FIELD: machine building.
SUBSTANCE: three-stage electrohydraulic amplifier with electric flow feedback is designed for automatic systems in which two- and three-stage quick-acting electrohydraulic amplifiers are used. Amplifier includes the first summing operating amplifier with two inputs to one of which a control signal is supplied, the second summing operating amplifier one input of which is connected to output of the first summing operating amplifier; electronic power amplifier the input of which is connected to output of the second summing operating amplifier; electromechanical converter the control winding of which is connected to output of electronic power amplifier, and armature is kinematically connected to movable element of hydraulic valve of the first stage; hydraulic valve of the first stage is hydraulically connected to pressure and drain hydraulic lines; hydraulic valve of the second stage is kinematically connected to movable element of electric feedback transducer hydraulically connected to pressure and drain hydraulic lines and two hydraulic lines, hydraulically connected to hydraulic valve of the first stage; matching device the input of which is connected to signal winding of electric feedback transducer of hydraulic valve of the second stage, and output of matching device is connected to the second input of the second summing operating amplifier; hydraulic valve of the third stage is kinematically connected to movable element of electric feedback transducer, hydraulically connected to pressure and drain hydraulic lines, hydraulically connected via two hydraulic lines to hydraulic valve of the second stage and having two output hydraulic lines to be connected to consumer; matching equipment the input of which is connected to signal winding of electric feedback transducer of hydraulic valve of the third stage; electrohydraulic differential pressure transmitter hydraulically connected via two hydraulic lines to output hydraulic lines of hydraulic valve of the third stage; electronic computing device one input of which is connected to output of matching equipment of electric feedback transducer of hydraulic valve of the third stage, and the other input is connected to electric output of electrohydraulic differential pressure transmitter, output of electronic computing device is connected to the second input of the first summing operating amplifier.
EFFECT: improved electrohydraulic amplifier at operation as a part of electrohydraulic follow-up drive of throttle control provides the following: 1) invariance of drive speed performance in relation to the change of load pressure difference, 2) increasing the efficiency coefficient of power part of drive in working range of the change of load pressure difference, 3) possibility, if necessary, of implementing the speed limitation of output link of actuating mechanism due to limitation of input signal at the input of the first summing operating amplifier.
2 dwg
