-molecular Pumps (TMPs) is developed. The mechanism of CAT is to handle the axial lift force, exerted by a large amount of gas as the high-speed impeller rotor of Turbo-Molecular Pump (TMP) is instantaneously exposed to the atmosphere, by immediately adjusting the magnetic force induced by the axial magnetic bearing. As the axial force induced by the air to the rotor is reduced, the current supplied to the axial magnetic bearing is adjusted back to the normal value by the controller of CAT. Not only the coils of AMB are prevented from being burned out, but energy consumption is reduced.