Abstract: In a compressor and turbine wheel for a secondary air feed device formed as a single component, a rotor which includes a center disc structure consisting of at least two discs of different materials is provided at one side with compressor blades and on the opposite side with turbine blades, and the discs consist of an alloy based on Al, Mg, Ti, Fe, or Ni and are preferably arranged in axially spaced relationship with a disc carrier of a plastic material disposed in the space between the two bladed discs.

Abstract: In a method of operating a compressor near the compressor pumping limit wherein the compressor includes a control arrangement for adjusting the momentary operating state of the compressor, the flow velocity of a mass flow through the compressor in the boundary layer along the wall of the flow passage is determined for detecting operation of the compressor close to the pumping limit from a reversal of the direction of the mass flow vector in the boundary layer and the control arrangement is actuated so as to prevent the compressor from transgressing the pumping limit.

Abstract: In an engine braking method and an internal combustion engine including an engine braking arrangement, wherein the engine has high pressure and low pressure exhaust gas turbochargers connected in series, with a bypass (12) around the high-pressure compressor allowing the air mass flow selectively to bypass the high pressure compressor which is arranged near the engine, and bypasses around both turbines permitting the exhaust gas mass flow selectively to bypass the high-pressure exhaust gas turbine which is near the engine and also the low pressure turbine the intake air and the exhaust gas flow are controlled so as to accurately provide for a desired engine braking power for example for maintaining a desired vehicle speed.

Abstract: In an exhaust-gas turbine of an exhaust-gas turbo-charger including a turbine wheel which is rotatably supported in a housing and to which exhaust gas can be supplied via an inlet channel and discharged out of the exhaust-gas turbine via an outlet duct, wherein a guide vane structure and an axial slide which interacts with the latter, are disposed in the turbine inlet at the transition from the inlet channel to the turbine wheel, the guide vane structure is fixedly mounted with respect to the housing and the axial slide is arranged at the turbine outlet side and is movably supported on an outlet duct contour sleeve and provided with an axial opening for accommodating the guide vane structure, and the contour sleeve includes openings which conduct exhaust gas from the inlet channel directly to the outlet duct and which are arranged so that they are covered by the axial slide when the axial slide is moved out of its open position, the guide vane structure extending axially over the contour sleeve openings so as

Abstract: In an exhaust gas turbocharger for an internal combustion engine having a turbine wheel connected, by means of a shaft, to the compressor wheel of a compressor which includes a variable inlet geometry comprising a plunger and a sleeve-shaped partition for controlling an auxiliary duct leading radially to the compressor wheel, which is provided with compressor wheel blades to which air is supplied axially via an axial inlet passage and radially via a radial wheel inlet area, the compressor wheel includes a contoured ring provided at its outer circumferential surface with auxiliary blades disposed over, and aligned with, the compressor wheel blades in the radial and the axial wheel inlet region of the compressor wheel.

Abstract: An exhaust gas turbocharger for an internal combustion engine has an exhaust gas turbine in the exhaust gas train and a compressor in the intake tract, whereby an adjustable throttle device is provided upstream from the compressor wheel, for regulating the air mass stream to be supplied. The throttle device comprises a first guide grid and a second guide grid in the inflow region to the compressor wheel. Each guide grid possesses an adjustable grid geometry.

Abstract: In an exhaust gas turbocharger for an internal combustion engine including an exhaust gas turbine in the exhaust line and a compressor in the intake tract of the internal combustion engine, and the exhaust gas turbine includes a gas inlet passage with a variable guide vane structure supported on one side of a support ring arranged in the inlet flow passage to the turbine wheel, the support ring is mounted in a floating manner such that the side thereof, which faces away form the guide vanes is exposed to the gas pressure in the inlet flow passage in order to bias the support ring toward the opposite inlet flow passage wall and spacer sleeves with expansion properties similar to those of the guide vanes are provided between the support ring and the opposite flow passage wall for delimiting the clearance between the guide vanes and the opposite flow passage wall.

Abstract: In an internal combustion engine and a method of operating the engine which comprises a compressor having an impeller disposed in a housing including a main inlet duct in which the impeller is supported and an additional inlet duct joining the main inlet duct in the area of the compressor impeller, and valving means for controlling the gas supply to the inlet ducts and an electric motor connected to the compressor impeller for rotation therewith so that the compressor is operable by the electric motor and by the pressure drop in the air intake line of the engine, a flywheel is coupled to the impeller for storing rotational energy when the impeller is driven by the intake gas and returning the energy to the impeller when the pressure drop collapses upon a sudden increase in the demand for engine power.

Abstract: In a compressor of an exhaust gas turbocharger for an internal combustion engine including a compressor wheel which is rotatably mounted in a compressor inlet duct and an auxiliary rotor wheel arranged so as to be movable axially between a coupled position in engagement with the compressor wheel and a decoupled position, disengaged from the compressor wheel, an adjustable guide vane structure is provided which is movable by an adjusting element together with the auxiliary rotor wheel and a contoured flow control ring for controlling the combustion air flow to the compressor wheel and to the auxiliary rotor wheel.

Abstract: In a compressor of an exhaust gas turbocharger of an internal combustion engine including a compressor wheel with an auxiliary rotor wheel which is rotatably supported adjacent to, and upstream of, the compressor wheel and which is movable axially between a coupled position with the compressor wheel and a decoupled position, wherein, in the coupled position, the auxiliary rotor wheel is rotationally connected to the compressor wheel, without contacting the compressor wheel, by means of a magnetic clutch for transferring a torque from the auxiliary rotor wheel to the compressor wheel in a low engine power operating range in order to maintain the compressor wheel at an increased speed.

Abstract: In an internal combustion engine and a method of operating the engine which comprises a compressor having an impeller disposed in a housing including a main inlet duct in which the impeller is supported and an additional inlet duct joining the main inlet duct in the area of the compressor impeller, and valving means for controlling the gas supply to the inlet ducts and an electric motor connected to the compressor impeller for rotation therewith so that the compressor is operable by the electric motor and by the pressure drop in the air intake line of the engine, a flywheel is coupled to the impeller for storing rotational energy when the impeller is driven by the intake gas and returning the energy to the impeller when the pressure drop collapses upon a sudden increase in the demand for engine power.

Abstract: A rotor for exhaust-gas turbochargers having a turbine wheel (3) made of a metal aluminide, a hollow shaft (2) made of steel or of a nickel-based alloy, and a compressor wheel (1), the compressor wheel (1) having a journal (5), which partially extends into the hollow shaft (2) made of steel or of nickel-based alloy and which forms a positive connection (6) with the same, as well as a method for manufacturing rotors for exhaust-gas turbochargers having a turbine wheel (3), a metal hollow shaft (2), and a compressor wheel (1), including the steps of substance-to-substance bonding of the turbine wheel (3) and of the metal hollow shaft (2), positively connecting the compressor wheel and the metal hollow shaft (2), the positive connection (6) being produced by a journal (5) of the compressor wheel (1) projecting into metal hollow shaft (2), and by the inside of the metal hollow shaft.

Abstract: An exhaust gas turbocharger for an internal combustion engine comprises a turbine in the exhaust line and a compressor, which is driven by the turbine and which is located inside the intake tract of the internal combustion engine. The turbine comprises a flow duct having a radial flow entrance cross-section, and a flow ring is provided that delimits the flow entrance cross-section. An adjustable vane is placed in the radial flow entrance cross-section for variably adjusting this flow entrance cross-section. The flow ring inside the housing of the exhaust gas turbine can be axially displaced between a contact position toward the vane and a position that frees a gap toward the vane.

Abstract: In a compressor and turbine wheel for a secondary air feed device formed as a single component, a rotor which includes a center disc structure consisting of at least two discs of different materials is provided at one side with compressor blades and on the opposite side with turbine blades, and the discs consist of an alloy based on Al, Mg, Ti, Fe, or Ni and are preferably arranged in axially spaced relationship with a disc carrier of a plastic material disposed in the space between the two bladed discs.

Abstract: In a method for operating a supercharged internal combustion engine, the exhaust gas turbine of which is equipped with a variable turbine geometry, if the pressure upstream of the compressor is higher than the pressure downstream of the compressor in the lower load/speed of the internal combustion engine, the variable turbine geometry is adjusted in the direction of its back-up position until the turbine efficiency is at least approximately in the region of the optimum efficiency.

Abstract: In a variable exhaust gas turbocharger for an internal combustion engine having an exhaust gas turbine and a compressor with a variable vane structure wherein the exhaust gas turbocharger comprises a housing and a compressor wheel which is connected to an exhaust gas turbine wheel via a shaft, the compressor has a radial inflow flow passage in which a variable vane structure or throttle device is arranged upstream of the compressor wheel and another vane structure is arranged in the radial flow passage downstream of the compressor wheel in the direction of flow.

Abstract: An exhaust-gas turbocharger in an internal combustion engine having a compressor in the induction tract and an exhaust-gas turbine in the exhaust-gas line wherein the exhaust-gas turbine has at least two spiral ducts which in each case open into a radial flow inlet passage. Arranged in the radial flow inlet passage is a guide cascade ring which is disposed between two axially delimiting walls. One of the walls is designed to be axially displaceable and adapted to accommodate the vanes of the guide cascade ring. The wall is displaceable axially outward to such an extent that the vanes of the radial guide cascade ring are no longer in contact with the wall and there is a direct, unobstructed flow path to an outflow duct in the exhaust-gas turbine.

Abstract: An exhaust gas turbocharger for an internal combustion engine has an exhaust gas turbine in the exhaust gas train and a compressor in the intake tract, whereby an adjustable throttle device is provided upstream from the compressor wheel, for regulating the air mass stream to be supplied. The throttle device comprises a first guide grid and a second guide grid in the inflow region to the compressor wheel. Each guide grid possesses an adjustable grid geometry.

Abstract: In an exhaust gas turbocharger for an internal combustion engine comprising a radial flow exhaust gas turbine and a compressor, which is connected to the turbine via a shaft, the turbine having a radial inflow duct and a radial inlet flow passage, which leads to the turbine wheel and in which a variable geometry vane structure for changing the cross-section of the radial inlet flow passage is supported between two support walls fixed to the turbine casing, one of the support walls projects into the inflow duct, in such a manner that the rear side of this support wall is spaced from the inner wall of the inflow duct wall so that the exhaust gas within the inflow duct is in contact also with the rear side of this support wall.

Abstract: An exhaust gas turbocharger for an internal combustion engine comprises a turbine in the exhaust line and a compressor, which is driven by the turbine and which is located inside the intake tract of the internal combustion engine. The turbine comprises a flow duct having a radial flow entrance cross-section, and a flow ring is provided that delimits the flow entrance cross-section. An adjustable vane is placed in the radial flow entrance cross-section for variably adjusting this flow entrance cross-section. The flow ring inside the housing of the exhaust gas turbine can be axially displaced between a contact position toward the vane and a position that frees a gap toward the vane.