GrindBall - Novel drive and bearing concept for micro grinding tools

• Applicants: Professor Dr.-Ing. Ekkard Brinksmeier; Professor Dr.-Ing. Rodion Groll; Professor Dr.-Ing. Bernd Orlik
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 171780428

The manufacturing of small scaled parts with complex geometries requires a purposeful miniaturisation of machine tools. One approach for the adaption of machining modules into reduced work spaces is the combination of tool drive and bearing in one compact module. During the first funding period, an electromagnetic bearing and a fluidic drive were fused into the innovative GrindBall module for the purpose of micro grinding small cavities. This concept allows a contact-free support, positioning and drive of a small scaled, spherical grinding tool in order to achieve material removal.Based on the successful implementation of the machining module's prototype, micro grinding of brittle materials and its novel, module inherent machining kinematics shall be investigated in the second funding period. The grinding results generated in this investigation will be used to develop a process window for the micro grinding with a shaft-free grinding tool (axis-free grinding) for the first time. New methods to increase drive power and tool positioning dynamics shall be developed by further research in the fields of hybrid and multi-phase fluidic drives, low remanence and highly ferromagnetic materials as well as investigations of electromagnetic effects during the positioning of the grinding tool. In addition, the available machining power shall be used in a more efficient way by means of force controlled grinding, developing and investigating the control of selected process parameters. The control route may be the GrindBall module itself or feed modules of research partners within the priority programme. The analysis of interactions between the GrindBall module and measurement modules or feed modules during micro grinding is also a research topic in the next funding period. GrindBall's ad hoc combinability with further modules of the small machine tool shall be intensified by a continuously exchange of information with research partners during the complexity phase of the priority programme and the deployment of the programme's own common mechanical, informational and energetic interface. The ultimate goal within the proposed project is to implement axis-free micro grinding of brittle materials in a small machine tool through the planned investigations and cooperation activities within the priority programme 1476.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1476: Small Machine Tools for Small Work Pieces
• Participating Person: Professor Dr.-Ing. Hans Josef Rath (†)