The Design and Analysis of a Servovalve With Flow Feedback

Abstract

Almost all conventional servovalves operate on the principle of controlling the position of a four-way or three-way valve made with very high precision with the hope that the flow rate will follow accurately the input signal to the valve. In this paper, an entirely new approach to the servovalve design is presented. A flow signal instead of valve position is used in the feedback loop. This design eliminates the necessity of a high precision valve, gives a greater length of the life expectancy of the valve, and minimizes the effect of load variation as well as supply pressure variation. Dynamic analysis and test results of the flowmeter and the complete valve are given.