摘要 |
<p>An epicyclic gear train (40) includes planetary gears (74) rotatably mounted on spindles (75) supported by an annular carrier (72) and including axially spaced apart forward and aft sets of output teeth (94, 96) extending radially outwardly from a planetary gear hub (92) and axially spaced apart forward and aft roller bearings (111, 112) disposed between planetary gears (74) and spindles (75). The forward and aft roller bearings (111, 112) are axially aligned with or adjacent to spaced apart forward set of output teeth (94) and input gear (104) respectively. A ring gear (100) meshes with forward set of output teeth (94) and an external gear (102) meshes with aft set of output teeth (96). An input gear (104) fixedly attached to hub (92) aft of aft set of output teeth (96) and engaged with a sun gear (108). The output teeth (94, 96), input gear (104), ring gear (100), external gear (102), and sun gear (108) may all be helical. A turbofan gas turbine engine (10) may include counter-rotatable first and second fan stages (60, 62) driven by a low pressure turbine (32) through the gear train (40).</p> |