Patent ID: 8911203
Filing Date: 2014-12-16
Classification: F01D,F02C,F02K

Abstract:
1. 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 (θ 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 (θ 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.