Gehring: Stator production process step impregnation
For the first time, the general public will have the opportunity to find out about HQ bending. The new bending technology from Wafios makes it possible to produce hairpins with a very flat head geometry. This reduces the required installation space, making it possible to produce very compact stators. Many electric motor manufacturers are already waiting for this, as installation space is scarce everywhere. Wafios uses a special rotation unit and a newly developed tool concept to manufacture the hairpin tip. The quality of the output is on a par with competing technologies such as die forming. However, the 3D bending process from Wafios is more flexible, as a large number of hairpin geometries can be produced without changing the tool. In addition, the insulation of the starting material remains 100% undamaged. “We combine the advantages of 3D bending with those of die forming,” emphasizes Tobias Single, Head of E-Mobility at Wafios. “We therefore see our process as the technologically more advantageous alternative to die forming for our customers.”
Another trade fair focus in this context is the application of HQ bending on the SpeedFormer systems from Wafios. These forming machines are designed for large quantities and outputs. “Thanks to their great flexibility, our SpeedFormers are suitable for both automotive and non-automotive applications, e.g. for various industrial engines,” emphasizes Tobias Single.
Flexible production lines
With additional modules, the SpeedFormer systems can be expanded into complete production lines, for example for stator production. This is where Gehring comes in. The company’s experts in prototype stator construction create feasibility analyses and holistically designed processes for electric motor production, among other things. Gehring acts as a general contractor in the partnership with Wafios and initially supplies the setting machine, the so-called SNT machine, after the SpeedFormer. Using a jointly developed interface, this machine takes the hairpins and assembles them into a complete stator-pin package. All developments here focus on reducing the cycle time so that the complete Haripin basket can also be placed in the stator package on the stator assembly machine. “Our further developed SMB machine is used here,” says Marcell Wardin, Head of Sales and Marketing at Gehring.
The Ostfildern-based company also has solutions for typical connection processes such as twisting, contacting and potting in its portfolio. The lines are scalable, depending on process requirements or quantities. In addition, the concept of both companies allows “set-up in cycle”. This means that switching to a different product variant does not cause any additional non-productive time. “The principle of the current line developments is based on three key features – highly flexible production, reduced set-up times and increased capacity utilization of the production lines,” emphasizes Marcell Wardin.
Coils for axial flux motors
Wafios is presenting a second new bending concept for coil production, more precisely, for the production of coils, in particular single and double coils for
Axial flux motors. The bending technology requirements for this type of coil are even higher than for hairpins. Due to their electromagnetic advantages, extremely flat bent single and double coils are mainly used in high-performance e-drives, e.g. in premium sports cars. Wafios has realized a project for this with the Swedish sports car manufacturer Koenigsegg. The production of double coils in the 3D bending process is a major challenge. According to Wafios, there is currently no comparable bending process available on the market that delivers results of comparable quality.
A bending challenge: coils for axial flux motors in single and double design
Flat-bent coils for axial flux motors are increasingly found not only in main drive units but also in small motors, e.g. in steering systems. There is nothing to prevent the bending process from being used in this segment. “We also see a future market for our technology in various non-automotive applications, an important example being power tools,” says Tobias Single. Product samples for demonstration purposes – hairpins, coils, busbars, stators, etc. – will be available at the Gehring and Wafios stand. Other future-oriented topics of the two trade fair partners are stators with waveguides and aluminum stators.
“Comparison: Hairpin using the standard bending process and the new HQ bending process (below) with a significantly flatter geometry. Image source: WAFIOS.”
Gehring and Wafios at Coiltech Germany, Augsburg March 20-21, 2024: Booth 2-F16
