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A foil journal bearing applicable to high speed machining and grinding machines for machining microscopic features. A single foil is secured to and supported by a hollow, generally cylindrical, housing. The foil has a length substantially equal to twice the interior circumference of the housing and

A foil journal bearing applicable to high speed machining and grinding machines for machining microscopic features. A single foil is secured to and supported by a hollow, generally cylindrical, housing. The foil has a length substantially equal to twice the interior circumference of the housing and a mounting feature, extending across its width, for engagement with a feature of complementary shape in the housing. One portion of the foil has a length approximately equal to one half of the foil length, and comprises a bump foil and a plurality of regions comprising groups of generally uniformly-spaced ridges and flats, the regions being separated by extended flat regions. The other portion of the foil has a length approximately equal to one half of the foil length, and comprises the top foil and is generally flat and overlies the bump foil which overlies the interior of the housing.

대표청구항 ▼

1. A foil journal bearing comprising a plurality of top foils overlying a like number of bump foils, supported by a hollow, generally cylindrical housing with a length and a cylinder axis and an interior circumference, the bump foils comprising a plurality of ridges and flats oriented generally para

1. A foil journal bearing comprising a plurality of top foils overlying a like number of bump foils, supported by a hollow, generally cylindrical housing with a length and a cylinder axis and an interior circumference, the bump foils comprising a plurality of ridges and flats oriented generally parallel to the cylinder axis; the top foils each having a length, a width generally equal to the length of the housing and two ends, the ends being unsecured, each top foil having a mounting feature, extending across its width, for engagement with one of a plurality of features of complementary shape in the housing;the number of complementary-shaped features in the housing being equal to the number of top foils;the complementary-shaped features being spaced-apart and uniformly distributed around the interior circumference of the housing;the mounting feature of each top foil being located between the ends of the top foil to divide the length of the top foil into a leading segment and a trailing segment;the lengths of the top foils being constructed to ensure that a portion of the leading segment of a first top foil positioned in a first complementary feature overlaps the trailing segment of a second top foil positioned in a second complementary feature immediately adjacent to the first complementary feature;with each bump foil having width generally equal to the width of the top foil and a length generally equal to the length of the leading segment and being positioned under the leading segment and secured to the housing across its width at a single location;wherein the bearing housing is split along a plane containing the cylinder axis of the housing. 2. The foil journal bearing as set forth in claim 1, wherein each bump foil is secured to the housing at the respective complementary-shaped feature of the housing. 3. The foil journal bearing as set forth in claim 1, wherein each bump foil is secured to the housing by a weld. 4. The foil journal bearing as set forth in claim 1, wherein said bump foils are first bump foils, the bearing further comprising a second like number of bump foils which are positioned respectively between the first bump foils and the top foils. 5. The foil journal bearing as set forth in claim 4, wherein the bump foils of each pair of the first and second bump foils are nested with each other. 6. The foil journal bearing as set forth in claim 1, wherein the top foil mounting features comprise longitudinal openings. 7. A foil journal bearing comprising a plurality of top foils overlying a like number of bump foils, supported by a hollow, generally cylindrical housing with a length and a cylinder axis and an interior circumference, the bump foils comprising a plurality of ridges and flats oriented generally parallel to the cylinder axis; the top foils each having a length, a width generally equal to the length of the housing and two ends, the ends being unsecured, each top foil having a mounting feature, extending across its width, for engagement with one of a plurality of features of complementary shape in the housing;the number of complementary-shaped features in the housing being equal to the number of top foils;the complementary-shaped features being spaced-apart and uniformly distributed around the interior circumference of the housing;the mounting feature of each top foil being located between the ends of the top foil to divide the length of the top foil into a leading segment and a trailing segment;the lengths of the top foils being constructed to ensure that a portion of the leading segment of a first top foil positioned in a first complementary feature overlaps the trailing segment of a second top foil positioned in a second complementary feature immediately adjacent to the first complementary feature;with each bump foil having width generally equal to the width of the top foil and a length generally equal to the length of the leading segment and being positioned under the leading segment and secured to the housing across its width at a single location;wherein said bump foils are first bump foils, the bearing further comprising a second like number of bump foils which are positioned respectively between the first bump foils and the top foils; andwherein the bump foils of each pair of the first and second bump foils are constructed and arranged so that ridges of a first bump foil are juxtaposed with flats of the respective second bump foil and ridges of the respective second bump foil are juxtaposed with flats of the first bump foil. 8. The foil journal bearing as set forth in claim 7, wherein the bearing housing is split along a plane containing the cylinder axis of the housing. 9. The foil journal bearing as set forth in claim 7, wherein each bump foil is secured to the housing at the respective complementary-shaped feature of the housing. 10. The foil journal bearing as set forth in claim 7, wherein the top foil mounting features comprise longitudinal openings. 11. A foil journal bearing comprising a plurality of top foils overlying a like number of bump foils, supported by a hollow, generally cylindrical housing with a length and a cylinder axis and an interior circumference, the bump foils comprising a plurality of ridges and flats oriented generally parallel to the cylinder axis; the top foils each having a length, a width generally equal to the length of the housing and two ends, the ends being unsecured, each top foil having a mounting feature, extending across its width, for engagement with one of a plurality of features of complementary shape in the housing;the number of complementary-shaped features in the housing being equal to the number of top foils;the complementary-shaped features being spaced-apart and uniformly distributed around the interior circumference of the housing;the mounting feature of each top foil being located between the ends of the top foil to divide the length of the top foil into a leading segment and a trailing segment;the lengths of the top foils being constructed to ensure that a portion of the leading segment of a first top foil positioned in a first complementary feature overlaps the trailing segment of a second top foil positioned in a second complementary feature immediately adjacent to the first complementary feature;with each bump foil having width generally equal to the width of the respective top foil and a length generally equal to the length of the respective trailing segment and being positioned under the respective trailing segment and secured to the housing across its width at a single location;wherein the bearing housing is split along a plane containing the cylinder axis of the housing. 12. The foil journal bearing as set forth in claim 11, wherein each trailing segment has a trailing edge and wherein the single location at which each bump foil is secured is directly below the trailing edge of the respective trailing segment it underlies. 13. The foil journal bearing as set forth in claim 11, wherein each bump foil is secured to the housing by a weld. 14. The foil journal bearing as set forth in claim 11, wherein each trailing segment has a trailing edge and wherein the single location at which each bump foil is secured is directly below the trailing edge of the respective trailing segment it underlies, and wherein each bump foil is secured to the housing by a weld. 15. The foil journal bearing as set forth in claim 11, wherein said bump foils are first bump foils, the bearing further comprising a second like number of bump foils which are positioned respectively between the first bump foils and the top foils. 16. The foil journal bearing as set forth in claim 15, wherein each pair of the first and second bump foils are nested with each other. 17. The foil journal bearing as set forth in claim 11, wherein the top foil mounting features comprise longitudinal openings. 18. A foil journal bearing comprising a plurality of top foils overlying a like number of bump foils, supported by a hollow, generally cylindrical housing with a length and a cylinder axis and an interior circumference, the bump foils comprising a plurality of ridges and flats oriented generally parallel to the cylinder axis; the top foils each having a length, a width generally equal to the length of the housing and two ends, the ends being unsecured, each top foil having a mounting feature, extending across its width, for engagement with one of a plurality of features of complementary shape in the housing;the number of complementary-shaped features in the housing being equal to the number of top foils;the complementary-shaped features being spaced-apart and uniformly distributed around the interior circumference of the housing;the mounting feature of each top foil being located between the ends of the top foil to divide the length of the top foil into a leading segment and a trailing segment;the lengths of the top foils being constructed to ensure that a portion of the leading segment of a first top foil positioned in a first complementary feature overlaps the trailing segment of a second top foil positioned in a second complementary feature immediately adjacent to the first complementary feature;with each bump foil having width generally equal to the width of the respective top foil and a length generally equal to the length of the respective trailing segment and being positioned under the respective trailing segment and secured to the housing across its width at a single location;wherein said bump foils are first bump foils, the bearing further comprising a second like number of bump foils which are positioned respectively between the first bump foils and the top foils; andwherein the bump foils of each pair of the first and second bump foils are constructed and arranged so that ridges of a first bump foil are juxtaposed with flats of the respective second bump foil and ridges of the respective second bump foil are juxtaposed with flats of the first bump foil. 19. The foil journal bearing as set forth in claim 18, wherein the bearing housing is split along a plane containing the cylinder axis of the housing. 20. The foil journal bearing as set forth in claim 18, wherein each trailing segment has a trailing edge and wherein the single location at which each bump foil is secured is directly below the trailing edge of the respective trailing segment it underlies.