After months of collaboration, Advanced Electric Machines (AEM) and SAF-Holland have brought the AEM HDRM150 motor to series production, following joint efforts in knowledge sharing and design refinement.
SAF-Holland set out to find a motor solution for its then-to-be-launched SAF Trakr e-axle. Their search led them to the AEM team, with the expertise to engineer a smaller, magnet-free motor that could freewheel when not in use.
“What struck us from the outset was AEM’s willingness to be flexible,” explained Olaf Drewes, director of group innovation trailer at SAF-Holland. “Both sides saw it as a good opportunity to develop a capable product that was tailored to our specification, but could also be adapted for other applications.”
SAF-Holland’s e-axle for commercial vehicle applications was announced in 2020 and enables the end user to recuperate energy otherwise lost during the braking and overrun phases of driving. The motor serves as a generator, converting the kinetic energy (motion) into electricity. This can then be stored in batteries and used to power auxiliary devices on the vehicle, such as refrigeration units, cargo lifts and walking floors.
“Most of the air-cooled motors available in this performance class (20 kW) are designed for stationary applications,” Drewes said. “As a result, they’re big and they’re heavy – the opposite of what we needed for our e-axle. Fleet operators want to maximize payload, which means keeping unladen vehicle weight to a minimum. It also needed to fit within the wheelbase of the vehicle as part of the axle assembly, which limits its overall size.”
“The motor that AEM has produced is the perfect technical fit for the SAF Trakr”, Drewes added. “It’s light, efficient, future-oriented and is built with no rare-earth metals, instead using materials that make it simple to recycle at the end of its working life.”
“We see our customers as partners in the process and that was definitely the case with SAF- Holland,” said AEM’s HDRM150 project manager, Kern Boyd. “We know it’s not solely about the building of a motor – the validation and testing process is just as important. The team at SAF-Holland was key to proving that this new-to-market machine works well in the environment in which it was designed to perform.”
“Equally as important to the success of this design is the support both parties offered when it came to addressing engineering challenges,” Boyd added. “When you’re creating something from the ground up, there are always going to be issues to overcome, both in the technology itself and with its intended application. We have processes in place to face these complexities head on and devise a solution. It took several revisions, for example, to ensure that the motor could be effectively air cooled. Each time, the team came together and sought a different approach.”
“Not only do we have a motor that is a bespoke fit for our axle – but it’s a solution that is extremely sustainable,” said Drewes. “As an organization, we’re committed to bringing sustainable products and innovations to market. AEM has undoubtedly played a major role in supporting us on this journey with SAF Trakr.”
In related news, Orbis Electric has introduced HaloDrive, an advanced axial flux motor-generator designed around a modular four-part architecture featuring an injection-molded plastic stator and a tunable gearset. Read the full story here