運轉中旋轉機械之軸承係數曲線鑑別

Identifying the Bearing Coefficient Curves of Operating Turbomachines

林楷翔(Kai-Shang Lin)

指導教授 ： 楊大中

元智大學/工程學院/機械工程學系/碩士(2008年)

https://doi.org/10.6838/YZU.2008.00146

摘要

本文研究動機為符合以軸承係數為轉速之函數，及以一次試運轉的狀況之兩大條件下鑑別出軸承係數。一次試運轉的情形下鑑別出軸承係數，其優點為不必停機做第二次不平衡配重配置之調整，故適合進行線上鑑別軸承係數之作業。本文以二階及三階多項式(可呈現2次彎曲之走勢)近似軸承係數曲線，由不平衡振動反應直接計算出該多項式的係數。在較窄之轉速區間中，以二階多項式近似軸承係數曲線，在較寬之轉速區間中，以三階多項式近似軸承係數曲線。尤其在較寬之轉速區間中，軸承係數曲線可能呈現2次彎曲之走勢，且在所選取的轉速區間內可能遇到系統之共振轉速。在較寬之轉速區間中遇到系統之共振轉速時，本文方法依然可相當精確地估算出軸承係數。本文方法同時可降低雜訊效應，又有利於內插法求取不同轉速下之軸承係數。

關鍵字

軸承係數；鑑別；試運轉；不平衡反應；多項式；共振轉速

並列摘要

This study aims at identifying the speed-dependent bearing coefficients with only one test run. The merits of identification with one test run are that it does not require the rotating machines to stop for the setting of independent unbalance configurations and is suitable for on-line identification of bearing coefficients. Second order polynomials and third order polynomials, which can follow the two-bend trends, are used to approximate the curves of bearing-coefficients in this paper. The coefficients of the polynomials are calculated from the unbalance responses directly. In wider ranges of operating speeds, the curves of bearing coefficients may have two bends, as well as the critical speeds may occur within the speed range. The effectiveness of the method around critical speeds is also justified in a wider range of operating speeds. In addition, this approach has the noise reduction effects and the bearing coefficients at different speeds can be obtained easily by interpolation.

並列關鍵字

bearing coefficient ； identification ； test run ； unbalance response ； polynomial ； critical speed

參考文獻

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