| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a ball screw device capable of giving proper pre-load without depending on machining precision of a ball rolling groove. <P>SOLUTION: A first fitting groove 33 and a second fitting groove 34 extending in parallel with the direction of axial line are formed at the outer peripheries of a first nut 23 and a second nut 24, respectively, and a step key 35 provided with a first fitting part 35a and a second fitting part 35b whose central lines A, B are deviated from each other in the circumferential direction is fitted into the first and second fitting grooves 33, 34. Rotation of a screw shaft 12b is regulated and the first and second nuts 23, 24 are relatively rotated in an abutted state to impart predetermined rotation torque. By fitting the step key 35 corresponding to deviation of phase of the first and second fitting grooves 33, 34 formed at the outer peripheries of the first and second nuts 23, 24 into the first and second fitting grooves 33, 34 in this condition, pre-load for rolling each ball 21 smoothly in the ball rolling grooves 22, 25, 26 at two point-contact can be easily imparted. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
