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A foil-fluid bearing assembly adapted for supporting a shaft within an outer bearing housing. The foil-fluid bearing assembly comprises a bearing sleeve having an outer surface and an inner circumferential surface diametrically sized to receive the shaft therewithin such that an annular clearance ga

A foil-fluid bearing assembly adapted for supporting a shaft within an outer bearing housing. The foil-fluid bearing assembly comprises a bearing sleeve having an outer surface and an inner circumferential surface diametrically sized to receive the shaft therewithin such that an annular clearance gap, radially defined between an outer surface of the shaft and the inner circumferential surface, is adapted for accommodating fluid therein and axially extends along a substantial portion of a length of the bearing sleeve, and has a foil element disposed therewithin. Compliant bearing supports between the outer surface of the bearing sleeve and the outer bearing housing, comprises at least two independent compliant support elements respectively having a first and a second modulus of elasticity, wherein the first modulus of elasticity is less than the second modulus of elasticity. Angular misalignment capability for the foil-fluid bearing is provided by the compliant support elements.

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1. A foil-fluid bearing assembly adapted for supporting a shaft within an outer bearing housing, the foil-fluid bearing assembly comprising:a bearing sleeve having an outer surface and an inner circumferential surface diametrically sized to receive the shaft therewithin such that an annular clearanc

1. A foil-fluid bearing assembly adapted for supporting a shaft within an outer bearing housing, the foil-fluid bearing assembly comprising:a bearing sleeve having an outer surface and an inner circumferential surface diametrically sized to receive the shaft therewithin such that an annular clearance gap is radially defined between an outer surface of the shaft and the inner circumferential surface, the annular clearance gap adapted for accommodating fluid therein and axially extending along a substantial portion of a length of the bearing sleeve;a foil element disposed within the annular clearance gap;a compliant bearing support contiguously disposed between the outer surface of the bearing sleeve and the outer bearing housing, and permitting elastic deflection of the compliant bearing support, independent of movement of the foil element; andthe compliant bearing support comprising at least two independent compliant support elements respectively having a first and a second modulus of elasticity, wherein the first modulus of elasticity is less than the second modulus of elasticity;whereby angular misalignment capability for the foil-fluid bearing is provided by the compliant bearing support. 2. The foil-fluid bearing as defined in claim 1, wherein the independent compliant support elements include two end supports, axially disposed at opposing ends of the bearing sleeve, and a central support axially located between the end supports. 3. The foil-fluid bearing as defined in claim 2, wherein the central support has the second modulus of elasticity and the two end supports both have the first modulus of elasticity, thereby permitting the bearing sleeve to axially pivot about the central support. 4. The foil-fluid bearing as defined in claim 3, wherein the first modulus of elasticity is low enough to permit deflection of the end supports, but high enough to provide sufficient damping to prevent natural frequency oscillation of the bearing sleeve. 5. The foil-fluid bearing as defined in claim 2, wherein the central support is substantially disposed at the axial midpoint of the bearing sleeve. 6. The foil-fluid bearing as defined in claim 2, wherein the modulus of elasticity of each independent compliant support element is different. 7. The foil-fluid bearing as defined in claim 2, wherein the end supports and the central support are replaceable. 8. The foil-fluid bearing as defined in claim 2, wherein axial location of the compliant central support relative to the compliant end supports can be modified to vary rotational flexibility of the bearing sleeve about an axis substantially perpendicular to a longitudinal :axis of the bearing sleeve. 9. The foil-fluid bearing as defined in claim 1, wherein the foil element substantially extends along the full length of the annular clearance gap. 10. The foil-fluid bearing as defined in claim 1, wherein the foil element comprises at least two foils. 11. The foil-fluid bearing as defined in claim 10, wherein the foil element comprises a radially inner smooth foil and at least one radially outer corrugated foil. 12. The foil-fluid bearing as defined in claim 1, wherein the foil-fluid bearing is an air bearing. 13. The foil-fluid bearing as defined in claim 12, wherein the air bearing is adapted for use in an air cycle machine. 14. The foil-fluid bearing as defined in claim 13, wherein the air cycle machine is adapted for use in an aircraft environmental control system. 15. A foil-fluid bearing assembly adapted for rotatably supporting a shaft within a bearing housing, the foil-fluid bearing assembly comprising:a bearing sleeve having an outer surface and an inner surface defining an inner race, said inner race diametrically sized to receive a rotating shaft therewithin and maintain an annular clearance gap radially between said rotating shaft and said inner circumferential surface, the annular clearance gap axially extending along a substantial portion of a length of the bearing sleeve, the b earing sleeve adapted, in use, to supply a support fluid to substantially fill said annular clearance gap;a foil element circumferentially disposed between said inner race and said shaft;a compliant bearing support disposed between the outer surface of the bearing sleeve and the bearing housing; andthe compliant bearing support having at least two independent compliant support elements, said at least two independent compliant support elements respectively having a first and a second modulus of elasticity, wherein the first modulus of elasticity is less than the second modulus of elasticity. 16. A foil-fluid bearing assembly comprising:a compliantly supported bearing sleeve, radially disposed between a rotating shaft and an outer housing, such that an annular clearance gap, adapted for receiving a support fluid therein, is provided between the rotating shaft and the bearing sleeve;a foil element being radially disposed within the annular clearance gap;the bearing sleeve being compliantly supported within the outer housing by at least two independent compliant supports, radially disposed between the bearing sleeve and the outer housing; andthe two independent compliant supports respectively having a first and second modulus of elasticity, the first modulus of elasticity being less than the second modulus of elasticity. 17. The foil-fluid bearing assembly as defined in one of claims 15 and 16 , wherein the at least two independent compliant supports include a central support having the second modulus of elasticity and opposing end supports having the first modulus of elasticity, thereby permitting the bearing sleeve to axially pivot about the central support. 18. The foil-fluid bearing assembly as defined in one of claims 15 and 16 , wherein the foil-fluid bearing is an air bearing. 19. The foil-fluid bearing assembly as defined in claim 18, wherein the air bearing is adapted for use in one of an air cycle machine and a gas turbine engine. 20. The foil-fluid bearing assembly as defined in claim 19, wherein the air bearing is adapted for use in an aircraft.