Dynamics of Constant-flow Valves in Pressure Compensation of Hydrostatic Bearing

Either constant-flow valve or pump is designed for supplying constant flow to compensate recess pressure when load changes. Because of the difference in device complexity, the cost of the former is lower than that of the latter. However, a specific relationship among design parameters must be complied in valve design for constant flow, which has been presented in our previous publication for three types of constant-flow valves. This study will investigate the dynamic characteristics of these constant-flow valves. An analytical method is used to determine the variations of the flow rate due to recess pressure fluctuation. The results give the variation spectra around the constant flow rates and various pressure ranges for their availability of different valves. Additionally, this study uses analytical results to compare dynamic behavior among various designs of valves. The result of this paper reveals both double-piston types have the same static characteristics, but the dynamic characteristics by single feedback are better than double feedback. And Both static and dynamic characteristics of the spool type surpass both double-piston types.