GEAR TRAIN WITH VARIABLE INPUT DIRECTION OF ROTATION AND CONSTANT OUTPUT DIRECTION OF ROTATION

An oil system for a gas turbine engine includes an oil pump (112) driven by a gear train (99) having a main input drive gear (101) rotating when a propulsor rotor (102) rotates. The gear train (99) includes two sets of gears (A, B) joined by two connection shafts (114, 116) each having a clutch (118, 120). The first set (A) of the gears include a forward input gear (104) and a reverse input gear (106) each driven by the main input drive gear (101). The forward and the reverse input gears (104, 106) drive a pinion gear (108, 110) in the second set (B) of gears through a clutch (118, 120). Each clutch (118, 120) transmits rotation driven in a same driving direction and slips in an alternate driving direction. The first set (A) of the gears has an even number of the gears, and the second set (B) of the gears has an odd number of the gears.