wbk Institut für Produktionstechnik

Neueste Publikationen

[ 1 ] Fleischer, J.; Pfund, T.; Wirth, F.; Fraider, F.; Halwas, M.; Hausmann, L. & Wößner, W. (2021), „Agile Produktion elektrischer Traktionsmotoren als Antwort auf volatile Märkte und Technologien“, ZWF Zeitschrift für wirtschaftlichen Fabrikbetrieb, Band 116, Nr. 3, S. 128-132. 10.1515/zwf-2021-0025 [30.11.-1].
Elektrische Traktionsmotoren nehmen - unabhängig von der Art der Elektrifizierung - eine zentrale Rolle im Mobilitätswandel ein. Volatile Rahmenbedingungen, Märkte und Technologien führen jedoch dazu, dass das Investitionsrisiko in dem Stand der Technik entsprechende Produktionssysteme mit eingeschränkter Flexibilität als hoch einzustufen ist. Vor diesem Hintergrund soll im Forschungsvorhaben AgiloDrive durch die integrierte Entwicklung modularer Produkt- und Produktionsbaukästen eine nachfrageorientierte Wandlungsfähigkeit des Produktionssystems befähigt werden.

[ 2 ] Hausmann, L.; Wirth, F. & Fleischer, J. (2021), „Opportunities of Model-Based Production-Oriented Design of Stators with Hairpin Winding“. IEEE, Piscataway, NJ, S. 01. Aug.
The hairpin technology is a promising and widely used production method that meets the growing demand for high productivity and quality in the manufacturing of electric drives caused by increasing sales of electric vehicles. In comparison to conventional winding technologies, the technology provides significant advantages regarding the ability for automation, the productivity as well as the attainable filling factors, but also exhibits weaknesses concerning the process reliability and manufacturing constraints, which limit important degrees of freedom in electric design. Within the process chain of stator manufacturing by hairpin technology, especially the manufacturing constraints of the multi-step shaping processes of hairpin coils as well as the twisting and subsequent welding processes of the open coil endings show a high interdependency with important design parameters such as wire dimensions, coil pitch, stator diameter and number of slots. However, the complex interactions can only be captured by experimental tests on machine prototypes, which often leads to numerous time- and resource-intensive adaptations of tool and machine. To enable a production-oriented, cost-efficient design of stators with hairpin winding, several process models are introduced within the scope of this paper that allow a consideration of manufacturing influences within early periods of electric drives development. For this purpose, numerical approaches of process modeling carried out in Abaqus FEA are presented for different types of tool-bound bending processes as well as the twisting process. Furthermore, a study on the influence of different wire dimensions is carried out using the examples of rotary draw bending and twisting processes. In addition, simplified mathematical models for minimizing the winding head size under consideration of manufacturing aspects are described. The proposed methodology of virtual process assessment by FE-based as well as simplified process models offers particular advantages in the early phase of product design.

[ 3 ] Ruhland, P.; Matveev, A.; Nielsen, K.; Kvinnesland, K.; Coutandin, S. & Fleischer, J. (2021), „New Production Techniques for Electric Motors in High Performance Lightweight Applications“. IEEE.
Lightweight high-efficiency electric motors are beneficial for mobility systems providing higher range for automotive applications or longer flight time for aerial applications. The emerging ironless motors already outperform iron-cored motors on efficiency and peak torque capability but still have lower rated specific power and torque. To close this gap and develop the all-around best motor technology for the automotive and aerial applications new production methods for both the stator and the rotor have been developed. For the stator the patented FiberPrinting technology is presented, which is based on a weaving process with the help of a tailor-made machinery, followed by molding process. In the rotor the rotating back iron of the double airgap motor design is made from a soft magnetic compound, produced with an injection molding process. To enable highest lightweight potential, the back iron is designed as a 2-component-part with soft magnetic material in the magnetic active areas and PA6-GF30 for the structural integrity. The combination of both technologies shows extreme potential in terms of lightweight design and electrical and magnetic losses, which is validated by simulations and first experiments of the manufactured components.

[ 4 ] Kupzik, D.; Bachtin, A.; Coutandin, S. & Fleischer, J. (2021), „Experimental Parameter Identification for the Bending Based Preforming of Thermoplastic UD -tape“. Technologies for economic and functional lightweight design, Hrsg. Dröder, K. & Vietor, T., Springer, Berlin, S. 313-325.
The combination of different types of plastics can be advantageous to obtain a good component performance at a reasonable price. For this, a compromise between mechanical properties and cheap manufacturing has to be found. In the research project GRK2078, the manufacturing of hybrid components consisting of long fiber reinforced thermoplastics (LFT) and unidirectional endless fiber reinforced material (UD-tapes) is researched. The LFT is the main constituent of the components. Local UD-tape reinforcements are added in areas with high load for a large effect or low geometric complexity to minimize preforming effort. To keep the cost low, a novel preforming process for the UD-tapes is in development at wbk Institute of Production Science. The aim is to enable the shape flexible, tool less forming of UD-tapes. To obtain this, the process is based on sequential bending of the UD-tape on several positions along its longitudinal axis during handling operations. To conduct the process, a supply unit and an industrial robot with a gripper with integrated heating devices are used. In this paper, the experimental examination of the process and the identification of suitable parameters on the shape of the preform are presented. The main influencing factors are the type of UD-tape, the heating of the tape and the movement of the robot. The processes are conducted with PA and PP carbon fiber tapes. The process quality with contact and radiation heating are compared and the respective heating duration is identified. For the robot movement, a kinematic description of the process is derived and compared to a circular bending movement. With the identified parameters, the process can be conducted reliably. The resulting accuracy limit and the process time with these parameters are described in this paper.

[ 5 ] Sell-Le Blanc, F.; Weiße, L.; Klusmann, B.; Lüttge, W.; Dunker, A.; Lindhorst, N. & Halwas, M. (2021), „Development of an alternative Round Wire Process Chain: Automated Trickle Winding“. IEEE.
In this paper the fundamental development of a new process chain for manufacturing of round wire windings will be presented. The development was carried out inside the project NeWwire which was a cooperation of several universities, the companies Volkswagen, Essex and Aumann. The project was publicly funded by the Federal Ministry of Education and Research (BMBF) in Germany. The basic approach of the new winding technology was motivated by the fact, that even with today's automated processes for the production of distributed round wire windings, a superior winding can still be created by a skilled worker. Based on the manual process and the need for automation, an alternative series of process steps was developed, tested with functional samples and implemented in machine prototypes for further development.

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