摘要 |
A dynamic pressure air bearing unit comprising a rotating shaft and a bearing member fitted around the rotating shaft, wherein a first spiral groove is disposed on a part of one of two cylindrical bearing surfaces facing each other, one being of the rotating shaft and the other of the bearing member, the first spiral groove acting to impel lubrication air between the cylindrical bearing surfaces toward the innermost portion of the bearing member with the rotation of the rotating shaft, and a second spiral groove is disposed on a portion of the cylindrical bearing surface adjacent to the open end of the bearing member, the second spiral groove acting to discharge, air toward the open end of the bearing member, an air conducting passage being provided to connect the boundary portion between the first and second grooves with the outside of the bearing unit, and the air passage having a filter installed at the open end thereof, thereby providing a dynamic pressure air bearing unit capable of operating in an environment subjected to floating dust.
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