| 摘要 |
<p>PURPOSE:To provide a motor-driven power steering desirable in durability and fit for high-accuracy control without unreasonable force acting upon a steering shaft and a rack gear and without the power direction being reversed by noise or the like. CONSTITUTION:A motor-driven power steering 1 is provided with ball nuts 11, 13 to be engaged with a right screw 5 and a left screw 7 formed at a rack shaft 3, and an electric motor 15 disposed between them. Friction-engaged type clutches 25, 27 are formed at the facing parts between the respective ball nuts 11, 13 and a rotor 17. The respective ball nuts 11, 13 move to the left at the time of an input shaft 41 being rotated clockwise and move to the right at the time of the input shaft 41 being rotated counterclockwise by the action of a cam ring 43, a direct-acting converter rod 61 and a spring 63. With the engagement of the clutches 25, 27, the counterclockwise rotation of the electric motor 15 is transmitted to either of the ball nuts 11, 13 so as to execute power assist coinciding with the steering direction.</p> |
