A turbocharger is of reduced size and easy to assemble. A rotor blade upstream flow channel space has a cylindrical portion that is gradually reduced in the downstream direction of exhaust gas flow corresponding with a reduction in volume of the scroll chamber. A back plate is formed so as to swell out toward the rotor blade gradually in the downstream direction corresponding with the reduction in volume of the scroll chamber. The back plate, at a termination end thereof, approaches the rotor blade and reaches a position adjacent to a leading edge of the rotor blade whereby the flow channel space disappears substantially at this termination end.

A valve body includes an arm inserted portion that accommodates a part of a valve arm. A relation of hx<h1 is satisfied, provided that: a surface of the valve body that is in contact with a valve seat when an opening/closing valve closes a passing hole is a sealing surface; the valve arm and the opening/closing valve are in contact with each other on a contact surface when the opening/closing valve closes the passing hole; a surface of the contact surface that is the closest to the sealing surface is a valve-closed contact surface; hx is a size of thickness from the sealing surface to the valve-closed contact surface; and h1 is a size of thickness of the valve body.

Turbine housing assemblies and related fabrication methods are provided. A turbine housing assembly includes a bearing flange, a tongue member, a first sheet metal structure providing an inner contour of an inlet passage and joined to the tongue member, and a second sheet metal structure including an inlet portion providing an outer contour of the inlet and a volute portion providing an outer contour of a volute in fluid communication with the inlet. The volute portion is joined to the tongue member to define the volute, and the inlet portion of the second sheet metal structure is joined to the first sheet metal structure to define the inlet passage.

A scroll structure of a centrifugal compressor includes, of a flow passage connection section where a scroll start portion and a scroll end portion of a scroll flow passage intersect, a connection region where a first inner circumferential surface of the scroll end portion in the centrifugal compressor and a second inner circumferential surface of the scroll start portion in the centrifugal compressor are connected. The connection region includes a turning start point where a direction starts to change from the first inner circumferential surface toward the second inner circumferential surface, and a turning end point where the change in direction from the first inner circumferential surface toward the second inner circumferential surface comes to an end. Where a cross-section orthogonal to an extension direction of a center line of the scroll flow passage in the connection region is a first cross-section, the turning start point on the first cross-section is a first turning start point, a turning end point on the first cross-section is a first turning end point, and a tangent line to the first inner circumferential surface passing through the first turning start point on the first cross-section is a first direction, the first turning start point exists at a position away from the first turning end point along the first direction by a distance not less than 30% of a height dimension along an axial direction of the centrifugal compressor at a minimum cross-sectional area position of the scroll flow passage.

A turbocharger includes a turbine housing. The turbine housing includes a turbine inlet wall defining an inlet passage, an exducer shroud wall defining an exducer interior, a turbine outlet wall defining an outlet passage, a wastegate port wall defining a wastegate channel, and a bushing wall coupled to the wastegate port wall and defining a bushing boss extending along a bushing axis, and a valve seat disposed about the wastegate channel. The turbocharger also includes a wastegate assembly. The wastegate assembly includes a valve element engageable with the valve seat. The wastegate port wall is disposed outside of the exducer interior such that the wastegate port wall and the bushing wall are configured to be thermally decoupled from the turbine inlet wall and such that relative displacement between the valve seat and the bushing axis is reduced during operation of the turbocharger.

A diffuser and deswirl flow structure includes a plurality of tube structures with an outer wall that is hollow and elongate and that extends between a first portion and a second portion. The plurality of tube structures is disposed in an annular arrangement about the longitudinal axis. The flow structure also includes a plurality of flow passages extending through the tube structures. The plurality of flow passages extend from the first portion to the second portion, respectively. The plurality of flow passages respectfully include a diffuser portion, which is proximate the first portion and configured to diffuse a fluid flow from a compressor wheel. The plurality of flow passages respectfully include a deswirl portion, which is proximate the second portion and configured to deswirl the fluid flow from the diffuser portion. The outer wall defines the diffuser portion and the deswirl portion. The outer wall is self-supporting.

A turbine includes: an inner diameter side exhaust flow path; an outer diameter side exhaust flow path having a flow path cross-sectional area smaller than a flow path cross-sectional area of the inner diameter side exhaust flow path; an inner diameter side bypass flow path connecting the inner diameter side exhaust flow path and a discharge flow path; and an outer diameter side bypass flow path connecting the outer diameter side exhaust flow path and the discharge flow path, the outer diameter side bypass flow path having a flow path cross-sectional area larger than a flow path cross-sectional area of the inner diameter side bypass flow path.

In a centrifugal compressor, when the position of the tongue of the scroll section in the circumferential direction of the impeller is defined as 60° and the downstream direction in the rotation direction of the impeller is defined as the positive direction of the position in the circumferential direction, a diffuser section outer diameter distribution indicating a relationship between the position in the circumferential direction and outer diameter R of the diffuser section includes an outer diameter increasing portion where the outer diameter R increases going toward the positive direction, and in the diffuser section outer diameter distribution, the position of a start point of the outer diameter increasing portion is 150° or less, and the position of an end point of the outer diameter increasing portion is 270° or more.

In a manufacturing method of a turbine housing having an exhaust gas flow path, the exhaust gas flow path in the turbine housing is formed of a sheet-metal-made divided body and a cast-metal-made divided body, the sheet-metal-made divided body is formed by press molding a sheet metal material, and the cast-metal-made divided body is molded by casting, when the cast-metal-made divided body is cast, one end of the sheet-metal-made divided body is cast into the cast-metal-made divided body by melting the one end of the sheet-metal-made divided body such that the original shape thereof is disappeared.

The present invention relates to a valve arrangement (100) for a multi-channel turbine (10), having a housing section (300) with a first volute (320), with a second volute (340) and with a connecting region (360) between the first volute (320) and the second volute (340), and having a valve body (110) for closing off the connecting region (360) in a closed position of the valve body (110). A wall region (370) of the housing section (300), which wall region is arranged in the connecting region (360) and is situated opposite the valve body (110) in the closed position, is configured to be optimized in terms of flow to increase, during operation of the valve arrangement (100), a rate of flow transfer of exhaust gas between the first volute (320) and the second volute (340) in an open position of the valve body (110).