| 摘要 |
PROBLEM TO BE SOLVED: To reduce the contamination source of gas discharge with a high repetition count, by supporting a fan for circulating a laser gas by an active magnetic bearing device, and by sealing the rotor of a brushless DC motor and that of two bearings in the gas environment of a laser cavity. SOLUTION: Each end part of a shaft 13 of a 26-inch fan 46 for circulating a laser gas is supported by two radial magnetic bearing devices 20 and 22. The radial magnetic bearing devices 20 and 22 position each of four electromagnets 26 at positions with the radius directions of 45, 135, 225, and 315 degrees. A brushless DC motor is formed by a stator 140 and a rotor. The rotor of the brushless DC motor and that of two bearings are sealed against the stator 140 by a sealing member 136 in the gas environment of a laser cavity. |
