| 摘要 |
PROBLEM TO BE SOLVED: To make a replacement arm operate a linear movement quickly and smoothly. SOLUTION: A ball screw mechanism 30 converting the rotational movement of a first servo motor 7 into the linear movement of a replacement arm 6, is provided for a first power transmission mechanism 8 transmitting the driving force of the first servo motor 7. Besides, a second servo motor 9 for rotationally driving the replacement arm 6 is also provided, when the replacement arm 6 is to be rotationally moved, the first servo motor 7 together with the second servo motor 9, are driven in such a way that a relative rotational quantity caused by the rotational movement of the replacement arm 6 will be zero between a ball screw shaft 32 and a ball nut 31. |
