Cost reduction for manufacturing of electric drives

Fraunhofer IFAM is developing solutions for more economical and efficient Induction machine (IM). IMs are still widely used in electrical drive applications, particularly in the field of industrial drives. They are robust and cost-effective and can start up directly from the line without a frequency converter if required. Even in vehicle technology, IMs are certainly far from being replaced . New manufacturing approaches continue to offer potential for increasing efficiency, improving production quality and reducing costs.

Multi-material connections for squirrel cage rotor

Our experts focus their research and development efforts on manufacturing innovations of rotors. In addition to process and design optimizationin rotor production, these also include the technological evaluation and development of multi-material connections for squirrel cage rotor. Cost reductions and efficiency increases (Higher efficiency class but equal design dimensions) promise hybrid rotors with squirrel cage fabricated from copper and aluminum or from composites of different aluminum alloys. We provide significant inputs for the industry so that it can produce these in series in the future. To this end, we rely on various process routes. One approach, for example, is the compound casting for joining the rotor bars to the end rings, another is using ultrasonic welding for the connection between end rings and rotor bars. This new joining technology was developed as part of the "UltraHybro" project.

In-house prototype manufacturing of rotors for IMs

With its interdisciplinary team, Fraunhofer IFAM also has the necessary expertise to calculate, design and manufacture prototypes of IMs. The team applies methodical approaches for integrated multidisciplinary development across domain boundaries. These are combined with many years of expertise in the automation of design processes for greatly accelerated development. We are able to incorporate specific manufacturing knowledge about casting processes for the production of squirrel cages rotors directly into the design process.

With the help of our in-house system technology for laser cutting and packaging of laminated core as well as for high pressure die casting, we can manufacture entire prototype rotors for IMs. We enable experimental validation through the use of metallographic analysis and the scanning of rotors using computer tomography (rotor CT). Complete system tests are possible on our in-house test bench for electric motors.