Basic research of a non-contact bidirectional actuator for the design of cutting machine tool guide systems without a wrap-around construction

• Applicant: Professor Dr.-Ing. Berend Denkena
• Subject Area: Production Automation and Assembly Technology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 496161268

The objective of the presented research proposal is the development of fundamental knowledge concerning a contactless bidirectional actuator, which offers a sufficiently high force density and robustness for the design of guides and bearings without a wrap-around construction in cutting machine tools.The solution approach involves the use of electromagnetic actuators to generate tensile forces. Accordingly, the focus is on the design and research of a complementary guide element for the contactless introduction of repelling forces. In combination with an electromagnet, a hybrid actuator is created which can provide sufficiently large bidirectional forces over a positioning range of at least ±250 µm. The working range of the hybrid actuator of at least 0.5 mm provides sufficient reserves for low-cost commissioning, reliable operation and the implementation of additional functions of the active guide system. Especially for machine axes with large travel ranges, significant advantages regarding the achievable linearity and the required manufacturing and assembly tolerances result from the advanced functions of the active guide, i.e. fine positioning and error compensation.The functional principle of a fluid pad is intended as a solution for the repulsive force effect. This technology allows for the contactless introduction of repelling forces with compressed air as an easy to handle medium. In addition, the operating principle enables comparatively large variations of the levitation height of the guide element independent of the downstream air gap and places only minor demands on the guide surface quality. However, currently available solutions are unsuitable for use in machine tools: On the one hand the supply pressure and thus the achievable forces are severely limited, on the other hand the use of flexible sealing elements leads to a load-dependent change in the levitation height of the guide element. The use of more rigid materials for higher pressures and forces with sufficient decoupling of the downstream gap and the floating height of the guided component is therefore expedient. A controlled adjustment of the levitation height of the hybrid actuator therefore requires an adaptive mechanism for setting a constant downstream air gap. In particular, the scientific challenge in designing this mechanism for a self-regulating air gap is the consideration of interactions of the air flow with rigid and flexible mechanical components. In addition to the identification of relevant design parameters - including the specification of the materials used - the interactions between the fluidic and electromagnetic actuators also represent important research topics.

• DFG Programme: Research Grants