ELECTROHYDRAULIC SERVO DRIVE Russian patent published in 1994 - IPC

FIELD: test facilities. SUBSTANCE: electrohydraulic amplifiers 3, 13 have nozzle-flap valves 4-6 and 14-16 with electric control inputs connected, respectively, to outputs of summing amplifiers 7-8 and 17-19. Each of hydraulic distributors 27, 28 has butt-end spaces 28, 29 and 39, 40 and floating slide valves 37, 18. Force transmitter 23 and rod 24 speed sensor 26 of hydraulic motor 25 are linked, respectively, with first inputs of comparing and summing amplifiers. Second input of first amplifier is connected to set-point element and its output, to second inputs of amplifiers 7-9. Nozzles of valves 4-6 are connected in parallel to spaces 28, 39 of distributors 27, 38 and communicate through throttles over hydraulic line 49 with pressure source. Nozzles of valves 14-16 are connected in parallel with spaces 29, 40 of distributors 27, 39 and communicate through throttles over hydraulic lines 30, 31 and 41, 42 of distributors 27, 38 connected to spaces 32, 43. Displacement of rod 24 passes signal from sensor 26 to amplifiers 7-9, 17-19 and 3, 13. Displacement of flaps of valves 4-6 and 14-16 varies pressure within spaces of distributors 27, 39 and moves slide valves 37, 49 through distance at which working fluid flow corresponding to speed of rod 24 is ensured without changing force applied to it. EFFECT: improved reliability of servo drive and dynamic accuracy of gain reproduction. 1 dwg