- 學位論文
具人字型溝槽液體動壓軸承的動態係數與穩定性分析
Identification of Dynamic Coefficients and Stability Analysis of a Herringbone-Grooved Journal Bearing
摘要
本研究之目的是要建立一套量測實驗設備，並利用靜態負載增量法與動態負載不平衡量法量測具有人字型溝槽液體動壓軸承(Herringbone-Grooved Journal Bearing, HGJB)之葉片轉子主軸，且被操作在蘇馬費數(Sommerfeld Number)由14到106範圍內的靜態特性與動態係數，以做為穩定性的分析。另外，由量測主軸軌跡的動態行為，可瞭解到主軸動態穩定性與抗振能力的關係。結果顯示，主軸無因次臨界旋轉速度會隨著蘇馬費數的增加而減小。當實驗的葉片轉子主軸被操作在蘇馬費數大於49到106的條件時，即偏心比小於0.18的運轉情形下，顯示出葉片轉子主軸會處於不穩定的運轉。且由實驗量測主軸軌跡的動態行為，也顯示出操作在蘇馬費數大於49到106不穩定區域的葉片轉子主軸亦不具有抗振能力。
並列摘要
The purpose of this study is to build up an instrument that can experimentally investigate the static characteristics and dynamic coefficients by using the incremental static load method and unbalance-excitation method on stability analysis of an impeller-spindle with herringbone-grooved journal bearing (HGJB) for the experimental device operated at Sommerfeld Number from 14 to 106. In addition, the relation between the dynamic stability and shock resistance were obtained by measuring the dynamic behaviors of spindle trajectory. Results show that the dimensionless threshold speed of rotation decreased as the Sommerfeld Number increased and the proposed impeller-spindle is unstable when the Sommerfeld Number is greater than 49 to 106, indicating that the spindle should not operate at the condition with an eccentricity ratio below 0.18. The spindle can’t sustain the shock excitation when it is operated in this unstable region according to measurements of dynamic trajectories of journal.