外供壓頸軸承動態特性及穩定性研究

Analysis in Dynamics and Stability of Externally-Pressurized Journal Bearings

林則均(Ze-Jun Lin)

指導教授 ： 康淵 ； 張永鵬

中原大學/工學院/機械工程研究所/碩士(2015年)

https://doi.org/10.6840/cycu201500805

摘要

本論文研究使用毛細管節流器的液靜壓頸軸承之動態特性，以及其所支撐Jeffcott轉子─軸承系統之穩定性。具有空蝕效應的油膜潤滑方程式，探討軸承徑長比、油腔軸向節流長度比、油腔周向節流長度比、油腔深度比、油腔個數及外部供壓，對於系統動態特性和穩定性之影響。
初始軸承間隙內油膜壓力假設為線性分佈，使用微擾法將Reynolds方程式線性化，且建立其外部油壓系統經毛細管節流器流入軸承與各油區間流量守恆方程式，最後利用有限差分法聯立求解軸承動態特性，以及使用Routh-Hurwitz法來判別系統穩定性。
本文僅改變單項設計參數，經過數值分析得到結果的比較，對於系統慣性力門檻以及臨界漩振比影響之顯著性，依次為軸承徑長比、油腔軸向節流長度比、油腔深度比和油腔周向節流長度比，而只改變油腔個數或者供油壓力之影響較小。

關鍵字

靜壓頸軸承 ； 動態特性 ； 穩定性 ； 空蝕效應

並列摘要

In this article, determined the dynamic characteristics of hydrostatic plain/multi-recess journal bearing, and its stability with Jeffcott rotor-bearing system. Considering the cavitation effect, discussing the impact of dynamic characteristics and stability, which used different diameter-length ratio of bearing, axial length ratio of sill, circumferential length ratio of sill, depth ratio of recess, number of recess and external pressure.
To start with using perturbation method to linearize Reynolds equation, it based on film pressure distribution is assumed to be linear. Obviously, building the conservation equations for external hydraulic system through capillary restrictor and each pad section. Finally, solving the simultaneous by finite differential method. Then, determining the dynamic characteristics and stability with Routh-Hurwitz method.
Through numerical analysis, changing one of design parameters to calculating the critical mass and critical whirl ratio of bearing system. Comparing the significant of influence for results, followed by diameter-length ratio of bearing, axial length ratio of sill, depth ratio of recess and circumferential length ratio of sill. But it less affected by changing number of recess and external pressure.

並列關鍵字

hydrostatic journal bearing ； dynamic characteristic ； stability ； cavitation

參考文獻

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