Hydrostatic guide device and machine tool using the hydrostatic guide device

A hydrostatic guide device comprising:

• a fixed member having a pair of vertical guide faces that face in opposite directions;
• a movable member having a pair of vertical slide faces that are opposed to the respective vertical guide faces;
• a fluid supply device;
• a hydrostatic pocket that is formed in one of the vertical slide faces, the one of the vertical slide faces being opposed to one of the vertical guide faces, the one of the vertical guide faces serving as a reference face, to which a fluid is supplied by the fluid supply device, to which a first fluid pressure based on a dimension of a gap between the one of the vertical guide faces and the one of the vertical slide faces is applied, and that urges the movable member toward the other of the vertical guide faces with a first urging force;
• and
• a hydraulic pocket that is formed in other one of the vertical slide faces, the other of the vertical slide faces being opposed to the other one of the vertical guide faces, to which the fluid is supplied by the fluid supply device, to which a second fluid pressure based on a dimension of a gap between the other one of the vertical guide faces and the other one of the vertical slide faces is applied, and that urges the movable member toward the one of the vertical guide faces with a second urging force, wherein
• a variation of the second fluid pressure with respect to a variation of the gap between the other one of the vertical guide faces and the other one of the vertical slide face is smaller than a variation of the first fluid pressure with respect to a variation of the gap between the one of the vertical guide faces and the one of the vertical slide faces, and
• when the first urging force and the second urging force are balanced with each other in a horizontal direction, the gap between the one of the vertical guide faces, the one of the vertical guide faces serving as the reference face, and the one of the vertical slide faces becomes a set value.