| 摘要 |
PURPOSE:To reduce local fatigue of a material owing to repetition of a stress by forming a bellows such that the bellows are welded in a meandering state by using the different numbers of bellows. CONSTITUTION:In a bellows type fluid forced feed device, through drive rotation of a pulley 12, an eccentric shaft part 13 is eccentrically rotated, a bellows 4 is expanded and contracted by vertical movement of a moving support 6 through a roller 20 and a rod 8, and fluid sucked through a suction valve 22 by expansion and contraction of the bellows is delivered as a delivery valve 23 is forcibly opened. In this case, the bellows 4 is formed such that the different numbers of bellows are welded in a meandering state. Namely, a bellows part 4a where a deformation amount of the bellows 4 is low is formed of one bellows and bellows parts 4b and 4c where a deformation amount is high are formed of two or three bellows each having thickness lower than that of the bellows part 4a. This constitution causes the parts 4b and 4c to reduce the occurrence of local material fatigue. |
