Throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block

A static pressure bearing device in a structure with a linear motion axis or a structure with a rotation axis, in which a static pressure bearing is constituted between a movable portion and a fixed portion of the structure with the linear motion axis or the structure with the rotation axis, the device comprising:

• a fluid supply line configured to supply a working fluid to a static pressure pocket formed in the movable portion or the fixed portion;
• and
• a throttle unit provided in the fluid supply line,
• wherein the throttle unit is a throttle unit in which the working fluid is introduced from at least one supply hole, the introduced working fluid flows in a minute throttle fluid path, and the working fluid which has passed through the throttle fluid path is discharged from at least one discharge hole, the unit comprising:
• a grooved block including at least one minute groove on a plane surface;
• an opposite block including a plane surface that is opposite to the minute groove,
• wherein the grooved block and the opposite block are opposite to each other and detachably joined to each other,
• the throttle fluid path is formed by the minute groove and the plane surface of the opposite block,
• at least one surface of the minute groove is constituted by a curved surface or an inclined surface that is inclined with respect to the plane surface of the grooved block.

A method of manufacturing a grooved block that includes at least one minute groove on a plane surface, wherein the grooved block is a component of a throttle unit, in which a working fluid is introduced from at least one supply hole, the introduced working fluid flows in a minute throttle fluid path, and the working fluid which has passed through the throttle fluid path is discharged from at least one discharge hole,

• wherein the throttle unit comprises the grooved block and an opposite block including a plane surface that is opposite to the minute groove, the grooved block and the opposite block are opposite to each other and detachably joined to each other, and the throttle fluid path is formed by the minute groove and the plane surface of the opposite block,
• the method comprising:
• a cutting step of cutting a plane surface of a workpiece block to form the minute groove, at least one surface of the minute groove being constituted by a curved surface or a inclined surface that is inclined with respect to the plane surface of the workpiece block;
• a depth calculating step of calculating a groove depth of the minute groove that has been formed in the machining step, observing the minute groove with a microscope from a direction perpendicular to the plane surface of the workpiece block;
• and
• a correcting step of making a correction of a machining device that performs the cutting, based on the calculated groove depth.