Patent ID: 6900564

Claim:
An electric power steering system, comprising: a steering assist electric motor; a reduction gear mechanism for reducing a rotation speed of a rotatable shaft of the electric motor, the reduction gear mechanism comprising a worm shaft driven by the rotatable shaft of the electric motor, and a worm wheel driven by the worm shaft; a joint for coupling the rotatable shaft of the electric motor to the worm shaft for transmission of a driving force; and longitudinally biasing means, provided in association with the joint for longitudinally biasing the worm shaft; wherein first and second sleeves are provided in an opposed relation as respectively extending from the first end portion of the worm shaft and from an end of the rotatable shaft of the electric motor located adjacent the first end portion; wherein the joint comprises a joint having a drive shaft coupled to the first and second sleeves for transmission of a driving force; wherein the drive shaft is in serration engagement with the first and second sleeves; wherein the drive shaft comprises a drive shaft having a spring housing hole; and wherein the longitudinally biasing means comprises a spring housed in the spring housing hole.