BUP3 - ProTrakt

Process development for lightweight rotors of high-speed electric traction drives

Speeds occurring during operation in permanent magnet excited synchronous machines lead to high mechanical loads on the rotor components. These lead to settling processes, which cause permanent changes in the rotor unbalance during operation. These in turn can exceed the permissible residual unbalance and lead to impairment of the so-called NVH behavior of the electric traction drive. NVH in this context refers to the audible or perceptible vibrations in the electric motor (noise, vibration, harshness). In addition, permanent magnet rotors should be particularly lightweight.

In the ProTrakt project, therefore, a novel process chain was developed that enables both low rotor mass and low set effects at high speed loads. The core of the approach is a novel process for fixing the magnets within the magnet pockets of the laminated core and for connecting the laminated core to the rotor shaft. Experimental validation of the approach was successfully completed using runout and unbalance measurements (as shown) as well as static torsion tests.