Abstract
Hybrid ceramic type and normal type bearings used for a 3kHz high-repetition-rate XeCl excimer laser, which contained a high speed three-stage axial blower and a magnetic coupling whose rotating speed were 2, 000rpm to 8, 000rpm typically 3, 000rpm, have been evaluated in excimer laser gas and atmosphere, respectively. These bearings were tested from Dec./1987 to Mar./1991, actual using time was over 5, 000hours.
Only a few erosions in sintering additive alumina Al2O3 and yttria Y2O3 of a silicon nitride Si3N4 ceramic ball have been observed with a SEM photograph and an EDS method, but didn't affect for a long time operation. No corrosion in a flouried grease BARRIERTA IEL/V has been detected with FT-IR technique which indicated the ingredients of oil. A heavy erosion in inner and outer raceways made by SUS440C with Ni coating on the surface has been detected. Two of four hybrid ceramic type bearings were rocked between inner raceway and ceramic balls and all Ni coating of them were split away. Two normal type bearings used in atmosphere did indicate no erosion and no abrasion at just the same rotating speed and the using time.
For a long time operation, it is necessary to reconsider about the materials of the raceways, but the silicon nitride Si3N4 ceramic balls and the flouried grease BARRIERTA IEL/V are possible to use.
