To make it possible to brake a rotor rotor under control effectively and automatically at emergency time.
A turbo-molecular pump has a sealed container 100 including an inner vertical supporting member for supporting a hollow rotor through a dynamic magnetic bearing. The hollow rotor with a fixed fin is driven by an n-phase brushless motor, where n is an integer. In the container 100, at least one of emergency resistors 131 to 133 and a connecting means are provided. The emergency resistors 131 to 133 are connected automatically with the n-number of phases of the electric motor if an outer control module 10 for controlling the electric motor and the magnetic bearing is out of order or a defect in the cable is caused between the outer control module 10 and the sealed container 100. Then, the electric motor is operated as a generator, and an electrical braking means for the hollow rotor is provided.
JP2568364 | TURBOPUMP WITH TRAP PANEL |
JPH11247790 | VACUUM PUMP |
JP5809218 | Vacuum pump |
SCHROEDER ULRICH
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