Patent attributes
Left and right front wheels are steered by rotation of steering shafts, and a steering force from a steering wheel is inputted into the steering shaft. Mutually adjacent ends of the shafts are coupled to a ring gear and a sun gear of a planetary gear set, a steering angle adjustment motor is drivably coupled to a carrier of the planetary gear set, and the rotation ratio between the shafts is made changeable. Left and right rear wheels are steered by rotation of steering shafts, and a steering force from a steering motor is inputted into the shaft. Mutually adjacent ends of the shafts are respectively coupled to a ring gear and a sun gear of a planetary gear set, a steering angle adjustment motor is drivably coupled to a carrier of the planetary gear set, and the rotation ratio between the shafts is made changeable.