| 摘要 |
PURPOSE:To effectively suppress the temperature rise of the screw shaft and consequently prevent its thermal expansion and at the same time improve the feeding accuracy of a movable table threadingly engaged with the screw shaft by a structure wherein a heat pipe is inserted in the hole part provided at the shaft center of the screw shaft. CONSTITUTION:The frictional heat produced at the engaged part of the threads 6 and 8, which are cut on the screw shaft 2 and in the movable table 7 respectively, is transmitted to the heat pipe 11 inserted in the hole part 10 provided at the center of the screw shaft 2. Disc fins 12 are provided at one end of the heat pipe 11 and the heat pipe 11 and the disc fins 12 are rotated with the rotation of the screw shaft 2. The frictional heat transferred to the heat pipe 11 is radiated from the fins 12 to the ambient air. At this time, the radiation characteristics of the heat pipe 11 are further improved by the stirring effect of the ambient air followed by the rotation of the fins 12. |
