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 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 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 through-hole penetrating through in the axial direction of shaft, a bearing holder accommodated in the through-hole, a semi-floating metal bearing accommodated in the bearing holder and supporting the shaft inserted into the inside, and a positioning member being inserted into a radial direction of the shaft for both the bearing holder and the semi-floating metal bearing and regulating movement of the semi-floating metal bearing in the axial direction and in a rotating direction of the shaft relative to the bearing holder. For the bearing holder, a press-fit portion to be press-fitted into the through-hole is formed. A gap is formed between at least one of outer circumferential surfaces of both end parts of the bearing holder in the axial direction and the inner circumferential surface of the through-hole.

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: A turbocharger includes: a shaft provided with a small-diameter portion, and two large-diameter portions formed on two sides of the small-diameter portion; and a semi-floating bearing to rotatably support the shaft. The semi-floating bearing includes a cylindrical body into which the shaft is inserted. An inner peripheral surface of the body includes: two bearing surfaces opposed to the large-diameter portions of the shaft; a non-bearing surface located between the two bearing surfaces, having a larger inner diameter than inner diameters of the bearing surfaces; and an oil passage opened to the non-bearing surface to supply lubricant oil to a gap in a radial direction between the non-bearing surface and the shaft. At least one of the two bearing surfaces extends more in an approaching direction of the two bearing surfaces than does the large-diameter portion opposed in the radial direction to the one bearing surface.

Abstract: A bearing structure includes: a bearing hole formed in a bearing housing, a semi-floating metal bearing accommodated in the bearing hole and having a pin hole formed therein; a through-hole formed in the bearing housing and facing the pin hole in the semi-floating metal bearing; a regulating member which is inserted into the through-hole and in which a fixed portion is pressed onto an inner surface of the through-hole for the regulating member to be fixed to the bearing housing at a fixed position where a distal end portion is inserted into the pin hole; a regulating hole opened at a base end in the insertion direction of the regulating member and extending at least to the fixed portion toward the distal end side; and a pressing member provided in the regulating hole to expand the regulating hole by pressing an inner surface of the regulating hole.

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 includes: an outer circumferential groove formed on an outer circumferential surface of a cylindrical portion of a semi-floating metal bearing, and including two opposed surfaces opposed to each other in an axial direction of a shaft and a bottom surface connected to the two opposed surfaces; a radial hole penetrating a wall portion defining the bearing hole so as to communicate with the bearing hole, and facing the outer circumferential groove of the semi-floating metal bearing; a locking member having a body inserted into the radial hole from the outer side of the shaft, wherein at least part of the body is interposed between the two opposed surfaces and fixed to the outer circumferential groove; and an opposed portion provided in the housing, and opposed to the part of the body of the locking member when the locking member is fixed to the outer circumferential groove.

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, 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 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: A turbocharger includes: a turbocharger main body; a bearing hole formed in the turbocharger main body; a turbine shaft rotatably inserted into the bearing hole and having a turbine wheel provided on one end and a compressor wheel provided on the other end; a turbine-side bearing part and a compressor-side bearing part rotatably supporting the turbine shaft and disposed in the bearing hole on a relatively turbine wheel side and on a relatively compressor wheel side, respectively; a cooling oil passage provided radially outside the bearing hole in the turbocharger main body and configured to cool the turbocharger main body with lubricating oil circulated inside; a first oil duct configured to guide lubricating oil after lubricating the compressor-side bearing part to the cooling oil passage; and a second oil duct configured to guide lubricating oil after lubricating the turbine-side bearing part to the cooling oil passage.

Abstract: An wheel fastening inspection method includes: directly or indirectly applying vibration to a turbine shaft to be inserted to a bearing housing, the turbine shaft being provided with wheels at both ends protruding from the bearing housing, at least one of the wheels being fastened by a fastening member, and a rotary member being fastened by a fastening force generated by the fastening member to the turbine shaft to be integrally rotated with the wheel; measuring the vibration of the turbine shaft; and determining whether or not a vibration frequency at which a peak of the measured vibration of the turbine shaft is given is included in a setting range previously set.

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 apposing 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 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 bearing structure includes: a bearing hole formed in a bearing housing, a semi-floating metal bearing accommodated in the bearing hole and having a pin hole formed therein; a through-hole formed in the bearing housing and facing the pin hole in the semi-floating metal bearing; a regulating member which is inserted into the through-hole and in which a fixed portion is pressed onto an inner surface of the through-hole for the regulating member to be fixed to the bearing housing at a fixed position where a distal end portion is inserted into the pin hole; a regulating hole opened at a base end in the insertion direction of the regulating member and extending at least to the fixed portion toward the distal end side; and a pressing member provided in the regulating hole to expand the regulating hole by pressing an inner surface of the regulating hole.

Abstract: A bearing structure includes a through-hole penetrating through in the axial direction of shaft, a bearing holder accommodated in the through-hole, a semi-floating metal bearing accommodated in the bearing holder and supporting the shaft inserted into the inside, and a positioning member being inserted into a radial direction of the shaft for both the bearing holder and the semi-floating metal bearing and regulating movement of the semi-floating metal bearing in the axial direction and in a rotating direction of the shaft relative to the bearing holder. For the bearing holder, a press-fit portion to be press-fitted into the through-hole is formed. A gap is formed between at least one of outer circumferential surfaces of both end parts of the bearing holder in the axial direction and the inner circumferential surface of the through-hole.

Abstract: A bearing structure includes a bearing holder that has a hollow main body and an oil hole penetrating through from an outer circumferential surface to an inner circumferential surface of the main body to thereby guide a lubricating oil to the inside of the main body, and that is fixed in a bearing housing; two full-floating metal bearings that are arranged separated from each other in the axial direction of the shaft and support the shaft, in the bearing holder; two thrust bearing surfaces each arranged on the outside of two full-floating metal bearings in the axial direction of the shaft; and two collars each arranged on the outside of two thrust bearing surfaces in the axial direction of the shaft and provided for the shaft. The lubricating oil lubricates thrust bearing surfaces after lubricating full-floating metal bearings.