Hydraulic steering system for a vehicle

A hydraulic steering system for a vehicle comprising:

• at least one steering control member;
• a hydraulic pump provided with a driving shaft rotatable in two directions, wherein said steering control member is fitted on said hydraulic pump to cause a rotation of said driving shaft;
• at least one hydraulic actuating cylinder connected to a delivery side and a return side of said pump;
• an electric motor/transmission assembly;
• and
• a control unit generating a power supply signal of the electric motor/transmission assembly, said control unit being connected to a plurality of sensors each detecting a specific movement condition of the vehicle, said plurality of sensors being selected from the group consisting of position sensors, speed sensors, sensors of steering angle, sensors of a number of revolutions of a motor of the vehicle, sensors of wind direction or strength, sensors of obstacles, and accelerometers,
• wherein said actuating cylinder forms a hydraulic circuit with said hydraulic pump;
• wherein said actuating cylinder is mechanically articulated with a direction changing member, said direction changing member determining a change in direction by modifying orientation of said direction changing member with respect to an axis of the vehicle;
• wherein the change in the orientation of said direction changing member is performed by said actuating cylinder as a function of supply of hydraulic fluid to said actuating cylinder caused by operation of the hydraulic pump by the steering control member;
• wherein the driving shaft of the hydraulic pump is connected with the electric motor/transmission assembly, which is configured to perform each of the following functions:
• (a) generating a first rotational force auxiliary to a manually exerted movement on the steering control member;
• (b) generating a second rotational force opposing said manually exerted movement and sufficient to generate a predetermined resistance to a displacement of the direction changing member, thereby preventing an accidental steering of the steering control member;
• or
• (c) rotatably driving the driving shaft of the pump to drive the vehicle autonomously independently of the manually exerted movement, and
• wherein the control unit is configured to activate the electric motor/transmission assembly to perform each of the following functions:
• functions (a) or (b), based on signals generated from the plurality of sensors, and
• function (c), based on direction settings entered by a user, and signals of travel conditions along a path or presence of obstacles along a path transmitted to said control unit by the plurality of sensors.