| 摘要 |
PROBLEM TO BE SOLVED: To prevent rotation by a simple method when fastening a screw part to a gear part.SOLUTION: A gear part 20 is a gear part 20 for preventing slipping-out of a second gear 23 fitted to a spline part 201 in a shaft part 200 of a gear shaft 21 by a nut 30 fastened to the shaft part 200, and includes in a through-hole 210 a fitting part 221 having a cross section of forming the apexes of a triangle in a circular arc shape on the shaft end of the shaft part 200. In the gear part 20, the nut 30 is fastened to the shaft end side on the side for inserting the second gear 23 into the spline part 201, and the fitting part 221 is arranged on the shaft end on the opposite side of the side for inserting the second gear 23. A small diameter part 222 having a circular cross section of a smaller diameter than the fitting part 221, coaxially continues with the innermost part of the fitting part 221 in the shaft part 200. The rotation of the shaft part 200 is prevented by fitting the fitting part 221 of the shaft part 200 to a fitting shaft part of a fastening tool, and slipping-out of the second gear 23 fitted to the shaft part 200 is prevented by fastening the nut 30 to the shaft part 200. |
