Patent ID: 7490695

Claim:
An electric power steering apparatus that generates an assist steering torque by an electric motor in response to a steering torque applied on a steering wheel and transmits it to an output shaft of a steering mechanism while reducing it by means of a reduction gear, comprising: a drive gear shaft in said reduction gear that has a distal end portion and a proximal end portion, the proximal end portion being connected to an output shaft of the electric motor so as to transmit torque from the electric motor output shaft to the drive gear shaft; a first bearing device supported in a housing of the reduction gear and supporting the distal end portion of the drive gear shaft; a second bearing device supported in said housing and including a rolling bearing arranged about the proximal end portion of the drive gear shaft with a small gap in a radial direction of the drive gear shaft; a driven gear supported on the steering mechanism output shaft and engaging, between the first and second bearing devices, with a worm gear supported on the drive gear shaft; preload means disposed in a vicinity of the first bearing device for preloading the drive gear shaft in a meshing direction of the worm gear with the driven gear; and support means cooperable with the second bearing device for elastically supporting the drive gear shaft such that the drive gear shaft is coaxial with the second bearing device and tiltable relative to a portion of the second bearing device.