Rear-wheel steering apparatus for wheeled vehicle

A rear-wheel steering apparatus for a wheeled vehicle having a linkage mechanism for effecting steerage of a set of dirigible rear road wheels, comprising:

• a planetary gear unit the carrier of which is adapted as an output element drivingly connected to an input member of said linkage mechanism;
• a first electric motor the output shaft of which is drivingly connected to a sun gear of said planetary gear unit;
• a first electrically operated brake mechanism connected to and operatively engaging said sun gear for restricting rotation of said sun gear only when the vehicle is travelling at a higher speed than a predetermined speed;
• a second electric motor the output shaft of which is drivingly connected a ring gear of said planetary gear unit;
• and
• a second electrically operated brake mechanism connected to and operatively engaging said ring gear for restricting rotation of said ring gear only when the vehicle is travelling at a lower speed than the predetermined speed.