Emitec Gesellschaft Fur Emissionstechnologie Mbh

Rudolf Schulze

Helmut Swars

Herbert Frielingsdorf

Helmut Riemscheid

Karl Weiss

Heribert Grewe

Engelbert Schwarz

Arnold Palussek

Wolfgang Maus

Klaus Greulich

Hans-Jurgen Breuer

Hans Hanswillemenke

A device for the simultaneous hydraulic expansion of a plurality of longitudinal portions of a hollow shaft for the production of force-locking and/or positive-locking connections between the latter and elements slid thereon, (such as cams, toothed wheels or bearing seats), in the form of a pressure medium probe. This comprises at least one longitudinally extending feed channel and radial feed bore holes to every longitudinal portion of the hollow shaft to be expanded, which is characterized by a sealing arrangement which seals longitudinal portions of the hollow shaft remaining undeformed against the action of the pressure medium from longitudinal portions of the hollow shaft to be expanded. These lie between them wherein the probe includes a one-piece probe body with annular grooves arranged in a spaced manner, wherein expansion arrangements are received by the grooves and an expansion arrangement includes a one-piece expansion sleeve which covers the entire expansion area; it can be acted upon from the inside by pressure medium along substantial portions of its length and is radial expandable, wherein its surface contacts the inner surface of the hollow shaft during the hydraulic expansion of the hollow shaft.

Device for hydraulic expansion

In the production of an assembled camshaft slid-on elements, such as control cams, bearing rings, gear wheels or bevel gears, are placed on an axially extending shaft tube. The slid-on elements are secured in place by expanding the shaft tube in the region of the elements by applying internal pressure. In producing the camshaft, a high strength material is used for the slid-on elements and an inferior strength material for the shaft. In the expanding step, an axially extending portion of the shaft tube is plastically deformed and the slid-on element is predominately elastically deformed. After expansion, the outer zone of the slid-on elements are elongated in the tangential direction in the range of 1%.

Process for producing an assembled camshaft as well as assembled

Devices are described which are suitable for simultaneous hydraulic expansion of several longitudinal sections of a hollow shaft for the production of connections by interlocking or frictional engagement between said sections and elements fitted thereto such as cams, toothed wheels and bearing seats. The devices include pressure probes with a longitudinal hydraulic fluid channel and a radial inlet bore to each longitudinal section of the hollow shaft to be expanded and, if necessary, with a longitudinal discharge channel and a radial discharge bore to the undeformed longitudinal sections of the hollow shaft between the sections to be expanded. Sealing means are provided which seal the undeformed longitudinal sections of the hollow shaft against penetration of the hydraulic fluid from the intermediate longitudinal sections of the hollow shaft to be expanded. It is possible to fit individual sealing elements and/or expansion sleeves with intermediate spacer sleeves onto the body of a probe of uniform cross-section to permit rapid exchange of worn seals. In addition, the probe body can consist of sections screwed together axially which, when of small cross-section, accept sealing elements and, when of larger cross-section serve as spacer pieces. Examples of novel and improved seal shapes are also given.

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Much, Germany

Rudolf Schulze