Patent ID: 8316523

Claim:
A method for centering a bearing housing during a mid turbine frame assembly procedure, the mid turbine frame to be assembled including at least an inner case co-axially supported in an outer case by a plurality of radial spokes, and the bearing housing attached to the inner case, each of the spokes having an inner end abutting and connected to one of axial surfaces of the inner case, the method comprising: a) selecting one of the inner end of each spoke and each said axial surface to be machined for concentric adjustment of the bearing housing within the outer case before the respective spokes are connected to the inner case; b) measuring a radial distance D 1 between the respective axial surfaces of the inner case and an inner diameter surface of the bearing housing when the respective inner ends of the spokes are selected to be machined; c) measuring a radial distance D 2 between respective inner ends of the spokes and an inner diameter surface of the outer case when the respective axial surfaces are selected to be machined; d) machining the inner end of the individual spokes to suit the respective measurements taken in step (b), thereby obtaining a predetermined radial distance D between the inner diameter surface of the outer case and the inner diameter surface of the bearing housing when the mid turbine frame is assembled; or e) machining the respective axial surfaces of the inner case to suit the respective measurements taken in step (c), thereby obtaining a predetermined radial distance D between the inner diameter surface of the outer case and the inner diameter surface of the bearing housing when the mid turbine frame is assembled; f) connecting the inner ends of the spokes to the axial surfaces of the inner case, Respectfully after step (d) or (e); and wherein the sum of D 1 and D 2 is greater than or equal to D.