PURPOSE: To enhance mechanical rigidity of a static pressure air bearing composed of a static pressure air layer to be interposed between a male screw and a female screw of a static pressure air screw.
CONSTITUTION: To trapezoidal male screws 5, flat land areas 20 are arranged on both crest and valley sides of circular arc-shaped recessed surfaces 18a in engaging surfaces 18 of a female screw 17 having the circular arc shaped recessed surfaces 18a, and a plate-like pressure air layer is formed between them and trapezoidal screw engaging surfaces 6 of the male screws 5 opposing in these flat land areas 20, and corner parts formed as an acute angle are removed from the engaging surfaces 18 of the female screw 17, and bearing rigidity of a static pressure air bearing is improved.
YAMAMOTO AKIRA
SHIMURA NORIHISA
