Material-independent Dimensioning of Knurled Interference Fits of arbitrary Shape

• Applicants: Professorin Dr.-Ing. Birgit Awiszus; Professor Dr.-Ing. Erhard Leidich
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing ; Engineering Design, Machine Elements, Product Development
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 249500173

Shaft-Hub-Connections are frequently used for the transmission of dynamic forces and torques. In most cases, frictionally engaged or form closed connections are used. The Knurled-Interference-Fit (KIF) represents a combination of friction and form closure. Based on the joining process a friction closure occurs in the axial direction. Additionally, a form closure occurs in the tangential direction, because of the knurled shape which is formed into the relevant complement (hub or shaft). The importance of KIFs continuously increases. But there is a considerably insecurity regarding the dimensioning and the design of KIFs, because there is no general guideline like DIN 7190 for cylindrical press-fits. Therefore, the primary aim of the project is the material-independent dimensioning of KIFs with arbitrary shape. For the first time a validated design-algorithm for the continuous numerical simulation as well as for the (semi)analytical computation of KIFs will be available. For automotive lightweight design concepts the material combination steel/aluminum pressure die casting, with knurled shafts, will be investigated. Furthermore, the material combination steel/steel with knurled hubs, for gear wheel applications, will be analyzed. Based on the knowledge of the things past project in conjunction with the planned material combinations 42CrMo4 / EN AC-46000 and C45 / 16MnCr5 the specific material and the geometry-specific basis, for the desired target is given.The arbitrary shape refers at this point to the variation of the flank pitch, the pitch angle and the position of the knurls. For a reliable static and dynamic design as well as for the validation of the continuous numerical simulation of KIFs gaining of knowledge is necessary. Another aim is the enhancement and the generalization of analytical computation approaches for the joining-force and the torque.Based on the mentioned material and geometry-specific base the prospective commercial usability is ensured by the following strategies:Analytical: Design of KIFs with analytical approachesNumerical: Guideline for the continuous numerical simulation for the material-independent dimensioning of axial joint KIFs, of arbitrary shape

• DFG Programme: Research Grants