Mid turbine frame system for gas turbine engine
AssigneePratt & Whitney Canada Corp.
InventorsEric DUROCHER, John PIETROBON, Lam NGUYEN
Life of this patent
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Abstract
A gas turbine engine has a mid turbine frame system which includes an outer case surrounding a spoke casing. Spokes of the spoke casing are detachably connected to the outer case and radially extend through hollow struts of a segmented interturbine duct which is disposed between the outer case and an inner case of the spoke casing. A bearing housing is supported by the inner case of the spoke casing. The mid turbine frame is assembly by inserting the interturbine duct segments over the spokes and then inserting the spoke casing into the outer case.
Claims14
A gas turbine engine having a mid turbine frame, the mid turbine frame comprising:
- an annular outer case connected to and providing a portion of the engine casing;
- an interturbine duct (ITD)-vane ring assembly disposed within and supported by the outer case, the ITD-vane ring assembly including a plurality of circumferential segments of the assembly each having outer and inner ring segments radially spaced and interconnected by at least one radially extending hollow strut and a plurality of radial airfoil vanes, the segments of the assembly co-operating to provide the ITD-vane ring assembly, an inner ring and an outer ring formed by the inner and outer ring segments co-operating to provide a portion of a gas path through the engine;
- a spoke casing including an annular inner case disposed within the inner ring of the ITD-vane ring assembly, the spoke casing having at least three load transfer spokes integrally affixed to the inner case and radially outwardly extending therefrom through respective hollow struts, an outer end of the respective load transfer spokes being detachably secured to the outer case;
- and
- an annular bearing housing for supporting a bearing assembly around an engine shaft, the housing supported by the spoke casing.
A gas turbine engine having a mid turbine frame, the mid turbine frame comprising.
- an annular outer case providing a portion of the engine casing;
- an interturbine duct (ITD) disposed within the outer case, the ITD including a plurality of circumferential segments each having outer and inner ring segments radially spaced and interconnected by at least one radially extending hollow strut, the segments co-operating to provide the ITD, an inner ring and an outer ring formed by the inner and outer ring segments co-operating to provide a portion of a gas path through the engine;
- and
- a spoke casing including an annular inner case disposed within the ITD, the inner case having a bearing support apparatus for supporting an engine shaft bearing, the spoke casing having at least three load transfer spokes radially outwardly extending from the inner case through respective hollow struts of the segments, an outer end of the load transfer spokes detachably secured to the outer case.
A method of assembly for a mid turbine frame of a gas turbine engine, the method comprising the steps of:
- a) providing a spoke casing having an inner annular casing supporting a bearing housing, at least three load transfer spokes extending radially outwardly of the inner annular casing;
- b) providing a plurality of interturbine duct (ITD) segments, the segments having inner and outer duct walls separated by at least one hollow strut extending therebetween;
- c) assembling a spoke-ITD sub-assembly by inserting at least some of the segments radially inwardly over the load transfer spokes so that the load transfer spoke extends through the hollow struts, the load transfer spokes of the spoke casing extending radially outwardly through respective hollow struts of the segments when the segments are installed thereon;
- d) circumferentially aligning the sub-assembly with an outer case of the mid turbine frame and then axially moving the outer case and the sub-assembly towards one another until the sub-assembly is located within the outer case;
- and
- e) connecting the outer case to the load transfer spokes.
Dependencies are inferred from the claim text.