Mid turbine frame 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 casing component, such as a mid turbine frame system, which includes an outer case surrounding a spoke or strut casing. Load transfer spokes of the spoke casing are detachably connected to the outer case and radially extend 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. An arrangement for radially centring the bearing within the outer case is provided, the arrangement including at least three radial locators mounted to the outer case.
Claims20
A method of assembly for a mid turbine frame of a gas turbine engine, the method comprising the steps of:
- a) assembling a sub-assembly including an annular bearing housing, an annular spoke casing and an annular interturbine duct, at least three spokes of the spoke casing radially outwardly extending through respective hollow struts of the annular interturbine duct and radially projecting from the annular interturbine duct;
- b) inserting the sub-assembly within an outer case;
- and
- c) adjusting at least three radial locators adjustably attached to the outer case and circumferentially aligned with respective spokes to abut outer ends of the respective spokes, the radial locators adjusted to adjust a radial gap between the outer ends of the spokes and the outer case to thereby center the annular bearing housing within 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 mid turbine frame sub-assembly, the sub-assembly including at least an inner annular casing supporting at least one bearing and having at least three struts extending radially outwardly therefrom, the sub-assembly defining a portion of an engine gas path, the struts extending across the gas path;
- b) inserting the sub-assembly within an outer annular case of the mid turbine frame, a radial gap provided between a periphery of the sub-assembly and the outer case, the outer case having at least three radial locators threaded through the engine case and disposed around a circumference of the outer case, the radial locators having a terminal end extending radially inwardly of the outer case;
- and
- c) threadingly adjusting the radial locators until each terminal end abuts an outer periphery of the sub-assembly, the radial locators individually adjusted to adjust the radial gap between the sub-assembly and the outer case to centre the at least one bearing relative to the outer case.
A gas turbine engine having a mid turbine frame, the mid turbine frame comprising:
- an annular outer case connected to and forming a portion of an engine casing;
- a spoke casing including an annular inner case disposed within the outer case, the spoke casing having at least three load transfer spokes affixed to the inner case and extending radially outwardly therefrom, an outer end of the respective load transfer spokes being detachably secured to the outer case, a radial gap provided between the outer ends of the load transfer spokes and the outer case, the inner case supporting at least one bearing disposed around an engine main shaft;
- and
- a radial locator radially adjustably attached to the outer case and abutting the outer end of at least three of the at least three load transfer spokes, a radial inward extent of the locator being adjustable to vary a radial position of an outward extent of the corresponding spoke for radially positioning the spoke casing within the outer case.
Dependencies are inferred from the claim text.