| 摘要 |
PURPOSE:To reduce manufacturing cost and permit safe use thereof by a method wherein a screw rod is formed by connecting a drawn wire member to the outer peripheral surface of a steel pipe having an outer diameter corresponding substantially to the diameter of the bottom of thread. CONSTITUTION:The screw rod 30 is formed by connecting the drawn wire member 33, having a chevron type section, spirally and integrally to the outer peripheral surface of the steel pipe 32 having an outer diameter corresponding substantially to the diameter of the bottom of a male thread. According to this method, the screw rod may be manufactured with a cost more inexpensive than the cost by machining or rolling. This ball screw may hold a necessary strength and further the screw rod 30 and a nut 40 can maintain the engaging condition thereof by the engagement between the threads of each others even if a ball 50 escapes from a space between both screw threads due to some reasons, therefore, the ball screw may be used safely. |
