Hydrostatic bearing apparatus with a cooling function

Abstract

In a hydrostatic bearing apparatus, a bearing bushing is formed at its internal surface with a plurality of circumferentially separate fluid pockets, into which pressurized fluid is conducted via respective throttle elements for rotatably supporting a spindle received in the internal surface, by means of static pressure generated in each of the fluid pockets. The bearing surface is further formed with a plurality of exhaust grooves, each of which extends in the axial direction of the bearing bushing between contiguous two of the fluid pockets. Pressurized fluid cooled by a cooler device is supplied to flow along the exhaust grooves in the axial direction of the bearing bushing, so that heated pressurized fluid in each fluid pocket is prevented from being carried by rotation of the spindle into another fluid pocket circumferentially next thereto. Further, a plurality of axial through holes are formed in the bearing bushing, and a pair of annular cap members are respectively secured to axial opposite ends of the bearing bushing. The annular cap members are formed at their inner end surfaces with a plurality of arcuate elongated holes, which make the axial through holes communicate in series. Pressurized fluid cooled by the cooler device is conducted to pass through the through holes for heat exchange with the bearing bushing.