STATIC PRESSURE PNEUMATIC SCREW

摘要

PROBLEM TO BE SOLVED: To provide a static pressure pneumatic screw having a mechanical rigidity improved pneumatic bearing comprising a static air pressure layer formed between a male thread and a female thread. SOLUTION: In the static pressure pneumatic screw, a static air pressure layer is formed between meshing surfaces 6 on the trapezoidal section of the male thread 5 and meshing surfaces 18 having arch cavities 18a on the trapezoidal section of the female thread 17. It is characterized in that the female thread 17 has linear land portions 20 at the both sides of the arc cavities 18a opposed in parallel to the surfaces 6 of the male thread 5 so as to reinforce the mechanical rigidity of the static air pressure layer. Furthermore, the linear land portions 20 and the arc cavities 18a of the meshing surfaces 18 can be ground at one time in the grinding process of the female thread 17.