| 摘要 |
PROBLEM TO BE SOLVED: To avoid deterioration of sealability even when the outer diameter of a seal member is reduced.SOLUTION: When reducing, for downsizing of a pump, the outer diameter of a seal member 23 that comprises a resin ring member 24 and an O-ring 25, gaps are caused between both side ends in a plunger reciprocation direction of the O-ring 25, and a cylinder 13 and a cover 22, and the O-ring 25 moves in the plunger reciprocation direction to cause wear or the like of the O-ring 25 and reduce the sealability. Accordingly, an annular O-ring receiving groove 241 is formed on the outer peripheral side of the resin ring member 24, and the O-ring 25 is received in the O-ring receiving groove 241, so that the O-ring 25 is prevented or inhibited from moving.SELECTED DRAWING: Figure 2 |
