| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the press-fit work of a bearing to a nut of a ball screw mechanism, smoothly guide it in assembling a rotor for an electric motor, and enhance the rotation preventive effect of the rotor relative to the nut. SOLUTION: A part of a steering shaft 2 advancing/retreating freely is set to a ball screw shaft 2a of a ball screw mechanism 13 and a rotor 10 of an electric motor 8 for compensating a steering force is fitted on a rotation nut 14. The rotation nut 14 is formed by connecting end caps 18, 19 to a nut body 17. The end outside diameter of the nut body 17 is formed into tapered face 29, 30 gradually enlarging their diameters. A rotation preventive knurled part 31 is formed in a part from the cylindrical face of the nut body 17 to a part of the tapered face 30. The nut body 17 is made of sintered alloy. |
