Aerostatic bearing device of high speed spindle for milling processing

摘要

PURPOSE: An aerostatic bearing unit of a high speed spindle for a milling machine is provided to improve surface roughness of a workpiece by using air as a medium of the aerostatic bearing unit. CONSTITUTION: An aerostatic bearing unit includes a plurality of radial bearing pads(3,4,5,8), a thrust bearing disc(2), at least one pair of thrust bearing pads(13), and at least one exhaust hole(14) formed in a spindle housing(16). An air feeding passage(22) is formed in the spindle housing(16) so as to feed air in radial and axial directions of a spindle(1). The radial bearing pads(3,4,5,8) have a plurality of air feeding holes(21) communicated with the air feeding passage(22). The thrust bearing disc(2) is provided at one end of the spindle(1). The thrust bearing pads(13) are formed with a plurality of air feeding holes(21).