| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily change a torsional natural frequency constituted by a rack shaft and a rotor of an electric motor, to damp cogging of the electric motor and vibration of a tire, to relieve impact force of a torque transmission passage of the electric motor, and to improve a steering wheel feeling of a steering wheel in a motor driven power steering device. SOLUTION: In this motor-driven power steering device 10, a meshing surface 61 of a driving member 54 integrally joined in the rotational direction to a rotor side member (a sleeve 33) of the electric motor 30 and a meshing surface 62 of a driven part 58 integrally joined in the rotational direction to a nut 42 are oppositely arranged in the shaft direction, and a spring 55 is provided for energizing at least one of the driving member 54 and the driven part 58 in the meshing direction of these meshing surfaces 61 and 62.</p> |
