The shaft-hub connections are a group of machine elements which are the focus of the institute's scientific research. In addition to services for industry partners in the form of advice on the selection, design and constructive integration of shaft-hub connections, the experimental development of special shaft-hub connections is a central task. These are self-cutting and -forming connections, in particular knurl connections. These alternatives to conventional shaft-hub connections have a high regarding load transfer capability and space optimization. Special feature of this type of connection is the double function of the forming toothing. On the one hand, this produces a counter-toothing during axial pressing into the hub body, cutting or reshaping, and thus serves as a tool. On the other hand, the shaft toothing serves as a positive transmission element.
Verzahnte Welle und gebohrte Nabe vor dem Fügen
Splined shaft and bored hub before joining © TU Graz/IME
Due to the nature of the toothing production - the forming toothing produces the counter-toothing - mating construction is the case. This results in a favorable design a backlash-free connection with uniform load of the individual distributed over the circumference teeth. This results in a high load transfer capability. Another positive aspect is the multitude of geometric parameters that can be varied for application-specific adaptation and optimization.
Eingepresste Verbindung im Querschnitt
Pressed connection in cross section © TU Graz/IME
Although there is a wealth of experience in the field, it covers only a narrow range of parameters. Generally valid and secure guidelines for constructive design and computational interpretation of this type of connection are therefore not yet available. For each application, therefore, a tailor-made development that takes into account stress, material combination and other framework conditions is necessary. A test stand-based protection is unavoidable.
Verschlissene und Unverschlissene Welle-Nabe-Verbindung
© TU Graz/IME
© TU Graz/IME
Circulation-loaded connections after > 2*106 load changes, left shaft without visible wear, right-side wear, friction grate and material transfer  Here are some aspects of the interpretation of the connection
  • Estimating the suitability of a self-cutting or forming connection in   comparison to conventional connections
 Depending on requirements and targets in the design and optimization of shaft-hub connections, such as the load type and height to be transferred, geometrical, manufacturing and materials-related restrictions give an indication for the usefulness of the use of self-tapping and -shaping shaft-hub connections.
  •  Design of the connection
Depending on the requirements of the connection arise, depending on the geometric restrictions, or degrees of freedom, a variety of basic manufacturing and embodiments of the compound (machining, reshaping, or conventional geometries established shaft-hub connections and alternative contours). Both aspects of the production, the joining process and the load transfer are of relevance. In general, the joining process and the load transfer behavior are of central interest. An attempt is made to describe these by analytical / empirical models. Their validity and limits must be verified by testing
  • Verification of the connection
From preliminary studies to series applications, the verification of properties is very important. The hedging of behavior is predominantly experimental. The qualitative and quantitative assessment is strongly based on experience.

Institute of Machine Components and Methods of Development

Inffeldgasse 21b/II
8010 Graz

Tel.: +43 316 873 7361 
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