Seal device of the non-contact type

摘要

A seal device of the non-contact type having seal faces formed by those end faces of a rotating seal ring and a stationary ring which are perpendicular to axes of the two rings, and also having dynamic pressure generating grooves formed in one of the seal faces at a certain interval in the circumferential direction of the seal face each groove having a first spiral groove portion and a second terminal portion being formed continuous from the front end of each of the first spiral groove portions, extending along the circumferential direction of the seal face but across its corresponding first spiral groove portion, and provided with a closed front end. The seal device can be used at high speed and under high pressure and it can correct the tilting of its seal faces, which is caused by pressure and heat added, to prevent them from being contacted with each other. Even when the difference of pressures added to them changes, the seal device can keep them parallel to each other to reduce the amount of liquid leaked to a greater extent.