Patent ID: 6854556

Claim:
A motor operated power steering device, comprising: a steering shaft; a gear fitted around the outer circumference of the steering shaft; a steering assistance motor which transmits a rotational force via the gear to the steering shaft; and a torque limiter, fitted in between the steering shaft and the gear, and having a diametric direction defined by a diameter of the torque limiter; wherein: the torque limiter includes a torque setting member, which is subject to diametric deformation along the diametric direction as a result of being fitted in between the outer circumference of the steering shaft and the inner circumference of the gear; the torque setting member includes a ring with a circumference around which plural projections are spaced and project diametrically; the torque setting member causes a diametric force corresponding to its diametric deformation to act on the steering shaft and the gear; a limit torque value of the torque limiter, corresponds to the diametric deformation of the torque setting member; when the diametric deformation of the torque setting member is less than a specific value, the diametric force increases in proportion to the diametric deformation; when the diametric deformation exceeds the specific value, a ratio of increase in the diametric force to the diametric deformation is smaller than when the diametric deformation is less than the specific value; and the diametric deformation of the torque setting member is a value in a range in which the diametric deformation exceeds the specific value.