POWER-ASSISTED STEERING SYSTEM FOR MOTOR VEHICLES

摘要

A power assisted steering system for motor vehicles has a steering gear casing and two separate hydraulic steering circuits. The first of said circuits includes a servo pump, driven by the vehicle engine, with an oil reservoir and a first adjusting motor which is constituted by a power piston and which is combined with a first control valve, constructed as a rotary valve, and with a steering gear including a steering spindle and steering worm. The second steering circuit includes a servo pump with an oil reservoir and a second control valve constructed as a rotary valve which is arranged co-axially with the first rotary valve. The second control valve is combined with the steering gear and acts on a second adjusting motor. The rotary valves are coupled to one another and are operable jointly in dependence on the rotary movement of the steering spindle. The second rotary valve is accommodated in a flange which is screwed to the housing at its end adjacent the spindle, whereby a conventional steering gear casing for a single-circuit system can be easily converted to a dual-circuit system.