| 摘要 |
<p>PURPOSE: To minimize unnecessary inclination of a travelling body by supporting the travelling body on a reference plane by a hydrostatic bearing so that it is in non-binding condition for the other travelling body mutually as regards to vertical direction for the reference plane and providing a travelling body pre-load mechanism. CONSTITUTION: Y-stage 4 is floated from a surface plate 1 by supplying air into a hydrostatic air bearing and is moved in Y direction along a fixing guide 2 by two drive actuators 4c. Moreover, X-stage 5 is floated from the surface plate 1 in the same way as Y-stage 4 by supplying air into the hydrostatic air bearing to move a side of the Y-stage 4 in X-direction by a drive actuator 5c as guide in the horizontal direction. At this time, the X-stage 5 and the Y-stage 4 are adjusted in such a way that they keep a constant posture at all times by a plurality of magnet units 6 for pre-load which are provided on respective rear surface.</p> |
