本研究使用有限元素軟體及潤滑模型，針對旋轉軸用U型截面彈簧增力式鐵氟龍密封件，探討其洩漏率。此類密封件包含密封套與簧片兩個構件，計算轉軸與密封套之間的接觸寬度以及接觸壓力分布作為數值分析的輸入條件，並以簡化的潤滑模型計算穩態運轉時轉軸與密封件間的油膜厚度、油膜壓力及洩漏率。同時調整密封件的幾何形狀尺寸，包括密封套的懸臂長度、懸臂角度、唇部角度與勾狀寬度，以及簧片的彎曲半徑與厚度，以材料力學理論探討設計參數對密封套的撓曲量與簧片的束緊力之影響。
由兩種不同定義的設計圖，逐一調整設計參數得到34種設計。統計分析結果發現，較大的接觸寬度，或接觸壓力最大值的位置越接近油端，其有較小的洩漏率，但是接觸壓力最大值對密封效能的影響並不顯著。結果亦顯示增長懸臂長度、懸臂角度與縮小簧片彎曲半徑，可增加接觸干涉量，進而增加接觸寬度。為使接觸壓力集中油端，透過調整唇部角度與勾狀寬度來達成。而為了減少磨耗，給予較小的接觸壓力，採用較薄的簧片厚度。
以上述原則調整設計參數得出的優化設計，其洩漏相較基礎案例減少了66%，具有較佳的表現。

This study aimed to explore the leakage of a U-section spring-energized Polytetrafluoroethylene (PTFE) rotary seal using finite element software with the lubrication model. This seal includes a jacket and a spring as components. The contact width and pressure between the seal jacket and the shaft were calculated. Simplified lubrication model was numerically analyzed using this contact width and pressure to determine the film thickness and pressure distributions under the steady state condition. Design parameters of the seal include a cantilever length and angle, a hook thickness, and a lip angle of the seal jacket with a bending radius and a thickness of the spring. Effects of design parameters on the deflections of the seal jacket and the energized force of the spring were investigated with material mechanics.
Using two different design criteria, 34 design possibilities were obtained by adjusting the design parameters one by one. Results from the statistics analysis indicated that the seal had smaller side leakage as the contact width was wider and the position of maximum contact pressure was much closer to the oil side, but the effect of the maximum contact pressure on the leakage was not significant. The contact width increased along with the cantilever length and angle due to the larger contact interference. However, it increased with decreasing the bending radius of the spring. The position of the maximum contact pressure closer to the oil side could be achieved by adjusting the lip angle of the seal jacket and a hook thickness. To reduce the wear of the seal, the spring with minimum thickness was suggested due to the lower contact pressure. Based on the principles mentioned above, the leakage of seal was 66% less than the base case.

學位論文審定書 i
誌謝 ii
摘要 iii
Abstract iv
目錄 vi
圖目錄 viii
表目錄 xiv
符號表 xv
1. 第一章 緒論 1
1.1 前言 1
1.2 文獻回顧 10
1.3 旋轉密封機制 13
1.4 研究目的 15
1.5 本文架構 16
2. 第二章 有限元素分析 17
2.1 基礎案例 17
2.1.1 前處理與後處理 22
2.1.2 影響係數 29
2.2 密封件的材料力學分析 35
2.3 設計參數之影響分析 44
2.3.1 基礎案例的設計參數探討 45
2.3.2 延伸探討 73
3. 第三章 潤滑分析 84
3.1 分析模型 84
3.1.1 無因次化 88
3.1.2 空蝕係數 89
3.1.3 座標轉置 90
3.2 基礎案例 94
3.2.1 數值分析參數對洩漏率的影響 103
4. 第四章 設計參數對洩漏率之影響解析 106
4.1 洩漏率與FEA結果的關聯性分析 108
4.2 FEA結果與設計參數的關聯性 114
5. 第五章 結論 123
5.1 設計原則 123
5.2 總結 129
5.3 未來展望 130
6. 參考文獻 131

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