POSITIVE DISPLACEMENT STEERING GEAR Russian patent published in 1995 - IPC

FIELD: automotive vehicles. SUBSTANCE: positive displacement steering gear has three-position eight-line servo control valve unit 1, pump-motor 3, two-position five-line control valve unit 4. Novelty in offered positive displacement steering gear is that flow amplifier is made in form of two-position five-line hydraulically controlled valve unit 4. Installed in fourth and fifth lines of five-line control valve unit 4 are check valves 10, 11 and restrictors 12,13. In left-hand position of valve unit 4 fourth and fifth lines are interconnected and connected with first line, and second and third lines are not connected to each other; in right-hand position of control valve unit 4 fourth and fifth lines are interconnected but are not connected to first line, and second line is connected with third line. Control valve unit 4 is arranged in spool of control valve unit 1 coaxially with the latter and is made in form of cylinder with groove which serves as mixing space 21. Flow amplifier serves simultaneously as priority valve and second line of hydraulically controlled control valve unit 4 is coupled with other consumers. EFFECT: enhanced reliability of operation. 3 cl, 3 dwg