Abstract
This paper presents static rigidity of hydrostatic ead-screw which has modified thread profile. Hylrostatic lead-screw has the following merits, i, e, no stick-slip, no wear of screw thread flanks and soon. On the contrary it has a defect of difficulty of machining recesses. In this study, considering that crapezoidal thread supports thrust force and that criangle thread supports radial force as well as chrust force, the thread profile is decided to have a modified thread form. In order to get it easy to make the nut which has four divided recesses, the method of four divided nut is applied. As a fundamental study, an annular rotor type thrust hydrostatic bearing was made and static rigidity is investigated. Based on this result, a practical hydrostatic lead-screw is made. As a result of examining static rigidity, it is ascertained that experimental rigidity of rotor type hydrostatic bearing agrees with theoretical one by compensating structural rigidity and that experimental static rigidity of practical hydrostatic lead-screw agrees with theoretical one comparatively well.
