Support assembly having variable stiffness member
A support assembly for a load-bearing unit, a gas turbine engine including the support assembly, and a method of operation of the support assembly are provided. The support assembly includes a support element, a damper, and a variable stiffness member. The support element supports the load-bearing unit. The damper supports the support element and is configured to provide dampening of the load-bearing unit. The variable stiffness member is positioned between the damper and the load-bearing unit. The variable stiffness member is configured to provide a serial dampening of the load-bearing unit with the damper. The variable stiffness member includes a shape memory alloy.
1. A support assembly for a bearing, the support assembly comprising:
a support element supporting the bearing;
a damper supporting the support element and configured to provide dampening of the bearing; and
a variable stiffness member positioned in between the damper and the bearing, the variable stiffness member configured to provide a serial dampening of the bearing with the damper, wherein the variable stiffness member comprises a shape memory alloy;
wherein the damper is a squeeze film damper.
2. The support assembly of claim 1 , further comprising a static frame, wherein the support element is attached to the static frame at a first location, wherein the damper is attached to the static frame at a second location, and wherein the variable stiffness member is free of any direct attachment with the static frame.
3. The support assembly of claim 1 , wherein the variable stiffness member is positioned in between the damper and the support element.
4. The support assembly of claim 1 , wherein the variable stiffness member has a hairpin structure.
5. The support assembly of claim 1 , wherein the shape memory alloy comprises a NiTi alloy.
6. The support assembly of claim 1 , further comprising a fluid supply means to supply a fluid proximal to the variable stiffness member.
7. A gas turbine engine comprising:
a compressor section and a turbine section arranged in serial flow order;
a shaft, rotatable in at least a portion of the compressor section and at least a portion of the turbine section;
a bearing, supporting rotation of the shaft; and
a support assembly for the bearing, the support assembly comprising:
a support element supporting the bearing;
a damper supporting the support element and configured to provide dampening of the bearing; and
a variable stiffness member positioned in between the damper and the bearing, and configured to provide a serial dampening of the bearing with the damper, wherein the variable stiffness member comprises a shape memory alloy;
wherein the damper is a squeeze film damper.
8. The gas turbine engine of claim 7 , wherein the variable stiffness member provides a variable stiffness along a radial direction towards a centerline axis of the gas turbine engine during normal operation of the gas turbine engine.
9. The gas turbine engine of claim 7 , wherein the support assembly comprises a plurality of variable stiffness members spaced along a circumferential direction of the gas turbine engine, and wherein each of the plurality of variable stiffness members comprises the shape memory alloy.
10. The gas turbine engine of claim 7 , wherein the variable stiffness member has a hairpin structure.
11. The gas turbine engine of claim 7 , wherein the support assembly further comprises a static frame, wherein the support element is attached to the static frame at a first location, wherein the damper is attached to the static frame at a second location, and wherein the variable stiffness member is free of any direct attachment with the static frame.
12. The gas turbine engine of claim 11 , wherein the support assembly further comprises a fluid supply means to supply a fluid proximal to the variable stiffness member.
13. The gas turbine engine of claim 7 , wherein the support assembly further comprises a fluid supply means to supply a fluid proximal to the variable stiffness member.
14. The gas turbine engine of claim 7 , wherein the variable stiffness member is also positioned in between the damper and the support element.
15. The gas turbine engine of claim 7 , wherein the shape memory alloy comprises a NiTi alloy.
16. A method of operating a support assembly comprising: a support element supporting a bearing; a damper supporting the support element; and a variable stiffness member positioned in between the damper and the bearing, and comprising a shape memory alloy, the method comprising:
changing in-situ a stiffness of the variable stiffness member via heat transfer between a fluid and the shape memory alloy by passing the fluid proximal to the variable stiffness member; and
providing a serial and variable dampening of the bearing during operation of the support assembly.
17. The method of claim 16 , wherein passing the fluid proximal to the variable stiffness member comprises spraying at least one of a coolant fluid or a lubricating oil on the variable stiffness member.
18. The method of claim 16 , further comprising varying temperature of the fluid by passing the fluid through a heat exchanger.
19. The method of claim 16 , wherein passing the fluid proximal to the variable stiffness member is in response to a control algorithm of the support assembly.
20. The method of claim 16 , wherein the damper is a squeeze film damper.