| 摘要 |
PURPOSE:To prevent thermal deformation in a spindle from occurring as well as to keep bearing accuracy constant, by forming both feed and recovery pipelines of a fluid for a hydrostatic bearing in the spindle. CONSTITUTION:Turning force of a motor is transmitted to a turning member 12 consisting of a driving pulley 16 and a grinding wheel 30 via a belt and this turning member 12 is rotated by the periphery of the spindle 10 cantileveringly supported by a spindle holder 14. At this time, the temperature regulated fluid of a hydrostatic bearing is fed to each throttle 25 of a radial bearing 20 and a thrust bearing 22 passing through a feeder 24 of the spindle and supporting the turning member 12 on the spindle 10. On the other hand, the fluid upped in temperature due to frictional heat by rotation of the turning member 12 is recovered by a recovery pump 52 via a recovery pipeline 26 passing through a recovery branch pipeline 28, through an axial center of the spindle 10 and formed in the radial central part. The fluid is fed out of the feed pipeline 24 formed at the outside of this recovery pipeline 26, whereby the spindle 10 is cooled so that any thermal deformation is abviated.
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