| 摘要 |
PURPOSE:To prevent any thermal deformation in a rotary table from occurring and make high speed rotation possible to be done and keep off any drop in accuracy in precision machining by making a temperature on a sliding surface of the rotary table so as not to be changed separately at the center side and the outer circumferential side. CONSTITUTION:In a hydrostatic table unit, supporting a rotary table 2 rotationally on a bed 1 via hydrostatic oil being fed to one side of opposed joining surfaces 1a, 2a between the bed 1 and the rotary table 2 through a recess 4 concentrically formed each sectional form of hydrostatic gap between the bed 1 and the rotary table 2 is made larger gradually or stepwise ranging from the center side to the outer circumferential side. In addition, it is featured that the hydrostatic gap 3 between the bed 1 and the rotary table 2 is set to be constant thickness and, what is more, outer circumferential side land width of the recess 4 is set to be smaller than the inner circumferential side width. |
