New motor cooling solution could lead to lighter EVs

Researchers from the Fraunhofer Institute for Chemical Technology and the Karlsruhe Institute of Technology have developed a new method for cooling electric motors, which could help reduce the weight of EVs. With the new cooling method, motors can be housed in lighter-weight polymer materials, and they also benefit from increased efficiency and power density.

The new method involves directly cooling the stator and rotor, the two components of an electric motor. Currently, the typical cooling method is to conduct heat from the stator through the motor’s metal housing into a cooling sleeve filled with cold water. In the new method, the researchers replaced the conventional round wires in the stator with rectangular flat wire, creating space for an integrated cooling channel.

“In this optimized design, the heat losses can be dissipated through the cooling channel inside the stator, eliminating the need to transport the heat through the metal housing to an exterior cooling sleeve,” said researcher Robert Maertens. “In fact, you no longer need a cooling sleeve at all in this concept. It offers other benefits, too, including lower thermal inertia and higher continuous output from the motor.”


Coolant circuit in the stator

The direct-cooling solution also allowed the researchers to replace the metal housing of the motor with lighter-weight polymer materials.

“Polymer housings are lightweight and easier to produce than aluminum housings,” said Maertens. “They also lend themselves to complex geometries without requiring post-processing, so we made some real savings on overall weight and cost.”

So far, the new design has only been validated through simulation, in which the researchers found it can dissipate 80 percent of the expected heat from the electric motor. The next step is to assemble the motor and validate its performance in real-world operation.

 

Source: Fraunhofer Institute for Chemical Technology

  • freedomev

    I don’t think so. First others do this so not new but making parts of a motors from heat insulating polymers is not bright, especially a these power levels.

  • Dan Cizmarov

    And now electric motor will be less reliable than aluminium housed motors .lol . ok have fun kids consumer will pay all that unnecessary modifications / stuff when gets broken.

  • Solarman

    “So far, the new design has only been validated through simulation, in which the researchers found it can dissipate 80 percent of the expected heat from the electric motor. The next step is to assemble the motor and validate its performance in real-world operation.”

    Yeah, I read this as vaporware until a proof of concept has at least 20,000 miles in operation under (wet) and dry with cold and hot temperatures. I’m gonna go out on a limb and say IF this gets to the mule testing mode, they will quickly find operational vibration and torques will break the cooling system.