Provided is a rotating body, including: a shaft; and a compressor impeller including: a main body having an insertion hole, which extends from one end to another end side and is configured to receive the shaft inserted therethrough; a boss portion formed at one end side of the main body; and a joint portion, which is formed on an inner peripheral surface of the insertion hole at the boss portion and is welded to the shaft.

Disclosed is an austenitic stainless steel alloy that includes or consists of, by weight, about 20.0% to about 21.5% chromium, about 8.5% to about 10.0% nickel, about 4.0% to about 5.0% manganese, about 0.5% to about 2.0% silicon, about 0.4% to about 0.5% carbon, about 0.2% to about 0.3% nitrogen, and a balance of iron with inevitable/unavoidable impurities. The elements niobium, tungsten, and molybdenum are excluded beyond impurity levels. Turbocharger turbine housings made of the stainless steel alloy, and methods of making the same, are also disclosed. The stainless steel alloy is suitable for use in turbocharger turbine applications for temperatures up to about 1020° C.

A compressor housing includes: an intake flow path-forming section configured to form an intake flow path; a shroud portion including a shroud surface curved in a protruding manner to face blades of an impeller; and a scroll flow path-forming section configured to form a scroll flow path through which gas is guided outside the compressor housing. A groove portion extending in a circumferential direction is defined in the shroud surface and, in a cross-sectional view taken along an axis of the impeller, the groove portion includes a downstream side wall surface, wherein a distance from the axis of the impeller to the downstream side wall surface increases toward an upstream side from a downstream side end portion of the groove portion, and an upstream side curved surface that is recessed between an upstream end of the downstream side wall surface and an upstream side end portion of the groove portion.

A method for constructing a nozzle ring for a turbocharger turbine nozzle includes the steps of: providing a nozzle ring in the form of an annular flat disk, the nozzle ring having a first face and an opposite second face; forming a plurality of circumferentially spaced circular bores extending through the nozzle ring from the first face to the second face; providing a plurality of vanes, each vane having a circular vane shaft extending from one end of the vane; inserting the vane shafts respectively into the bores in the nozzle ring from said first face thereof and orienting each vane to achieve a desired setting angle for the vane; and rigidly affixing the vane shafts to the nozzle ring to fix the vanes at the desired setting angles.

Methods and systems are provided for a turbocharger. In one example, a method may include bypassing exhaust gases flowing to the turbocharger in response to a catalyst temperature being less than a threshold temperature. The bypassing includes opening a bypass valve and adjusting a position of one or more turbine nozzle vanes.

An impeller for a centrifugal turbomachine includes: a hub having a small-diameter portion positioned at a first end portion in an axial direction and a large-diameter portion positioned at a second end portion in the axial direction, the large-diameter portion having a greater diameter than the small-diameter portion; and a blade having a first edge positioned at an axial-directional position of the small-diameter portion and a second edge positioned at an axial-directional position of the large-diameter portion, the blade being disposed on an outer peripheral surface of the hub. The impeller is configured such that, when a first radial-directional cross section is a cross section of the impeller at an axial-directional position passing a tip of the first edge, at least a part of the first radial-directional cross section in a blade-height range of 50% or more is inclined downstream in a rotational direction of the impeller with respect to a radial direction.

An exhaust gas-conducting section of an exhaust turbocharger comprises a duct with a through-flow opening which can be fully or at least partially blocked or released by a closure element of a control device. The closure element is designed as a poppet valve. The closure element can be moved by an actuator can be disposed in a wall of the exhaust gas-conducting section. The closure element has a closure body with an annular section surface on its bottom surface which faces the through-flow opening. The section surface corresponds to an element seat formed in the wall. Its top surface faces away from the bottom surface and is designed in a profiled manner in order to produce a top surface at least partially corresponding to another element seat and/or to achieve flow-optimized circulation.

A turbine shaft used for a turbocharger including a turbine and a compressor includes a turbine impeller, and a rotor shaft joined on one end side to the turbine impeller. The rotor shaft includes a fitting region configured to fit with a compressor impeller of the compressor by inserting the other end side of the rotor shaft into a through hole formed in the compressor impeller, a fastening region formed between the fitting region and the other end side of the rotor shaft, and configured to allow fastening by a fastening part, and a tapered part having a maximum outer diameter at a position closest to the turbine impeller in the fitting region and formed such that an outer diameter of the rotor shaft decreases from the position closest to the turbine impeller toward a tip side of the compressor impeller.

An impeller of a centrifugal compressor is an impeller 5 of a centrifugal compressor, that is, a compressor impeller 5 and includes a hub, at least one airfoil portion erected on a hub surface of the hub, and a first fillet. The at least one airfoil portion has a trailing edge configured such that a distance between the trailing edge and an axis of the centrifugal compressor increases with increasing distance from a back surface of the hub. The first fillet is formed on a radially outer side of an outer peripheral surface of a back plate portion forming a back surface portion of the hub. The first fillet connects the outer peripheral surface of the back plate portion and the trailing edge of the at least one airfoil portion.

An inlet shield with a first portion that is configured to be secured to an inlet of a turbocharger, and a second portion that is configured to be removably coupled to the first portion via magnets, wherein different second portions may have different mesh layouts allowing a consumer to choose different levels of protection and air flow based on desired use.