PEM Works to Reduce Tooling Costs for E-Motor Production


The chair "Production Engineering of E-Mobility Components" (PEM) of RWTH Aachen University has started the "variTwist" project with its Berlin-based industrial partner Röscher GmbH. In the joint project, which is funded by the German Federal Ministry for Economic Affairs and Climate Action, the partners are researching how to significantly reduce the high costs of certain processes in electric motor production. To this end, a marketable, flexible tooling system for twisting flat copper conductors shall be developed over the next two years.

  A constrained hairpin stator Copyright: © Röscher GmbH

Strictly defined production steps not only advantageous

As a result of the ongoing electrification of mobility, demand in the field of electric drives is steadily increasing. To meet market demand, hairpin technology has become established for electric motors in recent years. Due in particular to the strictly defined manufacturing steps, it is said to offer high potential at both product and process level. On the other hand, the process chain is characterized by tool-bound manufacturing steps that can only be varied with great effort and high investment.

Investment for tools currently up to 200,000 euros

"The step of twisting is a particular cost driver in the production of hairpin stators for electric motors," says PEM Director Professor Achim Kampker. "Here, special tools with high requirements for tolerance, accuracy, and strength are needed." The corresponding investment for a tool set is therefore in the range of 100,000 to 200,000 euros – representing a considerable hurdle in terms of flexibility, especially in the prototype sector. The soon to be developed system is to be adaptable to the different variant drivers in hairpin stator production and shall thus bring a massive reduction in tool costs as well as delivery times, especially in prototype and small series production.

Further information on the project is provided here.