Abstract: A semi-floating bearing (multi-lobe bearing) includes a radial bearing surface that is formed on an inner circumferential surface of a body, and that includes a plurality of arcuate surfaces having mutually different centers of curvature and arranged adjacent to each other in a circumferential direction of the body; and axial grooves formed on the radial bearing surface and extending in an axial direction of the shaft, a center position of the axial groove in the circumferential direction being located at a position spaced apart rearwardly from a boundary portion between the plurality of arcuate surfaces in the circumferential direction of the shaft within an area from the boundary portion to a central position of the arcuate surfaces in the circumferential direction.

Abstract: A semi-floating bearing (multilobe bearing) including: an annular main body through which a shaft is inserted; and a radial bearing surface formed on an inner peripheral surface of the main body, the radial bearing surface including a plurality of arc surfaces having different curvature centers and disposed adjacent to each other in a circumferential direction of the main body, and a minimum distance Ra between a central axis of the shaft and the arc surface, a curvature radius Rb of the arc surface, and a radius Rs of the shaft satisfying relationships expressed by the following Formulas (1) and (2). Ra/Rs?1.001 . . . (1), (Rb?Ra)/0.9?(Rb?Rs)?(Rb?Ra)/0.6 . . . (2) provided that Ra is the minimum distance between the central axis of the shaft and the arc surface, Rb is the curvature radius of the arc surface, and Rs is the radius of the shaft.

Abstract: A bearing structure includes: a shaft provided with a turbine impeller; a pair of rolling bearings accommodated in a bearing hole and each including: an inner ring provided to the shaft; and an outer ring having a damper portion formed on an outer periphery of the outer ring; an opposing surface opposed to, from a turbine impeller side, a lateral surface of the outer ring of the rolling bearing provided on the turbine impeller side; and a first oil supply groove formed in the opposing surface and opposed to at least the damper portion and the lateral surface of the outer ring.

Abstract: A turbocharger includes ball bearings each including an inner ring and an inner ring mounted to a shaft, and an outer ring and an outer ring provided so as to be relatively rotatable in a bearing hole, and damper portions formed in at least one of outer peripheral surfaces of the outer ring and the outer ring and opposed surfaces of inner peripheral surface of the bearing hole opposed to the outer peripheral surfaces of the outer ring and the outer ring.

Abstract: A semi-floating bearing (multi-lobe bearing) includes a radial bearing surface that is formed on an inner circumferential surface of a body, and that includes a plurality of arcuate surfaces having mutually different centers of curvature and arranged adjacent to each other in a circumferential direction of the body; and axial grooves formed on the radial bearing surface and extending in an axial direction of the shaft, a center position of the axial groove in the circumferential direction being located at a position spaced apart rearwardly from a boundary portion between the plurality of arcuate surfaces in the circumferential direction of the shaft within an area from the boundary portion to a central position of the arcuate surfaces in the circumferential direction.

Abstract: Provided is a bearing structure including a recess portion, which is formed in at least one of a first opposed surface of a positioning pin or a second opposed surface of a through hole, and is recessed in a separating direction in which the first opposed surface and the second opposed surface separate apart from each other.

Abstract: Provided is a bearing structure, including: a damper groove formed in at least one of an outer peripheral surface of an outer ring of a rolling bearing or an inner peripheral surface of a bearing hole so as to extend in a circumferential direction of a shaft; and a second oil drain hole having one end communicating with the damper groove, and another end opened to an outside of a cylindrical portion.

Abstract: A turbocharger includes: a bearing; a bearing wall portion having a bearing hole in which the bearing is arranged; a separation wall portion, which is provided on a radially outer side of the bearing hole with respect to the bearing wall portion, and forms an internal space with the bearing wall portion; an oil discharge port, which is formed in the separation wall portion, and communicates with the internal space; and a guide portion, which is provided to the bearing wall portion facing the internal space, and separates away from the oil discharge port in a direction of a plane perpendicular to a center axis of the bearing as approaching the oil discharge port in a direction of the center axis.

Abstract: A bearing structure includes: a shaft provided with a turbine impeller; a pair of rolling bearings accommodated in a bearing hole and each including: an inner ring provided to the shaft; and an outer ring having a damper portion formed on an outer periphery of the outer ring; an opposing surface opposed to, from a turbine impeller side, a lateral surface of the outer ring of the rolling bearing provided on the turbine impeller side; and a first oil supply groove formed in the opposing surface and opposed to at least the damper portion and the lateral surface of the outer ring.

Abstract: Provided is a bearing structure, including: a damper groove formed in at least one of an outer peripheral surface of an outer ring of a rolling bearing or an inner peripheral surface of a bearing hole so as to extend in a circumferential direction of a shaft; and a second oil drain hole having one end communicating with the damper groove, and another end opened to an outside of a cylindrical portion.

Abstract: Provided is a bearing structure including: a shaft; a first opposed surface, which is formed on the shaft or a member mounted to the shaft; a first bearing portion, which is opposed to the first opposed surface from one end side of the shaft; a second opposed surface, which is formed on the shaft or the member mounted to the shaft, and is positioned on the one end side of the shaft with respect to the first opposed surface and the first bearing portion; and a second bearing portion, which is opposed to the second opposed surface from the one end side of the shaft.

Abstract: Provided is a bearing structure including a recess portion, which is formed in at least one of a first opposed surface of a positioning pin or a second opposed surface of a through hole, and is recessed in a separating direction in which the first opposed surface and the second opposed surface separate apart from each other.

Abstract: A bearing structure S includes: a bearing hole formed in a housing; a main body portion of a bearing provided in the bearing hole and inserted with a shaft therethrough; damper surface and provided on an outer circumferential surface of the main body portion, the damper surface facing an inner circumferential surface of the bearing hole; thrust surface provided at end portions of the main body portion in an axial direction of the shaft; and thrust back surface portions provided in the main body portion and having an outer diameter larger than those of the damper surface, the thrust back surface portions spaced apart from the damper surface by a distance farther than a distance between each of the damper surface and the inner circumferential surface of the bearing hole and positioned on back sides of the thrust surface.

Abstract: A bearing structure includes: a housing; a bearing hole, which is formed in the housing, and receives a bearing configured to axially support a shaft having one end provided with an impeller; a clearance groove, which is formed in an inner circumferential surface of the bearing hole, and communicates with a passage formed on a lower side of the shaft; and an inclined portion formed on an inner wall surface of the clearance groove, which is positioned at least above the shaft.

Abstract: A turbocharger includes: a bearing; a bearing wall portion having a bearing hole in which the bearing is arranged; a separation wall portion, which is provided on a radially outer side of the bearing hole with respect to the bearing wall portion, and forms an internal space with the bearing wall portion; an oil discharge port, which is formed in the separation wall portion, and communicates with the internal space; and a guide portion, which is provided to the bearing wall portion facing the internal space, and separates away from the oil discharge port in a direction of a plane perpendicular to a center axis of the bearing as approaching the oil discharge port in a direction of the center axis.

Abstract: A turbocharger includes: a bearing housing (housing); a bearing disposed in the housing and having a thrust bearing surface; and a partition wall portion assembled to the housing, the partition wall portion including an inclined surface positioned on an outer side in a radial direction of the thrust bearing surface, extending at least vertically above the thrust bearing surface, and inclined with respect to a direction perpendicular to the axial direction of a shaft.

Abstract: A bearing structure includes: a housing; a bearing hole formed in the housing and provided with a bearing for pivotally supporting a shaft; a clearance groove provided in the bearing hole, having an opposing wall portion radially opposed to the shaft, and communicating with an oil drainage passage provided below a shaft center of the shaft; and at least one of a narrow portion or a wide portion in the opposing wall portion of the clearance groove with a boundary right above the shaft center of the shaft, the narrow portion provided in a rear side in a rotation direction of the shaft, the narrow portion having a narrower gap from the shaft than that in a front side in the rotation direction of the shaft, the wide portion provided in the front side in the rotation direction of the shaft, the wide portion having a wider gap from the shaft than that in the rear side in the rotation direction of the shaft.

Abstract: A bearing structure includes: a housing; a bearing hole formed in the housing; a bearing, which is provided in the bearing hole, and is configured to axially support a shaft having one end provided with a turbine impeller; a space, which is formed in the housing, and is positioned between the impeller and the bearing hole; a passage, which communicates with the space, and extends to a vertically lower side of the bearing hole; a communication opening portion, which allows the passage and the bearing hole to communicate with each other; and a lower wall portion, which is provided in a lower portion including a portion directly below an axis of the shaft between the passage and the bearing hole, and has an inner wall surface being opposed to the shaft and having a curved surface shape with a curvature center positioned on the shaft side.

Abstract: Provided is a bearing structure including: a shaft; a first opposed surface, which is formed on the shaft or a member mounted to the shaft; a first bearing portion, which is opposed to the first opposed surface from one end side of the shaft; a second opposed surface, which is formed on the shaft or the member mounted to the shaft, and is positioned on the one end side of the shaft with respect to the first opposed surface and the first bearing portion; and a second bearing portion, which is opposed to the second opposed surface from the one end side of the shaft.

Abstract: A turbocharger includes: a bearing housing (housing); a bearing disposed in the housing and having a thrust bearing surface; and a partition wall portion assembled to the housing, the partition wall portion including an inclined surface positioned on an outer side in a radial direction of the thrust bearing surface, extending at least vertically above the thrust bearing surface, and inclined with respect to a direction perpendicular to the axial direction of a shaft.