Abstract
Hydraulic servomechanisms have come into wide use in recent years as a result of the low inertia of hydraulic servomotors compared to electric servomotors of the same power rating. This paper discusses the theory of operation, static characteristics, and dynamic characteristics of some hydraulic components that have been used for many years in regulator applications. Previously, the dynamics of these components were not of great importance because of the slowness of the processes controlled. The important considerations were static gain and static accuracy. The dynamic characteristics have been investigated more recently as a result of the high dynamic-performance demands of servomechanism applications. Dynamics are considered from the frequency-response approach.
