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.

Provided is a foil air bearing having a herringbone pattern to sustain a load of a rotor rotating in a predetermined rotation direction around a center line, the foil air bearing including an upper top foil disposed to face a surface of the rotor, a middle top foil disposed under the upper top foil, a lower top foil disposed under the middle top foil, a bump foil provided as an elastically deformable member and disposed under the lower top foil, and a plurality of slots provided as holes penetrating from an upper surface to a lower surface of the middle top foil, and extending along a lengthwise direction forming a predetermined angle with a rotation direction of the rotor, wherein the upper top foil is deformed in a downward concave shape at locations corresponding to the slots due to air pressure generated by rotation of the rotor, so as to form a herringbone pattern. As such, a herringbone pattern satisfying design requirements may be easily formed and an overall manufacturing cost may be reduced by forming the slots through pressing without using etching or welding.

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 gas dynamic bearing includes a shaft extending along a central axis extending vertically, and a sleeve with a hole opening at least at one end of the sleeve in an axial direction, at least a portion of the shaft housed inside the hole. The sleeve includes dynamic pressure grooves in an inner peripheral surface of the hole. The shaft includes a core portion, and a protective portion that is disposed on an outer peripheral surface of the core portion and that includes at least a portion facing the inner peripheral surface of the hole in a radial direction. The protective portion includes a first protective portion and a second protective portion. The first protective portion is at least above or below the second protective portion in the axial direction, and includes at least a portion with a thickness in the radial direction more than a thickness of the second protective portion in the radial direction.

A radial force support apparatus includes: a shaft coupled to an impeller and configured to rotate together with the impeller; and a foil radial bearing supporting the shaft. The foil radial bearing includes a top foil disposed on an inner circumferential surface of the foil radial bearing and facing at least a part of an outer circumferential surface of the shaft, and the shaft facing the top foil includes at least one groove provided on the outer circumferential surface of the shaft.

A gas dynamic pressure bearing includes a shaft centered on a central axis extending in an up-down direction, and a sleeve that faces at least a portion of the shaft in a radial direction. The portion in which the sleeve and the shaft face each other in the radial direction includes a first dynamic pressure portion at each of both ends in the axial direction, and a second dynamic pressure portion between the first dynamic pressure portions. In the first dynamic pressure portion, one of the sleeve and the shaft includes dynamic pressure grooves arranged in a circumferential direction. A sum of center angles of groove widths of the dynamic pressure grooves in a cross-section cut along a plane orthogonal to the central axis is about 144 or more and about 216 or less.

A radial force support apparatus includes: a shaft coupled to an impeller and configured to rotate together with the impeller; and a foil radial bearing supporting the shaft. The foil radial bearing includes a top foil disposed on an inner circumferential surface of the foil radial bearing and facing at least a part of an outer circumferential surface of the shaft, and the shaft facing the top foil includes at least one groove provided on the outer circumferential surface of the shaft.

A gas dynamic bearing includes a shaft extending along a central axis extending vertically, and a sleeve with a hole opening at least at one end of the sleeve in an axial direction, at least a portion of the shaft housed inside the hole. The sleeve includes dynamic pressure grooves in an inner peripheral surface of the hole. The shaft includes a core portion, and a protective portion that is disposed on an outer peripheral surface of the core portion and that includes at least a portion facing the inner peripheral surface of the hole in a radial direction. The protective portion includes a first protective portion and a second protective portion. The first protective portion is at least above or below the second protective portion in the axial direction, and includes at least a portion with a thickness in the radial direction more than a thickness of the second protective portion in the radial direction.

A gas dynamic pressure bearing includes a shaft centered on a central axis extending in an up-down direction, and a sleeve that faces at least a portion of the shaft in a radial direction. The portion in which the sleeve and the shaft face each other in the radial direction includes a first dynamic pressure portion at each of both ends in the axial direction, and a second dynamic pressure portion between the first dynamic pressure portions. In the first dynamic pressure portion, one of the sleeve and the shaft includes dynamic pressure grooves arranged in a circumferential direction. A sum of center angles of groove widths of the dynamic pressure grooves in a cross-section cut along a plane orthogonal to the central axis is about 144 or more and about 216 or less.

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.