ThinKing February 2019 - 3D printing enables cooling channel to be “concealed” in housing



Benefit from less weight and functional integration.

From the outside the part looks pretty unremarkable. But there is much more to discover: Parare GmbH has integrated the spiral-shaped cooling channel right in middle of the electric motor housing. The motor now takes up less space as the cooling is integrated in the housing – and what was previously an entire component assembly is now just one component. This transformation has been made possible by metal 3D printing, which also ensures that only as much material is actually used as it is necessary.

The lighter the vehicle, the less energy it needs. In motor racing every gram counts. As the power increases it becomes an increasing challenge for electric motors in particular to dissipate motor heat in a very limited installation space. Why not integrate the cooling channel in the motor housing itself and in this way give the part an additional function? This was the concept behind the new motor housing produced by Frickenhausen-based company Parere GmbH. “Maximum weight savings, minimum installation space and same strength – that was the simple but brilliant idea behind the new motor housing designed by young engineers at the Karlsruhe Institute of Technology and adapted and manufactured with us,” says Matthias Bath, Managing Director of Parare GmbH. The project and design benefited from the lessons learned from manufacturing prototype castings, continues Bath.

30 to 40 percent lighter

The result is a complex part which, at first glance, does not look special at all. A second look, however, reveals the cooling channel just apparent on the exterior of the motor housing. “The channel spirals through the part inside the housing and ensures that heat can be dissipated efficiently,” explains Bath. This means that a separate cooling element is not required because the housing now takes on this function. “What was previously an assembly has been turned into one single component by integrating the function. It is therefore difficult to quantify exactly how much weight has been saved as several parts have now been merged into one – but it is likely to be somewhere between 30 and 40 percent lighter,” says Bath.

Two-fold added value: less weight, more function

The housing is made of aluminium alloy and was manufactured by 3D printing. It weighs in at just 440 grams. “The motor housing with integrated cooling is a great example of the new ways offered by additive manufacturing to produce parts which could not be realized by traditional processes,” says Dr. Wolfgang Seeliger, Managing Director of Leichtbau BW GmbH. Lightweight technology is not just about leaving things out: “3D printing can be used to integrate functions in parts and to optimise the parts in the process. What is really needed in this context is engineering know-how to design parts with complex geometries so that they can do more than they ever could in the past,” says Seeliger. The added value is therefore not only derived from lower weight, but also from enhanced functions.

Get to know Parare as well as other lightweight solutions live at the Hannover Messe

Parare GmbH is one of 14 exhibitors who will be showcasing their innovative lightweight solutions at the joint stand “Lightweight Technologies from Baden-Württemberg” in Hall 5, C18. More information about the joint stand and the press kit with images and information about the exhibitors is available at: