| 摘要 |
PROBLEM TO BE SOLVED: To efficiently cool a rotating shaft constituting a rotor, particularly, a part of the rotor, so that, for example when clearance between a moving blade and a stationary blade provided facing the moving blade is changed, resulting in exhaust performance being changed, an alarm is issued, or operation of a pump is stopped, allowing the pump to be protected. SOLUTION: A turbo-molecular pump, in which the rotor is magnetically levitated by magnetic bearings 50, 52 and 58 and the rotor is rotated at high speed by a motor 12 so that gas is exhausted, includes: a cooling gas introducing portion 64 introducing cooling gas to the magnetic bearing 50, 52 and 58; and a pressure detecting portion 68 detecting a pressure of the cooling gas introduced to the magnetic bearings. When the pressure detected by the pressure detecting portion 68 during operation of the pump becomes a specified pressure or below, the alarm is issued, or the operation of the pump is stopped. COPYRIGHT: (C)2011,JPO&INPIT |
