Back to results
US 8,371,127 B2Granted
Cooling air system for mid turbine frame
AssigneePratt & Whitney Canada Corp.
InventorsEric Durocher, Pierre-Yves Legare
Life of this patent
Estimating the term…
Abstract
A mid turbine frame is disposed between high and low pressure turbine assemblies. A cooling air system defined in the mid turbine frame of a gas turbine engine includes internal cavities for containing pressurized cooling air to cool the inter-turbine duct and the hollow struts, and discharges the used cooling air to further cool respective high and low pressure turbine assemblies.
Claims20
A gas turbine engine comprising:
- a first turbine rotor assembly and a second turbine rotor assembly axially spaced apart from each other;
- a mid turbine frame (MTF) disposed axially between the first and second turbine rotor assemblies, including an annular outer case, annular inner case and annular bearing housing with bearing seals, the annular bearing housing being connected to the annular inner case, a plurality of load spokes radially extending between and interconnecting the annular outer and annular inner cases to transfer loads from the annular bearing housing to the annular outer case;
- an annular inter-turbine duct (ITD) disposed radially between the annular outer and annular inner cases of the MTF, the ITD including an annular outer duct wall and annular inner duct wall, thereby defining an annular hot gas path between the annular outer and annular inner duct walls for directing hot gases from the first turbine rotor assembly to the second turbine rotor assembly, a plurality of hollow struts radially extending between and interconnecting the annular outer and annular inner duct walls, the load transfer spokes radially extending through at least a number of the hollow struts;
- and
- wherein the MTF defines a cooling air system, the system being formed with a first cavity between the annular outer case and the annular outer duct walls of the ITD with a first inlet defined in the annular outer case, a second cavity between the annular inner duet wall and the annular inner case, the first cavity, second cavity and the respective hollow struts being in fluid communication with the first inlet for receiving pressurized cooling air, the cooling air system including a cooling air discharge device at respective upstream and downstream sides of the MTF for discharging cooling air from the system to further cool the respective first and second rotor assemblies, and a flow restrictor supported between the annular inner duct wall and the annular inner case to defines an annular gap and configured for metering a cooling air flow escaping from the second cavity in order to provide a pressure margin within the first and second cavities in the MTF and the hot gas path to impede hot gas ingestion into the first and second cavities of the MTF.
2 more elements
A gas turbine engine comprising:
- a first turbine rotor assembly and a second turbine rotor assembly axially spaced apart from each other;
- a mid turbine frame (MTF) disposed axially between the first and second turbine rotor assemblies;
- a cooling air system including a first inlet defined in the MTF and a second inlet defined in a rotating shaft of the gas turbine engine for receiving pressurized cooling air from separate passages, the cooling air system having a first cavity between an outer case and an outer duct wall of an inter-turbine duct (ITD) disposed inside the outer case, a second cavity between an inner duct wall of the ITD and an inner case, a third cavity between the inner case and a bearing housing mounted to the inner case, a cooling air passage in the bearing housing, and a chamber defined by an arch structure integrated with the inner case and communicating with the first inlet through a first flow path, the first flow path extending from the first cavity through a hollow passage in the ITD to the second cavity, the chamber communicating with the second inlet through a second flow path, the second flow path extending through the cooling air passage in the bearing housing, the chamber also communicating with the third cavity, and at least one of the first, second and third cavities including a cooling air discharge device located at respective upstream and downstream sides of the MTF for discharging cooling air from the system to the respective first and second rotor assemblies.
Dependencies are inferred from the claim text.