Patent ID: 8342536

Claim:
A sealing device that hermetically seals a gap to seal liquid supplied into a pressurizing chamber, the sealing device comprising: a first member and a second member that is reciprocally movable with respect to the first member, the first and second members defining a gap there between and surrounding the pressurizing chamber, the first and second members each having an annular shape and arranged coaxially relative to each other; and a sliding portion attached to the second member and slidable relative to the first member while in contact with the first member, the sliding portion including a base portion and a plurality of protruding portions that protrude from the base portion toward the first member to separate the first member from the base portion and that elastically deform to bring the base portion into close contact with the first member after the liquid is supplied into the pressurizing chamber to fill the pressurizing chamber with the liquid, the sliding portion being disposed between the first and second members, the plurality of protruding portions being formed so that, when the second member is rotated by a predetermined angle less than 360 degrees, the arrangements of the protruding portions before and after the rotation coincide with each other, wherein the protruding portions include at least two protrusions arranged at an interval of P, the interval P is less than the distance between the plurality of protruding portions.