Hydraulic circuit for power assisted steering - has auxiliary pump which runs at speed corresponding to vehicle speed

摘要

The power assisted steering system of a motor vehicle has a main pump (P) which delivers hydraulic fluid through a control valve CV(15) to the servo cylinder (P/C). The reaction pressure in the servo cylinder (P/C) is controlled by means of an auxiliary pump (subP) which is connected to the hydraulic reaction device (20) and to the variable throttling orifices (5,6). The auxiliary pump (subP) operates at a speed corresponding to the vehicle speed and the hydraulic reaction device (20) has an input shaft which controls the effective cross-sectional areas of the throttling orifices (5,6). USE - Power assisted steering for road vehicle.