VACUUM PUMP

摘要

PROBLEM TO BE SOLVED: To provide a safe vacuum pump which prevents damages to the pump case, peripheral apparatus and the like by reducing parts broken concurrently in rotor breakage accident and weakening instant breakdown torque. SOLUTION: The rotor 2 is divided into two which is an upper part rotor 21 in a turbine side and a lower part rotor 22 in a skirt side. Time difference for breakage occurring in either of the upper or the lower rotor to spread to breakage of another rotor is generated, so as to reduce peak value of breakdown torque.