THREE-CHANNEL ELECTROHYDRAULIC SERVO UNIT Russian patent published in 1995 - IPC

FIELD: aviation. SUBSTANCE: servo unit has electrohydraulic actuator 5 in each subchannel 1, actuating hydraulic cylinder 8 with hollow rod 9 which is brought in communication with delivery line and two pistons 10 and 11 located inside it, feedback transmitter 14, electrohydraulic valve 7, cross-feed valve 6, failure indication microswitch 13, delivery and return lines; piston 11 is hollow and has piston 10 inside it forming working chamber between pistons. Hollow rod 9 is provided with projection engageable with hollow piston 11 which is provided with shoulder engageable with piston 10 connected with bell crank by means of articulated rod. EFFECT: improved static and dynamic characteristics through avoidance of backlash. 2 dwg