Patent ID: 8020647

Claim:
A steering control system for a vehicle wherein a first wheel system is driven by a first axle shaft, a second wheel system is driven by a second axle shaft, said first axle shaft and said second axle shaft being driven by a power shaft powered by an engine of the vehicle, a differential gear being interposed between said power shaft and said first and second axle shafts, said steering system comprising: a first hydraulic unit associated with said first axle shaft, a second hydraulic unit associated with said second axle shaft, a hydraulic circuit connecting an input of said first hydraulic unit to an output of said second hydraulic unit and an output of said first hydraulic unit to an input of said second hydraulic unit, a control unit connected to said hydraulic circuit and configured for varying a flow rate of an hydraulic fluid in said first hydraulic unit and said second hydraulic unit; and an actuator for controlling said control unit, said actuator responsive to a rotation of a steering wheel of said vehicle; the control unit comprising a double acting positive displacement control pump with a variable flow rate; said actuator comprising a double acting hydraulic cylinder that drives said flow rate control device of the control pump.