Seal ring

A circular annular seal ring made from a resin adapted to be disposed between an outer member and an inner member that rotate relative to each other, the seal ring being formed from an elongated and arcuate rod to define a circle by joining ends of the rod, the seal ring comprising:

• a junction formed from the ends;
• and
• a radial thickness continually decreasing from two points that are apart from the junction toward the junction,
• the points being separated from the junction by an angle of not less than 60 degrees and not more than 150 degrees about a central axis of the circle, wherein the outer member comprises a hole having a cylindrical inner peripheral surface and a liquid space communicating with the hole and containing a liquid disposed therein, and wherein
• the inner member is disposed in the liquid space and is inserted into the hole,
• the cylindrical inner peripheral surface of the hole of the outer member has a circumferential groove, and
• the seal ring is adapted to be disposed within the circumferential groove on the cylindrical inner peripheral surface of the hole of the outer member so as to be slidable on the outer member, and the seal ring is adapted to surround the inner member in such a manner that the seal ring is stationary relative to the inner member, wherein the seal ring isolates the liquid space within the outer member from an external space.

A sealing structure comprising:

• an outer member that has a hole having a cylindrical inner peripheral surface and a liquid space communicating with the hole and containing a liquid disposed therein;
• an inner member that is disposed in the liquid space and is inserted into the hole, the inner member having an outer peripheral surface having a circumferential groove, the outer member and the inner member rotating relative to each other;
• and
• a circular annular seal ring made from a resin and inserted into the hole of the outer member so as to be stationary relative to the outer member, the seal ring being disposed within the circumferential groove on the outer peripheral surface of the inner member so as to be slidable on the inner member, wherein the seal ring isolates the liquid space within the outer member from an external space, the seal ring being formed from an elongated and arcuate rod to define a circle by joining ends of the rod, the seal ring comprising:
• a junction formed from the ends;
• and
• a radial thickness continually decreasing from two points that are apart from the junction toward the junction,
• the points being separated from the junction by an angle of not less than 60 degrees and not more than 150 degrees about a central axis of the circle.

A sealing structure comprising:

• an outer member that has a hole having a cylindrical inner peripheral surface and a liquid space communicating with the hole and containing a liquid disposed therein, the cylindrical inner peripheral surface of the hole having a circumferential groove;
• an inner member that is disposed in the liquid space and is inserted into the hole, the outer member and the inner member rotating relative to each other;
• and
• a circular annular seal ring made from a resin and disposed within the circumferential groove on the cylindrical inner peripheral surface of the hole of the outer member so as to be slidable on the outer member, the seal ring surrounding the inner member in such a manner that the seal ring is stationary relative to the inner member, wherein the seal ring isolates the liquid space within the outer member from an external space, the seal ring being formed from an elongated and arcuate rod to define a circle by joining ends of the rod, the seal ring comprising:
• a junction formed from the ends;
• and
• a radial thickness continually decreasing from two points that are apart from the junction toward the junction,
• the points being separated from the junction by an angle of not less than 60 degrees and not more than 150 degrees about a central axis of the circle.