Lightweight journal support pin
A journal support pin to support intermediate gears for use in gas turbine engine comprises a titanium body, and an outer surface outside of the titanium body having a surface hardness that is harder than the body. A gas turbine engine and a method of forming a journal support pin to support intermediate gears for use in gas turbine engine are also disclosed.
1. A journal support pin to support intermediate gears for use in a gas turbine engine comprising:
a titanium body, and an outer surface outside of said titanium body having a surface hardness that is harder than said body;
said outer surface is provided by a coating; and
oil supply holes extend from a central bore in said body through said coating.
2. The journal support pin as set forth in claim 1 , wherein said oil supply holes extend through said coating at a recess, wherein a thickness of said coating is thinner at said recess than at axial ends of said titanium body.
3. The journal support pin as set forth in claim 2 , wherein said recess extends only over a limited circumferential portion of said outer surface.
4. The journal support pin as set forth in claim 3 , wherein said coating is one of silver, steel and titanium nitride.
5. The journal support pin as set forth in claim 1 , wherein said coating is one of silver, steel and titanium nitride.
6. A gas turbine engine comprising:
a fan and a fan drive turbine, said fan drive turbine driving said fan through a gear reduction;
said gear reduction including a sun gear engaging intermediate gears and said intermediate gears engaging a ring gear, said intermediate gears being supported on journal support pins;
said journal support pins having a titanium body and an outer surface outside of said titanium body having a surface hardness that is harder than said body, said outer surface provided by a coating; and
oil supply holes extend from a central bore in said body through said coating.
7. The gas turbine engine as set forth in claim 6 , wherein said oil supply holes extend through said coating at a recess, wherein a thickness of said coating is thinner at said recess than at axial ends of said titanium body.
8. The gas turbine engine as set forth in claim 7 , wherein said recess extends only over a limited circumferential portion of said outer surface.
9. The gas turbine engine as set forth in claim 6 , wherein said coating is one of silver, steel and titanium nitride.
10. The gas turbine engine as set forth in claim 6 , wherein a reduction ratio of said gear reduction is greater than about 2.3.
11. The gas turbine engine as set forth in claim 6 , wherein a flexible connection connects said fan drive turbine to said sun gear.