| 摘要 |
PURPOSE:To prevent dust in the compressed gas supporting a main spindle from adhering to the surface of a workpiece placed on a table. CONSTITUTION:A chuck sleeve 5 and a bearing sleeve 3 are vertically fitted into the sleeve fitting hole of a housing 1, and an exhaust space 19 formed between both sleeves 3, 5 is communicated with the outside through an exhaust passage 21 provided at the housing 1. A table 7 for supporting a workpiece is fitted to the upper end of a main spindle 6. The chuck sleeve 5 is provided with a suction passage 22 communicated with a workpiece suction recessed part 26 formed at the table 7. Compressed gas fed into a radial bearing clearance 10 between the main spindle 6 and the bearing sleeve 3 is exhausted outside from the exhaust space 19 and the exhaust passage 21. In the case of the compressed gas flowing into a clearance between the chuck sleeve 5 and the main spindle 6, this compressed gas is sucked into the suction passage 22 formed at the chuck sleeve 5 so as to prevent the compressed gas from flowing out onto the housing 1. |
