Patent ID: 8328509
Filing Date: 2012-12-11
Classification: F01D,F02C,F05D,F16C,F16J,Y10T

Abstract:
1. A turbomachine comprising: a housing defining a bearing cavity and a turbine chamber separated by a first wall; a turbine wheel mounted to a shaft for rotation within said turbine chamber about a machine axis; a heat shield disposed between the first wall and the turbine wheel, a heat shield cavity being defined between the first wall and the heat shield, and contact between the heat shield and the housing substantially seals a periphery of the heat shield cavity; the shaft extending from the turbine chamber into the bearing cavity through a passage defined at least in part by a first aperture in said wall and a second aperture in the heat shield, the shaft being mounted for rotation on a bearing assembly provided in the bearing cavity; a first seal between the shaft and said first aperture; the housing defining a first gas channel communicating with the heat shield cavity for connection to a pressure source for raising pressure within the heat shield cavity; and a second channel between the heat shield cavity and said passage, the second channel opening to said passage on the opposite side of said first seal to said bearing assembly; wherein: