Deutsche Forschungs- Und Versuchsanstalt Fur Luft- Und Raumfahrt E.v.

Deutsche Forschungsanstalt Fur Luft-und Raumfahrt E.v.

Deutsche Forchungsanstalt Fur-und Raumfahrt E.v.1

Richard Kochendorfer

Walter Krenkel

Bernhard Hinz

Helmut Vogler

Method of manufacturing a friction element

Friction element

A process is provided for permanently joining at least two structural components together to form a molded body, in which a carbon-containing paste is introduced between the structural components to be joined and heated to form a carbon skeleton. This skeleton is then infiltrated with silicon at a temperature above 1,410.degree. C. to form silicon carbide. As one of the structural components, a carbon fiber-reinforced component with a system of microcracks is used. One of the structural components is aligned with the other structural component in such a way as to leave a joint gap. For cases in which the width, defined as the distance between the two surfaces to be joined, is .ltoreq.80 .mu.m, the joint gap is filled with a paste which contains an organic, carbon-containing binder with a carbon content of at least 30 wt. % and carbon powder with a particle size of less than 15 .mu.m. In cases where the width of the gap is more than 80 .mu.m, carbon fibers are introduced into the joint gap in addition to the paste. The paste is pyrolyzed at a temperature in the range of 800-1,200.degree. C. to form a system of microcracks which approximately corresponds or is analogous to that of the carbon fiber-reinforced structural components. The system of microcracks of the pyrolyzed paste is then infiltrated with liquid silicon at a temperature above the melting point of silicon, which is thus converted to silicon carbide.

Process for permanently joining at least two structural components

To avoid the necessity of piston rings in a piston-cylinder set, it is prsed that the cylinder liner be surrounded by a band consisting of a fiber composite whose thermal expansion in a radial direction is less than that of the cylinder liner, the impediment to expansion presented by the band varying over the length of the cylinder housing; that the piston be constructed with a cap consisting of a piston head facing the combustion chamber and an essentially cylindrical piston skirt adjacent to the cylinder bearing surface, and a force-transmitting core that contains the bearing for the piston pin and the spherical pressure pad; that a force-transmitting connection rotationally symmetrical to the piston's longitudinal axis be provided above the spherical pressure pad; that the cap be connected at the lower edge of the piston skirt to the force-transmitting core, but otherwise no contact be provided between cap and force-transmitting core except in the area of the force-transmitting connection; and that both cylinder liner and cap be fabricated from ceramic material.

Piston-cylinder set for reciprocating internal-combustion engines,

A disc is centered and secured on a shaft by means of flexible webs which extend parallel to the shaft and lie against the inner surface of a central aperture in the disc, and by radially extending tongues fixed to the shaft and entering into corresponding radial slots in the disc. As the assembly rotates, the webs are urged outwards by centrifugal force, to apply a radial compression force to the material of the disc.

Shaft-disc assembly

Growing community of inventors

Stuttgart, Germany

Richard Kochendorfer