| Summary: | 碩士 === 國立臺灣大學 === 機械工程學研究所 === 95 === Aerostatic bearings have been widely applied in high-speed and high-precision systems, but the need of high precision machining and low loading capacity retard their development. This thesis is to design and develop a novel type of restrictor, and to study the influences of the geometric shape and size of the surface orifice on the aerostatic bearing characteristics. The electro discharge machined surface orifice can avoid machining difficulties in drilling the tiny orifice and can also afford diverse variation possibilities in shape and size which are very useful to fulfill different requirements on the aerostatic bearings. Through uniting the surface orifice and the corresponding surface, the radial or the axial aerostatic bearing can be realized. The electro discharge machining process can substantially solve the misalignment problem of the radial orifices and get rid of the restriction of the aspect-ratio. By using the fluid analysis software FLUENT, the influences of design parameters on the pressure distribution over the bearing gap are studied. Furthermore, the loading capacity and the stiffness are derived by the numerical analytical calculation. Besides the theoretical and the finite element analyses, the performances of the developed aerostatic bearing are verified by the experimental testing. It comprehends the relationship between the design parameters and the bearing performance and examines the deviations between the experimental and the analytical data and their occasions.
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