Patent ID: 7845257

Claim:
An ultra-precision machine tool, which is provided with: a base ( 1 ), an X axis slider ( 3 ) provided movably in X direction horizontally on said base, a pair of X axis guide members ( 31 , 31 ) which are disposed at positions symmetric about the center of mass of said X axis slider so as to movably guide said X axis slider in X direction, a pair of X axis linear motors ( 32 , 32 ) which are disposed at positions symmetric about the center of mass of said X axis slider so as to drive said X axis slider in X direction, a table ( 33 ) which is rotatably supported on said X axis slider and on which is mounted a workpiece, a pair of Y axis sliders ( 4 , 4 ) which are disposed on said base on both sides of said X axis slider for X direction respectively so that said X axis slider is interposed therebetween and are provided movably in horizontal Y direction perpendicular to X direction, a pair of Y axis guide members ( 41 , 41 ) which are disposed on said base on both sides of said X axis slider for X direction respectively so as to movably guide said Y axis sliders in Y direction respectively, a pair of Y axis linear motors ( 42 , 42 ) which are disposed on said base on both sides of said X axis slider for X direction and at positions symmetric about the center of mass of the combination of said Y axis sliders so as to drive said Y axis sliders in Y direction, a pair of Z axis sliders ( 5 , 5 ) which are provided movably in Z direction perpendicular to X and Y directions on said pair of Y axis sliders respectively, two pairs of Z axis guide members ( 51 , 51 ) of which each pair of Z axis guide members are disposed at positions symmetric about the center of mass of each of said Z axis sliders on each of said Y axis sliders so as to movably guide said pair of Z axis sliders in Z direction respectively, two pairs of Z axis linear motors ( 52 , 52 ) of which each pair of Z axis linear motors are disposed at positions symmetric about the center of mass of each of said Z axis sliders on each of said Y axis sliders so as to drive said pair of Z axis sliders in Z direction, a spindle head supporting beam ( 6 ) in which both ends for X direction are rotatably supported on said Z axis sliders respectively so as to be capable of indexing rotationally about A axis parallel with X axis and a spindle head ( 61 ) which is secured to said spindle head supporting beam at the central position thereof and has a spindle for holding a tool.