Variable stator vane bushing assembly

Abstract

Systems and methods include providing a variable stator vane assembly with a stator vane bushing disposed in a housing of the variable stator vane assembly and annularly about the stator vane of the stator vane assembly. One or more tolerance rings are disposed between the housing and the bushing to maintain alignment between the between the stator vane and the bushing, the housing and the bushing, or a combination thereof when the variable stator vane assembly is operated at elevated temperatures.

Description

[0001] VARIABLE STATOR VANE BUSHING ASSEMBLY

[0002] TECHNICAL FIELD

[0003] Bushings are used in many industrial applications between components of an assembly. The bushings are utilized to maintain alignment and / or control relative movement between components during operation. In some applications, bushings such as those utilized in variable stator vane assemblies in gas turbine engines, are often subjected to extreme operating conditions, such as extreme forces, pressures, and / or temperatures. To withstand these extreme operating conditions, these bushings are commonly formed from graphite or other high performance polymeric materials. However, these materials still present considerable performance limitations, where oxidation of these materials can negatively affect performance and reliability. Accordingly, the industry continues to demand improvements in bushing technology for such applications.

[0004] BRIEF DESCRIPTION OF THE DRAWINGS

[0005] So that the manner in which the features and advantages of the embodiments are attained and can be understood in more detail, a more particular description may be had by reference to the embodiments thereof that are illustrated in the appended drawings. However, the drawings illustrate only some embodiments and therefore are not to be considered limiting in scope as there may be other equally effective embodiments.

[0006] FIG. 1 is a partial cross-sectional view of an assembly according to an embodiment of the disclosure.

[0007] FIG. 2 is an oblique view of a tolerance ring according to an embodiment of the disclosure.

[0008] The use of the same reference symbols in different drawings indicates similar or identical items.

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0010] FIG. 1 shows a partial cross-sectional view of an assembly 100 according to an embodiment of the disclosure. In some embodiments, the assembly 100 may be a jet engine compressor or a gas turbine engine. More particularly, in some embodiments, the assembly may be a variable stator vane assembly of a jet engine compressor or a gas turbine engine.

[0011] The assembly 100 may generally comprise an outer component, such as a stator vane housing 102, and an inner component, such as a movable or rotatable stator vane 104. The housing 102 may generally be disposed annularly about the stator vane 104. In some embodiments, the housing 102 and / or the stator vane 104 may be formed from aluminum, magnesium, carbon steel, stainless steel, titanium, tungsten, an alloy thereof, a carbide thereof, or a polymer composite.

[0012] The assembly 100 may also comprise an annular bushing 150 at least partially disposed within the housing 102 and annularly about the stator vane 104. The bushing 150 may comprise a flange 152, a barrel 154 extending from the flange 152, and a central aperture 156 extending through the flange 152 and the barrel 154. More specifically, the bushing 150 may be disposed such that the barrel 154 is disposed within the housing 102 and radially between the housing 102 and the stator vane 104. The flange 152 may be disposed adjacent an outer surface 106 of the housing 102. The stator vane 104 may be received through the central aperture 156 of the bushing 150. In some embodiments, the flange 152 may substantially abut the outer surface 106 of the housing 102. However, in some embodiments, a washer 108 may be disposed between the flange 152 and the outer surface 106 of the housing 102.

[0013] In some embodiments, the bushing 150 may be formed from a material comprising a coefficient of thermal expansion (CTE) that is greater than or equal to a CTE of the housing 102, the stator vane 104, or a combination thereof. The assembly of any of claims 1 to 5, wherein the bushing is formed from a material comprising a CTE that is 0%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, or at least 15% greater than the CTE of the housing 102, the stator vane 104, or the combination thereof. In some embodiments the bushing may be formed from a material comprising a CTE that is not greater than 30%, not greater than 25%, not greater than 20%, not greater than 15%, not greater than 10%, not greater than 9%, not greater than 8%, not greater than 7%, not greater than 6%, not greater than 5%, not greater than 4%, not greater than 3%, not greater than 2%, or not greater than 1% greater than the CTE of the housing 102, the stator vane 104, or the combination thereof. Further, it will be appreciated that the bushing 150 may be formed from a material comprising a CTE between any of these minimum and maximum values, such as 0% to not greater than 30%, 0% to not greater than 20%, or even at least 0% to not greater than 10% greater than the CTE of the housing 102, the stator vane 104, or the combination thereof.

[0014] In some embodiments, the bushing 150 may be formed from a material comprising a polymer, a plastic, a polyimide, a composite, carbon fibers, glass fibers, graphite, or a combination thereof. In some embodiments, the bushing 150 may be formed from a material comprising a CTE of at least 2 E6 / K, at least 3 E6 / K, at least 4 E6 / K, at least 5 E6 / K, at least 6 E_6 / K, at least 7 E_6 / K, at least 8 E_6 / K, at least 9 E_6 / K, at least 10 E_6 / K, at least 11 E_6 / K, at least 12 E6 / K, or at least 13 E6 / K. In some embodiments, the bushing 150 may be formed from a material comprising a CTE of not greater than 14 E6 / K, not greater than 13 E6 / K, not greater than 12 E6 / K, not greater than 11 E6 / K, or not greater than 10 E6 / K. Further, it will be appreciated that the bushing 150 may be formed from a material comprising a CTE between any of these minimum and maximum values, such as at least 2 E6 / K to not greater than 10 E6 / K, at least 3 E6 / K to not greater than 10 E6 / K, or even at least 5 E6 / K to not greater than 12 E6 / K.

[0015] In some embodiments, the bushing 150 may be formed from a ceramic material comprising a coefficient of thermal expansion (CTE) lower than or equal to a CTE of the stator vane, the housing, or a combination thereof. In some embodiments, the bushing 150 may be formed from a ceramic material comprising a CTE that is 0%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, or at least 15% lower than the CTE of the stator vane, the housing, or a combination thereof. In some embodiments, the bushing 150 may be formed from a ceramic material comprising a CTE that is not greater than 30%, not greater than 25%, not greater than 20%, not greater than 15%, not greater than 10%, not greater than 9%, not greater than 8%, not greater than 7%, not greater than 6%, not greater than 5%, not greater than 4%, not greater than 3%, not greater than 2%, or not greater than 1% lower than the CTE of the stator vane, the housing, or a combination thereof. Further, it will be appreciated that the bushing 150 may be formed from a ceramic material comprising a CTE between any of these minimum and maximum values, such as 0% to not greater than 30%, 0% to not greater than 20%, or even at least 0% to not greater than 10% lower than the CTE of the housing 102, the stator vane 104, or the combination thereof.

[0016] In some embodiments, the bushing 150 may be formed from a ceramic material comprising aluminum, aluminum nitride, aluminum oxide, boron, boron nitride, chromium, copper, copper oxide, hafnium, silicon, silicon nitride, silicon oxide, tantalum, titanium, titanium nitride, tungsten, yttrium, zircon, zirconium oxide, a composite thereof, or a combination thereof. In some embodiments, the bushing 150 may be formed from a ceramic material comprising a CTE of at least 0.5 E6 / K, at least 1.0 E6 / K, at least 1.5 E6 / K, at least 2 E_6 / K, at least 3 E_6 / K, at least 4 E_6 / K, at least 5 E_6 / K, at least 6 E_6 / K, at least 7 E_6 / K, at least 8 E6 / K, at least 9 E6 / K, or at least 10 E6 / K. In some embodiments, the bushing 150 may be formed from a ceramic material comprising a CTE of not greater than 16 E6 / K, not greater than 15 E6 / K, not greater than 14 E6 / K, not greater than 13 E6 / K, not greater than 12 E6 / K, not greater than 11 E6 / K, or not greater than 10 E6 / K. Further, it will be appreciated that the bushing 150 may be formed from a ceramic material comprising a CTE between any of these minimum and maximum values, such as at least 0.5 E6 / K to not greater than 10 E6 / K, at least 2 E6 / K to not greater than 10 E6 / K, or even at least 3 E6 / K to not greater than 12 E_6 / K.

[0017] Further, the bushing 150 may be designed to have beneficial tolerances between the barrel 154 of the bushing 150 and the housing 102, the stator vane 104, or a combination thereof. In some embodiments, the barrel 154 of the bushing 150 may comprise a substantially zero tolerance with the housing 102, such that the bushing 150 comprises a press-fit installation with the housing 102. In some embodiments, the barrel 154 of the bushing 150 may comprise a minimal tolerance with the housing 102, such that the bushing 150 comprises minimal movement within the housing 102. In some embodiments, the tolerance between the barrel 154 of the bushing 150 and the housing 100 may be 0%, at least 0.005%, at least 0.01%, at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.10%, or at least 0.15% of the diameter of the barrel 154 of the bushing 150. In some embodiments, the tolerance between the barrel 154 of the bushing 150 and the housing 100 may be not greater than 5%, not greater than 4%, not greater than 3%, not greater than 2.5%, not greater than 2%, not greater than 1.5%, not greater than 1%, not greater than 0.75%, not greater than 0.50%, not greater than 0.25%, not greater than 0.20%, not greater than 0.15%, not greater than 0.10%, or not greater than 0.05% of the diameter of the barrel 154 of the bushing 150. Further, it will be appreciated that the tolerance between the barrel 154 of the bushing 150 and the housing 100 may be between any of these minimum and maximum values, such as 0% to not greater than 5%, or even at least 0.10% to not greater than 0.20%.

[0018] The assembly 100 may also comprise one or more tolerance rings 200 disposed between the housing 102 and the bushing 150. In some embodiments, the one or more tolerance rings 200 may comprise 1, 2, 3, 4, 5, or even more tolerance rings 200. In embodiments comprising a plurality of tolerance rings, 200, the plurality of tolerance rings 200 may be spaced apart along an axial length of the bushing 150. In some embodiments, the housing 102 may comprise one or more grooves 110 configured to at least partially receive the one or more tolerance rings 200. In some embodiments, the bushing 150 may also comprise one or more grooves 158 formed in the barrel 156 of the bushing 156 and configured to at least partially receive the one or more tolerance rings 200. Further, in some embodiments, the one or more grooves 158 formed in the barrel 154 of the bushing 150 may align radially with the one or more grooves 110 in the housing 102 when the barrel 154 of the bushing 150 is received within the housing 102. It will be appreciated that the grooves, 110, 158 may be deep enough receive the one or more tolerance rings 200 and prevent the one or more tolerance rings 200 from sliding axially with respect to the housing 102 and / or the bushing 150.

[0019] Additionally, in some embodiments, the assembly 100 may comprise at least one metallic seal 170 configured to form a fluid tight seal between the bushing 150 and the housing 102. In some embodiments, the at least one metallic seal 170 may comprise a metallic lip seal. In some embodiments, the at least one metallic seal 170 may be a standalone metallic lipseal. However, in some embodiments, the at least one metallic seal 170 may be integrated into the one or more tolerance rings 200. Further, it will be appreciated that the at least one metallic seal 170 may be disposed axially along the barrel 154 of the bushing 150. In some embodiments, the at least one metallic seal 170 may be disposed adjacent to the one or more tolerance rings 200.

[0020] FIG. 2 shows an oblique view of a tolerance ring 200 according to an embodiment of the disclosure. The one or more tolerance rings 200 may generally comprise an annular band of material or a substrate 202 formed into an annular ring shape. In some embodiments, the tolerance ring 200 may comprise a gap 204 defining a first circumferential end 206 and a second circumferential end 208. In some embodiments, the tolerance ring 200 may be formed from a resilient metallic material. In some embodiments, the metallic material may comprise aluminum, beryllium, bronze, copper, iron, magnesium, steel, spring steel, stainless steel, tin, titanium, tungsten, or an alloy thereof.

[0021] The tolerance ring 200 may comprise a plurality of projections 210 (e.g., waves 212, fingers 214, or a combination thereof). In some embodiments, the projections 210 may protrude radially inward from an inner surface 222. More specifically, in some embodiments, the plurality of waves 212, the plurality of fingers 214, or a combination thereof may protrude radially inward from the inner surface 222 of the tolerance ring 200 and are in contact with the grooves 158 of the bushing 150. In some embodiments, the projections 210 may protrude radially outward from an outer surface 224. More specifically, in some embodiments, the plurality of waves 212, the plurality of fingers 214, or a combination thereof may protrude radially outward from the outer surface 224 of the tolerance ring 200 and are in contact with the grooves 110 in the housing 102.

[0022] In some embodiments, the projections 210 may be disposed circumferentially about the tolerance ring 200. In some embodiments, the projections 210 may comprise the same geometric shape and / or size as compared to each other. In other embodiments, a number of projections 210 may have different geometric shapes and / or sizes as compared to each other. In yet other embodiments, all of the projections 210 may have different geometric shapes and / or sizes as compared to each other.

[0023] In some embodiments, the plurality of projections 210 may comprise a plurality of waves 212, a plurality of fingers 214, or a combination thereof. In some embodiments, the plurality of waves 212 may be disposed in one or more bands 216 circumferentially about the tolerance ring 200. In some embodiments, the plurality of waves 212 may be grouped into a plurality of groups 218 of waves 212. In some embodiments, each of the plurality of groups 218 of waves 212 may comprise the same number of waves 212 per group 218. However, in some embodiments, at least one of the plurality of groups 218 of waves 212 may comprise a different number of waves 212. In some embodiments, each of the plurality of groups 218 of waves 212 may comprises at least 1, at least 2, at least 3, at least 4, or at least 5 waves per group 218. Further, in some embodiments, each of the plurality of groups 218 of waves 212 may be divided by one or more flat portions 220, one or more fingers 214, or a combination thereof.

[0024] It will be appreciated that the projections 210 (e.g., waves 212, fingers 214, or a combination thereof) may be selected to provide desired elastic / plastic deformation characteristics, desired force transfer properties, to account for manufacturing tolerances of hardware components, and / or to compensate for thermal expansion and wear that may occur between hardware components during operation. More specifically, the projections 210 may be selected to accommodate the stress levels and deformations capable of holding normal loads acting on the bushing 150, while allowing some compression when a bending moment is applied to the bushing 150, thereby minimizing the stresses at each end of the bushing 150.

[0025] When polymers are used in variable stator vane bushings, the plasticity of the material allows the bushing to compensate for the misalignment between the bushing and the stator vane, thus allowing some deformation to occur while limiting wear. For harder materials, such as the material used for the bushings 150 disclosed herein, plastic deformation is virtually non-existent, and the loads applied to the bushing 150 due to bending moments may damage the bushing 150. However, the one or more tolerance rings 200 may compensate for the rigidness of the bushing 150 and may prevent or substantially reduce bending moments applied to the bushing 150 resulting from radial and / or axial forces caused by operation of the gas turbine engine, thereby allowing the bushing 150 to withstand higher operating temperatures than traditional bushings.

[0026] Accordingly, in some embodiments, the one or more tolerance rings 200 may be configured to compensate for a mismatch in tolerances, a misalignment, a difference in CTE between the stator vane 104 and the bushing 150, the housing 102 and the bushing 150, or a combination thereof. In some embodiments, the one or more tolerance rings 200 may be configured to maintain alignment between the between the stator vane 104 and the bushing 150, the housing 102 and the bushing 150, or a combination thereof. Further, in some embodiments, the one or more tolerance rings 200 may be configured to maintain alignment between the between the stator vane 104 and the bushing 150, the housing 102 and the bushing 150, or a combination thereof while withstanding operating temperatures of at least 350 degrees Celsius, at least 400 degrees Celsius, at least 450 degrees Celsius, at least 500 degrees Celsius, at least 600 degrees Celsius, at least 700 degrees Celsius, at least 800 degrees Celsius, at least 850 degrees Celsius, at least 900 degrees Celsius, at least 950 degrees Celsius, at least 1000 degrees Celsius, or even higher under air (e.g., airflow). Operation at these temperatures may be at standard atmospheric pressure up to a pressure of at least 10 bar, at least 20 bar, at least 30 bar, at least 40 bar, at least 50 bar, or even as high as at least 60 bar.

[0027] While a bushing assembly comprising the bushing 150 and the one or more tolerance rings 200 may be disclosed as applicable to a stator vane assembly for a jet engine compressor or a gas turbine engine, it will be appreciated that the bushing assembly comprising the bushing 150 and the one or more tolerance rings 200 may be applicable to a variety of other applications where tolerance compensation is needed.

[0028] Embodiments of an assembly 100 disclosed herein may include one or more of the following embodiments:

[0029] Embodiment 1. A variable stator vane assembly, comprising: a movable stator vane; a stator vane housing disposed annularly about the movable stator vane; a bushing disposed in the housing and annularly about the stator vane; and one or more tolerance rings disposed between the housing and the bushing, wherein the one or more tolerance rings comprises a plurality of projections protruding radially inward from an inner surface of the tolerance ring or radially outward from an outer surface of the tolerance ring.

[0030] Embodiment 2. The assembly of embodiment 1, wherein the housing is formed from aluminum, magnesium, carbon steel, stainless steel, titanium, tungsten, an alloy thereof, a carbide thereof, or a polymer composite.

[0031] Embodiment 3. The assembly of any one of embodiments 1 to 2, wherein the housing comprises one or more grooves, and wherein each of the one or more grooves is configured to at least partially receive the one or more tolerance rings. Embodiment 4. The assembly of any one of embodiments 1 to 3, wherein the bushing is formed from a material comprising a coefficient of thermal expansion (CTE) that is greater than or equal to a CTE of the stator vane, the housing, or a combination thereof.

[0032] Embodiment 5. The assembly of any one of embodiments 1 to 4, wherein the bushing is formed from a material comprising a polymer, a plastic, a polyimide, a composite, carbon fibers, glass fibers, graphite, or a combination thereof.

[0033] Embodiment 6. The assembly of any one of embodiments 1 to 5, wherein the bushing is formed from a material comprising a CTE that is 0%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, or at least 15% greater than the CTE of the stator vane, the housing, or a combination thereof.

[0034] Embodiment 7. The assembly of any one of embodiments 1 to 6, wherein the bushing is formed from a material comprising a CTE that is not greater than 30%, not greater than 25%, not greater than 20%, not greater than 15%, not greater than 10%, not greater than 9%, not greater than 8%, not greater than 7%, not greater than 6%, not greater than 5%, not greater than 4%, not greater than 3%, not greater than 2%, or not greater than 1% greater than the CTE of the stator vane, the housing, or a combination thereof.

[0035] Embodiment 8. The assembly of any one of embodiments 1 to 7, wherein the bushing is formed from a material comprising a CTE of at least 2 E6 / K, at least 3 E6 / K, at least 4 E6 / K, at least 5 E6 / K, at least 6 E6 / K, at least 7 E6 / K, at least 8 E6 / K, at least 9 E6 / K, at least 10 E_6 / K, at least 11 E_6 / K, at least 12 E_6 / K, at least 13 E_6 / K, at least 14 E_6 / K, or at least 15 E_6 / K.

[0036] Embodiment 9. The assembly of any one of embodiments 1 to 8, wherein the bushing is formed from a material comprising a CTE of not greater than 16 E6 / K, not greater than 15 E6 / K, not greater than 14 E6 / K, not greater than 13 E6 / K, not greater than 12 E6 / K, not greater than 11 E6 / K, or not greater than 10 E6 / K.

[0037] Embodiment 10. The assembly of any one of embodiments 1 to 3, wherein the bushing is formed from a ceramic material comprising a coefficient of thermal expansion (CTE) lower than or equal to a CTE of the stator vane, the housing, or a combination thereof.

[0038] Embodiment 11. The assembly of any one of embodiments 1 to 3 or 10, wherein the bushing is formed from a ceramic material comprising aluminum, aluminum nitride, aluminum oxide, boron, boron nitride, chromium, copper, copper oxide, hafnium, silicon, silicon nitride, silicon oxide, tantalum, titanium, titanium nitride, tungsten, yttrium, zircon, zirconium oxide, a composite thereof, or a combination thereof. Embodiment 12. The assembly of any one of embodiments 1 to 3 or 10 to 11, wherein the bushing is formed from a ceramic material comprising a CTE that is 0%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, or at least 15% lower than the CTE of the stator vane, the housing, or a combination thereof.

[0039] Embodiment 13. The assembly of any one of embodiments 1 to 3 or 10 to 12, wherein the bushing is formed from a ceramic material comprising a CTE that is not greater than 30%, not greater than 25%, not greater than 20%, not greater than 15%, not greater than 10%, not greater than 9%, not greater than 8%, not greater than 7%, not greater than 6%, not greater than 5%, not greater than 4%, not greater than 3%, not greater than 2%, or not greater than 1% lower than the CTE of the stator vane, the housing, or a combination thereof.

[0040] Embodiment 14. The assembly of any one of embodiments 1 to 3 or 10 to 13, wherein the bushing is formed from a ceramic material comprising a CTE of at least 0.5 E

[0041] 6IK, at least 1.0 E_6 / K, at least 1.5 E_6 / K, at least 2 E_6 / K, at least 3 E_6 / K, at least 4 E_6 / K, at least 5 E6 / K, at least 6 E6 / K, at least 7 E6 / K, at least 8 E6 / K, at least 9 E6 / K, or at least 10 E6 / K.

[0042] Embodiment 15. The assembly of any one of embodiments 1 to 3 or 10 to 14, wherein the bushing is formed from a ceramic material comprising a CTE of not greater than 16 E6 / K, not greater than 15 E6 / K, not greater than 14 E6 / K, not greater than 13 E6 / K, not greater than 12 E6 / K, not greater than 11 E6 / K, or not greater than 10 E6 / K.

[0043] Embodiment 16. The assembly of any one of embodiments 1 to 15, wherein the bushing comprises a flange, a barrel extending from the flange, and a central aperture extending through the flange and the barrel.

[0044] Embodiment 17. The assembly of embodiment 16, wherein the barrel of the bushing is received within the housing, and wherein the stator vane is received through the central aperture of the bushing.

[0045] Embodiment 18. The assembly of any one of embodiments 16 to 17, wherein the bushing comprises one or more grooves formed in the barrel of the bushing, and wherein each of the one or more grooves is configured to at least partially receive the one or more tolerance rings.

[0046] Embodiment 19. The assembly of embodiment 18, wherein the one or more grooves formed in the barrel of the bushing align radially with the one or more grooves in the housing when the barrel of the bushing is received within the housing. Embodiment 20. The assembly of any one of embodiments 16 to 19, wherein the flange of the bushing substantially abuts the housing.

[0047] Embodiment 21. The assembly of any one of embodiments 17 to 20, further comprising: a washer disposed between the flange of the bushing and the housing.

[0048] Embodiment 22. The assembly of any one of embodiments 17 to 21, wherein the tolerance between the barrel of the bushing and the housing is 0%, at least 0.005%, at least 0.01%, at least 0.02%, at least 0.03%, at least 0.04%, at least 0.05%, at least 0.10%, or at least 0.15% of the diameter of the barrel of the bushing.

[0049] Embodiment 23. The assembly of any one of embodiments 17 to 22, wherein the tolerance between the barrel of the bushing and the housing is not greater than 5%, not greater than 4%, not greater than 3%, not greater than 2.5%, not greater than 2%, not greater than 1.5%, not greater than 1%, not greater than 0.75%, not greater than 0.50%, not greater than 0.25%, not greater than 0.20%, not greater than 0.15%, not greater than 0.10%, or not greater than 0.05% of the diameter of the barrel of the bushing.

[0050] Embodiment 24. The assembly of any one of embodiments 1 to 23, wherein the one or more tolerance rings are formed from a metallic material comprising aluminum, beryllium, bronze, copper, iron, magnesium, steel, spring steel, stainless steel, tin, titanium, tungsten, or an alloy thereof.

[0051] Embodiment 25. The assembly of embodiment 24, wherein the one or more tolerance rings comprises a plurality of tolerance rings.

[0052] Embodiment 26. The assembly of embodiment 25, wherein the plurality of tolerance rings are spaced apart along an axial length of the bushing.

[0053] Embodiment 27. The assembly of any one of embodiments 1 to 26, wherein the plurality of projections comprises a plurality of waves, a plurality of fingers, or a combination thereof.

[0054] Embodiment 28. The assembly of embodiment 27, wherein the plurality of waves are disposed in one or more bands circumferentially about the tolerance ring, wherein the plurality of waves are grouped into a plurality of groups of waves, or a combination thereof.

[0055] Embodiment 29. The assembly of embodiment 28, wherein each of the plurality of groups of waves comprises the same number of waves per group.

[0056] Embodiment 30. The assembly of embodiment 28, wherein at least one of the plurality of groups of waves comprises a different number of waves. Embodiment 31. The assembly of any one of embodiments 28 to 30, wherein each of the plurality of groups of waves comprises at least 1, at least 2, at least 3, at least 4, or at least 5 waves per group.

[0057] Embodiment 32. The assembly of any one of embodiments 28 to 31, wherein each of the plurality of groups of waves is divided by one or more flat portions, one or more fingers, or a combination thereof.

[0058] Embodiment 33. The assembly of any one of embodiments 27 to 32, wherein the plurality of waves, the plurality of fingers, or a combination thereof protrude radially inward from the inner surface of the tolerance ring and are in contact with the grooves of the bushing.

[0059] Embodiment 34. The assembly of any one of embodiments 27 to 33, wherein the plurality of waves, the plurality of fingers, or a combination thereof protrude radially outward from the outer surface of the tolerance ring and are in contact with the grooves of the housing.

[0060] Embodiment 35. The assembly of any one of embodiments 1 to 34, further comprising: at least one metallic seal configured to form a fluid tight seal between the bushing and the housing.

[0061] Embodiment 36. The assembly of embodiment 35, wherein the at least one metallic seal comprises a metallic lip seal.

[0062] Embodiment 37. The assembly of any one of embodiments 35 to 36, wherein the at least one metallic seal is integrated into the one or more tolerance rings.

[0063] Embodiment 38. The assembly of any one of embodiments 1 to 37, wherein the plurality of tolerance rings are configured to compensate for a difference in CTE between the stator vane and the bushing, the housing and the bushing, or a combination thereof.

[0064] Embodiment 39. The assembly of any one of embodiments 1 to 38, wherein the plurality of tolerance rings are configured to compensate for a mismatch in tolerances, a misalignment, or a combination thereof between the stator vane and the bushing, the housing and the bushing, or a combination thereof.

[0065] Embodiment 40. The assembly of any one of embodiments 1 to 39, wherein the plurality of tolerance rings are configured to maintain alignment between the between the stator vane and the bushing, the housing and the bushing, or a combination thereof.

[0066] Embodiment 41. The assembly of any one of embodiments 1 to 40, wherein the plurality of tolerance rings are configured to maintain alignment between the between the stator vane and the bushing, the housing and the bushing, or a combination thereof at operating temperatures of at least 350 degrees Celsius, at least 400 degrees Celsius, at least 450 degrees Celsius, at least 500 degrees Celsius, at least 600 degrees Celsius, at least 700 degrees Celsius, at least 800 degrees Celsius, at least 850 degrees Celsius, at least 900 degrees Celsius, at least 950 degrees Celsius, or at least 1000 degrees Celsius under air.

[0067] Note that not all of the activities described above in the general description or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed are not necessarily the order in which they are performed.

[0068] In the foregoing specification, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of invention.

[0069] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0070] Also, the use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

[0071] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

[0072] After reading the specification, skilled artisans will appreciate that certain features are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, references to values stated in ranges include each and every value within that range.

Claims

WHAT IS CLAIMED IS:

1. A variable stator vane assembly, comprising: a movable stator vane; a stator vane housing disposed annularly about the movable stator vane; a bushing disposed in the housing and annularly about the stator vane; and one or more tolerance rings disposed between the housing and the bushing, wherein the one or more tolerance rings comprises a plurality of projections protruding radially inward from an inner surface of the tolerance ring or radially outward from an outer surface of the tolerance ring.

2. The assembly of claim 1, wherein the housing is formed from aluminum, magnesium, carbon steel, stainless steel, titanium, tungsten, an alloy thereof, a carbide thereof, or a polymer composite.

3. The assembly of claim 1, wherein the housing comprises one or more grooves, and wherein each of the one or more grooves is configured to at least partially receive the one or more tolerance rings.

4. The assembly of claim 1, wherein the bushing is formed from a material comprising a coefficient of thermal expansion (CTE) that is greater than or equal to a CTE of the stator vane, the housing, or a combination thereof.

5. The assembly of claim 1, wherein the bushing is formed from a material comprising a polymer, a plastic, a polyimide, a composite, carbon fibers, glass fibers, graphite, or a combination thereof.

6. The assembly of claim 1, wherein the bushing is formed from a material comprising a CTE that is at least 0.1%, at and not greater than 30% of the CTE of the stator vane, the housing, or a combination thereof.

7. The assembly of claim 1, wherein the bushing is formed from a ceramic material comprising aluminum, aluminum nitride, aluminum oxide, boron, boron nitride, chromium, copper, copper oxide, hafnium, silicon, silicon nitride, silicon oxide, tantalum, titanium, titanium nitride, tungsten, yttrium, zircon, zirconium oxide, a composite thereof, or a combination thereof.

8. The assembly of claim 1, wherein the bushing comprises a flange, a barrel extending from the flange, and a central aperture extending through the flange and the barrel.

9. The assembly of claim 8, wherein the barrel of the bushing is received within the housing, and wherein the stator vane is received through the central aperture of the bushing.

10. The assembly of claim 8, wherein the bushing comprises one or more grooves formed in the barrel of the bushing, and wherein each of the one or more grooves is configured to at least partially receive the one or more tolerance rings.

11. The assembly of claim 10, wherein the one or more grooves formed in the barrel of the bushing align radially with the one or more grooves in the housing when the barrel of the bushing is received within the housing.

12. The assembly of claim 10, further comprising: a washer disposed between the flange of the bushing and the housing.

13. The assembly of claim 1, wherein the one or more tolerance rings are formed from a metallic material comprising aluminum, beryllium, bronze, copper, iron, magnesium, steel, spring steel, stainless steel, tin, titanium, tungsten, or an alloy thereof.

14. The assembly of claim 1, wherein the plurality of projections comprises a plurality of waves, a plurality of fingers, or a combination thereof.

15. The assembly of claim 1, further comprising: at least one metallic seal configured to form a fluid tight seal between the bushing and the housing.

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