Gas turbine engine with geared architecture

1. A gas turbine engine comprising:

a fan shaft and a fan supported on said fan shaft;

an epicyclic gear system which drives said fan shaft, said gear system comprising:

a carrier supporting intermediate gears that mesh with a sun gear; and

a ring gear surrounding and meshing with said intermediate gears, said ring gear including first and second portions each having an inner periphery with teeth, said first and second portions abutting one another at a radial interface, each of said first and second portions including a flange extending radially outward, and said flange secured to said fan shaft, and said first and second portions having grooves at said radial interface which forms a hole that expels oil through said ring gear to a gutter; and

a torque frame which at least partially supports said gear system.

2. The gas turbine engine as recited in claim 1 , further comprising a compressor shaft which drives said fan shaft through said gear system, said compressor shaft connected to said sun gear.

3. The gas turbine engine as recited in claim 2 , wherein each of said intermediate gears are supported on a respective journal bearing.

4. The gas turbine engine of claim 3 , wherein said fan shaft includes a radially extending flange that is secured to said flange of each of said first and second portions.

5. The gas turbine engine as recited in claim 4 , wherein said flange of each of said first and second portions is fixed to said fan shaft by a fastening element.

6. The gas turbine engine as recited in claim 4 , further comprising a compressor having three compressor hubs each with blades, said compressor hubs supported by said compressor shaft.

7. The gas turbine engine as recited in claim 6 , wherein said sun gear is connected to said compressor shaft by a splined connection.

8. The gas turbine engine as recited in claim 7 , further comprising a bypass flow ratio of greater than 10.

9. The gas turbine engine as recited in claim 8 , further comprising a fan pressure ratio of less than 1.45.

10. The gas turbine engine as recited in claim 9 , wherein said gear system has a gear reduction ratio of greater than 2.3.

11. The gas turbine engine as recited in claim 9 , further comprising a low pressure turbine having a pressure ratio of greater than 5:1.

12. The gas turbine engine as recited in claim 11 , wherein said gear system has a gear reduction ratio of greater than 2.5.

13. The gas turbine engine as recited in claim 12 , wherein said low pressure turbine is downstream of at least one turbine.

14. The gas turbine engine as recited in claim 12 , further comprising an input coupling that is coupled to said sun gear, wherein said input coupling transfers torque from said compressor shaft and facilitates segregation of vibrations between said compressor shaft and said gear system.

15. The gas turbine engine as recited in claim 14 , wherein said input coupling includes a splined connection joined to said sun gear.

16. The gas turbine engine as recited in claim 12 , said torque frame is mounted to a front center body, and a housing includes a bearing support frame supporting bearing systems, said bearing systems supporting said fan shaft.

17. The gas turbine engine as recited in claim 16 , wherein said bearing systems include tapered roller bearings.

18. The gas turbine engine as recited in claim 16 , wherein said low pressure turbine is downstream of at least one turbine.

19. The gas turbine engine as recited in claim 18 , wherein said gear system is intermediate a compressor rotor and a shaft driven by said low pressure turbine such that said fan shaft and said compressor rotor are rotatable at a common speed.

20. The gas turbine engine of claim 6 , wherein said first and second portions each have a generally S-shaped outer circumferential surface that provide a first thickness and a second thickness axially inward from said first thickness, said second thickness greater than said first thickness.

21. The gas turbine engine as recited in claim 6 , wherein said carrier is fixed to a housing by said torque frame.

22. The gas turbine engine of claim 21 , wherein said gutter is secured to said carrier.

23. The gas turbine engine of claim 21 , wherein said first and second portions include facing recesses that form an annular cavity, said teeth are oppositely angled teeth on each of said first and second portions which mesh with complementary oppositely facing teeth on said intermediary gears, and a trough separates said oppositely angled teeth.

24. The gas turbine engine of claim 21 , further comprising a first seal and a second seal each secured to a respective one of said flange or said radially extending flange.

25. The gas turbine engine of claim 24 , wherein each of said first and second seals includes an oil return passage that drains oil on a respective side of said ring gear into said gutter.

26. The gas turbine engine of claim 25 , wherein said oil return passage is provided by a slot.

27. The gas turbine engine of claim 26 , wherein said slot is a first slot and a second slot each located in a respective one of said first and second seals.

28. The gas turbine engine of claim 26 , wherein said slot is located in said radially extending flange of said fan shaft.

29. The gas turbine engine of claim 26 , wherein said first and second seals include knife edges formed from a first material, and said gutter is formed from a second material that is relatively softer than said first material such that said knife edges cut into said gutter in response to interference between said knife edges and said gutter.