An electrically actuated, hydraulic power steering system is provided. The
steering system includes a hydraulic pump for generating hydraulic
pressure, a hydraulic fluid reservoir, a hydraulic cylinder, and a
control valve arrangement that selectively connects the hydraulic
cylinder to the pump and the hydraulic fluid reservoir. The control valve
arrangement is characterized during the on-center position by a first and
a second chamber of the hydraulic cylinder being in fluid communication
with each other but not with the fluid reservoir. In one embodiment, the
steering system has a steering sensor, a control box, and two pressure
accumulators for providing at least two levels of steering assist.