초록 ▼

A bearing foil assembly includes a top foil, an intermediate foil, and a bump foil. The bump foil is provided with corrugations at circumferentially spaced locations. The bump foil has an end that is bent radially outwardly from a center of the foil assembly. The top foil has a bent portion extendin

A bearing foil assembly includes a top foil, an intermediate foil, and a bump foil. The bump foil is provided with corrugations at circumferentially spaced locations. The bump foil has an end that is bent radially outwardly from a center of the foil assembly. The top foil has a bent portion extending radially outwardly and adjacent to the bent end of the bump foil. A first radius of curvature is defined to a curved portion leading into the bent portion at a first end adjacent to the bent end. A second radius of curvature is defined at an end of the bent portion on an end opposed to the bent end. A ratio of the first radius of curvature to the second radius of curvature is between 0.6 and 10. A bearing assembly, a shaft sub-assembly, an air machine, and a method of assembling a bearing into an air machine are also disclosed.

대표청구항 ▼

1. A bearing foil assembly comprising: a top foil, an intermediate foil, and a bump foil, said bump foil being provided with corrugations at circumferentially spaced locations about a center axis, said bump foil having a bent end that is bent radially outwardly from the center axis;said top and inte

1. A bearing foil assembly comprising: a top foil, an intermediate foil, and a bump foil, said bump foil being provided with corrugations at circumferentially spaced locations about a center axis, said bump foil having a bent end that is bent radially outwardly from the center axis;said top and intermediate foils having a bent portion extending radially outwardly and adjacent to said bent end of said bump foil, and there being a first radius of curvature to a curved portion of the bent portion at a first end adjacent to said bent end, and a second radius of curvature at an end of said bent portion on an end opposed to said bent end, with a ratio of said first radius of curvature to the second radius of curvature being between 0.6 and 10;a pitch distance of the corrugations in the bump foil is defined, and a ratio of the pitch distance to a radius of a shaft which is to be supported within the foil assembly is between 0.25 and 0.70;a ratio of said pitch distance to a thickness of said bump foil is between 25 and 60;a wedge step distance is defined between the top and intermediate foils, a ratio of the pitch distance to the wedge step distance is between 6 and 17; anda ratio of the first radius of curvature to the radius of the shaft that is to be supported within the foil assembly is between 0.02 and 0.08. 2. The bearing foil assembly as set forth in claim 1, wherein the ratio of said first radius of curvature to the second radius of curvature being between 0.6 and 4. 3. A bearing assembly comprising: a sleeve defining a radially inner surface, said sleeve having a key slot;a foil assembly received within the radially inner surface, the foil assembly comprising a top foil, an intermediate foil, and a bump foil, said bump foil being provided with corrugations at circumferentially spaced locations about a center axis, said bump foil having a bent end that is bent radially outwardly from the center axis and into the key slot, said top and intermediate foils having a bent portion extending radially outwardly into the key slot, and there being a first radius of curvature to a curved portion of the top foil leading into the bent portion at a first end adjacent to said bent end, and a second radius of curvature at an end of said bent portion on an end opposed to said bent end, with a ratio of said first radius of curvature to the second radius of curvature being between 0.6 and 10;a pitch distance of the corrugations in the bump foil is defined, and a ratio of the pitch distance to a radius of a shaft which is to be supported within the foil assembly is between 0.25 and 0.7;a ratio of said pitch distance to a thickness of said bump foil is between 25 and 60;a wedge step distance is defined between the top and intermediate foils, a ratio of the pitch distance of the corrugation of the bum foil to this is between 6 and 17; anda ratio of the first radius of curvature to the radius of the shaft that is to be supported within the foil assembly is between 0.02 and 0.08. 4. The bearing assembly as set forth in claim 3, wherein the ratio of said first radius of curvature to the second radius of curvature being between 0.6 and 4. 5. A shaft sub-assembly comprising: a shaft supported within a journal sleeve, said journal sleeve including a foil assembly intermediate an outer periphery of said shaft and an inner periphery of said journal sleeve, said journal sleeve also including a key slot;the foil assembly including a top foil, an intermediate foil, and a bump foil, the bump foil including a plurality of circumferentially spaced corrugations, and the bump foil having a bend end received within said key slot, said top and intermediate foils having a bent portion extending radially outwardly into said key slot, and there being a first radius of curvature to a curved portion of the bent portion at a first end adjacent to said bent end, and a second radius of curvature at an end of said bent portion on an end opposed to said bent end, with a ratio of said first radius of curvature to the second radius of curvature being between 0.6 and 10;a pitch distance of the corrugations in the bump foil is defined, and a ratio of the pitch distance to a radius of the shaft is between 0.25 and 0.7;a ratio of said pitch distance to a thickness of said bump foil is between 25 and 60, and a ratio of the first radius of curvature to the radius of the shaft is between 0.02 and 0.08; anda wedge step distance is defined between the top and intermediate foils, a ratio of the pitch distance of the corrugation of the bump foil to this wedge step is between 6 and 17. 6. The shaft sub-assembly as set forth in claim 5, wherein the ratio of said first radius of curvature to the second radius of curvature being between 0.6 and 4. 7. An air machine comprising: a compressor rotor, said compressor rotor being connected to rotate with a turbine rotor, an outlet of said compressor rotor passing at least a portion of air over the turbine rotor;a shaft rotating with the turbine rotor and supported within a journal sleeve, said journal sleeve including a foil assembly intermediate an outer periphery of said shaft and an inner periphery of said journal sleeve, said journal sleeve also including a key slot;the foil assembly including a top foil, an intermediate foil, and a bump foil, the bump foil including a plurality of circumferentially spaced corrugations, and the bump foil having a bend end received within said key slot, said top and intermediate foils having a bent portion extending radially outwardly into said key slot, and there being a first radius of curvature to a curved portion of the bent portion at a first end adjacent to said bent end, and a second radius of curvature at an end of said bent portion on an end opposed to said bent end, with a ratio of said first radius of curvature to the second radius of curvature being between 0.6 and 10;a pitch distance of the corrugations in the bump foil is defined, and a ratio of the pitch distance to a radius of the shaft is between 0.25 and 0.7;a ratio of said pitch distance to a thickness of said bump foil is between 25 and 60;a ratio of the first radius of curvature to the radius of the shaft is between 0.02 and 0.08; anda wedge step distance is defined between the top and intermediate foils, a ratio of the pitch distance of the corrugation of the bump foil to this wedge step is between 6 and 17. 8. The air machine as set forth in claim 7, wherein the ratio of said first radius of curvature to the second radius of curvature being between 0.6 and 4. 9. A method of assembling a bearing into an air machine comprising the steps of: inserting a bearing sleeve, the bearing sleeve having a foil assembly including a top foil, an intermediate foil and a bump foil in an inner periphery of the bearing sleeve, said bump foil having a bend end that is bent radially outwardly into a key slot in the bearing sleeve, and said top and intermediate foils having a bent portion extending radially outwardly, and positioned in said key slot, and there being a first radius of curvature to a curved portion leading into the bend portion at a first end adjacent to said bend end, and a second radius of curvature of an end of said bent portion on an end opposed to said bend end, with a ratio of said first radius of curvature to the second radius of curvature being between 0.6 and 10;a pitch distance of the corrugations in the bump foil is defined, and a ratio of the pitch distance to a radius of the shaft is between 0.25 and 0.7;a ratio of said pitch distance to a thickness of said bump foil is between 25 and 60;a ratio of the first radius of curvature to the radius of the shaft is between 0.02 and 0.08; anda wedge step distance is defined between the top and intermediate foils, a ratio of the pitch distance of the corrugation of the bump foil to this wedge step is between 6 and 17. 10. The method as set forth in claim 9, wherein the ratio of said first radius of curvature to the second radius of curvature being between 0.6 and 4.