A gas turbine engine comprises at least a power output turbine unit (POT), which is rotatably arranged inside an outer housing unit, and a compressor-turbine unit (CTU), which is rotatably arranged inside the POT, and the CTU, POT and outer housing unit are arranged about a common axis of rotation (CL). The POT and the CTU are arranged in such close proximity (d) that a dynamic friction coupling is generated between the POT and the CTU.

A gas turbine engine comprises at least a power output turbine unit (POT), which is rotatably arranged inside an outer housing unit, and a compressor-turbine unit (CTU), which is rotatably arranged inside the POT, and the CTU, POT and outer housing unit are arranged about a common axis of rotation (CL). The POT and the CTU are arranged in such close proximity (d) that a dynamic friction coupling is generated between the POT and the CTU.

A highly efficient gas turbine engine includes the fan of the gas turbine engine driven from a turbine via a gearbox, such that the fan has a lower rotational speed than the driving turbine, thereby providing efficiency gains. The efficient fan system is mated to a core that has low cooling flow requirements and/or high temperature capability, and which may have particularly low mass for a given power.

A highly efficient gas turbine engine includes the fan of the gas turbine engine driven from a turbine via a gearbox, such that the fan has a lower rotational speed than the driving turbine, thereby providing efficiency gains. The efficient fan system is mated to a core that has low cooling flow requirements and/or high temperature capability, and which may have particularly low mass for a given power.

A turbofan engine (10), including a ducted fan (22) and an engine (16) having a nozzle (24) for expelling burnt gases (N1) by the engine in the upstream direction of the turbofan engine, the free end (26) of the nozzle being located upstream of the fan (22).

A turbofan engine (10), including a ducted fan (22) and an engine (16) having a nozzle (24) for expelling burnt gases (N1) by the engine in the upstream direction of the turbofan engine, the free end (26) of the nozzle being located upstream of the fan (22).

A non-metallic tailcone (202) in a tip turbine engine includes a tapered wall structure disposed (208) about a central axis. The non-metallic tailcone is fastened to a structural frame (44) in the aft portion of the tip turbine engine. The tip turbine engine produces a first temperature gas stream from a first output source and a second temperature gas stream from a second output source. The second temperature gas stream is a lower temperature than the first temperature gas stream. The second temperature gas stream is discharged at an inner diameter of the tip turbine engine over an outer surface of the tailcone. Discharging the cooler second temperature gas stream at the inner diameter allows a non-metallic to be used to form the tailcone.

A non-metallic tailcone (202) in a tip turbine engine includes a tapered wall structure disposed (208) about a central axis. The non-metallic tailcone is fastened to a structural frame (44) in the aft portion of the tip turbine engine. The tip turbine engine produces a first temperature gas stream from a first output source and a second temperature gas stream from a second output source. The second temperature gas stream is a lower temperature than the first temperature gas stream. The second temperature gas stream is discharged at an inner diameter of the tip turbine engine over an outer surface of the tailcone. Discharging the cooler second temperature gas stream at the inner diameter allows a non-metallic to be used to form the tailcone.

A disclosed fan drive gear system includes a sun gear rotatable about an axis of rotation, a plurality of intermediate gears rotatable about an intermediate gear rotation axis in meshing engagement with the sun gear and a ring gear circumscribing the intermediate gears. A bearing assembly supports at least one of the plurality of intermediate gears and includes a first beam extending in a first direction and a second beam extending from an end of the first beam in a second direction. The bearing surface supported on the second beam such that first and second beams are configured to maintain the bearing surface substantially parallel to the intermediate gear rotation axis during operation.

A disclosed fan drive gear system includes a sun gear rotatable about an axis of rotation, a plurality of intermediate gears rotatable about an intermediate gear rotation axis in meshing engagement with the sun gear and a ring gear circumscribing the intermediate gears. A bearing assembly supports at least one of the plurality of intermediate gears and includes a first beam extending in a first direction and a second beam extending from an end of the first beam in a second direction. The bearing surface supported on the second beam such that first and second beams are configured to maintain the bearing surface substantially parallel to the intermediate gear rotation axis during operation.