Investigation of the formation mechanisms of micro lead during external cylindrical plunge grinding of sealing counterfaces

• Applicants: Privatdozent Dr.-Ing. Frank Bauer; Professor Dr.-Ing. Thomas Bergs
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering ; Engineering Design, Machine Elements, Product Development
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 509140813

Radial shaft sealing systems are used in many technical applications and products for the sealing of shaft openings. Components of a radial shaft sealing system are the radial shaft seal ring (RWDR), the shaft counterface and the fluid to be sealed. In dynamic operation, these three components are in complex tribological interactions. Thus, in addition to the RWDR and the fluid, the function depends significantly on the shaft counterface. In external ciylindrical plunge grinding, a stochastic surface structure is created under optimum conditions with a large number of grinding grooves oriented in the circumferential direction. Under unfavourable conditions, cylindrical plunge grinding can also produce surface structures that deviate from the circumferential direction. When the shaft to be sealed rotates, these structures are able to convey the fluid through the sealing contact and beyond. Such critical surface structures on sealing counterfaces are referred to as lead. A further distinction is made between macro and micro lead. Especially micro lead is particularly harmful for a radial shaft sealing system due to a high conveying effect. How and under which conditions a micro lead occurs during the grinding of shaft counterfaces has not yet been scientifically investigated.The aim of the research project is therefore an empirical-analytical model for the prediction of the influence of the tool and process parameters on the resulting micro lead structures during external ciylindrical plunge grinding. On the basis of the experimental investigations, the cause-effect relationships between the process and tool parameters and the formation of micro lead during grinding of shaft counterfaces are explained. With the knowledge of these correlations, micro lead can be predicted and avoided by a suitable process design, selection and preparation of the grinding wheels. In order to achieve these goals, an interdisciplinary cooperation between the Department of Sealing Technology of the Institute for Machine Elements at the University of Stuttgart and the Chair of Manufacturing Technology of Laboratory for machine tools and production engineering WZL at RWTH Aachen University takes place.

• DFG Programme: Research Grants