Turbofan engine main bearing arrangement

摘要

A turbofan engine (20; 300; 400) comprises a fan (28), a fan drive gear system (60), a fan shaft (120) coupling the fan drive gear system to the fan, a low spool, an intermediate spool, and a core spool. The low spool engages at least three main bearings of which at least two are non-thrust bearings and at least one is a thrust bearing. The fan shaft engages at least two bearings (148, 150). The core spool engages at least two bearings (250, 260). The intermediate spool engages at least two of said bearings (220, 200, 230; 220, 200, 230-2; 200, 220, 230-3).