| 摘要 |
<p>PURPOSE:To use a ball screw driving motor for positioning only for the positioning and thereby to make the positioning accurate by a method wherein a ball screw being rotated by a motor subjected to an open-loop control and compensating acceleration of gravity applied to a member is provided for the member to be transferred. CONSTITUTION:A motor 3 is subjected to a closed control by a control means 2 on the basis of an information from a position detecting means 1, and a ball screw 4 is rotated by the motor 4 to transfer a member 5 in the vertical direction. A ball screw 7 being rotated by a motor 6 subjected to an open-loop control and compensating the gravity applied to the member 5 is provided for the member 5. Since the correction for the gravity of the member 5 is executed by the ball screw 7 rotated by the motor 6 subjected to the open-loop control, the original member 5 alone is an object of transfer. Therefore, the mass of a transfer system is not increased, an output of the motor 6 for driving the ball screw does not need to be large, and the intrinsic frequency does not lower.</p> |
