Research Of Working Characteristics Of Hydrostatic Guideway Of Nanosys-1000Aspherical Machining Tool

Abstract:Hydrostatic guideways, crucially basic components of ultra-precision machining tool, play a crucial role for the cutting performance of the machine. Based on inspection of relevant literaturary review home and abroad, working characteristic and its influencing factors of hydrostatic guideways are studied in this paper. The following researches are done in this paper.l.The motion straightness of hydrostatic guideway slide carriage was studied by theoretical modeling under the half wave surface shape error and whole wave surface shape error respectively. A mathematical model was established to describe the influence on error of hydrostatic guideway slide carriage of static guideway error, the length of pane, journey, stiffness of oil film, and number of opposed oil pads. And principles of how these parameters mentioned affect the motion straightness of Slide carriage are also studied.2.A model describing the fluid field of oil film in the gaps between guide pair is established by a computational liquid mechanics method, and the supporting mechanism and supporting characteristic of supporting oil film of hydrostatic guideway were also studied, how some unconsidered factors as designing hydrostatic bearing, such as surface roughness of supporting parts, depth of oil cavity, length of orifice, of entrance chamfer and exit chamfer of orifice influence the supporting performance of oil film is studied. It is found that depth of oil cavity almost exerts little influence on the supporting characteristic of hydrostatic guideway, while others factors all have impact on the supporting characteristic. The relevant principles were verified by experiments.3. The finite element method was applied to investigate the influence of deformation of guide pair on the stiffness of the oil film in the oil cousin and the motion straightness of slide carriage, which draws a conclusion that under oil film pressure the guide pair happens to deforming,then leads to a decrease in stiffness and motion straightness of guideways. To improve the stiffness and motion straightness guideways, a novel structure was proposed, which improves the stiffness and motion straight of guideways to some extent when it deforms. The new structure was implemented in X direction hydrostatic guideway of Nanosys-1000type aspherical processing machine. And the rationality of X direction liquid hydrostatics design was verified by experiments.