Abstract: An exhaust-gas turbocharger (1) having a turbine housing (2), which has a bypass duct (10) with a bypass opening (9); and having a control flap (3), which is mounted pivotably between a closed position and an open position in the turbine housing (2), the control flap (3), when in its closed position, resting on a bearing region (8) of a housing wall (11) which conducts exhaust gas and contains the bypass opening (9), wherein at least one flow imperfection (12A, 12B; 23A, 23B) is arranged in the turbine housing wall (11) in the bearing region (8) of the control flap (3) and/or in the control flap (3).

Abstract: An exhaust-gas turbocharger (1) having a turbine housing (2), which has a bypass duct (10) with a bypass opening (9); and having a control flap (3), which is mounted pivotably between a closed position and an open position in the turbine housing (2), the control flap (3), when in its closed position, resting on a bearing region (8) of a housing wall (11) which conducts exhaust gas and contains the bypass opening (9), wherein at least one flow imperfection (12A, 12B; 23A, 23B) is arranged in the turbine housing wall (11) in the bearing region (8) of the control flap (3) and/or in the control flap (3).

Abstract: A compressor (8) of an exhaust-gas turbocharger (1), having a compressor wheel (11) which can be driven in a compressor wheel direction of rotation (VR); having a compressor housing (10) in which the compressor wheel (11) is arranged, as viewed in the flow direction of the inducted air, between a preferably tubular compressor inlet (12) and a compressor outlet (13), and having an overrun air recirculation valve inflow duct (14, 15) which runs in the compressor housing (10) from the compressor outlet (13) to the compressor inlet (12), wherein the inflow duct (14, 15) opens into the compressor inlet (12) substantially in the circumferential direction with respect to the inner diameter (DI) of said compressor inlet (12).

Abstract: The present invention relates to a method for balancing an exhaust-gas turbocharger, having the following method steps: installing the exhaust-gas turbocharger in a balancing test stand; driving the exhaust-gas turbocharger by loading the turbine with a pressurized fluid; determining the imbalance; and compensating for the determined imbalance. As pressurized fluid for the loading of the turbine, use is made of hot gas which is heated to a temperature of higher than 90° C.

Abstract: A fluid flow engine comprises a shaft supported in a bearing housing by means of a bearing shell. There are at least two lubricating bores in the bearing shell each having a predetermined geometry as to diameter, length and angular arrangement with respect to the bearing shell. At least one turbine rotor is on one end of the shaft. A turbine housing provides a turbine space for accommodating the turbine rotor, the turbine housing being connected to the bearing housing. There are sound suppressing means arranged within the bearing housing.

Abstract: A fluid flow engine comprises a shaft supported in a bearing housing by means of a bearing shell. There are at least two lubricating bores in the bearing shell each having a predetermined geometry as to diameter, length and angular arrangement with respect to the bearing shell. At least one turbine rotor is on one end of the shaft. A turbine housing provides a turbine space for accommodating the turbine rotor, the turbine housing being connected to the bearing housing. There are sound suppressing means arranged within the bearing housing.