Abstract: An exhaust gas turbo-charger for internal combustion engines of the type having turbine rotor blades rotatable about an axis and a vaned guide device located upstream of turbine rotor blades, which vaned guide device includes a butterfly valve, a main guide vane ring and an auxiliary guide vane ring. Each guide vane ring is provided with a mutually separate supply duct, and the butterfly valve controls exhaust gas flow to the auxiliary guide vane ring. The auxiliary guide vane ring is located radially inside of the main guide vane ring and the butterfly valve is located upstream of the auxiliary guide vane ring.

Abstract: An exhaust-gas turbocharger includes a low pressure stage having a compressor wheel and a turbine wheel mounted on one shaft and a high pressure stage having a compressor wheel and a turbine wheel mounted on another shaft. The two shafts are arranged coaxially one within the other, and the compressor and turbine units of either stage can be located on the inner or outer shaft.

Abstract: A dual bearing structure for supporting the rotor shaft of a rotatable machine such as a turbocharger includes antifriction bearings of the inclined contact ball type which accommodate radial forces and also axial forces acting in one direction on the shaft and a plain thrust bearing located adjacent the antifriction bearings which accommodates axial forces acting in the opposite direction. The fixed ring of the thrust bearing includes radial oil guide slots and lubricating oil for the bearings admitted into the bearing housing forms a rotatable ring of oil which owing to the action of centrifugal force passes from the antifriction bearing into the oil guide slots in the fixed ring of the thrust bearing.