| 摘要: | 本研究針對中科院所開發渦輪引擎中之高轉速齒輪箱進行強度與動態分析，此齒輪箱功用為將渦輪引擎之動力傳遞至燃油與滑油之附件箱作為動力源，由於引擎為高速運轉(最高轉速近三萬轉)，且現有設計於運轉過程會發生齒面刮傷甚至輪齒斷裂現象，因此本研究規劃以三年(107-109年)時間逐步進行高轉速正齒輪系統強度與動態特性分析，提出高速齒輪改善優化設計以避免斷齒與高速振動問題。本計畫共三年，目前正執行於第一年(107年)之研究，針對現有設計之齒輪對進行準靜態強度與動態分析，以及高轉速齒輪測試平台規劃與設計。於108年起之第二年期，則將先針對實際齒輪箱的軸、軸承以及齒輪箱體進行變形量分析，建立考慮軸、箱體變形以及組裝誤差之最適當齒面的修整參數，然後考慮潤滑油、油溫與運轉條件，計算齒面溫度分布與傳動效率等特性值，得到齒輪對之抗刮傷強度、齒面強度及齒根彎矩強度等，接著整合最佳化數值程式與上述齒輪準靜態強度計算程式，以多目標最佳化求取三種齒輪強度與效率等指標均具優化效果之齒輪修整設計參數。此外，並將所得的幾組準靜態優化設計進行動態分析，計算其振動幅值、動態傳動誤差及嚙合頻能量等，確認優化設計之齒輪對之準靜態與動態特性皆優於原始設計。最後，挑選合適的幾組優化齒輪對參數進行雛形齒輪加工，也將於第二年完成高轉速齒輪動態測試平台建立，以供第三年進行實驗驗證。第三年期(109年)之研究則將先針對齒輪對、軸、軸承與齒輪箱體建模，使用多體動力學方法進行動態特性分析驗證，並且加入符合實際情況之柔(彈性)體與接觸設定進行整個齒輪箱各元件的速度、加速度、受力負載以及動態變形量與應力分布等分析，並以有限元素準靜態分析結果進行應力與變形比對與驗證，以確保多體動力學之求解設定之正確性。此外，將前一年所得的各組雛形齒輪進行於額定負載且不同轉速下之動態實驗，利用加速規擷取振動訊號，並將訊號經過適當訊號處理，計算得到振動訊號之極值、均方根值與嚙合頻能量等實驗動態特性值，並將動態實驗結果與多體動力學模擬分析結果比對，亦將與第二年以自行建立之動態傳動誤差數值模型計算之結果進行比對與驗證，確認本研究之數值與多體動力學模擬齒輪箱動態特性的正確性。最後，藉由所建立之分析流程提出最佳的齒輪箱設計參數，以供中科院研發渦輪引擎之高速齒輪箱優化設計之參考依據。 ;This research focuses on the strength and dynamic analysis of the high speed gear box attached to an engine turbine developed by NCSIST. The engine exhibits an ultra-high speed (near 30000 rpm), and both scuffing and tooth breakage have been observed on the gears. Consequently, this three-year research project was carried out to investigate the strength and dynamic characteristics of the high speed gear system, in order to improve the high-speed gear design such that tooth breakage and vibration can be avoided. This project is planned to be conducted in three-years. In the current (first-year) project, strength analysis and dynamic analysis of the original design of the high speed gear system are studied. Besides, high-speed gear tester is also designed. In the second (2019) year, firstly, the deformations of the shafts, bearings and gear box will be estimated, then, these deformations as well as assembly tolerances are taken in consideration when calculating the gear design and tooth modification parameters. The lubrication and temperature under various operation conditions are considered when determining the efficiency of the gear system. In addition, the gear strengths and safety factors, including scuffing, pitting and bending strengths/safety factors, are obtained. Moreover, a multi-objective optimization integrating with the gear strength calculation subroutine will be performed to achieve an optimum design parameters set of the spur gear system. Dynamic analysis will also be conducted to verify the dynamic characteristics of the proposed optimum gear design calculated based on static strength calculations. Finally, the test gear will be manufactured according to the optimum gear parameters, and the high-speed gear tester will also be established and tested in the second year.In the third (2020) year, multi-body dynamic simulation software will be utilized to study the dynamics of the high speed gear system, including the spur gear set, shafts, bearings and gear box. Suitable flexible body and contact settings will be considered, attempting to simulate the speed, acceleration, force, and stress distribution of each component in the gear box. Quasi-static finite element analysis will be applied to verify the stress results of the multi-body dynamic analysis. Meanwhile, the manufactured gear with optimum parameters will be applied to explore the dynamic characteristics by using the high-speed gear tester established in the second year. Dynamic signals from experiments under various speed will be acquired by an accelerometer, and then by processed by adequate process, including filtering, FFT, EEMD and time averaging. The experimental results and the simulation results, including the magnitude, RMS values, and meshing frequency, will be compared, and the settings of the multi-body dynamic simulations can be adjusted based on the comparisons. Finally, the optimum design of the high-speed gear system will be delivered to NCSIST for their engine turbine. The methodology and design process of gear strength calculation, dynamic analysis, and optimization algorithm can be applied to other gear transmission designs, speeding the developed time as well as improving the strength and quality of gear transmission system. |
