Abstract: Oil hydrostatic guideways are widely applied in ultra-precision machine tools, the structural parts are often considered as rigid bodies without deformations in the process of design and calculation. In other words, the effects of the structural parts on the oil film thickness and the pressure distribution are ignored in the course of working. The fluid-structure interactions model of oil hydrostatic guideways with annular slit restrictors is established. This model is based on the dynamic Reynolds equation on the land, the elastic deformation equation of the upper slideway and the table dynamic equilibrium equation. The effects of fluid-structure interactions on the deformations, static and dynamic stiffness and settling time under the step load are explored. The results show that the deformations of the upper slideway increase linearly with recess pressure, the static and dynamic stiffness are decreased by the deformations, the settling time is extended by the deformations. Measured values of the static and dynamic stiffness agree well with the theoretical values with the deformations.

Key words: oil hydrostatic guideways;annular slit restrictors;fluid-structure interactions;static and dynamic characteristics