| 摘要 |
PURPOSE:To eliminate a cause of occurrence of vibration due to a roller bearing in the chuck device of a machine tool, by providing such an arrangement that hydraulic pressure is introduced into and discharged from a cylinder in a spindle through the bearing surfaces of fluid bearings for journalling the spindle. CONSTITUTION:A chuck device 12 is provided at the front end of a spindle 14 which is rotatably journalled to fluid bearing metals 13a, 13b. Further, a cylinder 26 for clamping and unclamping the device 12 is disposed in the spindle 14. The set position of the cylinder 14 is near to the device 14, and is preferably in the spindle 14 in a part where the spindle 14 is journalled by the bearing surface of the front fluid bearing metal 13a. Further, a piston 27 is fitted in the cylinder 26, extendably and retractably in the axial direction of the spindle 14, and a piston rod 29 integrally incorporated with the piston 27 is coupled with an actuating member 23 in the above-mentioned device 12. With this arrangement a cause of occurrence of vibration due to a roller bearing may be eliminated. |
