| 摘要 |
A motor (20), a ball screw shaft (12) and so forth are accommodated in a frame (18) constituting an outer frame, and direct-drive guides (23) are provided on both sides of a groove-like opening (22) formed in this frame. The ball screw shaft (12) is provided at the central portion of the frame (18), and a table (16) slides along the direct-drive guides (23) by virtue of rotational action of the ball screw shaft (12). A ball screw spline (26) is provided along the full length of the ball screw shaft (12), which is supported at the ends thereof by means of the motor (20) and the bearing (14), respectively. The rotational centers of the ball screw shaft (12), motor (20) and bearing (14) are aligned with each other by means of balls (32) inserted into the spline (26). |
