Abstract: One embodiment includes a plurality of equally spaced top foils and corrugated springs with one or more shims underneath the trailing edge of each corrugated spring. The corrugated spring forms an underspring for the top foil. Another embodiment incorporates one or more shims at the outer radius region of the corrugated spring in addition to the shim at the trailing edge of the corrugated spring. The shim under the trailing edge of the corrugated spring results in increased load capacity and stability and a decrease in lift-off speed of the rotating thrust disk. The shims located at the outer radii of the corrugated springs result in increased bearing stiffness at the outer region of the compliant foil thrust bearing where the highest pressure occurs.

Abstract: An improved foil thrust bearing includes a pair of members arranged for relative rotation with respect to one another. One of the pair of members is adapted to rotatably support the other. A thrust bearing disk is operatively disposed between the pair of relatively rotatable members. The thrust bearing disk has a plurality of diverging surface ramps. The surface ramps can comprise an inner ramp and an outer ramp. The thrust bearing disk can also comprise a plurality of radial slots. A plurality of separately formed, converging surface compliant foils are disposed on the thrust bearing disk and between the ramps. An underspring element is operatively disposed between the thrust bearing disk and one of the rotatable members, with the underspring element having a plurality of alternating upper and lower ridges.

Abstract: A gas dynamic foil bearing comprises a plate (13) attached to a base (10), support members (14) fixed on the plate (13) at predetermined intervals, elastic foils (15) fixed to the support members (14) at one end thereof to overlap each other, a thrust disk (11) connected to a rotating rotor and placed on the elastic foils (15), and bent springs (17) interposed between the elastic foils (15) and the plate (13) in the overlapping area of the elastic foils (15) for supporting the elastic foils (15).

Abstract: An improved foil thrust bearing having a thrust runner and a thrust plate includes an underspring element positioned adjacent to the thrust plate. The underspring element comprises, in one embodiment, a plurality of alternating first apertures and spring portions, with at least one spring portion having a periodic configuration and comprising a leading edge and a trailing edge. The periodic configuration is defined by a plurality of pitches that vary between the leading and trailing edges. Also defining the periodic configuration is a plurality of periodic elements that vary in longitudinal length between the leading and trailing edges. A thrust bearing disk is disposed intermediate the underspring element and the thrust runner. The disk comprises a plurality of transition areas that provide a stepped configuration to the disk. The transition areas match a plurality of circumferential positions of the first apertures in the underspring.

Abstract: A compliant hydrodynamic fluid film journal bearing for handling high loads. The bearing assembly includes a first thin smooth compliant sheet for facing a shaft, one or more corrugated foils, and a second sheet between the foils and the compliant sheet for supportedly underlying the compliant sheet for preventing sagging of the first sheet between ridges of the foils. A foil element is anchored at a position intermediate its ends to the bearing sleeve whereby both ends thereof are unanchored. A pair of radially outer and inner corrugated foils have outer foil ridges which underlie some inner foil ridges and outer foil furrows which underlie others of the inner foil ridges. A bearing assembly includes a plurality of rows of corrugated foil elements wherein ends of foil elements are offset circumferentially from ends of foil elements in adjacent rows symmetrically from the radial centerplane to provide a herringbone pattern effect.

Abstract: A foil air bearing for a rotatable shaft comprises a plurality of discrete air chambers disposed in a circumferential array. Each of the chambers has a radially displaceable radially inner wall for positioning a bearing foil disposed radially inwardly thereof. A like plurality of valves control the flow of pressurized air to the air chambers, respectively. Sensors respond to radial deflection of the shaft so as to control the flow of pressurized air to the chambers, selectively, thereby to compensate for radial deflection of the shaft.

Abstract: A compliant hydrodynamic fluid film journal bearing for handling high loads. The bearing assembly includes a first thin smooth compliant sheet for facing a shaft, one or more corrugated foils, and a second sheet between the foils and the compliant sheet for supportedly underlying the compliant sheet for preventing sagging of the first sheet between ridges of the foils. A foil element is anchored at a position intermediate its ends to the bearing sleeve whereby both ends thereof are unanchored. A pair of radially outer and inner corrugated foils have outer foil ridges which underlie some inner foil ridges and outer foil furrows which underlie others of the inner foil ridges. A bearing assembly includes a plurality of rows of corrugated foil elements wherein ends of foil elements are offset circumferentially from ends of foil elements in adjacent rows symmetrically from the radial centerplane to provide a herringbone pattern effect.

Abstract: A compliant hydrodynamic fluid film thrust bearing. A circumferential row of sectors of flexible sheets are positioned to face a shaft runner for relative rotation therebetween. The flexible sheets are supported by a flexible membrane which is in turn supported by a pair of rows of corrugated foil elements. Flexible strips are sandwiched between the trailing portions of the flexible sheets and the flexible membrane to provide a tapered/land effect. The corrugated foil elements are supported by a flexible diaphragm which is in turn supported by a row of corrugated support elements which are attached thereto along circumferentially intermediate portions thereof and are aligned with the flexible strips to provide a crowning effect. The ridges of at least one of the pair of rows of corrugated foil elements have truncated apex portions. In one embodiment, ridges in corrugated foil elements of one row thereof underlie only some ridges in the other row, and furrows underlie the other ridges.

Abstract: A follower spring for a foil thrust bearing includes a plate and a plurality of spring tabs extending from the plate. The spring tabs are elongated and offset at angles between approximately 45 degrees and approximately 75 degrees. The spring tabs can be arranged in pairs, with each pair defining a preload force center. The preload force centers can be located midway between a radial width of the plate and equally spaced apart about the plate in a circumferential direction.

Abstract: A journal bearing designed for use with a rotatable shaft of an air cycle machine is disclosed. The bearing includes a journal bearing housing, air bearings for facilitating rotation of the shaft, and a journal bearing shell positioned in the housing. The shell includes a single piece body structure having a first half integral with a second half. The first half includes a first outside end and the second half includes a second outside end. The first half is sufficiently spaced from the second half for supporting and aligning the air bearing for supporting the rotatable shaft. The first and second integral halves define a continuously formed inner diameter adapted to receive the air bearings between the rotatable shaft and the inner diameter for facilitating rotation of the shaft relative to the body structure.

Abstract: A compliant foil fluid film thrust bearing including a thrust disk rotor, fluid foils, spring foils, a thrust plate, and a housing thrust surface The non-rotating but compliant fluid foils, mounted on the thrust plate and/or housing thrust surface and positioned adjacent to the thrust disk, have open faced channels that induce regenerative vortex flow patterns in the process fluid. The multiple spring foils together provide a tilting pad support for the fluid foils but allow them to follow the axial and overturning motion of the thrust disk. The interaction of the tilting pad underspring supports and the circumferential fluid pressure gradients in the process fluid between the fluid foils and the thrust disk rotor assure that the fluid foils will assume hydrodynamically efficient convex shapes on the surfaces adjacent to the rotor regardless of the load applied to the thrust bearing.

Abstract: The present invention provides a foil journal bearing including at least one support pad mounted inside a journal sleeve, and onto which foils are mounted. The support pad is mounted to the journal sleeve in a manner allowing it to tilt in response to foil loading variations and shaft misalignment. The present invention further provides a foil thrust bearing including at least one support pad mounted to a thrust plate and onto which the foils are mounted. The support pad is similarly mounted in a manner allowing it to tilt. The support pads in either configuration may be tapered in thickness to provide an optimized compliant backing for the foils.

Abstract: A foil bearing allows bi-directional rotation of a shaft. The foil bearing includes a plurality of thin compliant foils secured to a housing, and spring segments underlying the foils. Each spring segment has a first stiffness profile in a first zone and a second stiffness profile in a second zone. The first stiffness profile allows rotation in one direction, and the second stiffness profile allows rotation in an opposite direction.

Abstract: A compliant hydrodynamic fluid film journal bearing for handling high loads. The bearing assembly includes a first thin smooth compliant sheet for facing a shaft, one or more corrugated foils, and a second sheet between the foils and the compliant sheet for supportedly underlying the compliant sheet for preventing sagging of the first sheet between ridges of the foils. A foil element is anchored at a position intermediate its ends to the bearing sleeve whereby both ends thereof are unanchored. A pair of radially outer and inner corrugated foils have outer foil ridges which underlie some inner foil ridges and outer foil furrows which underlie others of the inner foil ridges. A bearing assembly includes a plurality of rows of corrugated foil elements wherein ends of foil elements are offset circumferentially from ends of foil elements in adjacent rows symmetrically from the radial centerplane to provide a herringbone pattern effect.

Abstract: A spring assembly for a foil thrust bearing set includes a stiffener disc and a plurality of spring segments. Each spring segment has at least two anchoring tabs. When inserted into a slot in the stiffener disc, the anchoring tabs anchor the spring segment to the stiffener disc.

Abstract: A compliant hydrodynamic fluid film thrust bearing. A circumferential row of sectors of flexible sheets are positioned to face a shaft runner for relative rotation therebetween. The flexible sheets are supported by a flexible membrane which is in turn supported by a pair of rows of corrugated foil elements. Flexible strips are sandwiched between the trailing portions of the flexible sheets and the flexible membrane to provide a tapered/land effect. The corrugated foil elements are supported by a flexible diaphragm which is in turn supported by a row of corrugated support elements which are attached thereto along circumferentially intermediate portions thereof and are aligned with the flexible strips to provide a crowning effect. The ridges of at least one of the pair of rows of corrugated foil elements have truncated apex portions. In one embodiment, ridges in corrugated foil elements of one row thereof underlie only some ridges in the other row, and furrows underlie the other ridges.

Abstract: The top foil (12) of the hydrodynamic fluid film journal bearing (10) carries opposing tabs (23,25) at the side edges adjacent the free end (17) thereof and extends radially outward to fit adjacent to the side edges (19,21) of the intermediate foil 14 and the ends of the key 18 when rolled into a cylinder and inserted into the bore of sleeve (24) to prevent skewing of the top foil. In another embodiment skewing is prevented by incorporating opposing tabs (37,39,50,52) at the free ends (31,54) of the top foil (12a) and intermediate foil (14a) that project through predetermined sized slots (40,42) formed in the side edges (44,46) at the fixed end of intermediate slot (14a). The tabs overlie the side edges of the intermediate foil (14b) and bump foil (15) when rolled into a cylinder and prevent skewing and enhancing journal bearing performance.

Abstract: A hydrodynamic fluid film bearing has a stationary retaining member (12) having a cylindrical opening (14) to receive for rotation therein a rotatable shaft (16). The inner surface (20) of the opening (14) is lined by a generally cylindrical-shaped foil assembly (18) comprised of a plurality of foil sub-assemblies (24) each comprised of spring foils (26), contact foils (30) and, optionally, inner foils (32). Each foil sub-assembly (24) subtends a rotational segment, less than all, of the inner surface (20), e.g., from about 45 degrees to 120 degrees of rotation. The spring foils (26) and contact foils (30) are affixed to the retaining member (12) in such a way that sliding travel of the spring foils (26) along the inner surface (20) is in the opposite rotational direction of sliding travel of the contact foils (30) along the inner surface (20). The foil sub-assemblies (24) may be affixed to the retaining member (12) by means of keyways (22a-22e) within which the foil sub-assemblies (24) are mounted.

Abstract: A bump foil for a compliant foil gas bearing having parallel rows of corrugations or bumps, a first series of bumps of equal height spaced equidistant from one another and a second series of bumps of a lesser height with each bump of the second series disposed between bumps of said first series. The bump foil can be fabricated from metals having a thickness greater than that of conventional bump foils to increase load capacity of the gas bearing without sacrificing compliance required for Coulomb damping.

Abstract: The leading edges of the segmented corrugated springs of each of the two bump foils of a hydrodynamic thrust bearing are offset such that the leading edge in the upper segmented corrugated springs are circumferentially spaced relative to the leading edge of the lower segmented corrugated springs that is underlying each respective segment of the bump foils. In some embodiments the leading edge of the bump foil is attached and the trailing edge is free to move axially and in other embodiments the reverse occurs where the trailing edge of the bump foil is attached and the leading edge is free to move axially.

Abstract: A turbopump which operates at cryogenic temperatures to pump cryogenic liquid fuels to high pressure which includes a rotating group including a shaft mounted turbine to directly drive a multistage pump with the rotating group being supported on process fluid foil journal bearings and a hydrostatic and hydrodynamic hybrid thrust bearing.

Abstract: A method and apparatus for increasing the load capacity and damping capability of a three pad compliant foil gas bearing by establishing a gas pressure force between each pad and a shaft supported by a sleeve containing the bearings.

Abstract: A compliant foil hydrodynamic fluid film radial bearing is disclosed which is comprised of a cylindrical rotor, fluid foil(s), spring foil(s), and a foil retaining cartridge. The cartridge has circumferentially undulating cam shaped lobes or has circumferential ramps and joggles that induce the spring and fluid foils to form converging fluid-dynamic wedge channels which compress and pressurize the process fluid and diverging channels which draw in makeup fluid. A spring foil is formed as a thin, flat sheet having chemically etched slots of a pattern that causes cantilever beams to stand erect and function as springs when the foil is bent to install in the cartridge. When a single foil is used in lieu of a plurality of foils made up of segments, that foil is preloaded away from the rotor by bending stresses in the foil that are induced when the foil is bent to fit into the cartridge.

Abstract: The invention relates to a fluid film bearing, and more particularly the improvement of the load capacity and stability of such a bearing.The fluid film bearing comprises a housing 7 and several bearing sub-assemblies each comprising a flexible leaf 2, a leaf reinforcing element and a support bar (5), the sub-assemblies of the bearing being fixed to the housing by insertion of each bar 5 into a groove provided in the housing. The reinforcing element comprises an upper stiffener 3 secured to the bar of a sub-assembly, and a lower stiffener 4 secued to the bar of an adjacent sub-assembly, the two stiffeners 3 and 4 overlapping on at least one part of one of their faces. The bearing is advantageously provided with a preloading spring 6.The bearing is particularly useful in turbo engines, especially whey they form part of aircraft, more particularly military aircraft.

Abstract: A spring cluster disc (14) for a foil thrust bearing (10) is provided with a plurality of sets (52) of springs (62,64,66). The springs are configured to provide varying spring force and thus varying stiffness in radial and circumferential directions.

Abstract: A spring cluster disc (14) for a foil thrust bearing (10) is provided with a plurality of sets (52) of springs (62,64,66). The springs are configured to provide varying spring force and thus varying stiffness in radial and circumferential directions.

Abstract: A journal bearing including a plurality of individual foils mounted to one of a pair of relatively rotatable members, and a plurality of undersprings which provide resilient support for the foils. The foils include a transition area defined for example by a step, adjacent the trailing edge of the preceding foil. The use of the stepped foil optimizes the geometry of the air gap profile, and thereby increases the load capacity of the journal foil bearing.

Abstract: A disk drive motor having a low profile construction and a gas-lubricated deflecting pad support usable in the disk drive motor and elsewhere.The motor includes a cup-shaped rotor having an integral cylindrical portion extending from the base of the cup; the cylindrical extension may be a shaft or a large hollow extension which encloses the stator windings. The stator can be conventional or can have a closed end and/or a cup-like portion to simplify construction and eliminate the need for a seal. A support mounted on the stator or the rotor supports the rotor for rotation relative to the stator. The support can be a deflecting pad support such as a deflecting pad hydrodynamic bearing or the plane or gas-lubricated deflecting pad support disclosed herein.The gas-lubricated deflecting pad support member includes bearing pads and a support structure which supports the bearings for strictly radial movement. A contoured surface is formed on the pad surfaces or a support surface opposing the pad surfaces or both.

Abstract: A compliant hydrodynamic gas bearing comprises a nonlinear spring arrangement for supporting a plurality of tilting arcuate pads which hydrodynamically carry radial journal loads. The nonlinear spring support arrangement enables the bearing to provide increasing load-deflection capacity under extreme loads to limit deflection to a predetermined clearance. The spring arrangement provides nonlinear load-deflection capabilities while operating with a designed constant bending stress.

Abstract: A high load capacity journal foil bearing and more particularly undersprings therefor. The journal foil bearing preferably includes a number of individual pads or foils which are conventionally mounted to a journal and have a pad face proximate a rotating shaft. The undersprings each include a number of curvilinear support beams or corrugations which are varied in width and pitch to optimize the spring force supporting the overlying foil. The underspring is configured to have wider beams at their leading edge and progressively narrower beams for approximately the first one half of the circumferential length.

Abstract: A compliant bearing surface supported by an enclosed nearly incompressible fluid is described. A fluid supported compliant bearing surface has the ability to separate out the average load on the bearing surface from the local load variations across the surface. The average load is balanced directly by the supporting fluid leaving the compliant surface in a globally balanced condition and thus a able to readily conform in response to local load variations. A fluid supported compliant bearing surface has excellent compliance coupled with high unit load capacity. The applications include a wide range of bearing types from high pressure gas bearings to ball and socket joints. The fundamental elements of the fluid supported bearing surface are based on observations of nature's optimum design--the intervertebral discs of the spine.

Abstract: A foil thrust bearing including a thrust bearing underspring disk having a radially increasing spring force or load capacity. A plurality of spring sections formed in the underspring disk provided improved load capacity and pressure force distribution.

Abstract: The invention relates to a fluid film bearing and to a process for its production.The invention relates to a hydrodynamic fluid film bearing formed between a plurality of sheets (3) fixed to a casing (5) and a shaft (6) in rotation with respect to said casing. The invention has as an object to completely dissociate the control of the radial rigidity of the bearing in the startup phase and that in the rotational phase at working speed.A low rigidity, negligible or zero of the sheets (3) permits limiting the application forces of the sheets against the shaft and thus to reduce the wear upon startup of the bearing. After startup, the rotation of the shaft (6) at the interior of the sheet (3) causes a displacement of the sheets (3) which separate from the shaft (6) by the interposition of a hydrodynamic film of air. The new position occupied by the sheets (3) causes a return of the force of the sheets (3) by the restraining elements (4), as for example of leaf springs (40, 41, 42 or 43).

Abstract: A rotor shaft provided with a fan is rotatably supported by pneumatic bearings for the purpose of high speed rotation with low noise. The rotor shaft provided with the fan can also be supported at one end by a resilient bearing so as to provide high speed rotation even if the concentricity of the bearings is low.

Abstract: A compliant foil bearing comprises a relatively thin bearing foil that is supported in juxtaposed relation to both a shaft and a bearing housing by a pair of sinusoidally folded spacer foils.

Abstract: A hydrodynamic process or gas bearing is disclosed which includes an integral thrust disk defining a plurality of foil elements, the radially outer edge of the disk being displaced from the major bearing surface to form a circumferential step having a varying height profile. The integral thrust disk may in the alternative or in addition, include a plurality of radially outwardly extending tabs to locally increase the flexural rigidity of the disk.

Abstract: A spring support system for a compliant hydrodynamic gas lubricated bearing comprises a plurality of cylindrical spring elements that are retained by floating control rods in circumferential and axially extending arrays for the support of a compliant foil.

Abstract: A hydrodynamic bearing to support and guide a rotating machine shaft is disclosed. This bearing comprises, in the bore of a bearing body, an independent cartridge, designed to form the internal functional set of the bearing, said cartridge consisting of thin, curved foils fixed with respect to one another with overlapping parts, so as to make an independent unit having, firstly, an internal floating surface adapted to being placed around the shaft and to conditioning, during the rotation of the shaft, the formation of a fluid film between the shaft and the internal surface and, secondly, a peripheral external surface with a diameter corresponding to that of the bore of the bearing body. It further has means to immobilize the cartridge inside the bore in rotation and in internal translation. Furthermore, the external surface of the cartridge is surrounded with a flexible foil, fixed by one of its ends on an external generatrix of the cartridge, the other end being free.

Abstract: Cooling is provided for a foil journal bearing by means of flow openings in the individual overlapping foils and/or axially extending slots formed in the high lubricity coating on the surface of the foils.

Abstract: A spring support and Coulomb damping system for a compliant hydrodynamic gas lubricated bearing comprises a plurality of cylindrical spring elements arranged in a circumferential and axially aligned array for the support of a flexible foil.

Abstract: A fluid film foil bearing having a resilient trailing edge support.

Abstract: A self-pressurizing compliant gas thrust bearing includes a resilient support system having a multi-stage spring arrangement for supporting a flexible foil. The compliant and resilient support system enables the bearing to accomodate extreme transient loads, local thermal distortions, shaft misalignment and runout.

Abstract: A self-pressurizing compliant hydrodynamic gas bearing includes a resilient support system having a multi-stage spring arrangement for supporting a flexible foil. The compliant and resilient support system enables the bearing to provide greater load capacity under extreme transient loads while accommodating local thermal distortions, shaft misalignment and runout.

Abstract: Cooling is provided for a foil journal bearing by means of flow openings in the individual overlapping foils without adversely affecting the compliance of the foils.

Abstract: An aerodynamic radial bearing has two foil sections located in a gap between an outer bearing shell (1) and the bearing shaft. The foil sections encircle or loop around the bearing shaft in several layers and include an inner foil section and an outer foil section. Each section may have one or several foil or band portions. The inner foil section closer to the shaft forms the bearing running surface and the outer foil section closer to the shell wall forms a support of predetermined elasticity or desired stiffness. The outer end of the outer foil section is secured to the bearing shell. At least one foil or band portion of the inner foil section is wrapped in opposition to the direction (D) of rotation of the shaft (2) and is connected (at 5, 10 11) to at least one further foil or band portion of the outer foil section which is wrapped in the direction (D) of rotation of the shaft (2).

Abstract: A foil thrust bearing having an underspring formed from a uniform thickness sheet wherein the underspring includes a plurality of arcuate tabs extending toward the thrust disk in the direction of rotation of the thrust runner.

Abstract: A foil thrust bearing having an underspring with alternating upper ridges and lower ridges.

Abstract: A leaf-type foil thrust bearing, such as may be employed in a high-speed, light-load application, particularly, as a thrust bearing for a turbo charger, having a significantly reduced manufacturing cost. A plurality of recesses are formed in a thrust surface of a seat member disposed opposite the bearing surface of a rotating bearing member. The recesses gradually become shallower from their forward edges to the rearward edges in the direction of rotation of the rotating members. Corrugated foils are disposed in each of the recesses, with the corrugation height of each of the foils being constant. Top foils cover the respective corrugated foils, and each of the top foils has a forward edge attached to the thrust surface adjacent the forward edges of each of the recesses.

Abstract: A novel air bearing structure prevents destructive bending moments within the top foil. Welds are eliminated by mounting the top bearing foil in the bearing cartridge sleeve without using a spacer block.Tabs or pins at the end of the top bearing foil are restrained by slots or stops formed in the cartridge sleeve. These structural members are free to move in a direction normal to the shaft while being restrained from movement in the direction of shaft rotation.

Abstract: The invention relates to a foil bearing for high speed rotation such as a turbocharger, a high speed centrifugal separator or the like. The foil bearing according to the present invention can form at least three wedge-shaped spaces between the rotary shaft and the top foil along the direction of rotation of the rotary shaft. The rotary shaft can be supported by at least three portions of air sucked in the wedge-shaped spaces so that when the rotary shaft is rotated at a high speed, the axial center thereof is kept more adjacent to that of the top foil at all times based on the wedge effect by the air.