| 摘要 |
PURPOSE:To suppress wear of a bearing and prolong the life of a device by furnishing a fixed shaft, which guides a traveling unit slidingly, and a bracket having a bearing to support the free end of said fixed shaft, and thereby eliminating fear of deformation of the fixed shaft despite its elongation/contraction owing to thermal expansion. CONSTITUTION:Two brackets 7a, 7b are fixed on a base 6, and a fixed shaft 8 is installed in such a way that its one end is supported by the bracket 7a as a cantilever. A bearing 9 is fixed in the bracket 7b to bear the free end of said fixed shaft 8. A traveling unit 10 has a movable unit bearing and slides on the fixed shaft 8 in the axial direction under guidance of this shaft 8. During continuous use, the fixed shaft 8 elongates toward the free end owing to thermal conduction from the motor mounted on the unit 10 are frictional heat at the sliding surfaces. At this time, the bearing 9 can slide without causing hindrance to elongation of the fixed shaft 8. Therefore the fixed shaft 8 is free from fear of deformation. |
