Magnetically levitated turbomolecular pump

11/01/1996

Magnetically levitated turbomolecular pump

Designed for such applications as plasma etch, ion implant, and coating systems, the MAG 1200 turbomolecular pump relies on the magnetic bearing principle, in which the rotor of the pump is suspended by a permanent magnet passive bearing placed close to the center of gravity. This is combined with a permanent magnetic stabilizer, located at the lower shaft end, and coils that act in the axial direction. The position of the shaft is monitored by an axial sensor placed at the lower shaft; if a deviation from the normal position is detected, the electronics and the power amplifiers supply a drive signal to the coils so that the pump`s rotor position is always maintained at equilibrium without making contact. Leybold Vacuum Products Inc., Export, PA; ph 412/325-6506, fax 412/325-3577