| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a static pressure gas bearing spindle capable of preventing permeation of working fluid into a seal gap. <P>SOLUTION: The static pressure gas bearing spindle includes a rotating shaft 1 in which a through-hole 28 is formed. The static pressure gas bearing spindle includes a housing 2 which rotatably supports the rotating shaft 1 through a static pressure gas bearing. The bearing spindle further includes a sucking mechanism for depressurizing the inside of the through-hole 28 to suck and fix a workpiece to a workpiece chuck surface 30 to which one end of the through-hole 28 is open. A vent hole 26 for circulating a gas for changing the pressure inside the through-hole 28 is formed in a cover 8. The seal gap separating the vent hole 26 from the static pressure gas bearing is formed between the rotating shaft 1 and the housing 7. The bearing spindle further includes a fluid flow suppressing part which is formed in a passage allowing the vent hole 26 to communicate with the seal gap and which suppresses the permeation of the fluid flowing to the vent hole 26 side in the through-hole 28 into the seal gap. <P>COPYRIGHT: (C)2009,JPO&INPIT |
