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 a variable exhaust gas turbocharger for an internal combustion engine including an exhaust gas turbocharger to which exhaust gas is supplied from the engine to provide a torque for driving the turbocharger, an additional device is provided which includes an electrical or mechanical drive for supplying an additional torque to the exhaust gas turbocharger in order to maintain the exhaust gas turbocharger at a certain speed at which it is capable of generating a desired inlet air pressure for the charge air supplied to the internal combustion engine.

Abstract: In a motor vehicle drive arrangement having an electric motor with a rotor for driving an oil pump and being supported in an air space of a housing by a rotor disk of the rotor of the electric motor which is permanently connected to a pump rotor of the oil pump, a freewheeling mechanism for a mechanical drive of the pump rotor of the oil pump is provided for coupling the oil pump to a vehicle travel drive train of the vehicle drive arrangement when the travel drive train rotates faster than the electric motor.

Abstract: In a method for accelerated heating of a cleaning device in the exhaust gas train of an internal combustion engine, the temperature of the cleaning device is determined, and if the temperature lies below a reference value, a bypass is opened and a variable turbine geometry is closed.

Abstract: A method for connecting a wheel, such as a turbine wheel or compressor wheel, in a turbine wheel rotor. The method includes providing a shaft made of steel, and pouring a casting alloy around an end of the shaft, wherein the casting alloy includes an intermetallic compound of the system TiAl. The method is particularly well-suited making a connection of the turbine wheel and the shaft of an exhaust-gas turbocharger for motor vehicles using a casting process. In addition, a turbine wheel rotor, that includes a steel shaft, a cast wheel including a casting alloy fixedly connected to an end of the shaft. The casting alloy including an intermetallic compound of the system TiAl. A connection between the cast wheel and the shaft includes at least one of a friction fit, a positive fit, and an integral connection.

Abstract: In a variable exhaust gas turbocharger for an internal combustion engine including an exhaust gas turbocharger to which exhaust gas is supplied from the engine to provide a torque for driving the turbocharger, an additional device is provided which includes an electrical or mechanical drive for supplying an additional torque to the exhaust gas turbocharger in order to maintain the exhaust gas turbocharger at a certain speed at which it is capable of generating a desired inlet air pressure for the charge air supplied to the internal combustion engine.

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: 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 for an internal combustion engine includes an exhaust-gas turbine in the exhaust section and a compressor in the intake tract. The compressor includes a compressor impeller in an inflow passage in the compressor housing. Furthermore, there is an auxiliary-air feed device, which is assigned to the compressor region and has an auxiliary-air passage, in the compressor housing for supplying auxiliary air, which can be introduced via an injection opening in the wall of the inflow passage of the compressor into the flow-facing region of the compressor impeller.

Abstract: A fastening device for a convertible top according to the invention comprises a front bow; a front window frame; a bracket, which is arranged on one of the group of the front bow and the front window frame; a first catch element, which is assigned to the respectively other component of the group of the front bow and the front window frame, said first catch element being secured in a movable manner and being connectable to said bracket, it being possible for the first catch element to be pivoted about a first axis; and at least one second catch element, which can be connected to said bracket; wherein the second catch element can be pivoted about a second axis, said second axis being spaced apart from said first axis.

Abstract: An exhaust-gas turbocharger for an internal combustion engine has a turbine in the exhaust-gas tract and a compressor, driven by the turbine, in the intake tract, the turbine having a flow channel with a radial flow-inlet cross-section and a semi-axial flow-inlet cross-section, and a flow ring being provided which limits the two flow-inlet cross-sections. The turbine is furnished with variable turbine geometry for the changeable adjustment of the flow-inlet cross-section. To improve efficiency, the position of the flow ring in the housing of the exhaust-gas turbocharger is variably adjustable.

Abstract: A compressor in a turbocharger has a compressor impeller in an inflow passage and an outflow region downstream of the compressor-impeller outlet edge. The outflow region is assigned a connecting passage, a stabilizing chamber and an outflow passage, the connecting passage being arranged with a lateral offset with respect to a longitudinal center axis of the stabilizing chamber.

Abstract: In an air compressor, particularly for an internal combustion engine, which has a compressor housing with a flow duct structure and a recirculation arrangement including a bypass structure for recirculation some of the air entering the compressor wheel, a recirculating ring is arranged in the bypass flow structure around the compressor wheel and the ring has a plurality of flow passages distributed uniformly around its circumference with inflow orifices at the radial inner end in communication with the compressor flow duct and outflow orifice at the radial outer end in communication with a by-pass flow space.

Abstract: A method for connecting a wheel, such as a turbine wheel or compressor wheel, in a turbine wheel rotor. The method includes providing a shaft made of steel, and pouring a casting alloy around an end of the shaft, wherein the casting alloy includes an intermetallic compound of the system TiAl. The method is particularly well-suited making a connection of the turbine wheel and the shaft of an exhaust-gas turbocharger for motor vehicles using a casting process. In addition, a turbine wheel rotor, that includes a steel shaft, a cast wheel including a casting alloy fixedly connected to an end of the shaft. The casting alloy including an intermetallic compound of the system TiAl. A connection between the cast wheel and the shaft includes at least one of a friction fit, a positive fit, and an integral connection.

Abstract: In an internal combustion engine which is provided with exhaust gas re-circulation and an exhaust gas turbocharger with an exhaust gas turbine having variable turbine geometry, and wherein the exhaust gas turbine includes two separate inflow ducts, which are separated in a pressure-tight fashion, one inflow duct communicates with an exhaust gas duct from which a re-circulation line of the exhaust gas re-circulation system extends to an intake duct.

Abstract: An exhaust gas turbocharger for an internal combustion engine includes an exhaust gas turbine in the exhaust gas system and a compressor in the intake system for producing compressed charge air. A compressor rotor is arranged in a compressor inlet channel. In order to achieve a greater range of utilization, an adjustable shutoff element is arranged in the compressor inlet channel, upstream from the compressor rotor, for variable adjustment of the effective cross-section.

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 has a turbine in the exhaust-gas tract and a compressor, driven by the turbine, in the intake tract, the turbine having a flow channel with a radial flow-inlet cross-section and a semi-axial flow-inlet cross-section, and a flow ring being provided which limits the two flow-inlet cross-sections. The turbine is furnished with variable turbine geometry for the changeable adjustment of the flow-inlet cross-section.

Abstract: An exhaust-gas turbocharger for an internal combustion engine includes an exhaust-gas turbine in the exhaust section and a compressor in the intake tract. The compressor includes a compressor impeller in an inflow passage in the compressor housing. Furthermore, there is an auxiliary-air feed device, which is assigned to the compressor region and has an auxiliary-air passage, in the compressor housing for supplying auxiliary air, which can be introduced via an injection opening in the wall of the inflow passage of the compressor into the flow-facing region of the compressor impeller.

Abstract: An exhaust-gas turbocharger in an internal combustion engine has a turbine and a compressor which is driven by the turbine and contains, in a compressor flow duct, a compressor impeller. A bypass to the compressor impeller communicates with the inflow duct via a first flow opening and, via a second flow opening, communicates with the compressor outflow region downstream of the outlet edge of the compressor impeller. A shutoff element which may be adjusted between a closing position and an opening position is provided in the bypass for the purpose of variably setting the effective flow cross-section of the bypass. The adjustable shutoff element is arranged in the second flow opening to the compressor outflow region.