Epicyclic drive for gas turbine engine lubricant pump
A gas turbine engine includes a fan drive turbine driving a fan rotor through a main gear reduction. A primary lubricant system supplies lubricant to the main gear reduction. An auxiliary oil pump supplies oil to the main gear reduction. An auxiliary pump epicyclic gear train drives the auxiliary pump when the fan rotor is rotating in either direction. The main gear reduction is separate from the auxiliary pump epicyclic gear train.
1. A gas turbine engine comprising:
a fan drive turbine driving a fan rotor through a main gear reduction; and
a primary lubricant system for supplying lubricant to said main gear reduction, and an auxiliary oil pump for supplying oil to said main gear reduction, and an auxiliary pump epicyclic gear train for driving said auxiliary pump when said fan rotor is rotating in either direction, said main gear reduction being separate from said auxiliary pump epicyclic gear train, said auxillary pump epicyclic gear train including a ring gear engaged with a plurality of intermediate gears, and said plurality of intermediate gears engaged with a sun gear.
2. The gas turbine engine as set forth in claim 1 , wherein an input gear rotates when said fan rotor rotates, and in a direction of rotation of said fan rotor and engages said ring gear in said auxiliary pump epicyclic gear train, said ring gear having an outer peripheral envelope and an axis of rotation of said auxiliary pump is within said outer peripheral envelope.
3. The gas turbine engine as set forth in claim 2 , wherein said ring gear includes a first ring gear portion selectively driving a second ring gear portion through a first clutch, and said first ring gear portion driving an output shaft which is engaged to drive said auxiliary pump through a second clutch, wherein one of said first and second clutches is operable to transmit rotation when driven in a first direction of rotation, but does not transmit rotation when driven in a second direction of rotation, and the other of said first and second clutches is operable to transmit rotation when driven in said second direction of rotation, but not transmit rotation when driven in said first direction of rotation.
4. The gas turbine engine as set forth in claim 3 , wherein when said first ring gear portion drives said second ring gear portion, said second ring gear portion drives said plurality of intermediate gears to, in turn, drive said sun gear, with said sun gear rotating said output shaft.
5. The gas turbine engine as set forth in claim 4 , wherein said output shaft drives an output gear, which is, in turn, engaged with an auxiliary pump drive gear to drive said auxiliary pump.
6. The gas turbine engine as set forth in claim 5 , wherein said first and second clutches are sprag clutches.
7. The gas turbine engine as set forth in claim 6 , wherein said main gear reduction is also an epicyclic gear train.
8. The gas turbine engine as set forth in claim 7 , where said intermediate gears are supported in a fixed carrier.
9. The gas turbine engine as set forth in claim 3 , wherein said output shaft drives an output gear, which is, in turn, engaged with an auxiliary pump drive gear to drive said auxiliary pump.
10. The gas turbine engine as set forth in claim 9 , wherein said first and second clutches are sprag clutches.
11. The gas turbine engine as set forth in claim 10 , wherein said main gear reduction is also an epicyclic gear train.
12. The gas turbine engine as set forth in claim 3 , wherein said first and second clutches are sprag clutches.
13. The gas turbine engine as set forth in claim 12 , wherein said main gear reduction is also an epicyclic gear train.
14. The gas turbine engine as set forth in claim 3 , wherein said output shaft rotates on an output shaft axis, said auxiliary pump rotating on an auxiliary pump axis, and said input gear rotating about an input gear axis, and said input gear axis being on an opposed side of said output shaft axis relative to said auxiliary pump axis.
15. The gas turbine engine as set forth in claim 3 , wherein an output shaft drives an output gear, which is, in turn, engaged with an auxiliary pump drive gear to drive said auxiliary pump.
16. The gas turbine engine as set forth in claim 15 , wherein said first and second clutches are sprag clutches.
17. The gas turbine engine as set forth in claim 16 , wherein said main gear reduction is also an epicyclic gear train.
18. The gas turbine engine as set forth in claim 2 , wherein said main gear reduction is also an epicyclic gear train.
19. The gas turbine engine as set forth in claim 1 , wherein said main gear reduction is also an epicyclic gear train.
20. The gas turbine engine as set forth in claim 1 , wherein an output shaft drives an output gear, which is, in turn, engaged with an auxiliary pump drive gear to drive said auxiliary pump.