| 摘要 |
PURPOSE:To accurately stop and maintain a power transmission element at any position by screwing threaded shaft positioned inside a cylinder to a piston via a ball-screw means and a sealing means. CONSTITUTION:A position near by the blocking covers 12, 13 of a threaded shaft 18 is held by a bearing 19, a threaded shaft portion 182 positioned inside the cylinder 10 of the threaded shaft 18 is screwed to a piston 15 via a ball- screw means 15 and a fluid sealing state between the threaded shaft 18 and the piston 15 is kept via a sealing means 22. Accordingly, a braking device 23 is operated for stopping the threaded shaft 18 to securely hold the displacement of the piston 15 via the engaging force of a screw so that a power transmission element 16 can be forced to be stopped and maintained at a designated position. |
