| 摘要 |
PURPOSE:To reduce man-hours and the number of parts and to stably support the rotary pulley shaft which is rotated at a high speed, by providing a concave part at a central part of a shaft hole of a bearing tube part simultaneously when a counterframe is molded. CONSTITUTION:The central part of a metal mold, which forms the shaft hole of the bearing part 10 and has a round rod overall shape, is formed so that it is slightly protruded from both ends. When said metal mold is forcibly pulled out of a molded product, the concave part 12 is formed in the central part of the shaft hole of the bearing tube part 10. The overall shape of the rotary pulley shaft 13 which is supported by the bearing tube part 10 is of round rod shape. A worm 4 is provided at the top end, and a pulley 2 is provided in the lower end. The rotary pulley shaft 13 is stably supported by the upper end 10a and the lower end 10b of the shaft hole of the bearing tube part 10. The concave part 12 is utilized as an oil storage. |
