Patent ID: 8561753

Claim:
An electric power steering device comprising: a housing; an input shaft configured to be operably connected to a steering wheel; an output shaft connected to the power steering device a torsion bar provided between the input shaft and the output shaft; a torque sensor that detects steering torque input from the steering wheel; an electric motor driven in accordance with the steering torque detected by the torque sensor; a worm wheel provided within the housing and fitted around the output shaft to transmit rotation of the electric motor to the output shaft, the worm wheel including a boss fitted around an outer circumference of the output shaft and a bearing fitted around an outer circumference of the boss, the bearing being supported on the housing such that the bearing is held in an axial direction of the power steering device between a raised surface extending from the boss and an end face of a connection member attached to the outer circumference of the output shaft; and wherein at least a portion of the bearing fitted around the outer circumference of the boss is disposed within a space defined by the worm wheel in the axial direction such that teeth of the worm wheel at least partially surround the bearing in a radial direction of the worm wheel.