| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball screw far facilitating fixing work of a piece member, and to provide an electric power steering device having the ball screw which absorbs an impact load and suppresses miss alignment. SOLUTION: The ball screw 1 is used for the electric power steering device of an automobile, for example, and comprises: a screw shaft 2; a nut 3 engaged with the outside of the screw shaft 2; a spiral screw groove 4 formed in the outer periphery of the screw shaft 2; a plurality of balls 7 stored in a rolling passage 6 formed of a spiral screw groove 5 facing the screw groove 4 and formed in the inner periphery of the nut 3; a piece member 9 having a connecting groove 8 for connecting the screw groove 4 of the nut 3; and a synthetic resin layer 10 molded on the outer peripheral surface of the nut 3. The outer part of the piece member 9 is formed wide, and the wide part 9a is pressed into a piece window 12 of the nut 3 with a slight fastening allowance. Thus, a fused resin does not intrude from the piece window 12 into the ball screw 1. COPYRIGHT: (C)2004,JPO |
