Expanding circumferential seal with upper-cooled runner

摘要

A circumferential seal arrangement has one or more expanding carbon rings and a rotating runner concentric to and radially outside of the carbon rings. Cooling oil is injected directly onto the outer circumferential surface of the runner and also in the direction of the bearings. The runner shields the seal interface from the cooling oil. To facilitate scavenging of oil from the cavity between the bearings and seal assembly and thereby further reduce the amount of oil reaching the seal interface, a disk pump is mounted on the main shaft between the runner and the bearing. As the main shaft rotates,, the disk pump slings oil adhering on its surfaces into an annular oil purge channel. The sealing arrangement also incorporates a discourager which forms a barrier to direct oil leaking through the seal interface to an overboard drain.