Servo for vehicle steering system - has variable flow shunt across servo cylinder to modulate force in response to speed

摘要

The hydraulic steering servo has a hydraulic pump (5) driven off the engine and with the flow of fluid to the servo cylinder (4) controlled by a steering column valve (6). A variable flow shunt (8) is set across the output of the steering column valve to modulate the servo force with speed. The shunt valve opens progressively with vehicle speed, and closes with vehicle loading. It also opens with increasing wheel lock.