A valve-controlled hydraulic servomechanism

HYDRAULIC SERVOMECHANISMS with flow-control valves are applied in many systems that require high performance, light weight, and power output of several horsepower. Unfortunately, hydraulic servos are not widely understood, for there is very little relevant textbook material and only a few technical papers.¹ This investigation extends the now existing work by presenting an analysis of a complete hydraulic servo, together with experimental results that verify the analysis. The servo (Fig. 1) has an amplifier, a single-stage flow-control valve, a single-vane rotary motor with inertia load, and a position feedback.