具點接觸型態之歪斜軸錐形齒輪對齒面疲勞破壞之初步研究

許昭祥(Chao-Hsing Hsu)

指導教授 ： 蔡錫錚

國立中央大學/工學院/機械工程學系/碩士(2008年)

摘要

錐形齒輪在空間中使用時具有多樣化組合的優點，可運用於平行軸、直交軸與歪斜軸配置中。當運用於歪斜軸配置時，錐形齒輪之嚙合型態雖多為點接觸，可具有組裝誤差敏感度低之優點，但因其齒面接觸應力過大，易造成齒面疲勞破壞的現象，從而限制其運用與發展。本論文針對不同材料之直齒錐形齒輪(S45C)與螺旋齒輪(SCM440)所構成之大偏位歪斜軸齒輪對，進行齒面疲勞強度實驗，探討點接觸之歪斜軸齒輪對齒面破壞之型態，以做為後續齒面強度研究之參考。
研究中使用赫茲理論計算出齒面間之接觸應力，並配合有限元素模擬分析，驗證理論計算之準確性。由計算值與齒輪材料強度值推估出錐形齒輪疲勞壽命曲線，並據此規劃負載，進行齒面疲勞破壞之實驗分析，以求得不同負載下，齒面疲勞破壞時程與齒面疲勞破壞之型態與位置。實驗結果與文獻記載之齒面破壞相互驗證後，發現除點蝕破壞外，齒面磨料磨損在不同材料所構成歪斜軸錐形齒輪對亦不可忽視。對此在本文中亦提出齒面破壞之原因與對策，以供後續研究之參考。

關鍵字

點蝕破壞 ； 齒面疲勞破壞 ； 有限元素分析 ； 錐形齒輪 ； 赫茲應力

並列摘要

Concial gears as spatial gearing have the advantages of possibilities to form different combinations for application in parallel, intersecting and skew axes. Skew conical gear drives that are in general in point contact have advantage of less sensitivity to transmission error caused by the assembly errors, but have also the disadvantage of higher tooth contact stress. The small surface durability restricts thus the their application for power transmission. The aim of this thesis is to explore the patterns of fatigue damage of a skew conical gear pair with a large offset through a tooth surface fatigue test. The test gear pair is composed of a straight conical gear (material S45C) and a helcial gear (SCM440).
The tooth contact stresses were calculated by using the Hertz’s theory in the research, and also verified with finite element analysis simulation. The test load and time interval of the fatigue test were planned according to the calculated contact stress and estimated fatigue strength value of the applied gear material. The fatigue test was conducted under two different loads. The test results, compared with the literature, showed that in addition to micro pitting of the tooth surfaces, tooth abrasive wear due to different materials in contact also can not be ignored. The causes of surface failure and the possible measures to avoid has also proposed in this thesis as reference for further research.

並列關鍵字

conical gear ； Hertz stress ； tooth surface fatigue ； micro pitting ； finite element analysis

參考文獻

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