COMBINATION DRIVE Russian patent published in 2002 - IPC

FIELD: control systems. SUBSTANCE: drive has housing with channels connected with delivery and drain hydraulic lines, hydraulic motor, electrohydraulic power amplifier, servo unit, feedback transducer, spring-loaded stop, servo unit cross- feeding valve, combination mode cut-in electrohydraulic valve, double spool cylindrical distributor consisting of doubling spool and main spool placed inside doubling spool and mechanically coupled with input control rocker lever and provided with additional shoulder placed inside special bore of doubling spool in form of two grooves made through 180^° and forming two isolated spaces, one of which is constantly connected with drain line, and the other is connected with delivery line by special electromagnetic valve when valve is cut in, and is connected with drain line, when valve is cut out. Doubling spool is fixed in neutral position by means of centering springs. Two bushings with two grooves on outer surfaces and with inner through two-step cylindrical bores are installed in housing bore coaxially with spool distributor. Two-shoulder spring- loaded plungers are fitted in two-step cylindrical bores for displacement. One of plungers is in contact with shoulder of doubling spool by one end face, and with one of end faces of housing bore, and the other is in contact with stop on outer end face of doubling spool and with other end face of housing bore. Two cuts are made in inner bores of each bushing. Two of cuts are connected by radial holes of bushings and its grooves on outer surface with delivery line, and others are connected with space of doubling spool connected with electromagnetic valve. EFFECT: improved reliability. 3 cl, 3 dwg