IP Library › Patent Application 13486766
Patent Application
App. No. 13/486,766

EPICYCLIC GEAR TRAIN

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Quick Facts
Patent No.
US None
App. No.
13/486,766
Abstract

An epicyclic gear train includes a carrier that supports star gears that mesh with a sun gear. A ring gear surrounds and meshes with the star gears. Each of the star gears is supported on a respective journal bearing. Each journal bearing includes an internal central cavity and at least one passage that extends radially from the internal cavity to a peripheral journal surface of the respective journal bearing. The epicyclic gear train has a gear reduction ratio of greater than or equal to about 2.3.

Claims (23)

1 . A gear apparatus, comprising:

an epicyclic gear train including a carrier supporting star gears that mesh with a sun gear, and a ring gear surrounding and meshing with the star gears, each of the star gears being supported on a respective journal bearing, each journal bearing including an internal central cavity and at least one passage extending radially from the internal cavity to a peripheral journal surface of the respective journal bearing, wherein the epicyclic gear train has a gear reduction ratio of greater than or equal to about 2.3.

2 . The gear apparatus as recited in claim 1 , wherein the at least one passage includes a first passage and a second passage axially spaced from the first passage.

3 . The gear apparatus as recited in claim 2 , wherein the internal cavity extends between axial ends, and the first passage and the second passage are non-uniformly spaced with regard to the axial ends.

4 . The gear apparatus as recited in claim 1 , wherein the internal central cavity is axially blind.

5 . The gear apparatus as recited in claim 1 , wherein the epicyclic gear train has a gear reduction ratio of greater than or equal to 2.3.

6 . The gear apparatus as recited in claim 1 , wherein the epicyclic gear train has a gear reduction ratio of greater than or equal to about 2.5.

7 . The gear apparatus as recited in claim 1 , wherein the epicyclic gear train has a gear reduction ratio of greater than or equal to 2.5.

8 . A turbine engine comprising:

a turbine shaft;

a fan; and

an epicyclic gear train coupled between the turbine shaft and the fan, the epicyclic gear train including a carrier supporting star gears that mesh with a sun gear, and a ring gear surrounding and meshing with the star gears, each of the star gears being supported on a respective journal bearing, each journal bearing including an internal central cavity and at least one passage extending radially from the internal cavity to a peripheral journal surface of the respective journal bearing, wherein the epicyclic gear train defines a gear reduction ratio of greater than or equal to about 2.3.

9 . The turbine engine as recited in claim 8 , wherein the at least one passage includes a first passage and a second passage axially spaced from the first passage.

10 . The turbine engine as recited in claim 9 , wherein the internal cavity extends between axial ends, and the first passage and the second passage are non-uniformly spaced with regard to the axial ends.

11 . The turbine engine as recited in claim 8 , wherein the internal central cavity is axially blind.

12 . The turbine engine as recited in claim 8 , wherein the epicyclic gear train has a gear reduction ratio of greater than or equal to 2.3.

13 . The turbine engine as recited in claim 8 , wherein the epicyclic gear train has a gear reduction ratio of greater than or equal to about 2.5.

14 . The turbine engine as recited in claim 8 , wherein the epicyclic gear train has a gear reduction ratio of greater than or equal to 2.5.

15 . The turbine engine as recited in claim 8 , wherein the fan defines a bypass ratio of greater than about ten (10) with regard to a bypass airflow and a core airflow.

16 . The turbine engine as recited in claim 8 , wherein the fan defines a bypass ratio of greater than about 10.5:1 with regard to a bypass airflow and a core airflow.

17 . The turbine engine as recited in claim 8 , wherein the fan defines a bypass ratio of greater than ten (10) with regard to a bypass airflow and a core airflow.

18 . The turbine engine as recited in claim 8 , wherein the fan has a pressure ratio that is less than about 1.45.

19 . The turbine engine as recited in claim 8 , wherein the fan has a pressure ratio that is that is less than 1.45.