Abstract: A power steering system uses an electric motor to produce an auxiliary torque which is added to the torque applied to the steering wheel of a vehicle by the driver. The system includes a couple mechanism for coupling the motor to the steering shaft. The system further includes a converting mechanism for converting a part of rotating force in the motor in an axial force and installed in the coupling mechanism and an elastic member for absorbing the axial force and installed in the coupling mechanism. This permits the elastic member to absorb the momentary shock occurred at starting condition of motor due to backlash of gears in the coupling mechanism.

Abstract: Herein disclosed is an electric power steering system which comprises: a detecting unit for detecting the direction and magnitude of a relative angular displacement betweeen input and output shafts; and an electric motor connected to the output shaft and having its revolutions controlled through a controller in accordance with the output signal of the detecting unit. The detecting unit includes a converting mechanism for converting the relative angular displacement into an axial displacement, and a displacement detecting unit for detecting the magnitude of the displacement in the axial direction. The displacement detecting unit can have its neutral position adjusted independently of other parts.