Mechanical seal device

A mechanical seal device, wherein a rotational seal ring and a stationary seal ring are arranged to face to each other between a rotational shaft and a housing fit together, comprising:

• the rotational seal ring connected to said rotational shaft, having a rotational seal surface, and having a plurality of arc-shaped grooves arranged on said rotational seal surface to be a circular shape around an axis center of said rotational shaft, the grooves being sectionalized by partition walls;
• the stationary seal ring having a stationary seal surface facing the rotational seal surface of said rotational seal ring;
• a bias means for pressing said stationary seal ring against said rotational seal ring;
• and
• outlet portions formed on said stationary seal surface of said stationary seal ring and capable of connecting with a fluid supply path for supplying a pressure fluid,
• wherein said arc-shaped grooves are arranged at positions facing said outlet portions formed on said stationary seal surface,
• wherein said outlet portions are arranged at positions forming a circle around the rotational shaft and having an identical radius that is concentric with said arc-shaped grooves, and
• wherein a circumferential direction length (W3) of each of said outlet portions is made to be ½ of a circumferential direction length (W1) of each of said partition walls or longer (W3≧W1/2);
• the circumferential direction length (W3) of each of said outlet portions is made to be shorter than a circumferential direction length (W2) of each of said arc-shaped grooves (W3<W2).