Alumotor: the magnet-free engine design
Challenge
Since the UK government announced its commitment to reach net zero emissions by 2050, a range of programmes have been launched targeting the transport sector, which was known to be contributing around a quarter of the country’s greenhouse gas emissions.
A priority area of research is reducing the environmental impact of road vehicles across their full life cycle and, in 2022, the UK-ALUMOTOR programme was initiated to explore a sustainable electric motor concept that could be suitable for passenger and light commercial vehicles.
Without impacting on the motor’s eventual function or quality, the aim was to remove up to 12kg of rare-earth magnets per machine and reduce the use of high acidification materials such as copper. As well as reducing the motor's need for costly scarce materials, the design would be lowering the environmental impact of its production.
The final design was also to be tailored for UK manufacture at volume production.
Ricardo was to lead the consortium that included Aspire Engineering, Brandauer, Warwick Manufacturing Group at The University of Warwick, Phoenix Scientific Industries, and Global Technologies Racing. Government funding was provided by the UK Research and Innovation’s Driving Electric Revolution Challenge fund.
Approach
By following the principles of sustainability and replacing copper with aluminium windings, the Alumotor design concept was conceived as a simple, efficient, and robust synchronous reluctance motor.
Two power ratings are available. An 80-kW version and 100 kW high-performance version with a peak power of 150 kW. Both versions perform well against targets set by the US Department of Energy and the Advanced Propulsion Centre (APC) roadmaps.
The compact packaging of the standard Alumotor means that it’s easy to integrate with an EV transmission and inverter, with a high operating speed and a shared oil cooled thermal system. Typical applications are for the light commercial vehicle market, including 3.5 tonne vehicles. It’s also suitable for off-highway vehicle, such as construction equipment, articulated dump trucks and crop sprayers, where robustness and low cost are critical and there’s less of a focus on extreme weight reduction and performance.
The high-performance variate of Alumotor is likely to have permanent magnets of some sort, although they will not be rare earth, but ferrites. This will potentially be called a hybrid reluctance motor, as it uses both reluctance torque and magnetic torque – boosting performance characteristics.
Results
In April 2025, the Alumotor design was presented to the public at Materials and Manufacturing Showcase 2025 in London, organised by UKRI.
The aluminium hairpin winding, with the magnet free rotor alongside the innovative cooling technology, demonstrated increased vehicle operating efficiency whilst substantially reducing material costs (which could lead to a 40% reduction on total manufacturing cost).
It is hoped that successful programmes such as Alumotor will encourage other environmentally sustainable designs that target reducing the use of scarce material resources whilst helping to support the mass adoption of electrification.