PUMP-AND-ACCUMULATOR HYDRAULIC DRIVE Russian patent published in 2002 - IPC

FIELD: actuating mechanisms of control systems of machines, flying vehicles, robots, etc. SUBSTANCE: proposed hydraulic drive includes actuating hydraulic incomplete-turn motor whose output member is made in form of hollow cylinder; inner surface of this cylinder is designed for backlash- free securing of tailpiece of control member of object. Its external surface is provided with lugs; one lug is engageable with coaxial (or parallel) pistons by means of connecting rods. Other end of lug is provided with catcher for retainer to ensure backlash-free securing of output member in center position after disconnection of power supply. Hydraulic drive is provided with electromagnetic cross-feed valve whose inlet is communicated with pressure hydraulic line of low-pressure pump and with retainer control chamber and its outlet is communicated with hydraulic tank. External movable seals of retainer and hydraulic motor pistons are brought out to special closed cavity connected with hydraulic tank by means of hydraulic line. EFFECT: enhanced dynamic following of control signal; increased service life of hydraulic drive; enhanced reliability of automatic backlash-free securing of output member in center position after disconnection of power supply. 1 dwg