| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a touchdown bearing device capable of surely supporting a shaft predetermined times even if the shaft has a long lifetime and rotation speed of the shaft is high, and a turbo-molecular pump of which touchdown bearing device has a long lifetime. <P>SOLUTION: The touchdown bearing device 10 comprises an outer ring 31 fixed on a housing 2, an inner ring 32 including a thick part 70 and a thin part 71 in a radial direction section of an outer ring 31, and a ball 33 interposed between the outer ring 31 and the inner ring 32. The touchdown bearing device 10 is configured so that when a magnetic bearing does not normally operate, the rotary shaft 3 is supported by bringing the rotary shaft into contact with the inner circumference surface against the housing 2. <P>COPYRIGHT: (C)2008,JPO&INPIT |
