Fan rotor support
AssigneeUnited Technologies Corporation
InventorsGregory E. Reinhardt, Karl D. Blume, John P. Tirone, III, John C. Ditomasso, Enzo DiBenedetto, Jason W. Mazanec
Life of this patent
Estimating the term…
Abstract
A turbofan engine comprises an engine case. A gaspath extends through the engine case. A fan has a circumferential array of fan blades. A fan case encircles the fan blades radially outboard of the engine case. A plurality of fan case vanes extend aftward and outward from the engine case to the fan case. A forward frame comprises a plurality of vanes radially across the gaspath. A torque box couples the fan case vanes to the forward frame. A transmission couples a shaft to a fan shaft to drive the fan. A fan bearing assembly couples a stationary forward hub structure to the fan shaft.
Claims25
A turbofan engine comprising:
- an engine case, the engine case defining a centerline and a gaspath within the engine case;
- a fan having a circumferential array of fan blades;
- a fan case encircling the fan blades radially outboard of the engine case;
- a plurality of fan case vanes extending aftward and outward from the engine case to the fan case, the fan case vanes having a characteristic sweep angle (θ1) of less than 75° relative to the engine centerline;
- a forward frame comprising a plurality of vanes radially across the gas path;
- a shaft;
- a transmission coupling the shaft to a fan shaft to drive the fan;
- a stationary forward hub structure;
- and
- a fan bearing assembly coupling the stationary forward hub structure to the fan shaft, wherein:
- the stationary forward hub has a characteristic angle (θ3) of 55-70° relative to the centerline;
- there is only a single stage of said fan case vanes and wherein fan rotor loads are transmitted at least partially via internal bending moments in the single stage of said fan case vanes;
- and
- in section, a line between a center of the bearing assembly and a mounting structure on the fan case does not go more than half the local chord of an airfoil of the fan case vanes ahead of the vanes at any point along the airfoil.
A turbofan engine comprising:
- an engine case;
- a gaspath through the engine case;
- a fan having a circumferential array of fan blades;
- a turbine;
- a shaft coupled to the turbine;
- a fan case encircling the fan blades radially outboard of the engine case;
- only a single stage of fan case vanes extending aftward and outward from the engine case to the fan case, the fan case vanes having a characteristic sweep angle (θ1) of less than 75° relative to the engine centerline;
- a forward frame comprising a plurality of vanes radially across the gaspath;
- a stationary forward hub structure;
- an epicyclic transmission coupling the shaft to a fan shaft to drive the fan and having:
- a star carrier;
- a flange structure coupling the engine case to the star carrier and comprising:
- an outboard flange mounted to the engine case;
- an inboard flange spaced rearwardly of the outboard flange;
- a plurality of fingers extending from the inboard flange to engage the star carrier;
- and
- an axially compliant and radially compliant flexure between the outboard flange and the inboard flange;
- and
- a fan bearing assembly coupling the stationary forward hub structure to the fan shaft,
- wherein an overall conical profile from the forward hub structure to the fan case passes entirely locally through the fan case vanes.
A turbofan engine comprising:
- an engine case, the engine case defining a centerline and a gaspath within the engine case;
- a fan having a circumferential array of fan blades;
- a fan case encircling the fan blades;
- a shaft;
- a transmission coupling the shaft to the fan to drive the fan;
- a stationary forward hub structure;
- a fan bearing assembly coupling the forward hub structure to a fan shaft;
- a support frame coupling the fan case, the engine case, and the stationary hub and including a plurality of supports radially across the gaspath;
- and
- only a single stage of fan case vanes extending aftward and outward from the support frame to the fan case, the fan case vanes having a characteristic sweep angle (θ1) of less than 75° relative to the engine centerline,
- wherein:
- an overall conical profile from the forward hub structure to the fan case passes entirely locally through the fan case vanes.
Dependencies are inferred from the claim text.