Segmented variable fan outlet guide vane with cam assembly and unique actuation mechanisms
A fan assembly for a gas turbine engine includes a fan duct, a fan, and an outlet guide vane assembly located in the fan duct axially downstream of the fan. The outlet guide vane assembly includes a first variable leading edge outlet guide vane that extends radially relative to the central axis and includes a leading edge portion and a fixed aft portion, the leading edge portion including a tip segment configured to rotate about a leading edge pitch axis and a hub segment located radially inward of and separate from the tip segment, the hub segment configured to independently rotate about the leading edge pitch axis relative to the tip segment. The assembly further includes two unique actuation assemblies each including a cam rod and cams located thereon that are configured to rotate a respective tip or hub segment.
1. A fan assembly for a gas turbine engine the fan assembly comprising
a fan duct arranged circumferentially around a central axis,
a fan comprising a plurality of fan blades that extend radially outward relative to the central axis and that are adapted to rotate about the central axis to force fan exit air toward an aft end of the fan duct, and
an outlet guide vane assembly located in the fan duct axially downstream of the fan and configured to adjust a direction of incoming fan exit air received from the plurality of fan blades and reduce incidence between the outlet guide vane assembly and the fan exit air, the outlet guide vane assembly including
a first variable leading edge outlet guide vane that extends radially relative to the central axis and includes a leading edge portion and a fixed aft portion, the leading edge portion including a first tip segment configured to rotate about a leading edge pitch axis and a first hub segment located radially inward of and separate from the first tip segment, the first hub segment configured to independently rotate about the leading edge pitch axis relative to the first tip segment,
a first actuation assembly including a first cam rod and a first cam fixedly coupled to the first cam rod, wherein the first cam rod is configured to be selectively rotated so as to selectively rotate the first cam, wherein rotation of the first cam causes rotation of the first tip segment about the leading edge pitch axis to a first pitch angle relative to the incoming fan exit air, and
a second actuation assembly including a second cam rod and a second cam fixedly coupled to the second cam rod, wherein the second cam rod is configured to be selectively rotated independent of the first cam rod so as to selectively rotate the second cam, wherein rotation of the second cam causes rotation of the first hub segment about the leading edge pitch axis to a second pitch angle relative to the incoming fan exit air.
2. The fan assembly of claim 1 , wherein the first and second cams are configured to be selectively clocked to unique rotational positions on the first and second cam rods such that rotation of the first and second cams causes the first tip segment to be rotated to a first pitch angle relative to the incoming fan exit air and the first hub segment to be rotated to a second angle relative to the incoming fan exit air, and wherein the first actuation assembly is configured to rotate the first tip segment to the first pitch angle and the second actuation assembly is configured to rotate the first hub segment to the second pitch angle which is different than the first pitch angle.
3. The fan assembly of claim 2 , wherein the first actuation assembly further includes a first cam actuation rod rotatably coupled to the first tip segment and extending axially aft therefrom toward the first cam, and wherein the second actuation assembly further includes a second cam actuation rod rotatably coupled to the first hub segment extending axially aft therefrom toward the second cam.
4. The fan assembly of claim 3 , wherein an axially aft end of the first cam actuation rod engages an axially forward facing surface of the first cam such that rotation of the first cam in a first rotational direction causes the axially forward facing surface to move the first cam actuation rod axially forward, and wherein an axially aft end of the second cam actuation rod engages an axially forward facing surface of the second cam such that rotation of the second cam in the first rotational direction causes the axially forward facing surface to move the second cam actuation rod axially forward.
5. The fan assembly of claim 4 , wherein the first cam actuation rod is rotatably coupled to the first tip segment at a point offset from the leading edge pitch axis in a circumferential direction such that axially forward movement of the first cam actuation rod rotates the first tip segment in the first rotational direction, and wherein the second cam actuation rod is rotatably coupled to the first hub segment at a point offset from the leading edge pitch axis in the circumferential direction such that axially forward movement of the second cam actuation rod rotates the first hub segment in the first rotational direction.
6. The fan assembly of claim 5 , wherein the first tip segment includes a first cam actuation rod receiving recess formed at least partially in an aft side of the first tip segment, wherein the first cam actuation rod is rotatably mounted within the first cam actuation rod receiving recess, wherein the first hub segment includes a second cam actuation rod receiving recess formed at least partially in an aft side of the first hub segment, and wherein the second cam actuation rod is rotatably mounted within the second cam actuation rod receiving recess.
7. The fan assembly of claim 3 , wherein the first actuation assembly is arranged radially outward of the fixed aft portion and includes a first actuation head, wherein the first cam rod is fixedly coupled to the first actuation head such that rotation of the first actuation head causes rotation of the first cam rod, wherein the second actuation assembly is arranged radially inward of the fixed aft portion and includes a second actuation head, and wherein the second cam rod is fixedly coupled to the second actuation head such that rotation of the second actuation head causes rotation of the second cam rod.
8. The fan assembly of claim 7 , wherein the first actuation assembly further includes a first actuation arm coupled to the first actuation head and extending generally axially aft therefrom, wherein pivoting of the first actuation arm about a rotation axis of the first actuation head causes rotation of the first actuation head which causes rotation of the first cam rod, wherein the second actuation assembly further includes a second actuation arm coupled to the second actuation head and extending generally axially aft therefrom, and wherein pivoting of the second actuation arm about a rotation axis of the second actuation head causes rotation of the second actuation head which causes rotation of the second cam rod.
9. The fan assembly of claim 8 , wherein the outlet guide vane assembly further includes a first annular ring extending circumferentially about the central axis, wherein an axially aft end of the first actuation arm is connected to the first annular ring, and wherein circumferential movement of the first annular ring causes movement of the first actuation arm generally circumferentially relative to the first actuation head which causes the first actuation arm to pivot about the rotation axis of the first actuation head which causes rotation of the first actuation head which causes rotation of the first cam rod.
10. The fan assembly of claim 9 , wherein the outlet guide vane assembly further includes a second annular ring extending circumferentially about the central axis, wherein an axially aft end of the second actuation arm is connected to the second annular ring, and wherein circumferential movement of the second annular ring causes movement of the second actuation arm generally circumferentially relative to the second actuation head which causes the second actuation arm to pivot about the rotation axis of the second actuation head which causes rotation of the second actuation head which causes rotation of the second cam rod.
11. The fan assembly of claim 1 , wherein the first cam rod and the second cam rod are radially spaced apart.
12. The fan assembly of claim 1 , wherein the first variable leading edge outlet guide vane further includes a central segment arranged between the first tip segment and the first hub segment such that the first tip segment and the first hub segment are radially spaced apart.
13. The fan assembly of claim 12 , wherein the central segment is coupled to and extends axially away from an axially forward side of the fixed aft portion.
14. A fan assembly for a gas turbine engine the fan assembly comprising
a fan duct arranged circumferentially around a central axis, a fan adapted to rotate about the central axis to force fan exit air toward an aft end of the fan duct, and
an outlet guide vane assembly located in the fan duct axially downstream of the fan and configured to adjust a direction of incoming fan exit air received from the plurality of fan blades and reduce incidence between the outlet guide vane assembly and the fan exit air, the outlet guide vane assembly including
a first variable leading edge outlet guide vane that extends radially relative to the central axis and includes a leading edge portion and a fixed aft portion, the leading edge portion including a first tip segment configured to rotate about a leading edge pitch axis and a first hub segment located radially inward of and separate from the first tip segment, the first hub segment configured to independently rotate about the leading edge pitch axis relative to the first tip segment,
a first actuation assembly including a first cam, wherein rotation of the first cam is configured to cause rotation of the first tip segment about the leading edge pitch axis to a first pitch angle relative to the incoming fan exit air, and
a second actuation assembly including a second cam configured to be selectively rotated independent of the first cam, wherein rotation of the second cam is configured to cause rotation of the first hub segment about the leading edge pitch axis to a second pitch angle relative to the incoming fan exit air.
15. The fan assembly of claim 14 , wherein the first actuation assembly further includes a first cam rod, wherein the first cam is fixedly coupled to the first cam rod, wherein the first cam rod is configured to be selectively rotated so as to selectively rotate the first cam, wherein the second actuation assembly further includes a second cam rod, wherein the second cam is fixedly coupled to the second cam rod, and wherein the second cam rod is configured to be selectively rotated independent of the first cam rod so as to selectively rotate the second cam.
16. The fan assembly of claim 15 , wherein the first and second cams are configured to be selectively clocked to unique rotational positions on the first and second cam rods such that rotation of the first and second cams causes the first tip segment to be rotated to a first pitch angle relative to the incoming fan exit air and the first hub segment to be rotated to a second angle relative to the incoming fan exit air.
17. The fan assembly of claim 16 , wherein the first actuation assembly further includes a first cam actuation rod rotatably coupled to the first tip segment and extending axially aft therefrom toward the first cam, and wherein the second actuation assembly further includes a second cam actuation rod rotatably coupled to the first hub segment extending axially aft therefrom toward the second cam.
18. The fan assembly of claim 17 , wherein an axially aft end of the first cam actuation rod engages an axially forward facing surface of the first cam such that rotation of the first cam in a first rotational direction causes the axially forward facing surface to move the first cam actuation rod axially forward, and wherein an axially aft end of the second cam actuation rod engages an axially forward facing surface of the second cam such that rotation of the second cam in the first rotational direction causes the axially forward facing surface to move the second cam actuation rod axially forward.
19. The fan assembly of claim 18 , wherein the first cam actuation rod is rotatably coupled to the first tip segment at a point offset from the leading edge pitch axis in a circumferential direction such that axially forward movement of the first cam actuation rod rotates the first tip segment in the first rotational direction, and wherein the second cam actuation rod is rotatably coupled to the first hub segment at a point offset from the leading edge pitch axis in the circumferential direction such that axially forward movement of the second cam actuation rod rotates the first hub segment in the first rotational direction.
20. A method comprising
arranging a fan duct circumferentially around a central axis,
providing a fan comprising a plurality of fan blades that extend radially outward relative to the central axis and that are adapted to rotate about the central axis to force fan exit air toward an aft end of the fan duct,
arranging an outlet guide vane assembly in the fan duct axially downstream of the fan and configured to adjust a direction of incoming fan exit air received from the plurality of fan blades and reduce incidence between the outlet guide vane assembly and the fan exit air, the outlet guide vane assembly including a first variable leading edge guide vane that extends radially relative to the central axis and includes a leading edge portion and a fixed aft portion, the leading edge portion including a first tip segment configured to rotate about a leading edge pitch axis and a first hub segment located radially inward of and separate from the first tip segment, the first hub segment configured to independently rotate about the leading edge pitch axis relative to the first tip segment, arranging a first actuation assembly relative to the first tip segment, the first actuation assembly including a first cam rod and a first cam fixedly coupled to the first cam rod, wherein the first cam rod is configured to be selectively rotated so as to selectively rotate the first cam, wherein rotation of the first cam causes rotation of the first tip segment about the leading edge pitch axis to a first pitch angle relative to the incoming fan exit air, and
arranging a second actuation assembly relative to the first hub segment, the second actuation assembly including a second cam rod and a second cam fixedly coupled to the second cam rod, wherein the second cam rod is configured to be selectively rotated independent of the first cam rod so as to selectively rotate the second cam, wherein rotation of the second cam causes rotation of the first hub segment about the leading edge pitch axis to a second pitch angle relative to the incoming fan exit air.