| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance sealing performance of a ball screw by improving lubricating condition of a contact face of a lip part of a seal with a screw shaft. <P>SOLUTION: The cross-sectional shape of the spiral groove 21A of the screw shaft 2 is a Gothic arc shape in which two arcs with the same radius (larger than the radius of a ball and smaller than the diameter of the ball) and different centers are coupled and the shape in which the two arcs are smoothly coupled with an arc with the radius R. Further, the cross-section of the distal end of the lip part 42a is formed in an arc shape with a radius r (<R). <P>COPYRIGHT: (C)2012,JPO&INPIT |
