Device for supplying secondary air in a gas turbine engine

Abstract

In a device for supplying secondary air in a gas turbine engine provided with an inner shaft (8) supporting a low pressure compressor and a low pressure turbine and a hollow outer shaft (7) coaxially nested with the inner shaft and supporting a high pressure compressor and a high pressure turbine, a seal air introduction passage (41, 45, 48) for introducing a part of high pressure air drawn from the high pressure compressor into a seal section provided in each of the bearing boxes is provided with a high pressure air introduction turbine (62) attached to the outer shaft in a rotationally fast manner. Owing to the use of the high pressure air introduction turbine, work is extracted from the seal air and cooling air derived from the supplied air and having a high temperature and high pressure air so that an excessive rise in the seal pressure at the normal rotational speed can be avoided and, at the same time, the supplied air can be reduced in temperature thereby avoiding an excessive rise in the temperature of the lubricating oil for the bearing.

Dependencies are inferred from the claim text.