| 摘要 |
<P>PROBLEM TO BE SOLVED: To carry out highly precise positional correction of a workpiece receiving moving load. <P>SOLUTION: A top table 4a for holding the workpiece to which the moving load acts is arranged above a base 1, and supporting units 13 with three degrees of freedom of X, Y, θ and drive units 14A, 14B, 14C, 14D having ball screw direct moving mechanism 9 in one axial direction besides the similar constitution of the supporting units 13, are interposed in positions corresponding to the center and four corner parts of the top table 4a which are arranged in a zigzag pattern in the load moving direction L between the base 1 and the top table 4a. Ball screw direct moving mechanisms 9 are orthogonally arranged so as to locate the one and the other of the drive units 14A, 14B and 14C, 14D in the diagonal positions. The deformation of the top table 4a is suppressed by continuously receiving the moving load acting on the top table 4a via the workpiece while moving in the load moving direction L, by the respective drive units 14A, 14C, the supporting units 13 and the respective drive units 14B, 14D. <P>COPYRIGHT: (C)2011,JPO&INPIT |
