樹脂モールド空気静圧軸受面を有する送りねじの試作と性能評価

抄録

The objective of the present research is to conduct a trial production of an aerostatic lead screw system, in which all moving parts are supported by aerostatic bearings made of molded resin and to evaluate how much performance is achieved in this low cost system. Epoxy based resin available for slideway coating was used to make all bearing surfaces by means of casting or molding technique which is known to be able to produce complex shapes with low cost. The motion accuracy of the produced nuts was evaluated by measuring the straightness of straight line motion and the positional deviation. The results showed that the straightness was 0.15μm and the deviation was 3 to 4μm in the working distance from 0 to 60 or 84mm, which was almost same as the cumulative pitch error of the screw shaft. The nut positional deviation per one revolution was 2 to 3μm as a result of the 1.5μm axial travel variation of the screw and the 0.2μm axial run-out of the screw shaft. The slightly larger positional deviation of the nuts may be due to the low bearing stiffness of the nuts.