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A bushing and washer forming a bearing assembly at the outer radial end of a stator vane, the outer bearing assembly, and the bearing assembly at the inner radial end of the stator vane, the inner bearing assembly, that facilitate durability, effectiveness and reduced cost. Both the inner and outer

A bushing and washer forming a bearing assembly at the outer radial end of a stator vane, the outer bearing assembly, and the bearing assembly at the inner radial end of the stator vane, the inner bearing assembly, that facilitate durability, effectiveness and reduced cost. Both the inner and outer bearing assemblies are designed to rotate relative to the vane shaft and the respective mating shroud or case to even out the wear around the circumference of the bushing. When a rotating bushing is used, a flange on the bushing is designed to be positioned on the inside of the case, so that a pressure differential across the case applies a force to the vane to move it outwardly against the flange and the flange against the case, thereby minimizing air leakage.

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1. A bearing assembly for rotatively positioning a variable vane to an engine casing comprising a bushing wherein a first surface of the bushing contacts a variable vane stem; a second opposed surface of the bushing contacts the engine casing, and, upon installation of the bushing, the bushing rotat

1. A bearing assembly for rotatively positioning a variable vane to an engine casing comprising a bushing wherein a first surface of the bushing contacts a variable vane stem; a second opposed surface of the bushing contacts the engine casing, and, upon installation of the bushing, the bushing rotates relative to the variable vane stem and engine casing.2. The bearing assembly of claim 1 wherein a rotating bushing clearance is sized to effectively minimize air leakage past the bushing over an engine operating regime.3. The bearing assembly of claim 1 wherein the bushing further includes a surface positioned such that a pressure differential across the engine casing urges a vane assembly against the bushing, which in turn urges the bushing against an inside wall of the engine casing, thereby closing an air leakage path.4. The bearing assembly of claim 1 further comprising a first washer, wherein the first washer provides the engine casing a bearing surface, and the bearing surface is prevented from riding up on a filet of the vane stem.5. The bearing assembly of claim 1 wherein the bushing comprises a first horizontal portion in contact with a recessed portion of the casing and second vertical portion substantially at a right angle to the first portion, the second portion positioned between a substantially vertical portion of the casing and a substantially vertical surface of the vane stem.6. The bearing assembly of claim 5 wherein the bushing comprises two separate components, a washer portion wherein the washer portion is in contact with a recessed portion of the casing, and a bushing portion substantially at a right angle to the washer portion, the bushing portion positioned between the substantially vertical portion of the casing and the substantially vertical portion of the vane stem.7. The bearing assembly of claim 6 wherein the washer portion is prevented from riding up on a filet of the vane stem.8. The bearing assembly of claim 1 wherein the rotating bushing is a soft material that wears in relationship to the a harder variable vane stem.9. The bearing assembly of claim 8 wherein the bushing is further comprised of silicon nitride.10. The bearing assembly of claim 9 wherein the silicon nitride bushing has a thickness of at least about 0.050 inches.11. The bearing assembly of claim 8 wherein the bushing is further comprised of zirconium oxide.12. The bearing assembly of claim 11 wherein the zirconium oxide bushing has a thickness of at least about 0.050 inches.13. The bearing assembly of claim 1 wherein the wear rate of the bushing with respect to the vane stem is less than about 0.0002 inches after an effective wear distance of about 50,000 feet.14. A variable vane assembly for a gas turbine engine comprising:a variable vane, the vane including a first vane stem at a first vane end and a second vane stem at a second, opposing vane end positioned radially inward toward a center line of the engine;a first bearing assembly for rotatively positioning the first vane stem within an outer engine casing; a second bearing assembly for rotatively positioning the second vane stem within an inner engine shroud; and a lever arm fixedly attached to the first vane stem for variably altering an angular orientation of a vane airfoil; the first bearing assembly having a first bushing with an inner diameter wherein the inner diameter of the bushing contacts the first vane stem at the first vane end, and the outer diameter of the bushing contacts the outer engine casing, the bushing preventing contact between the outer engine casing and the first vane stem, the bushing providing a wear surface as the variable vane assembly is moved from a first position to a second position; the second bearing assembly having a second bushing with an inner diameter wherein the inner diameter of the bushing contacts the second vane stem at the second end positioned radially inward from the first vane end, and the outer diameter of the bushing contacts the outer engine casing, the bushing preventing contact between a seal and the second vane stem, the bushing providing a wear surface as the variable vane assembly is moved from a first position to a second position; and wherein at least one of the first bushing and the second bushing rotates relative to its respective vane stem. 15. The variable vane assembly of claim 14 wherein both the first bushing rotates relative to its vane stem and outer engine casing, and second bushing rotate relative to its vane stem and seal.16. The variable vane assembly of claim 14 wherein the vane further includes an axial bearing face having preselected diameter adjacent each vane stem.17. The variable vane assembly of claim 16 wherein at least one of each axial bearing face is fabricated with an effectively larger preselected bearing contact outer diameter when the vane is a harder, less wearing material than the bushing and wherein the bushing is designed to wear, being constructed of a softer material.18. The variable vane assembly of claim 17 wherein the bushing material is selected from the group consisting of a soft metal, a polymeric material, a carbon/graphite material, a ceramic material and a composite material.19. The variable vane assembly of claim 17 wherein the bushing material is selected from the group consisting of a ceramic cemented carbon material and a cemented carbide material.20. The variable vane assembly of claim 16 wherein at least one of each axial bearing face is fabricated with an effectively smaller preselected bearing contact outer diameter when the vane is a softer, wear-type material than the bushing and wherein the bushing is designed not to wear, being constructed of harder, wear resistant materials and not to rotate so as to minimize fretting of the axial bearing face.21. The variable vane assembly of claim 20 wherein the bushing material is selected from the group consisting of carbide materials, ceramic materials and substrate materials coated with carbide materials and ceramic materials.22. The variable vane assembly of claim 14 wherein the lever arm includes a bearing face having preselected diameter that bears against the first bushing of the first bearing assembly, wherein the preselected diameter of the bearing face is of an effectively larger preselected outer diameter for harder, less wearing materials when the bushing is designed to wear and is constructed of softer materials, and of an effectively smaller preselected outer diameter for softer wearing materials when the bushing is designed not to wear and is constructed of harder, wear-resistant materials so as to minimize fretting of the lever arm bearing face.23. The variable vane assembly of claim 14 wherein the second bearing assembly further includes a shroud, the bushing preventing contact between the second vane stem and the shroud, the second bearing assembly being captured by the shroud, the shroud located to minimize vibrational effects of airflow variation and leakage.