| 主权项 |
1. An XYθ table apparatus comprising:
a base having a flat surface; a movable table configured to linearly and rotationally move in a movement plane above the base in parallel to the flat surface; a plurality of plane guide bearings arranged between the base and the movable table to support the movable table above the base such that the movable table is capable of linearly and rotationally moving; three drive units arranged above the base, and configured to respectively exert drive forces to the movable table to move the movable table; a coupling unit configured to couple each of the three drive units and the movable table to be capable of relatively moving in a swinging manner and in a sliding manner; wherein the three drive units comprises: a first drive unit configured to advance or recede in an X-direction in the movement plane, and to exert the drive force in the X-direction to the movable table; and two second drive units configured to advance or recede in a Y-direction, which is perpendicular to the X-direction, in the movement plane, and to exert the drive forces in the Y-direction to the movable table, wherein the first drive unit is arranged to exert the drive force in the X-direction to a center position in the Y-direction of one of end parts in the X-direction of the movable table; wherein the two second drive units are arranged to be point-symmetric with respect to a center of the movable table as a symmetry center, and wherein the plurality of plane guide bearings are arranged at positons where a total sum of moment forces of the plurality of plane guide bearings is zero on a center axis line in the X-direction of the movable table, each of the moment forces of the plurality of plane guide bearings being calculated by multiplying a frictional force generated at each of the plurality of plane guide bearings by a movement of the movable table by a distance in the Y-direction between each of the plurality of plane guide bearings and the first drive unit. |
