| 摘要: | 動壓軸承具有低噪音、低磨耗、耐震等特性，且相較於傳統的滾珠軸承，動壓軸承更具備高精度、壽命長之優勢。由於動壓軸承是以黏性潤滑油作為介質，其主要利用微細溝槽的流力特性，促使軸與軸承間隙中充滿潤滑流體進而達到充份潤滑與建壓效果。為了將流體保留在間隙內，一般的做法是在軸承表面上刻有人字型溝槽，其目的除了讓主軸旋轉時，將油膜擠壓入微細溝槽，使流體壓力升高外，更可使流體集中於內部進而達到防漏的功能。因此，動壓軸承取代了傳統滾珠軸承已成為新一代資料儲存裝置所使用之軸承。
近年來，產品受到微型化設計之影響，因而衍生出零件微型化之後，動壓軸承建壓不足的缺點。根據文獻所知，當動壓軸承微型化之後會有建壓效果不足之問題。但由過往文獻中，大多是以內徑2 mm的動壓軸承為基礎去做分析研究，尚未有文獻針對市售最微型內徑0.6 mm之動壓軸承去做詳細分析。因此，本文係針對現今市售內徑0.6 mm的動壓軸承去做負載能力及洩漏量之分析。此外，為了進一步提升微型化後動壓軸承的負載能力，本實驗室團隊嘗試開發一新型橢圓多階動壓軸承，並透過數值模擬程式找出其最佳化設計。由於受限單一數值模擬程式僅能解析單一溝槽幾何外型，因此本實驗室團隊另外嘗試利用市售軟體Comsol來模擬分析，其主要優點僅利用單一程式就可模擬不同的溝槽外型。
本文研究之主題即是利用數值模擬程式和Comsol模擬軟體並搭配田口法來針對內徑0.6 mm的雙階人字型動壓軸承、橢圓多階動壓軸承和可反轉動壓軸承進行負載能力和洩漏量分析，並分別找出其最佳化溝槽設計參數。
Fluid dynamic bearings(FDB) possess some characteristics of low noise, low friction, and shock resistance. In contrast to conventional ball bearings, FDBs have the advantages of high precision and an extended service life. Since FDBs use lubricant as a medium, the conventional herringbone grooves (HGJB) pump the lubricant in the inward direction during operation, i.e. toward the center of the bearing. Thus it has been known that HGJB increases the pressure within the journal, and improve the bearing performances. Therefore, the use of FDB has attracted particular interest for next-generation data storage applications.
However, the conventional HGJB has a chief drawback. The load capacity of the conventional HGJB decreases with decreasing dimension of the bearing, thus the spindle stiffness could be insufficient for miniaturized conventional HGJB. Nonetheless, some studies in the past have investigated the inner diameter of bearing at only ?2 mm, and no study has analyzed the most miniature inner diameter of bearing at ?0.6 mm. Therefore, aim in this study, the load capacity and side leakage of FDB of ?0.6 mm inner diameter are analyzed respectively. In order to further improve the load capacity and provide greater spindle stiffness, this study will develop a newly designed multi-step elliptical groove journal bearing (Multi-step EGJB) and utilize numerical analysis program to find its optimal design parameters. In addition, this study also analyzes the performance of reversibl groove journal bearing (RGJB) using Comsol software. And this software can simulate different groove patterns.
Therefore, the aim of this study is to utilize numerical simulation program, Comsol software and Taguchi method to analyze the optimal design parameters of the HGJB, EGJB, and RGJB of ?0.6 mm inner diameter. |
