Seal body and rotary damper

A seal body provided in a seal groove formed in a groove shape at a tip end portion of at least one of a fixed vane formed in a wall shape protruding toward a center portion of a cylindrical inner chamber liquid-tightly housing fluid and interfering with a flow of the fluid in a circumferential direction or a movable vane sliding on an inner peripheral portion of the inner chamber to divide an inside of the inner chamber into multiple cells while turning to push the fluid in a rotary damper including a housing having the inner chamber and the fixed vane and a rotor having the movable vane at an outer peripheral portion of a shaft body sliding on the tip end portion of the fixed vane,

• the seal body having a seal main body which has a fitting outer peripheral surface to be fitted in the seal groove and a seal sliding surface exposed through the seal groove and extending along the seal groove, the seal main body comprising:
• a cavity formation groove formed in a groove shape extending along a direction of formation of the seal groove at the fitting outer peripheral surface, opening to an inner side surface extending in a depth direction of the seal groove at an inner surface of the seal groove, and forming a cavity by closing with the inner side surface;
• and
• a fluid guide groove formed at the fitting outer peripheral surface and allowing the cavity and the inner chamber to communicate with each other such that the fluid circulates therebetween.