| 摘要 |
PROBLEM TO BE SOLVED: To reduce gap in screwing of a screw shaft and an internal thread at more parts. SOLUTION: A nut member 42 is formed to have a cylinder 421, an internal thread 422 disposed inside the cylinder 421 and screwed in a screw shaft 41, a hole part 421c formed in the cylinder 421 and opposite to an outer periphery surface of the internal thread 422 and a pressure member 423 disposed in the hole part 421c and brought into contact with the outer periphery surface of the internal thread 422 for pressing the internal thread 422 radially so as to deflect the internal thread 422 toward the screw shaft 423. |
