ELECTRO HYDRAULIC SERVO DRIVE OF THROTTLING ADJUSTMENT Russian patent published in 2009 - IPC F15B9/00 

FIELD: machine building.

SUBSTANCE: proposed drive is intended for automatic control and comprises the following consecutively connected components, i.e. set-point device- comparator amplifier 1, electromechanical converter 2, hydraulic amplifier 3 connected to feed pressure source 4 and incorporating an inlet plate for rotary distributing element 5 (spray plug) arranged to interact with and change relative positioning with feedback nozzles 6, 7, as well as hydraulic cylinder 8 with its con rod 9 connected via a negative position feedback electric circuit 10 with comparator amplifier 1. The additional feedback device comprises, in compliance with the pressure difference derivative, a hydraulic condenser representing sleeve 11 with the piston spring-loaded on both sides and feedback cylinder with two partitions and two spring-loaded pistons 12, 13 arranged on double-sided con-rod 14 furnished with section parts intended for varying flow passages made in partitions of adjustable throttle holes 15, 16 whereto feedback nozzles 6, 7 are connected. The hydraulic cylinder space between the said partitions communicates with the control pressure source, the end face chambers 17, 18 of con rod 14 communicate with the spaces of hydraulic motor 8, while the spring spaces 19, 20 of pistons 12, 13 communicate with spring spaces of condenser sleeve 11. Both spaces of the latter are connected, via constant-section throttles 21, 22, to the spaces of hydraulic motor 8. The drive incorporates working fluid temperature pickup 23 arranged at the inlet of hydraulic booster 3, ambient air temperature pickup 24, processor (not shown) and working fluid temperature set-point and comparison device 25 connected with temperature pickups 23, 24. The drive is provided with compressor 26 with evaporator 28, condenser 28 and adjustable RPM blowers 29, 30, radiator 31, instantaneous water heaters 32 and distributing device 33 representing a three-line three-position distributor.

EFFECT: expanded operating temperature range, higher stability and accuracy, increased damping in resonance frequencies, eliminated scatter of characteristics in operation under varying ambient conditions, expanded performances.

4 cl, 1 dwg