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 full-floating bearing includes: an outer peripheral groove having a groove width larger than a value of 0.69, which is a value obtained by subtracting a chamfer width as a width of a chamfered portions in a center axis direction and the groove width as a width of the groove in the center axis direction from a total width being a width of a main body in the center axis direction and dividing a net width by a total width.

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 bearing structure includes: a rotation member including a plurality of extended portions extending radially outward from a shaft portion and arranged separated away from each other in an axial direction of the shaft portion; and a bearing member in which a counterface surface facing one of the plurality of extended portions in the axial direction is included in one or a plurality of main bodies.

Abstract: Provided is a rotating body, including: a shaft; an impeller (compressor impeller) having an insertion hole, which passes through the impeller in an axial direction of the shaft and is configured to receive one end side of the shaft inserted therethrough; an axial-end hole, which is formed in the shaft, is opened at one end of the shaft, and extends to a radially inner side of the insertion hole in the axial direction of the shaft; a radial-expansion member arranged in the axial-end hole; and a tubular wall portion, which forms the axial-end hole, and is configured to press an inner peripheral surface of the insertion hole.

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 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 bearing structure includes: a rotation member including a plurality of extended portions extending radially outward from a shaft portion and arranged separated away from each other in an axial direction of the shaft portion; and a bearing member in which a counterface surface facing one of the plurality of extended portions in the axial direction is included in one or a plurality of main bodies.

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: A full-floating bearing includes: an outer peripheral groove having a groove width larger than a value of 0.69, which is a value obtained by subtracting a chamfer width as a width of a chamfered portions in a center axis direction and the groove width as a width of the groove in the center axis direction from a total width being a width of a main body in the center axis direction and dividing a net width by a total width.

Abstract: Provided is a rotating body, including: a shaft; an impeller (compressor impeller) having an insertion hole, which passes through the impeller in an axial direction of the shaft and is configured to receive one end side of the shaft inserted therethrough; an axial-end hole, which is formed in the shaft, is opened at one end of the shaft, and extends to a radially inner side of the insertion hole in the axial direction of the shaft; a radial-expansion member arranged in the axial-end hole; and a tubular wall portion, which forms the axial-end hole, and is configured to press an inner peripheral surface of the insertion hole.

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: Provided is a mounting structure, including: an impeller including: a main body portion having a through hole; a plurality of blades provided to an outer peripheral surface of the main body portion; and a boss portion, which is a part of the main body portion, and protrudes toward one end side of the shaft with respect to the plurality of blades; a small-diameter portion, which is a part of the shaft; a first large-diameter portion, which is a part of the shaft, is located on another end side of the shaft with respect to the small-diameter portion; and a small-inner-diameter portion of the through hole, which is formed on a radially inner side of the boss portion, and has an inner diameter smaller than an inner diameter of a part of the through hole which is opposed to the first large-diameter portion in a radial direction.

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 provided in a turbocharger body, and configured to rotatably support a turbine shaft in an insertion hole formed in the bearing; and an opposing portion which faces an end surface of the bearing in an axial direction of the turbine shaft. An end-surface guide portion is provided to any one of an opposing surface of the bearing which faces the opposing portion, and an opposing surface of the opposing portion which faces the bearing. The end-surface guide portion configured to make the insertion hole and an outer peripheral edge of the end surface of the bearing in radial directions of the turbine shaft communicate with each other extends forward in a rotational direction of the turbine shaft from a part of the end surface of the bearing which communicates with the insertion hole.

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.