Mechanical seal device, double seal device and double mechanical seal device

摘要

A cup gasket 50a has a gasket body 52a that can be compressed and held between the outer peripheral surface of a static seal ring 40a and the inner peripheral surface 5a of part of a housing 4a, and an inward convexity 54a molded integrally with the gasket body 52a and protruding diametrically inward. The inward convexity 54a is able to be held and compressed between a back surface positioned on the side of the static seal ring 40a that is axially opposite a static sliding surface 42a, and a step difference surface 7a continuous with the inner peripheral surface 5a of the housing 4a.