VARIABLE GEAR RATIO TRANSMISSION AND ACTIVE FRONT WHEEL STEERING SYSTEM OF AUTOMOBILE INCLUDING THE SAME

摘要

A gear ratio changing device and an active front-wheel steering device of a vehicle are provided to limit shaft-way movement of a sun gear and a planetary gear by forming an elastic member in the gear ratio changing device of the active front-wheel steering device, to thereby prevent a clearance between gear teeth of the sun gear and the planetary gear and actively rotate the sun gear and the planetary gear, and to prevent noise from being generated due to collision of the sun gear or the planetary gear with other units. A gear ration changing device of a vehicle comprises an input shaft possibly rotated; a sleeve made hollow by penetrating the input shaft and formed with a worm wheel on the upper end of the outer peripheral surface and a sun gear on the lower end of the outer peripheral surface; a carrier(121) radially elongated of the lower end of the input shaft along the diameter of the input shaft; a planetary gear(123) rotatively supported by the carrier to be contacted on the sun gear externally; an inner gear formed to be internally contacted on the planetary gear; an output shaft connected with the lower end of the inner gear; an elastic member(403) formed at the lower surface of the carrier; and a thrust bearing(503) formed between the lower surface of the carrier and the elastic member. A thrust bearing guide(505) is formed under the thrust bearing.