| 摘要 |
PURPOSE: To perform high-precise feed control without using an expensive encoder by providing a rotation drive means with a detecting means to detect a rotation amount of each of nuts and using a device, having different resolution, in each detecting means. CONSTITUTION: An intermediate table 103 is disposed between a bed 101 and a moving table 102 and a set of motors 17 and 18 are mounted on each of the bed 101 and the intermediate table 103. By respectively starting the motors 17 and 18 to rotate nuts 15 and 16 in a reverse direction to each other, a screw shaft 12 is moved forward and backward. In this case, the intermediate table 103 to support the screw shaft 12 through a bearing 11 is moved in an Y- direction based on the bed 101 and the moving table 102 to support the screw shaft 12 through a bearing 11 is moved in an X-direction based on the intermediate table 103. A rotary encoder to detect a rotation amount is attached to each of the motors 17 and 18 and by differing the numbers of divisions of the rotary encoders from each other, resolution is improved. |
