PRELIMINARY CONTROLLED SERVOVALVE Russian patent published in 1999 - IPC

FIELD: mechanical engineering; valves; control of position, speed and force of hydraulic cylinders and position, speed and torque of hydraulic motors. SUBSTANCE: servovalve has at least three connections to main flow through holes in control sleeve which accommodates control spool with two end sections. One of holes in sleeve for connection to main flow is located opposite to end face surface of control spool on its first end section, and other holes are located at side of its side surface. Pressure relief space houses pressure relief surface of control spool provided with discharge channel. Pressure relief space communicates through channel with first connection of main flow. Device has return spring acting onto control spool in direction towards its first end section. EFFECT: possibility of using preliminarily controlled servovalve in control unit, reduced overall dimensions, enhanced reliability and improved dynamic characteristics. 14 cl, 8 dwg