An Investigation on the Effect of Flatness and Angularity for Open-type Hydrostatic Slideway
| Autor: | Chen-Hsuan Peng, 彭晨軒 |
|---|---|
| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 The hydrostatic slideway is widely employed in precision machine tools as it provides high loading capacity, high stiffness, high damping and low friction. In addition to the restrictor and bearing pads structural parameters, the performance of the hydrostatic slideway system is affected by the oil film thickness between the bearing pad and the guideway. The oil film thickness, however, is affected by the flatness and inclination produced in machining and assembly. In this study, the effect of flatness and angularity between the sliding surfaces of an open-type hydrostatic slideway on its performance is investigated by numerical analysis followed by experimental verification. Finite difference model is first established for a single-pocket open-type hydrostatic slideway under certain design structure parameters and capillary restrictors. Performance of the hydrostatic slideway under different surface flatness and angularity is then analyzed based on the Renold equation and flow conservation. The results showed that as the flatness and angularity increase, the oil chamber pressure, loading capacity and stiffness decrease at the same time while the sensitivities of loading capacity and stiffness to the flatness and angularity varied at different oil film thicknesses. The influence of flatness and angularity is more serious at small oil film thicknesses. Furthermore, a series of experiments were designed and conducted with various angularity and loading. The flow rate, hydrostatic pressure of the oil pocket pressure and the change of oil film thickness are measured. The results are further compared with that based on theoretical analysis. The results showed that theoretical analysis overestimated the influence though both results have the same trends. This indicates that the theoretical analysis needs further refinement. The main contribution of this study is to construct a finite-difference model with experimental verification for performance analysis of a single-pocket open-type bearing pads for hydrostatic slidway. It provides a foundation and reference for performance design of hydrostatic slideway. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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