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 side shoulders 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 method for machining ribs or grooves on a workpiece such as a shaft or an air or gas axial bearing intended to be rotated about a longitudinal axis of a centrifugal compressor. All of the ribs or grooves are obtained at once by the machining tool on a workpiece portion driven such that it rotates, by moving the workpiece or the tool holder in a longitudinal machining direction, the machining tool moving back and forth with a machining position in contact with the workpiece and a position wherein it is not in contact with the workpiece from the start to the end of the workpiece portion. The back-and-forth movements of the machining tool are synchronised with the sinusoidal program set up in the machining unit, as well as with the desired, programmed arrangement of the ribs or grooves to be produced on the workpiece portion.

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 side shoulders 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 sliding surface of a second sliding component is provided with a plurality of second positive pressure generation grooves communicating with a leakage side space, extending in a relative rotation direction of the second sliding component, and having closed terminating end portions, a sliding surface of a first sliding component is provided with a plurality of first positive pressure generation grooves communicating with the leakage side space, extending in a relative rotation direction of the second sliding component, and having closed terminating end portions, and the sliding surface and the sliding surface slide on each other at least in such a manner that the first positive pressure generation grooves and the second positive pressure generation grooves overlap and intersect with each other.

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 side shoulders 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 bearing includes a bearing pad for supporting a rotary component and a housing attached to or formed integrally with the bearing pad. The housing includes a flexible column extending towards the bearing pad for providing the bearing pad with an airflow. The column supports the bearing pad from a location inward of an outer periphery of the bearing pad along an axial direction of the bearing. With such a configuration, a resistance of the bearing pad along a radial direction of the bearing is less at the outer periphery than a resistance of the bearing pad along the radial direction proximate the column.

The present disclosure is directed to a bearing assembly for a gas turbine engine. The bearing assembly includes a bearing housing and a bearing pad for supporting a rotary component of the gas turbine engine. The bearing pad includes at least one gas inlet and a plurality of gas outlets configured on an inner surface thereof. The gas inlet is in fluid communication with the plurality of gas outlets via a gas distribution labyrinth. Further, the gas distribution labyrinth includes a plurality of passageways configured to evenly distribute pressurized gas entering the gas inlet to an interface between the inner surface of the bearing pad and an outer diameter of the rotary component.

A liquid guiding structure for a fluid dynamic pressure bearing, comprising: a fluid dynamic pressure bearing having an inner recess chamber and a liquid guiding trench which is formed between two sides of the inner recess chamber so as to form a circular close liquid guiding structure; wherein the liquid guiding trench includes at least two small V shape paths and at least one large V shape path; the large V shape path is larger than the small V shape paths and is located between the at least two small V shape paths. First angles at tip ends of the at least two small V shape paths are equal. A second angle between connections of the small V shape path and a respective large V shape path is larger than the first angle at tip ends of the at least two small V shape paths.

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 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 side shoulders 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.