EPICYCLIC GEAR TRAIN

摘要

A turbine engine (10) has a fan shaft (20) and at least one tapered bearing mounted on the fan shaft (20). The fan shaft (20) includes at least one passage extending in a direction having at least a radial component, and adjacent the at least one tapered bearing. A fan (18) is mounted for rotation on the tapered bearing. An epicyclic gear train (22) is coupled to drive the fan (18). The epicyclic gear train (22) includes a carrier (26) supporting intermediate gears (32) that mesh with a sun gear (30) and a ring gear (38) that surrounds and meshes with the intermediate gears (32). Each of the intermediate gears (32) are supported on a respective journal bearing (34). The epicyclic gear train (22) defines a gear reduction ratio of greater than or equal to about 2.3. A turbine section is coupled to drive the fan (18) through the epicyclic gear train (22) and has a fan drive turbine that includes a pressure ratio that is greater than about 5. The fan (18) includes a pressure ratio that is less than about 1.45, and a bypass ratio of greater than about ten.