A circumferential seal assembly suitable for forming a thin film between a rotatable runner and a sealing ring is presented. The assembly includes an annular seal housing, a rotatable runner, an annular seal ring, and a plurality of groove structures. Each groove structure includes a groove and an optional feed groove. The groove includes at least two adjoining steps defined by base walls arranged to decrease depthwise. Two adjoining base walls are disposed about a base shoulder. Each base shoulder locally redirects a longitudinal flow to form an outward radial flow in the direction of the annular seal ring. The base walls are bounded by and intersect a pair of side walls. A side wall includes at least one side shoulder which narrows the groove widthwise and locally redirects the longitudinal flow to form a lateral flow in the direction of the other side wall. Outward and lateral flows separately or in combination enhance stiffness of a thin-film layer between the annular seal ring and the rotatable runner.

A gas bearing system has at least one gas bearing (30, 32, 34) with a moving part and a static part and which can be operated in both aero-dynamic and aero-static modes. The system has a source (36) of pressurised gas fluidly connected with the bearing and a control system (134) for regulating the supply of pressurised gas to the bearing in dependence on the rotational speed of the moving part. The system has particular application in a turbocharger (1) where a flow of pressurised gas from the source is introduced into the bearing at the start-up and slow down phases of operation of the turbocharger, the flow being stopped, or reduced, when the turbocharger has reached normal operating speeds.

A gas bearing system has at least one gas bearing (30, 32, 34) with a moving part and a static part and which can be operated in both aero-dynamic and aero-static modes. The system has a source (36) of pressurized gas fluidly connected with the bearing and a control system (134) for regulating the supply of pressurized gas to the bearing in dependence on the rotational speed of the moving part. The system has particular application in a turbocharger (1) where a flow of pressurized gas from the source is introduced into the bearing at the start-up and slow down phases of operation of the turbocharger, the flow being stopped, or reduced, when the turbocharger has reached normal operating speeds.

A sintered metal bearing is formed of a porous body formed through sintering of a compact obtained through compression molding of raw-material power. The sintered metal bearing includes a dynamic pressure generating portion formed on an inner peripheral surface, the dynamic pressure generating portion including dynamic pressure generating groove array regions formed continuously to each other in an axial direction of the sintered metal bearing. The dynamic pressure generating groove array regions each include a plurality of dynamic pressure generating grooves arrayed so as to be inclined with respect to a circumferential direction of the sintered metal bearing. An axial dimension of the sintered metal bearing is set to 6 mm or less, and a density ratio of the sintered metal bearing is set to 80% or more and 95% or less.

A pair of sliding components are disposed at a relatively rotating position at the time of running a rotary machine and formed in an annular shape in which a sealed liquid is present on one side of an inner radial side and an outer radial side and a gas is present on the remaining side thereof. A sliding surface of a sliding component is provided with a dynamic pressure generation groove which communicates with the side of a gas in a radial direction and which is configured to generate a dynamic pressure between the sliding surfaces by the gas at the time of running the rotary machine. A sliding surface of a sliding component is provided with a groove which extends in a circumferential direction.

A hybrid dynamic pressure gas thrust bearing, comprises two outer discs, an inner disc clamped between the two outer discs, and foil type elastic parts arranged between each outer disc and the inner disc; and the two end faces of the inner disc are respectively provided with regular groove-type patterns, and the groove-type pattern in one end face is in mirror symmetry with the groove-type pattern in the other end face. The hybrid dynamic pressure gas thrust provided by the invention has the rigidity characteristic of the high-limit rotating speed of the groove-type dynamic pressure gas thrust bearing, and has the flexible characteristic of the high impact resistance and the load capacity of the foil type dynamic pressure gas thrust bearing, it can meet the application of dynamic pressure gas thrust bearings in ultra high-speed areas under larger loads.

A hybrid dynamic pressure gas radial bearing, which comprises a bearing outer sleeve, an inner sleeve and a foil type elastic part arranged between the bearing outer sleeve and the inner sleeve, the outer circumferential face and the left and right end faces of the bearing inner sleeve are respectively provided with regular groove-type patterns, and the groove-type patterns in one end face is in mirror symmetry with the groove-type pattern in the other end face, and the axial contour lines of the groove-type patterns in the outer circumference face and the radial contour lines of the groove-type patterns in the left and right end faces are in one-to-one correspondence and are connected with each other, has the rigidity characteristic of the high-limit rotating speed of the radial bearing of the groove-type dynamic pressure gas.

An air foil bearing assembly includes: a bearing housing having a hollow into which a rotary shaft is fitted and having a slot formed in an axial direction on an inner circumference surface of the hollow; a bump foil having a bending end engaged to the slot formed at one end portion, rolled in a circumferential direction inside the hollow, and having a free end of another end portion located on the bending end; a top foil having a bending end engaged to the slot formed at one end portion, rolled in a second circumferential direction inside the bump foil, and having a free end of another end portion located on the bending end; and a stopper provided on each of both sides of the top foil in the circumferential direction and preventing the bump foil from protruding radially outwards from the hollow.

An air foil bearing assembly includes: a bearing housing having a hollow into which a rotary shaft is fitted and having a slot formed in an axial direction on an inner circumference surface of the hollow; a bump foil having a bending end engaged to the slot formed at one end portion, rolled in a circumferential direction inside the hollow, and having a free end of another end portion located on the bending end; a top foil having a bending end engaged to the slot formed at one end portion, rolled in a second circumferential direction inside the bump foil, and having a free end of another end portion located on the bending end; and a stopper provided on each of both sides of the top foil in the circumferential direction and preventing the bump foil from protruding radially outwards from the hollow.

A gas bearing system has at least one gas bearing (30, 32, 34) with a moving part and a static part and which can be operated in both aero-dynamic and aero-static modes. The system has a source (36) of pressurised gas fluidly connected with the bearing and a control system (134) for regulating the supply of pressurised gas to the bearing in dependence on the rotational speed of the moving part. The system has particular application in a turbocharger (1) where a flow of pressurised gas from the source is introduced into the bearing at the start-up and slow down phases of operation of the turbocharger, the flow being stopped, or reduced, when the turbocharger has reached normal operating speeds.