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 to return oil to one or more collection chambers adjacent a rolling element bearing . a rotary impellor in the chamber forces the oil into a scavenge off - take passageway in the chamber wall leading to a scavenge pump . 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 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 .