Fan drive gear system with improved misalignment capability
An epicyclic gear assembly includes a carrier that includes a first plate axially spaced from a second plate. At least one epicyclic gear set is located between the first plate and the second plate. The first plate is configured to rotate with an output of the epicyclic gear assembly. A first bearing race is attached to the first plate for supporting a first bearing. A second bearing race is attached to the second plate for supporting a second bearing.
1. An epicyclic gear assembly comprising:
a carrier including a first plate axially spaced from a second plate;
a first epicyclic gear set including a first set of intermediate gear teeth in meshing engagement with a first set of sun gear teeth and a first set of ring gear teeth, wherein the first plate is configured to rotate with an output of the epicyclic gear assembly;
a second epicyclic gear set including a second set of intermediate gear teeth in meshing engagement with a second set of sun gear teeth and a second set of ring gear teeth; and
a first bearing race attached to the first plate for supporting a first bearing and a second bearing race attached to the second plate for supporting a second bearing;
wherein the first set of ring gear teeth extend from a first ring gear having a first flexible attachment and the second set of ring gear teeth extend from a second ring gear having a second flexible attachment;
wherein the first set of sun gear teeth includes teeth that are clocked relative to the second set of sun gear teeth and align with a set of tooth roots between the second set of sun gear teeth.
2. The assembly of claim 1 , wherein the first set of intermediate gear teeth and the second set of intermediate gear teeth are spur gear teeth.
3. The assembly of claim 1 , wherein the epicyclic gear assembly is a planetary gear assembly with the first ring gear and the second ring gear fixed from rotation.
4. The assembly of claim 1 , wherein the first set of intermediate gear teeth are rotatably connected to the first plate by at least one first post and at least one of the second set of intermediate gear teeth are rotatably connected to the second plate by at least one second post.
5. The assembly of claim 4 , including at least one first spherical bearing located between the at least one first post and the at least one of the first set of intermediate gear teeth and at least one second spherical bearing located between at least one second post and the at least one second set of intermediate gear teeth.
6. An epicyclic gear assembly comprising:
a carrier including a first plate axially spaced from a second plate;
a first epicyclic gear set including a first set of intermediate gear teeth in meshing engagement with a first set of sun gear teeth and a first set of ring gear teeth; and
a second epicyclic gear set includes a second set of intermediate gear teeth in meshing engagement with a second set of sun gear teeth and a second set of ring gear teeth;
wherein the first set of sun gear teeth includes teeth that are clocked relative to the second set of sun gear teeth and align with a set of tooth roots between the second set of sun gear teeth;
wherein an output of the first and second epicyclic gear sets includes a flexible connection.
7. The assembly of claim 6 , wherein the first set of ring gear teeth extend from a first ring gear and the second set of ring gear teeth extend from a second ring gear and the output having a flexible connection includes a first flexible connection with the first ring gear and a second flexible connection with the second ring gear.
8. A gas turbine engine comprising:
a fan section rotatable about an axis;
a turbine section having a fan drive turbine; and
a speed change mechanism in communication with the fan section and the turbine section, the speed change mechanism including:
a carrier including a first plate axially spaced from a second plate;
a first epicyclic gear set including a first set of intermediate gear teeth in meshing engagement with a first set of sun gear teeth and a first set of ring gear teeth;
a second epicyclic gear set including a second set of intermediate gear teeth in meshing engagement with a second set of sun gear teeth and a second set of ring gear teeth, wherein the first and second epicyclic gear sets are located between the first plate and the second plate and the first plate is configured to rotate with an output of the speed change mechanism;
a first bearing assembly attached to the first plate for supporting the first plate relative to an engine static structure; and
a second bearing assembly attached to the second plate for supporting the second plate relative to the engine static structure;
wherein the first set of ring gear teeth extend from a first ring gear having a first flexible attachment and the second set of ring gear teeth extend from a second ring gear having a second flexible attachment;
wherein the first set of sun gear teeth includes teeth that are clocked the second set of sun gear teeth and align with a set of tooth roots between the second set of ring gear teeth.
9. The gas turbine engine of claim 8 , wherein the first set of intermediate gear teeth and the second set of intermediate gear teeth are spur gear teeth.
10. The gas turbine engine of claim 8 , wherein the speed change mechanism is a planetary gear assembly with the first ring gear and the second ring gear fixed from rotation relative to an engine static structure.
11. The gas turbine engine of claim 8 , wherein the first set of intermediate gear teeth are rotatably connected to the first plate by at least one first post and at least one of the second set of intermediate gear teeth are rotatably connected to the second plate by at least one second post.
12. The gas turbine engine of claim 11 , including at least one first spherical bearing located between the at least one first post and the at least one of the first set of intermediate gear teeth and at least one second spherical bearing located between at least one second post and the at least one second set of intermediate gear teeth.