ELECTROHYDRAULIC REDUNDANT SERVO DRIVE Russian patent published in 2004 - IPC

FIELD: automatic control systems.

SUBSTANCE: proposed drive has housing with working medium delivery and drain channels, actuating mechanism-single-chamber hydraulic motor with space channels and series-connected electromagnetic cut-in-cross-feeding valve, electrohydraulic power amplifier and servocylinder, hydraulic distributor with mechanical nonpower run of drive connected with rod of servocylinder and hydraulic systems change-over valve communicating with two independent supply hydraulic systems. Hydraulic systems change-over valve is provided with automatic discrete action bypass devices with indicator rods and is made in form of two control devices built in opposite to each other in common cylindrical channel of housing and separated by disconnecting bushing of control devices with shutoff members of "valve-seat" type, each consisting of stationarily installed in housing channel following devices: cover, guide cup and three-step support bushing with sealing rings on outer cylindrical surfaces and inner stepped bores, and mechanically interconnected spring-loaded disk check valve with bypass device installed in bores of support bushing and spring-loaded plunger tightly fitted in bore of larger step of guide cup and provided with inner partition at one side of which spring is installed and at other side, working control chamber is formed for communication with delivery pressure main line and, through disk check valve built into smaller step of guide cup bore, with pressure channel of actuating mechanism. Bores of larger steps of support bushings of both control devices are cross-fed and are placed in communication with train channel of actuating mechanism. Said mechanical circuit is made in form axially movable spring loaded piston-seat of bypass device of check valve sealed over outer surface and arranged in inner bore, stepped cylindrical indicator rod installed for axial displacement and interaction by working end faces with end face surfaces of partition of plunger and shutoff member of check valve formed as flat plate shutoff with outer spherical guide part and lapped to sealing edges of piston-seat made in form of ring concentrically arranged knife projections. Guaranteed ring clearance to pass working medium is set between outer surface of smaller step of indicato5r rod and surface on inner bore of piston-seat.

EFFECT: improved reliability.

3 cl, 8 dwg