| 摘要 |
In the ball screw guide unit of the invention, since a guide rail is formed of a channel bar having a groove, and a ball screw shaft is engaged with a movable member which is reciprocatively movable in the groove along a lengthwise direction of the guide rail, so that the centroid of the guide rail is adjacent to the axis of the ball screw shaft. Therefore, when a pretension is applied to the ball screw shaft, a straightness of the guide rail is not impaired and a feed accuracy of the movable member can be maintained. Further, the guide rial may be provided at its lower and side surfaces with reference surfaces used for adjusting parallelism between the guide rail and the axis of the ball screw shaft, in which case assembly and adjustment of the table can be performed more easily. |
