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A gas turbine engine comprises a compressor section, a combustor section downstream of the compressor section, and a turbine section downstream of the combustor section. A mid-turbine frame includes an outer case portion and is configured to support the turbine section. At least one shaft defines an

A gas turbine engine comprises a compressor section, a combustor section downstream of the compressor section, and a turbine section downstream of the combustor section. A mid-turbine frame includes an outer case portion and is configured to support the turbine section. At least one shaft defines an axis of rotation, and the turbine section comprises an inner rotor directly driving the shaft. The inner rotor includes an inner set of blades. An outer rotor is positioned immediately adjacent to the outer case portion and has an outer set of blades interspersed with the inner set of blades. The outer rotor is configured to rotate in an opposite direction about the axis of rotation from the inner rotor. A gear system is positioned downstream of the combustor section, is mounted to the mid-turbine frame, and is coupled to the outer rotor to drive the at least one shaft.

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1. A gas turbine engine comprising: a compressor section;a combustor section downstream of the compressor section;a turbine section downstream of the combustor section;a mid-turbine frame configured to support the turbine section, the mid-turbine frame extending to an outer case portion;at least one

1. A gas turbine engine comprising: a compressor section;a combustor section downstream of the compressor section;a turbine section downstream of the combustor section;a mid-turbine frame configured to support the turbine section, the mid-turbine frame extending to an outer case portion;at least one shaft defining an axis of rotation, the at least one shaft driven by the turbine section; andwherein the turbine section comprises an inner rotor directly driving the shaft, the inner rotor including an inner set of blades,an outer rotor positioned immediately adjacent to the outer case portion and having an outer set of blades interspersed with the inner set of blades, the outer rotor configured to rotate in an opposite direction about the axis of rotation from the inner rotor, anda gear system mounted to the mid-turbine frame and coupling the outer rotor to drive the at least one shaft, wherein the gear system is positioned downstream of the combustor section;a first bearing supporting a fore end of the outer rotor for rotation relative to the mid-turbine frame structure;a second bearing supporting an aft end of the outer rotor for rotation relative to the shaft; anda third bearing supporting the shaft for rotation relative to a non-rotating structure of the gear system, wherein the first and third bearings are radially aligned with each other in an overlapping relationship. 2. The gas turbine engine according to claim 1, including at least one seal between the outer rotor and the outer case portion. 3. The gas turbine engine according to claim 1, wherein the gear system includes a ring gear engaged to the outer rotor, a plurality of star gears in meshing engagement with the ring gear, and a sun gear in meshing engagement with the star gears. 4. The gas turbine engine according to claim 3, wherein the sun gear is fixed for rotation with the shaft about the axis of rotation. 5. The gas turbine engine according to claim 3, wherein the star gears are supported within a carrier that is mounted to the mid-turbine frame. 6. The gas turbine engine according to claim 1, wherein the third bearing is positioned upstream of the inner and outer sets of blades. 7. The gas turbine engine according to claim 1, wherein a fore end of the at least one shaft is associated with a counter-rotating low pressure compressor, and wherein the gear system comprises a first gear system associated with the turbine section and including a second gear system associated with the counter-rotating low pressure compressor that is separate from the first gear system. 8. The gas turbine engine according to claim 1, wherein the mid-turbine frame extends to the outer case portion upstream of the inner and outer sets of blades. 9. The gas turbine engine according to claim 8, wherein a gear carrier of the gear system is fixed to the mid-turbine frame and wherein the third bearing supports the at least one shaft for rotation relative to the gear carrier. 10. A gas turbine engine comprising: a compressor section including a counter-rotating low pressure compressor;a combustor section downstream of the compressor section;a turbine section downstream of the combustor section;a mid-turbine frame configured to support the turbine section, the mid-turbine frame extending to an outer case portion;at least one shaft defining an axis of rotation, the at least one shaft driven by the turbine section; andwherein the turbine section comprises an inner rotor directly driving the shaft, the inner rotor including an inner set of blades,an outer rotor positioned downstream of the outer case portion and having an outer set of blades interspersed with the inner set of blades, the outer rotor configured to rotate in an opposite direction about the axis of rotation from the inner rotor, anda gear system comprising a first gear system associated with the counter-rotating low pressure compressor and a second gear system mounted to the mid-turbine frame and coupling the outer rotor to drive the at least one shaft, wherein the first gear system is positioned upstream of the combustor section and the second gear system is positioned downstream of the combustor section;a first bearing supporting a fore end of the outer rotor for rotation relative to the mid-turbine frame structure;a second bearing supporting an aft end of the outer rotor for rotation relative to the shaft; anda third bearing supporting the shaft for rotation relative to a non-rotating structure of the gear system, wherein the first and third bearings are radially aligned with each other in an overlapping relationship. 11. The gas turbine engine according to claim 10, wherein the second gear system has a ratio within a range of between about 0.5:1 to about 5.0:1. 12. The gas turbine engine according to claim 10, including at least one seal positioned directly between the outer casing and the outer rotor. 13. The gas turbine engine according to claim 10, wherein the second gear system includes a ring gear coupled to the outer rotor, a plurality of star gears in meshing engagement with the ring gear, a carrier mounted to the mid-turbine frame to support the star gears, and a sun gear in meshing engagement with the star gears, and wherein the sun gear is in direct driving engagement with the at least one shaft. 14. The gas turbine engine according to claim 13, wherein the first and third bearings are upstream of the inner and outer sets of blades. 15. The gas turbine engine according to claim 10, wherein the second gear system includes a ring gear, a plurality of star gears in meshing engagement with the ring gear, and a sun gear in meshing engagement with the star gears, and wherein the third bearing is positioned upstream of the sun gear. 16. The gas turbine engine according to claim 15, wherein the non-rotating structure of the second gear system comprises a carrier that is fixed to the mid-turbine frame to support the plurality of star gears. 17. The gas turbine engine according to claim 10, wherein the mid-turbine frame extends to the outer case portion upstream of the inner and outer sets of blades. 18. The gas turbine engine according to claim 17, wherein a gear carrier of the second gear system is fixed to the mid-turbine frame and wherein the third bearing supports the at least one shaft for rotation relative to the gear carrier.