Abstract: A method and apparatus for high-pressure end exhaust gas recirculation on a supercharged internal combustion engine which is relatively simple, low in cost and increases the efficiency of the engine. This is achieved by a third exhaust gas flow of the internal combustion engine expanding separately from a first exhaust gas flow and by providing power to compress a second exhaust gas flow. For this purpose, a turbine is arranged as the drive for the exhaust gas compressor. The exhaust gas duct system has a third exhaust gas duct connected to the turbine.

Abstract: In order to prevent losses of lubricant in the bearing housing of the high-pressure stage of an exhaust-gas turbocharger for two-stage supercharging, the interior space of the bearing housing is conductively connected via a blocking air ring duct, pipes connected to the latter and a balancing pipe, to the low pressure boost air pipe in front of the high-pressure compressor. An alternate connection between the bearing housing and the low-pressure boost air pipe may be made via an oil return pipe to a lubricating oil tank and a balancing pipe between the lubricating oil tank and the low-pressure boost air pipe.

Abstract: In an axial turbine for exhaust gas turbochargers, the inner wall of the rotationally symmetrical exhaust gas deflection duct is designed as a deflection collar rigidly connected to the turbocharger shaft and rotating with it. The outer diameter of the deflection collar is greater than the diameter of the turbine disc and, at maximum, equal to the outer diameter of the turbine rotor. An element for contactless sealing of the exhaust gas deflection duct is provided between the rotating deflection collar and the casing. The element for contactless sealing of the deflection duct preferably consists of two labyrinth seals located on a cylindrical surface opening inwards, the sealing air being supplied radially from within between the labyrinth seals by means of a sealing air duct.

Abstract: In an exhaust gas turbocharger with a radial or axial turbine and an at least partially radial flow turbine nozzle ring (8), a movable slide ring (2) makes possible an infinite adjustment of the turbine inlet cross-section. The movement of the slide ring (2), which slides between nozzle ring (8) and rotor blading (1), occurs by means of an axial displacement. The front edge around which the gas flows is shaped to conform with the flow in order to avoid downstream separations. With radial turbines, the inlet flow angle to the turbine rotor blading remains approximately constant over the whole control range. In consequence, the shock loss at the turbine rotor blading substantially disappears. The infinite adjustment of the turbine inlet cross-section results in an improved part load behavior of the supercharged engine because the air quantity supplied to the engine is matched to the combustion conditions and smokeless operation is obtained over the whole rotational speed range.

Abstract: In a bearing device of an exhaust gas turbocharger having tandem rolling-contact bearings, the bearing support rings (5,6) have dogs (16) on their mutually facing end surfaces, each of which dogs penetrates into an opposite recess (17) with axial clearance (18) and tangential clearance (19). An even number of rotationally symmetrically located spring rods (7) extend from a bearing flange (8) connected to the bearing housing (2) through the bearing support rings (5,6) and into a support ring (9) connected to the bearing housing (2), a centrally located collar (14) on the spring rods being located alternately, without clearance, in one or the other bearing support ring (5,6).In this bearing device, the effective bending length (L) of the spring rod (7) is relatively large compared to the total width of the bearing (B). By this means, the bending stress in the spring rods (7) can be kept low or the axial installation length (B) of the bearing device can be reduced.

Abstract: In a centrifugal lubrication system of an exhaust gas turbocharger, the pump rotor is provided with two laterally located hollow spaces and is fastened on the turbocharger shaft between two shaft bearings. The shaft bearings are each located between an oil suction pipe and a hollow space of the pump rotor. The oil is sucked up from the oil sump, through the injection nozzles and through the shaft bearings.

Abstract: An exhaust-gas turbocharger has a bearing system which is positioned between a compressor impeller and a turbine wheel which are positioned on respective ends of a rotor shaft. The compressor impeller is attached to the rotor-shaft via an intermediate bush. A conically mating fit, at one end of the intermediate bush directly adjacent to the bearing, serves to attach this intermediate bush to a shaft-stub of the rotor shaft. A frictionally-locked press fit serves, at the other end of the intermediate bush, to attach the compressor impeller to the intermediate bush, in a manner which transmits torque.

Abstract: In an exhaust-gas turbocharger having an uncooled gas duct, the hot gas casing is connected to the relatively cooler supporting casing by a supporting member resilient in the radial direction. The supporting member consists of an outer flange and an inner flange and of a diaphragm disposed therebetween and comprising at least one fold and two flanks extending predominantly in the axial direction. The coefficient of thermal expansion of the material of the diaphragm flanks is preferably from 5% to 40% higher than that of the hot gas casing.

Abstract: The support arrangement according to the present invention has an inner strap which surrounds the ball-bearing outer race or a bush receiving the ball bearing, and an outer strap intended for installation in a casing. These two straps are connected to one another by bending spring bars uniformly distributed over the periphery of the straps, in such a way that a coaxial gap is present between them.

Abstract: An internal combustion engine has a turbo-supercharger connected to an engine charge air intake manifold and an exhaust gas turbine connected to an engine exhaust manifold. An automatic bypass includes a bypass line interconnecting the exhaust manifold upstream of the exhaust gas turbine and the air intake manifold downstream of the compressor. A bypass valve in the bypass line comprising an adjustable throttle member for adapting the quantity of bypassed gas to the respective operating state of the engine. An actuating piston closes the throttle member in response to pressures from the compressor side above a pre-selected value. The actuating piston is disposed on a side of the throttle member facing away from the air intake manifold. The resistance of the valve to flow from the compressor side to the turbine side is less than the resistance in the opposite direction. The resistance to flow, and the fully unseated valve position define an operating curve of the engine which is adjustable.

Abstract: A supercharger for an internal combustion engine has a rotor provided with cells, and two side housing portions. One side housing portion has a high pressure feed duct for the hot high-energy engine exhaust gas and a low pressure discharge duct for the expanded low-energy exhaust gas. The other side housing portion has a low pressure feed duct for the combustion air to be compressed and a high pressure discharge duct for the compressed combustion air. In at least one side portion there is formed a pocket open towards the rotor in a web between a high pressure duct and a low pressure duct. An opening is provided for feeding of fluid to the pocket without being influenced by the pressure-wave process in the cells. The cross-sectional area of the opening is dimensioned as a function of engine horsepower. The height of the opening is less than the height of the associated high pressure duct.

Abstract: A silencer construction for connection to the intake side of a compressor comprises an assembly of axially spaced annular sound damping elements which form air in-flow passages therebetween. The sound damping assembly is located in a radially outer annular chamber of the silencer housing and the radially inner circumference of each of the sound damping elements merges into a curvilinear air guiding element which functions to deflect the partial air flows leaving the passages between the damping elements in the direction of the main air flow into a convergent intake manifold of the compressor.

Abstract: A method of, and apparatus for, intercooling the charge air of a pressure-charged internal combustion engine by way of an air-cooled heat exchanger, the internal combustion engine being pressure-charged by a gas-dynamic pressure-wave machine. The entire quantity of outside air drawn in by the pressure-wave machine is divided into a partial stream of scavenging air and a partial stream of charge air. The scavenging air flows through the heat exchanger as a coolant and upon leaving the latter performs its intended scavenging function in the pressure-wave process, and the charge air, having been compressed in the pressure-wave process, is intercooled in the scavenging air-cooled heat exchanger.

Abstract: A gas-dynamic pressure-wave machine comprises essentially a celled rotor operating within a stationary casing that includes a cylindrical middle portion co-extensive in length with the rotor and two side casing portions located respectively adjacent opposite ends of the rotor for entrance and discharge of a hot high-pressure gas and a cold gas respectively which flow through the cells, some of the energy in the hot high-pressure gas being imparted to the cold gas so as to cause the latter to be compressed as a result of the pressure-wave process which takes place within the cells. The rotor becomes heated by the hot gas to an operating temperature between those of the cold gas, to be compressed, e.g. air and the hot gas, e.g. engine exhaust gas causing it to expand in an axial direction.

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.