| 摘要 |
A mechanical seal device comprising a stationary side sliding ring (10), a rotating side sliding ring (20) capable of rotating and sliding in firm contact with the stationary side sliding ring (10), and an O-ring (30) interposed between the inner hole of the rotating side sliding ring (20) and a rotating shaft (200). The mechanical seal device further includes an annular ring member (60a) having a gas permeability lower than that of the O-ring (30). The ring member (60a) is installed in the inner hole of the rotating side sliding ring (20) so as to be adjacent to the O-ring (30) on the atmosphere side, and fulfills the requirement of the following conditional expression (1). In the conditional expression (1), (D1) is the diameter of the rotating shaft (200), (D2) is the inner diameter of the ring member (60a), and (D3) is the inner diameter of a portion of the inner hole of the rotating side sliding ring (20), which portion is located closer to the atmosphere side than the ring member (60a). D1 < D2 < D3 ... Expression (1) |
