Patent ID: 6973990
Filing Date: 2005-12-13
Classification: B62D,Y10T

Abstract:
1. An electric power steering apparatus for transmitting a driving force of a motor to a rack shaft via a reduction mechanism and a ball screw mechanism to assist movement of the rack shaft in a longitudinal axis thereof, wherein in the electric power steering apparatus: the reduction mechanism includes a drive gear connected to a rotating shaft of the motor, and a driven gear meshed with the drive gear and connected to the ball screw mechanism via an elastic member, wherein the ball screw mechanism includes a ball screw nut having a helical first ball groove extending along its inner circumferential surface, a helical second ball groove extending along an outer circumferential surface of the rack shaft, and a plurality of balls arranged between the helical first ball groove and the helical second ball groove, and the driven gear is provided on the outer circumferential surface of the ball screw nut.