閉式靜壓導軌設計與特性分析

Design and Characterization of the Closed-type Hydrostatic Slideway

王仁佑(Ren-Yu Wang)

指導教授 ： 宋震國

國立清華大學/工學院/動力機械工程學系/碩士(2014年)

https://doi.org/10.6843/NTHU.2014.00191

摘要

本文設計、製作並測試一組液靜壓線性平台系統。並將其裝配毛細管節流器，驗證其理論，並推導新型主動式補償節流器應用於其上之特性，此節流器係以一彈性元件的變形來感測油腔壓力的變化並作自動壓力補償，具有一體化的特色，故除了可以大幅提升軸承承載力、剛性及動態反應速度外，並有零件少、加工及組裝容易、成本低等優點。
在理論方面，首先建立毛細管節流液靜壓軸承與新型主動式補償液靜壓軸承的理論，推導出裝有不同節流器的對向墊液靜壓軸承之承載力與剛性公式。接著，針對軸承系統具多個油腔的實際應用狀況，推導公式並進行數值模擬，探討具不同節流器之液靜壓軸承系統中，各油腔剛性與系統剛性之關係，模擬結果證實各油腔剛性向量相加總合即為系統剛性值。
此外，本文亦針對液靜壓對向墊軸承系統配用毛細管節流器以及新型主動式補償液靜壓節流器，進行閉式靜壓導軌靜態特性的推導，並進一步設計一線馬驅動、光學尺回授之液靜壓導軌系統。同時針對液靜壓軸承均化誤差效應進行理論建模，對半波及全波兩種靜壓導軌平坦度誤差下，靜壓導軌的垂直度誤差進行研究，並獲得可得最佳均化誤差效果的設計參數。在實驗方面，本文針對承載力與剛性需求，設計製作毛細管節流器於液靜壓線性運動平台系統，以實驗證明理論推導與數值模擬的正確性，並對此滑軌進行導軌運動誤差量測

關鍵字

閉式靜壓導軌 ； 油膜均化誤差 ； 軸承剛性

並列摘要

This thesis designed, fabricated, and tested a linear stage equipped with hydrostatic bearings. We verified the theory by applying it with capillary restrictor and theoretically investigated its characteristics when it was equipped with a novel pressure self-sensing compensating restrictor. The restrictor features an elastic element that deforms in response of the pressure variation of the oil chamber. It results in the change of the flow resistance of the restrictor, therefore, achieves the function of self-sensing compensation. Since the design integrates the restrictor with the bearing pad, it possesses the advantages of high load capacity, stiffness, and damping, in addition to fewer components, easy manufacturing and assembly, less cost.
This study started with construction of theoretical models of the hydrostatic bearings installed with capillary and the novel self-regulating restrictors, respectively. The equations governing the load capacity and stiffness of these two-types of bearings with opposed pads, respectively, were derived. Then, the stiffness equation of the bearing system with multiple pads (oil chambers) was developed; we also simulated the stiffness relationship between discrete pocket and the whole system. The simulation results confirm the vector additive characteristic of the stiffness of multiple-pad bearing system.
This study also performed static analyses of closed-type hydrostatic slideway bearings installed with either a capillary or a self-sensing compensating restrictor. Furthermore, this study designed and fabricated a linear motor actuating, linear scales back feeding linear stage with the two-types of restrictors based on the desired load capacity and stiffness. Then, we study the error-averaging effect of the oil film on the hydrostatic slideway vertical straightness, in the half-wave and full-wave type surface form errors in order to gain the finest error-averaging parameter. The load capacity and stiffness of the closed-type linear systems were verified, first, with the numerical simulation, then, confirmed with experiments. The error motion of the hydrostatic slideway was also measured

並列關鍵字

Closed-type hydrostatic slideway ； Error-averaging effect ； Bearing stiffness

參考文獻

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