Lubrication and scavenge system

摘要

A lubrication and scavenge system for a gas turbine, capable continued operation in nose-down or nose-up orientations, has a number of oil drainage passages (42) to return oil to one or more collection chambers (30) adjacent a rolling element bearing (22). A rotary impellor (38) in the chamber forces the oil into a scavenge off-take passageway (36) in the chamber wall leading to a scavenge pump (16). However, in some orientations windage effects in the chamber can return the oil to the drainage passage rather than permitting the impellor to centrifuge it into the off-take passageway. As a result oil starvation may occur. To avoid this and improve scavenging a shield (44) is located between the drainage path and the off-take passageway adjacent to a face of the impellor. The shield may comprise an additional member, but preferably is formed integrally with a bearing race so as to ease assembly.