Aircraft gas turbine engine counter-rotatable generator
An aircraft gas turbine engine includes a counter-rotatable generator driven by a turbine includes a generator stator and counter-rotatable radially inner pole and outer magnet rotors. A gearbox may be used for counter-rotating the pole and magnet rotors. Counter-rotatable first and second sets of booster stages may be co-rotatable with corresponding ones of the pole and magnet rotors. The generator and the gearbox may be disposed within a booster cavity or a tail cone of the engine. The magnet rotor, the pole rotor, and the stator may be concentric. A particular embodiment of generator includes the magnet rotor encircling the pole rotor, the pole rotor encircling the stator, a rotor air gap between the magnet and pole rotors, and a transformer air gap between the pole rotor and the stator. The counter-rotatable generator may be driven directly by a counter-rotatable turbine.
1. An aircraft gas turbine engine comprising:
a low pressure turbine,
a counter-rotatable generator drivenly connected to the turbine,
the counter-rotatable generator including a generator stator and counter-rotatable radially inner pole and outer magnet rotors, and
the generator stator and the counter-rotatable radially inner pole and outer magnet rotors being concentric.
2. An aircraft gas turbine engine as claimed in claim 1 , further comprising a gearbox operably disposed between the turbine and the counter-rotatable generator for counter-rotating the radially inner pole and outer magnet rotors during engine operation.
3. An aircraft gas turbine engine as claimed in claim 2 , further comprising:
a fan section including a fan stage of fan blades,
a counter-rotatable booster including counter-rotatable first and second sets of booster stages downstream of the fan section,
the fan stage of fan blades and the first set of booster stages being co-rotatable with a first one of the radially inner pole and outer magnet rotors, and
the second set of booster stages being co-rotatable with a second one of the radially inner pole and outer magnet rotors.
4. An aircraft gas turbine engine as claimed in claim 3 , further comprising the counter-rotatable generator and the gearbox disposed within a booster cavity of the engine located radially inwardly of the counter-rotatable first and second sets of booster stages of the counter-rotatable booster.
5. An aircraft gas turbine engine as claimed in claim 4 , further comprising the radially outer magnet rotor, the radially inner pole rotor, and the generator stator being concentric.
6. An aircraft gas turbine engine as claimed in claim 5 , further comprising:
the radially outer magnet rotor encircling the radially inner pole rotor,
the radially inner pole rotor encircling the generator stator,
a rotor air gap between the magnet and pole rotors, and
a transformer air gap between the pole rotor and the stator.
7. An aircraft gas turbine engine as claimed in claim 3 , further comprising first booster blade rows of the first set of booster stages interdigitated with second booster blade rows of the second set of booster stages respectively.
8. An aircraft gas turbine engine as claimed in claim 3 , further comprising:
the turbine being a low pressure turbine;
the pole rotor, the fan stage, and the first set of booster stages drivenly connected to the low pressure turbine; and
the magnet rotor and the second set of booster stages drivenly connected counter-rotatably with respect to the fan stage through the gearbox to the low pressure turbine.
9. An aircraft gas turbine engine as claimed in claim 8 , further comprising:
the counter-rotatable generator and the gearbox disposed within a booster cavity of the engine located radially inwardly of the counter-rotatable first and second sets of booster stages of the counter-rotatable booster;
the radially outer magnet rotor, the radially inner pole rotor, and the generator stator being concentric;
the radially outer magnet rotor encircling the radially inner pole rotor;
the radially inner pole rotor encircling the generator stator;
a rotor air gap between the magnet and pole rotors; and
a transformer air gap between the pole rotor and the stator.
10. An aircraft gas turbine engine as claimed in claim 9 , further comprising:
the gearbox including an annular carrier supported by a fan frame of the engine and planetary gears rotatably mounted on pins cantilevered off the annular carrier,
the gearbox further including a sun gear meshed with and rotatably mounted radially inwardly of the planetary gears,
the gearbox further including a ring gear meshed with and rotatably mounted radially outwardly of the planetary gears,
the second set of booster stages connected to the sun gear, and
the sun gear drivenly connected to the low pressure turbine by a low pressure shaft.
11. An aircraft gas turbine engine as claimed in claim 10 , further comprising first booster blade rows of the first set of booster stages interdigitated with second booster blade rows of the second set of booster stages respectively.
12. An aircraft gas turbine engine as claimed in claim 2 , further comprising:
the gearbox disposed within a tail cone of the engine,
the gearbox including an annular carrier supported by an aft turbine fan frame of the engine and planetary gears rotatably mounted on pins cantilevered off the annular carrier,
the gearbox further including a sun gear meshed with and rotatably mounted radially inwardly of the planetary gears, and
the gearbox further including a ring gear meshed with and rotatably mounted radially outwardly of the planetary gears.
13. An aircraft gas turbine engine as claimed in claim 12 , further comprising:
the turbine being a low pressure turbine,
a fan section including a fan stage of fan blades,
a counter-rotatable booster including counter-rotatable first and second sets of booster stages downstream of the fan section,
the sun gear and the second set of booster stages drivenly connected to the low pressure turbine by a radially outer low pressure shaft, and
the fan stage and the first set of booster stages drivenly connected to the ring gear by a radially inner low pressure shaft.
14. An aircraft gas turbine engine as claimed in claim 13 , further comprising:
the radially outer magnet rotor, the radially inner pole rotor, and the generator stator being concentric;
the radially outer magnet rotor encircling the radially inner pole rotor;
the radially inner pole rotor encircling the generator stator;
a rotor air gap between the magnet and pole rotors; and
a transformer air gap between the pole rotor and the stator.
15. An aircraft gas turbine engine as claimed in claim 14 , further comprising first booster blade rows of the first set of booster stages interdigitated with second booster blade rows of the second set of booster stages respectively.
16. An aircraft gas turbine engine as claimed in claim 2 , further comprising:
a fan section including counter-rotatable forward and aft fan stages,
a counter-rotatable booster including counter-rotatable first and second sets of booster stages downstream of the fan section,
the first set of booster stages connected to and rotatable with the forward fan stage,
the second set of booster stages connected to and rotatable with the aft fan stages,
the turbine being a low pressure turbine, and
the counter-rotatable generator directly drivenly connected to the counter-rotatable first and second turbine sections of the low pressure turbine.
17. An aircraft gas turbine engine as claimed in claim 16 , further comprising:
the counter-rotatable generator disposed within a booster cavity of the engine located radially inwardly of the counter-rotatable first and second sets of booster stages of the counter-rotatable booster,
the pole rotor, the forward fan stage, and the first set of booster stages are drivenly connected to the first turbine section of the low pressure turbine by a radially outer low pressure shaft, and
the magnet rotor, the aft fan stage, and the second set of booster stages are drivenly connected to the second turbine section of the low pressure turbine by a radially inner low pressure shaft.
18. An aircraft gas turbine engine as claimed in claim 2 , further comprising:
the turbine being a low pressure turbine,
a fan section including counter-rotatable forward and aft fan stages,
a counter-rotatable booster including counter-rotatable first and second sets of booster stages downstream of the fan section,
the first set of booster stages connected to and rotatable with the forward fan stage,
the second set of booster stages connected to and rotatable with the aft fan stages,
the turbine being a low pressure turbine, and
the counter-rotatable generator directly drivenly connected to the counter-rotatable low pressure inner and outer drum rotors of the low pressure turbine.
19. An aircraft gas turbine engine as claimed in claim 18 , further comprising:
the radially outer magnet rotor, the radially inner pole rotor, and the generator stator being concentric;
the radially outer magnet rotor encircling the radially inner pole rotor;
the radially inner pole rotor encircling the generator stator;
a rotor air gap between the magnet and pole rotors; and
a transformer air gap between the pole rotor and the stator.
20. An aircraft gas turbine engine as claimed in claim 19 , further comprising first booster blade rows of the first set of booster stages interdigitated with second booster blade rows of the second set of booster stages respectively.
21. An aircraft gas turbine engine as claimed in claim 20 , further comprising:
the counter-rotatable generator disposed within a tail cone of the engine,
the pole rotor, the forward fan stage, and the first set of booster stages are drivenly connected to the first turbine section of the low pressure turbine by a radially outer low pressure shaft, and
the magnet rotor, the aft fan stage, and the second set of booster stages are drivenly connected to the second turbine section of the low pressure turbine by a radially inner low pressure shaft.
22. An aircraft gas turbine engine as claimed in claim 20 , further comprising:
the counter-rotatable generator disposed within a booster cavity of the engine,
the magnet rotor, the forward fan stage, and the first set of booster stages are drivenly connected to the low pressure inner drum rotor of the low pressure turbine by a radially inner low pressure shaft, and
the pole rotor, the aft fan stage, and the second set of booster stages are drivenly connected to the low pressure outer drum rotor of the low pressure turbine by a radially outer low pressure shaft.
23. An aircraft gas turbine engine as claimed in claim 1 , further comprising:
the radially outer magnet rotor, the radially inner pole rotor, and the generator stator being concentric about an engine centerline,
the pole rotor including pole assemblies having pole hubs supporting corresponding sets of rotatable axially extending bar poles,
each of the bar poles including a radially outer bar connected by a radially extending connector to a respective one of the pole hubs,
the stator including a generally cylindrically annular center pole section circumscribed and centered about a centerline,
the center pole section including stationary axial windings wound around annular axial poles,
radial poles extending radially outwardly from the center pole section and centered between the axial windings, and
radial windings wound around the radial poles.
24. An aircraft gas turbine engine as claimed in claim 23 , further comprising:
the radially outer magnet rotor encircling the radially inner pole rotor,
the radially inner pole rotor encircling the generator stator,
a rotor air gap between the magnet and pole rotors, and
a transformer air gap between the pole rotor and the stator.
25. An aircraft gas turbine engine as claimed in claim 24 , further comprising the counter-rotatable generator disposed within a booster cavity or a tail cone of the engine.
26. An aircraft gas turbine engine as claimed in claim 25 , further comprising a gearbox operably disposed between the turbine and the counter-rotatable generator for counter-rotating the radially inner pole and outer magnet rotors during engine operation.