REDUNDANT ELECTROHYDRAULIC SERVO DRIVE Russian patent published in 2004 - IPC

FIELD: flying vehicle control system drives.

SUBSTANCE: proposed servo drive has housing with working fluid delivery and drain channels, single-chamber hydraulic actuator with housing channels, series-connected closing/cross-feed valve, electrohydraulic booster and servo cylinder, hydraulic distributor with mechanical non-power wire lead coupled with servo cylinder rod, and hydraulic system selector valve communicating with two independent hydraulic supply systems; hydraulic system selector valve is made in the form of two control devices built in common cylindrical channel at opposite ends of body and separated by isolating bushing; they have shut-off members of valve-seat type each incorporating cap, guide sleeve, and seat-bushing fixed in position in body channel and provided with sealing rings on outer cylindrical surfaces and inner stepped drillings, as well as kinematically intercoupled spring-loaded check valve installed in small-step drilling of seat-bushing and spring-loaded plunger hermetically disposed in large-step drilling of guide sleeve and provided with inner partition carrying spring on one end and control chamber, on other end, this chamber communicating with delivery line and through check valve built in small step of guide sleeve drilling, with delivery channel of actuating mechanism; large-step drillings of seat-bushings of both control devices are interconnected and communicate with drain channel of actuating mechanism; mentioned kinematic coupling is made in the form of stepped cylindrical pusher disposed in small-step drilling of seat-bushing for their axial displacement and engagement with end surface of plunger partition and with ball-shaped shut-off member of check valve through their working butt-ends; guaranteed annular clearance is provided between outer surface of pusher small step and small-step drilling surface of seat-bushing for passing working medium.

EFFECT: enhanced reliability.

2 cl, 6 dwg