Patent ID: 6577664
Filing Date: 2003-06-10
Classification: F16C,H01S

Abstract:
A gas laser device including a halogen gas including magnetic bearings each having an inner ring section mounted on the outer periphery of a rotating shaft and an outer ring section supported by a chamber, and a cross flow fan rotatably supported in a non-contact state in said chamber by said magnetic bearings via said rotating shaft and circulating a laser gas in said chamber, comprising:touch-down bearings on the outer peripheral side of said rotating shaft, a partition wall provided at an inner peripheral side of said outer ring section, for insulating said outer ring section from the laser gas, wherein said outer ring sections of said magnetic bearings are sealed on the side of said partition wall away from said laser gas, and wherein said touch-down bearings are in the same space as said rotating shaft, wherein the inner peripheral face of an inner peripheral portion of said touch-down bearing and the outer peripheral face of said rotating shaft are disposed opposite each other with a predetermined clearance which is not substantially zero, and when said rotating shaft is normally rotated, said touch-down bearing and said rotating shaft are kept at a non-contact state, and wherein the predetermined clearance is smaller than a gap between the outer periphery face of said magnetic bearing inner ring section and an inner periphery face of said partition wall, and when said rotating shaft abnormally vibrates, said touch-down bearing and said rotating shaft are in contact with each other to prevent said magnetic bearing inner ring section from being in contact with said partition wall.