Provided is a turbocharger, including: a separation wall surface, which is a wall surface of a bearing housing on a turbine impeller side, is positioned on an inner side with respect to an outer periphery of a back surface of the turbine impeller on the bearing housing side in a radial direction of a shaft, and is separated from the back surface in an axial direction of the shaft; and a heat-shielding plate, including: a main body portion (separation portion), which is separated from the separation wall surface in the axial direction, and is positioned between the back surface of the turbine impeller and the separation wall surface; and an insertion through hole (insertion portion), which receives a fastening member inserted thereinto in a direction of intersecting the axial direction of the shaft, the heat-shielding plate being mounted to the bearing housing by the fastening member.

The present invention includes: a turbine wheel 24 that is attached to a rotating shaft 14 and that has a plurality of turbine blades in the circumferential direction; scroll passages 15Aa, 15Ab that are formed in a spiral shape on the outside of the turbine wheel 24, and that are formed by being divided into a plurality of sections in the circumferential direction, the passages communicating with each other at the position of the turbine wheel 24 disposed between respective tongue sections 15Ac, 15Ad; and threads 51 that are provided on an back facing surface 41 disposed so as to oppose the back surface of the turbine wheel 24, the back surface being on the axially opposite side from the turbine blade side, and the linear parts extending from starting points 51a near the tongue sections 15Ac, 15Ad toward the rotating shaft 14 side so as to control the passage of fluid between the back surface and the back facing surface 41.

The invention relates to a nozzle ring (10) for a radial turbine. The nozzle ring comprises a rotationally symmetrical, disk-shaped main body (11) with a central opening (12) for the leadthrough of a shaft (20). Furthermore, the nozzle ring comprises guide blades (14) which are arranged in a circumferential direction in a radially outer region of the main body (11) and which are designed to direct exhaust gases onto rotor blades (31) of a turbine wheel (30). The main body (11) of the nozzle ring is designed to, in the installed state, form a heat shield between a bearing space (40) of a bearing housing (41) and a turbine space (50).

Mistuned bladed rotors and associated manufacturing methods are disclosed. An exemplary method includes forming two or more blades of the bladed rotor where the two or more blades have substantially identical external aerodynamic surfaces and have different internal configurations causing the two or more blades to have different natural frequencies.

Turbomachine (10), in particular for a fuel cell system (1). The turbomachine (10) comprises a compressor (11), a drive device (20) and a shaft (14). The compressor (11) has a rotor (15) arranged on the shaft (14), a compressor inlet (11a) and a compressor outlet (11b). A working fluid can be delivered from the compressor inlet (11a) to the compressor outlet (11b). A drive cooling path (92) for cooling the drive device (20) branches off at the compressor outlet (11b). Also proposed is a fuel cell system (1) with a turbomachine (10) according to the invention, a method for operating the turbomachine (10) and a method for operating the fuel cell system (1).

A compressor wheel includes a compressor wheel body, and a thermal insulating coating layer disposed so as to cover at least a part of a back surface of the compressor wheel body.

A turbocharger includes a turbine and a compressor, each of which includes a rotor and a stator. At least one of the respective rotors and/or stators includes at least one interior flow passage at least partly or completely surrounded by a wall that provides cooling. The respective rotor and/or stator having the at least one flow passage is at least partly produced by additive manufacturing.

A turbine shaft includes: a turbine impeller having a protruding portion provided on a back surface of a main body portion thereof and a welded surface provided on the back surface of the main body portion in a radially outer side of the protruding portion; and a shaft having an end hole provided on the one end surface thereof, the end hole in which the protruding portion is inserted, a welding surface provided in a radially outer side of the end hole and welded to the welded surface, a second seal groove provided in another end side with respect to the welding surface, and an enlarged diameter portion formed between the welding surface and the second seal groove, a diameter of the enlarged diameter portion expanding radially outward from the welding surface side toward the second seal groove side.

A turbocharger includes a compressor housing, turbine housing, and center housing between the compressor and turbine housings. A turbine wheel is disposed in the turbine housing on a turbine shaft. A compressor wheel having a shank is disposed in the compressor housing on the turbine shaft. The shank has outer and reduced portions. The reduced portion has a smaller diameter than the outer portion. A backplate is mounted to the compressor housing adjacent the compressor wheel and defines a stepped cylindrical bore with a maximum diameter portion and a minimum diameter portion having a smaller diameter than the maximum portion. The outer portion is disposed in the maximum portion. The reduced portion is disposed in the minimum portion. The outer diameter of the shank is greater than or equal to the minimum diameter of the backplate, and the stepped cylindrical bore and the shank define a variable width gap.

A compressor section includes a compressor wheel and a compressor housing that surrounds the compressor wheel. The compressor housing includes a flow passage with an upstream area. The compressor section also includes a cooling pocket that is defined within the compressor housing. The cooling pocket is configured to receive a coolant for cooling the compressor housing. Furthermore, the compressor section includes a thermo-decoupling pocket that is defined within the compressor housing. The thermo-decoupling pocket is disposed between the cooling pocket and the upstream area of the flow passage. The thermo-decoupling pocket is fluidly connected to an exterior area outside the compressor housing.