| Aerostatic bearing has the advantages of small friction, high running speed, highaccuracy and wide range of work, etc. It is widely used in precision machining,microelectronics and aerospace fields. However, some problems have been encounteredin engineering applications, for example, when aerostatic bearing is working in anultra-high speed, especially in the speed of more than2×105RPM, for the role of theaerodynamic and rotor dynamic imbalance, the rotor is easy to lose stability and seriousbearing wear may occur and even lead to "stuck" phenomenon. Therefore how toimprove the load-carrying capacity and stability is very important to the promotion andapplication of externally pressurized aerostatic bearings. Traditional calculation methodof static properties is to solve the Reynolds equation under the assumption oftwo-dimensional simplification, but the static pressure effect and the dynamic pressureeffect are combined after they are calculated separately. In this thesis, one of thecomputational fluid dynamics(CFD) software, FLUENT, is used. Starting from theanalysis of the bearing’s internal flow field, the load and throtting characteristics ofaerostatic bearing is discussed in details.This study mainly includes four parts. Firstly, the possible influence of throttlingorifice diameter and gas film thickness on the performance of aerostatic cylinderbearing is considered. Secondly, a comparative study on load characteristics ofaerostatic bearing of two types of restrictors is carried out and the simulation values areverified by experimental values. Finally, the influence on the throttling characteristic ofaerostatic cylinder bearing from rotor whirl is considered.The present result can further enrich the aerostatic bearing’s design andmanufacture methods, as well as offers a certain reference value and is beneficial for thepeople who are engaged in this area. |
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