近年來，液靜壓軸承在高精密加工機台的應用有了很大的成長，因為液靜壓軸承沒有表面接觸，所以可以減少摩擦的影響；而毛細管節流器、孔口節流器、薄膜式節流器和流量控制閥等補償裝置有助於控制液靜壓軸承油腔壓力。
此研究中，使用薄膜節流器補償液靜壓軸承的上油墊，而使用毛細管節流器補償液靜壓軸承的下油墊，建立性能特性的理論方程，並對其表現進行理論計算，液靜壓軸承的承載力與剛性的理論公式是由上下油墊的油腔壓力比(P ̅_up,P ̅_lp) 、有效面積(A_e^up,A_e^lp)以及偏心率(ε)所建立。同時會藉由理論公式推導出上油墊所使用的薄膜節流器之無因次剛性(K_r^*)、設計流阻比(λ)以及下油墊的參考壓力比(β_lp)之間的關係。
藉由調整下油墊的油腔壓力能夠使軸承在不同負載條件下達到理想的軸承性能表現，本研究將能夠在K_r^*與λ已知的情況下，根據不同的負載需求，藉由調整下油墊的參考壓力比來達到軸承的最佳性能表現。

In recent years, the applications of hydrostatic bearing in high precision machine tools have increased considerably. This is because hydrostatic bearings reduce the effect of friction as there will not be any contact between the working surfaces. Compensating devices like capillary restrictor, orifice restrictor, membrane restrictor, and constant flow valves help hydrostatic bearings to manipulate the recess pressures.
In this research work, a membrane restrictor is used as the compensating device in the upper pad, and capillary restrictors are used in the lower pad of the hydrostatic bearing. All the theoretical equations for performance characteristics were formulated and these equations are employed to perform the theoretical calculations. The load capacity and stiffness equations were formulated using the pressure ratios (P ̅_up,P ̅_lp) and effective areas (A_e^up,A_e^lp) of both the pads and eccentricity ("ε" ). A relation between the dimensionless stiffness (K_r^*), design restriction ratio (λ) of the upper pad and reference pressure ratio of the lower pad (β_lp) is derived theoretically.
The desired bearing performance can be achieved at different load conditions with the help of lower pad. This research work would help to select a suitable reference pressure ratio (β_lp) of the lower pad according to the load requirements to obtain the best performance for a known value of K_r^* and λ.

Table of Contents
ABSTRACT--------I
1. INTRODUCTION --------1
2. LITERATURE REVIEW --------4
2.1 Hydrostatic bearing --------4
2.2 Membrane restrictor --------5
2.3 Summary --------9
3. OBJECTIVES AND FUNDAMENTAL THEORY --------10
3.1 Design of components --------12
3.2 Opposed pad hydrostatic bearing structure --------19
3.3 Theoretical Calculations for load capacity and stiffness of the
bearing --------20
3.4 Bearing pad design --------22
3.5 Miscellaneous equations --------24
4. THEORETICAL ANALYSIS --------25
4.1 Objective --------25
4.2 Procedure of analysis --------25
4.3 Simulation Results --------26
4.4 Conclusion from simulation results --------37
5. EXPERIMENTAL DESIGN AND RESULTS --------38
5.1 Three-dimensional model of the designed hydrostatic bearing
system --------38
5.2 Dimensional design --------42
5.3 Experimental equipment --------47
5.4 Estimation of flow resistance of capillary restrictors --------51
5.5 Estimation of flow resistance, Kr* and λ of membrane restrictor --------58
5.6 Performance of the bearing with both the pads in working
condition --------63
6. Conclusion --------67
6.1 Conclusion --------67
6.2 Future work --------68
REFERENCES --------69

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