The future of stator and rotor manufacturing

The principal trends in the manufacture of stators and rotors for e-mobility are the pursuit of CO2 neutrality and the S-curve of technological advancement. The next significant industrial transformation will be the attainment of CO2 neutrality across the entire value chain. The conventional progressive tools currently employed in the production of stators and rotors, which result in the generation of 50% of the electrical sheet material waste, will no longer be feasible in the next generation of motors. The high proportion of material results in a disproportionately high CO2 impact, which will no longer be financially viable. New processes, such as segmentation or axial flux motor concepts, which result in a reduction in material resource consumption, will become increasingly important.

The advent of ever larger punching presses and more complex progressive punching tools with a length of over 3 metres has presented two significant challenges. From the perspective of operational and maintenance requirements, these machines necessitate the presence of highly specialised personnel. Additionally, the availability of such machinery is constrained by factors such as coil changes and the aforementioned complexity, with a typical availability rate of only 60-70%. Moreover, there is an increasing tendency to integrate gluing or baking stations with the aforementioned machinery, which ultimately results in a further reduction in availability. Given the considerable investment involved, such low availability levels are not an efficient use of resources.

A trend towards segmentation can be derived from projects with our customers, often in the area of research or pre-development. The influencing factors mentioned above are being taken up by our customers, as evidenced by a complete redesign of assemblies, such as the stator and rotor. This includes not only the use of different materials for the stator and rotor, but also the segmentation of the rotors or the construction of the rotors from laminated individual components.

The optimal solution for future production is the formation of small production cells comprising segments and components for stator and rotor stacks. The manufacturing of the stator and rotor is conducted in a wholly independent manner, with distinct material selection and disparate packaging processes employed for each component. This approach allows for the optimal utilisation of materials. The production cells are equipped with a punching tool that has been designed for ease of handling. The tool is capable of achieving over 50 million strokes in the SWD industrialisations without the necessity for regrinding or revision. The availability of the cell is over 95%, and it is operated and maintained by a semi-skilled operator. The involvement of technical or tool specialists is not necessary. The cell is entirely digitalised. The continuous monitoring of all parameters and the storage of production data per component in the form of a digital twin represent integral components of the concept. The production cell is no longer situated in a central location within the stamping plant; rather, it is decentralised within the customer’s own production facility. In accordance with the intricacy of the product in question, remote assistance or an autonomous production line may be employed.