| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball screw device of a long service life wherein the linear motion of a nut is temporarily converted into the oscillating motion of an oscillating arm, and then converted into rotating motion to drive a driven body. SOLUTION: A contact point of the tip 21a of the oscillating arm and a recessed portion 13c of the nut is located at P when a central shaft of the oscillating arm 21 is located at a vertical position with respect to the shaft center of a ball screw shaft 12. When the nut 13 is moved right or left, the tip 21a of the oscillating arm is inclined in a circular arc-shaped recessed portion 13p of the recessed portion 13c of the nut in a state that a distance between a first member 21A and a second member 21B is adjusted at an oscillation connecting portion 21C, but the contact point P is not moved by the inclination of the oscillating arm. The oscillating center of the oscillating arm 21 constantly includes the shaft center of the ball screw shaft 12, and located on a plane in parallel with a driven shaft 30, and as an acting force generated at the nut 13 passes through the center of a nut ball circulation path, reaction force moment is not generated at the nut 13. COPYRIGHT: (C)2006,JPO&NCIPI
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