Fraunhofer ILT improves the hairpin laserwelding process with a CANUNDA-HP module

Hairpins Welding …

copper parts in motor windings that improve the efficiency of electric motors :

> Copper Cu ETP

> 4 x 1 mm harpins

> 1080nm

> 3500 W

> 175 mm/s.

… with a central spot surrounded by a ring

in the processing plane:

> Central Spot: 135 µm
> Ring: 520 µm
> Distribution(40% ; 60%)

Number of spatters /2

The partner

Fraunhofer Institute for Laser Technologies (ITL) is a German research institute whose aim is to transfer laser technology to industry, in particular through the development of new laser sources and photonic components for various processes such as cutting, welding, surface treatment and micro-fabrication.

The application

Hairpins are hairpin-shaped copper parts that replace the traditional round wires in the rotor and stator windings of motors. With a higher fill factor, they improve the efficiency of electric motors.

The problem

While the traditional round wires used in stators already form a continuous path, hairpins need to be connected to each other to form a complete electrical circuit. As the process of cutting hairpins is not very reproducible, welding requires a high degree of precision.

The CANUNDA-HP solution

CANUNDA-HP for copper welding delivers a beam consisting of a central spot surrounded by a ring, ideal for copper welding. With its fully reflective design, thanks to MPLC technology, and optimal optics cooling, it can handle high powers.

Industrial integration of the CANUNDA-HP

CANUNDA-HP module was used at Fraunhofer ILT to weld 4×1 mm ETP copper hairpins. The beam shaper was used with a Scanlab IntelliScan III 20 scanner and a 163mm F-theta lens.