Steer by wire road vehicle steering system provided with a mechanical limit stop device for the steering wheel

A steering system (4) for a road vehicle (1);

• the steering system (4) comprises:
• a steering wheel (6) provided with an outer ring (15), which is mounted so as to rotate around a rotation axis (13) and has no connection to steering wheels (2);
• a position sensor (8), which is designed to detect the angular position of the outer ring (15) of the steering wheel (6) around the rotation axis (13);
• and
• a mechanical limit stop device (30), which is coupled to the outer ring (15) of the steering wheel (6) and limits, in both directions, the maximum angular width of the rotation of the steering wheel (6) around the rotation axis (13), so that the steering wheel (6) can make, on the whole, a rotation around the rotation axis (13) that is greater than 360°;
• wherein the limit stop device (30) comprises:
• a groove (31), which is wound in a spiral shape around the rotation axis (13) over more than 360° and has, at the two opposite ends, two abutments (32), which define respective stop strikers;
• and a pin (33), which is arranged on the inside of the groove (31) so as to engage and follow the groove (31) from an abutment (32) to the opposite abutment (32);
• wherein the groove (31) is angularly integral to the outer ring (15) of the steering wheel (6) to rotate in an angularly integral manner with the steering wheel (6) and in use can axially slide relative to the outer ring (15) of the steering wheel (6) to allow the rotation of the steering wheel (6);
• and
• wherein the pin (33) is rigidly connected to a part that does not rotate together with the outer ring (15) of the steering wheel (6) and cannot slide relative to the outer ring (15) of the steering wheel (6).