套杯式氣靜壓軸承導引滯滑式壓電旋轉平台之設計開發

Abstract

氣靜壓軸承靠著低摩擦、自我降溫、零污染之特性被大量應用於高精度之導引設備中。壓電元件靠著驅動頻率高、剛性高及微小致動的特性被大量應用在高精度之致動器中。本論文提出一種新型精密旋轉平台，結合套杯式氣靜壓軸承高承載及低摸擦的特性，搭配以積層式壓電元件作為致動源的壓電致動器，透過慣性滯滑致動方式達到精密轉動，並開發出高承載與高轉動解析度的旋轉平台。運用理論計算和CFD軟體模擬，對氣靜壓軸承的構型及設計參數對承載力與剛性的影響進行分析探討。透過各種實驗測試壓電致動器的致動特性以及套杯式氣靜壓軸承的承載特性，並做整體系統性能測試驗證在受軸向負載時，旋轉平台確實可以透過慣性滯滑原理致動。依據實驗測試結果，旋轉平台在軸向供氣為2 bar以及徑向供氣為0.5 bar時，軸向承載力可達33 N，徑向承載力可達1.2 N；在驅動電壓為100 V且驅動頻率為500 Hz時，平均轉動角度度可達0.068 arcsec，轉動速度可達33.8 arcsec/s。

Aerostatic bearings are widely applied in high-precision guiding systems because of their low friction, self-cooling and no pollution characteristics. Piezo elements are widely applied in high-precision actuators because of their high driving frequency, high stiffness and tiny stroke characteristics. In this thesis, we have proposed a novel precision rotation stage, which combines the high bearing capacity and low friction characteristics of the aerostatic bearing and the piezo actuator which is driven by multilayer piezo element. We also develop the precision rotation stage with high capacity and high angular resolution which achieves precision rotation though the inertial slip-stick driving principle. By using theoretical analyses and computational fluid dynamics simulation, the influences of the constructions and design parameters of the cap-shaped aerostatic bearing on its bearing capacity and stiffness are analyzed. The displacement of the piezo actuator and the bearing capacity of the cap-shaped aerostatic bearing are tested by diverse experiments. Through the axial load experiment on the integrated system, it can be verified that the rotation stage can be driven through the inertial slip-stick driving principle. According to the testing results, the rotation stage has the axial capacity of 33 N and the radial capacity of 1.2 N when axial air supply is 2 bar and radial air supply is 0.5 bar. The rotation stage has the angular resolution of 0.068 arcsec and the angular velocity of 33.8 arcsec/s when the driving voltage is 100 V and the driving frequency is 500 Hz.