STATIC PRESSURE FLUID BEARING DEVICE

PROBLEM TO BE SOLVED: To provide a static pressure fluid bearing device capable of improving machining accuracy by appropriately controlling the fluctuation of a thickness (an interval between two members) of a fluid flow-out layer to be generated when increasing and decreasing a throttle opening, in regard to the static pressure fluid bearing device including a variable throttle means. SOLUTION: The static pressure fluid bearing device includes: a bearing pocket; a fluid supply means for pressure-feeding fluid; a fluid flow passage; a variable throttle means capable of changing a throttled amount; a throttled amount detecting means capable of directly or indirectly detecting the throttled amount; a volume changing means 56E provided in at least one part of the variable throttle means 56V or the fluid flow passage 56H or the bearing pocket 56P in a route from the variable throttle means 56V to the bearing pocket 56P to increase and decrease the volume of a part filled with the fluid; and a control means for computing a volume changed amount corresponding to the throttled amount detected by the throttled amount detecting mans and for increasing and decreasing the volume of the volume changing means 56E so as offset the computed volume changed amount. COPYRIGHT: (C)2011,JPO&INPIT