Bbc Brown, Boveri & Company, Limited

Bbc Brown Boveri Ag

Hubert Kirchhofer

Andreas Mayer

Fritz W Spinnler

Hansulrich Horler

Ibrahim El-Nashar

Josef Perevuznik

Christian Komauer

Francois A Jaussi

Raymond Schelling

Nicolaus Croes

In this pressure wave supercharger, the driving belt pulley (19) for the rotor having a freewheel clutch (23) and rolling contact bearings (22) provided on both sides of the same are supported on the rotor shaft (18+20). With respect to the operation of the pressure wave supercharger, this provides the advantages of drive by the engine with constant engine/rotor transmission ratio and of a free-running rotor driven by the gas forces alone.

Pressure wave supercharger

In a free-running pressure wave supercharger driven by the gas forces, nozzles (27) are provided in the gas casing (6) and possibly also in the air casing (5), which nozzles are connected--via a drive line (26)--with a position in the air casing (5), preferably with the high-pressure air port (2), at which position a surplus pressure relative to the nozzle entry occurs during the run-up phase of the pressure wave supercharger. A control device 15 actuates a supercharge air flat (14) in the port (2) and a valve device (23+25) in the drive line (26) in the opposite sense, i.e. if the supercharge air flap (14) holds the port (2) closed, the valve device (23+25) frees the flow through the drive line (26) to the nozzle (27) and vice versa. The diaphragm capsule (17) of the control device (15) is subjected, on one side, to the pressure in a compression pocket (11) via a control pressure line (19) and, on the other side, to the pressure before the supercharge air flap (14) in the port (2). During the run-up phase, the pressure in the compression pocket (11) exceeds the pressure in front of the supercharge air flap (14) and the nozzle (27) receives drive air. As soon as the pressure in front of the supercharge air flap (14) exceeds the pressure in the compression pocket (11), the supercharge air flap (14) opens and simultaneously closes the valve device (23+25). The nozzle (27) is switched off and the further drive is then mainly provided by the high-pressure exhaust-gas jet from the port (3) entering obliquely to the direction of the rotor peripheral velocity.

Free-running pressure wave supercharger driven by gas forces

In a gas dynamic pressure wave supercharger for vehicle internal combustion engines, at least one of the two mutually facing end surfaces of the rotor and the air casing is made convex on the air casing side in order to maintain an axial clearance which increases radially from the inside to the outside. On the gas casing side, at least one of the two mutually facing end surfaces of the rotor and the gas casing is made concave in order to maintain an axial clearance which decreases in the cold condition radially from the inside to the outside. The concave or convex end surfaces can be formed as truncated cone surfaces or as spherical surfaces. By the appropriate shaping of the rotor and casing end surfaces, the thermal expansion and rotor vibrations are compensated and the supercharger can run with a small axial clearance and good efficiency.

Gas dynamic pressure wave supercharger for vehicle internal combustion

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. One form of opening comprises an opening spaced from the rotor so that a web portion of the housing shields the opening from pressure waves generated by the rotor. Another form of opening comprises an opening arranged generally parallel to the gas flow and having its outlet in the pocket spaced sufficiently far from the rotor that there is no obstruction by pressure waves. Another form of opening means comprises an opening which is open toward the rotor, with the depth of the opening being sufficiently large that the outer portion of the opening is unobstructed by pressure waves.

Superchargers for internal combustion engines

Growing community of inventors

Gebenstorf, Switzerland

Hubert Kirchhofer