ROTARY JOINT

摘要

A mechanical seal which defines an annular space formed between a case body and a shaft body is included. The mechanical seal includes: a first sealing ring (11) having a first seal surface; a second sealing ring (12) having a second seal surface which slidably contacts with the first seal surface; and a plurality of coil springs (13) provided along the first sealing ring (11) in a circumferential direction and configured to apply axial forces to the first sealing ring (11) to press the first seal surface against the second seal surface. The plurality of coil springs (13) are divided into a plurality of groups, and first regions K1 in each of which occurring distortion is increased by the axial forces of the coil springs (13) that belong to the group and second regions K2 in each of which distortion is smaller than that in each first region K1 are present alternately along the circumferential direction in the first sealing ring (11).