氣靜壓磁浮混合式軸承之設計開發與性能探討

Design and Development of Hybrid Magnetic-Aerostatic Bearing and Performance Investigation

陳奕達(Yi-Ta Chen)

指導教授 ： 黃光裕

國立臺灣大學/工學院/機械工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.00587

摘要

本論文之研究目的在於設計開發微小型氣靜壓磁浮混合式軸承，以氣靜壓軸承結構為主，搭配以磁浮作用原理來穩定氣靜壓軸承之運轉條件。氣靜壓軸承結構上採用軸套式的設計，以獲得較佳承載能力及穩定性，磁浮裝置則是利用兩個強磁力的銣鐵硼磁石以斥力方式提供氣靜壓軸承軸向預力，以達到較穩定和較佳的氣膜間隙。軸承除了作用原理之整合外，還設計發展出短軸式和長軸式兩種混合式軸承系統，透過幾何尺寸和配置變化達到較佳性能。混合式軸承系統並且整合了氣渦輪的設計，完成整體高速主軸之開發，由高壓氣體之噴射驅動氣渦輪高速旋轉。氣靜壓軸承理論分析上採用了雷諾方程式之推導，分析得軸承設計和運轉參數對承載力和剛性之影響，並搭配Fluent有限元素3D流場模擬作細部設計參數之性能影響分析。磁浮裝置除了應用磁場等效迴路分析之外，也採用Maxwell電磁模擬軟體就磁石配置和幾何尺寸對磁預力影響進行分析。實驗測試主要項目為混合式軸承之承載力、剛性和振動以及氣渦輪轉速等，以確認各項影響因素和其對性能之影響效果。

關鍵字

氣靜壓軸承 ； 磁浮裝置 ； 混合式 ； 氣渦輪 ； 預力 ； 承載力 ； 剛性 ； 振動 ； 轉速

並列摘要

The aim of the thesis is to design and develop a micro aerostatic-magnetic hybrid bearing. The aerostatic bearing provides the main function to supply supporting force to the rotating shaft, and the magnetic levitation principle is applied to stabilize the operational condition of aerostatic bearing. For achieving high load capacity and stability, the sleeve type shaft is developed for the aerostatic bearing; the two NdFeB magnets are used in the magnetic device to produce the axial pre-load on the aerostatic bearing for realizing a stable and optimal air gap. Besides the combination of the aerostatic and the magnetic principles, a short-shaft bearing and a long-shaft bearing are designed and developed to study the influences of the geometric sizes and the structural arrangement on the performance. For generating high speed spindle’s rotation, an air turbine driven by the high pressured air jet is developed and integrated with the hybrid bearing.
The Reynold’s equation is derived and modified to analyze the influences of the design and operational parameters of the aerostatic bearing on the load capacity and the stiffness. Furthermore, the 3-D finite element software FLUENT is utilized to investigate the detailed influential effects of the design parameters. For developing and optimizing the magnetic device, the magnetic-circuit method and the Maxwell electromagnetic simulation software are used to analyze the influences of the arrangement and the geometric dimensions of the magnets on the magnetic pre-load. The main testing items for the hybrid bearing are load capacity, stiffness, vibration and rotating speed, which are measured to verify the effects of the influential parameters.

並列關鍵字

aerostatic bearing ； magnetic device ； hybrid ； air turbine ； pre-load ； load ； stiffness ； vibration ； rotating velocity

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