发明申请
WO2014152101A1 TURBOFAN ENGINE BEARING AND GEARBOX ARRANGEMENT 审中-公开
涡轮发动机轴承和齿轮架布置

TURBOFAN ENGINE BEARING AND GEARBOX ARRANGEMENT
摘要:
A turbofan engine (300; 600; 700) comprising a fan shaft (120) configured to rotate about an axis (500) of the engine. A fan drive gear system (60) is configured to drive the fan shaft. The fan drive gear system has a centerplane (540). A first spool comprises a high pressure turbine (326) and a high pressure compressor (324). A second spool comprises an intermediate pressure turbine (328), a lower pressure compressor, and a shaft (334) coupling the lower pressure turbine to the intermediate pressure compressor. A third spool comprises a lower pressure turbine (330) coupled to the fan drive gear system to drive the fan. The engine has a plurality of main bearings. The turbofan engine has a single stage fan. Of the main bearings, at least one is a shaft engaging bearing engaging a driving shaft (336) coupled to the fan drive gear system. A closest (340; 640) of the shaft engaging bearings engaging the driving shaft behind the fan drive gear system has a centerplane (550) and a characteristic radius (R B ). The half angle (θ) of a virtual cone (530) intersecting the core flowpath inboard boundary at the gear system centerplane (540) and said closest of the shaft engaging bearings at the characteristic radius (R B ) is greater than about 32°. A hub to tip ratio (H R :F R ) of the fan is less than about 0.38.
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