As the world accelerates towards electrification, both the automotive and aerospace industries face mounting pressure to innovate and deliver more efficient, cost-effective and sustainable electric machines (eMachines). Ben Hunt, Lead Engineer, WMG Winding Centre of Excellence at the University of Warwick explains.
At the WMG Winding Centre of Excellence at the University of Warwick, a team of academics and engineers are hoping to help original equipment manufacturers (OEMs) take significant steps towards providing faster, more efficient and cost-effective automotive and aerospace motor solutions. Central to this is the team’s work with continuous hairpin winding technology, and, as lead engineer Ben Hunt believes this presents a strategic opportunity for the UK to emerge as a leader in adopting and scaling this transformative technology.
“The WMG Winding Centre of Excellence is a part of the Driving the Electric Revolution Industrialisation Centres (DER-IC) network. Comprising over 30 research and technology organisations (RTOs), the network provides open access to expertise and state-of-the-art manufacturing, test and validation equipment. We are proud to share the latest innovations in PEMD with our clients, while continuously pushing the boundaries of what’s possible in our open-access facilities.
“We’re seeing first-hand how continuous hairpin winding accelerates time-to-market, offers greater design flexibility and enhances the performance of eMachine designs. This technology, which significantly reduces manufacturing complexity while enhancing design flexibility, is helping OEMs develop more reliable products with improved efficiency. Importantly, continuous hairpin winding also aligns with wider sustainability goals, reducing the environmental footprint of electric vehicle (EV) production while opening up new opportunities for high-power density applications.”
What sets continuous hairpin winding apart from traditional winding methods is its ability to reduce manufacturing complexity. The conventional hairpin design typically requires multiple assembly steps, including numerous welded joints, which can be prone to failure.
“By eliminating most of these welding points, continuous hairpin technology not only improves reliability but also enhances design freedom. The drive for higher power densities, particularly in high-speed electric machines, is reshaping the PEMD manufacturing sector. Continuous hairpin winding is a key enabler in this evolution. It simplifies the complex winding process of traditional hairpins, offering a more streamlined and efficient approach, which is essential for high-speed, high-voltage applications. For OEMs, this advancement holds significant promise.
“In automotive applications, for instance, the ability to improve motor efficiency means that vehicles can use fewer batteries—leading to lighter, more affordable, and environmentally friendly designs. This is especially relevant as the transition to electric propulsion accelerates. A more efficient motor results in fewer raw materials and reduced weight, enabling OEMs to offer cost-effective products without compromising on performance.”
Beyond the automotive sector, continuous hairpin technology presents opportunities beyond automotive, opening up possibilities in aerospace and other sectors where high-speed applications and energy efficiency are paramount.
Getting from concept to production faster
Despite the clear benefits, the adoption of continuous hairpin winding technology in the UK automotive and aerospace sectors is not without its challenges. High-speed, high-voltage eMachines, particularly in the automotive and aerospace sectors, present unique manufacturing difficulties, from insulation material challenges to the stress placed on components by higher switching frequencies.
The process of integrating continuous hairpin technology into production lines can also be capital-intensive, requiring significant investment in new equipment and longer lead times for implementation. However, partnerships with facilities within the DER-IC network, such as the WMG Winding Centre of Excellence, are helping to mitigate these barriers. Through collaborative projects, UK manufacturers can access the state-of-the-art winding technologies and testing capabilities required to bring continuous hairpin designs to market more quickly and with reduced financial risk.
Ben added: “The WMG Winding Centre of Excellence provides a unique, off-line facility equipped with a full suite of winding equipment that supports the development of volume processes and quality improvements. Our focus on discrete and continuous hairpin winding, along with other advanced winding techniques, enables us to work closely with OEMs to validate and optimise their designs before committing to costly hard tooling.
“By partnering with WMG Winding Centre of Excellence, OEMs can drastically reduce the lead time from concept to production. With access to cutting-edge facilities, including rotor assembly, magnetisation, and in-process testing for electrical, thermal, and mechanical effects across the DER-IC network, we can accelerate the development cycle and ensure that continuous hairpin designs meet the stringent performance and reliability standards required for high-volume production.”
Supporting sustainability and continuous innovation
Continuous hairpin winding supports broader sustainability goals. By improving motor efficiency and reducing manufacturing complexity, continuous hairpin technology enables OEMs to create more environmentally friendly products at a more attractive price point – often a key barrier to consumer adoption for the likes of EVs. The ability to use fewer materials and design more compact, efficient motors means less energy consumption, fewer emissions, and lower costs.
Ben highlights the crucial role advanced facilities like the WMG Winding Centre of Excellence play in positioning the UK as a global leader in continuous hairpin winding technology. By fully embracing these resources and enhancing collaboration between academia and industry, OEMs can unlock innovation and help secure the UK’s leadership in this cutting-edge field.
Ben added: “Our partnerships with industry players allow us to push the boundaries of what is possible in electric machine design, from testing new materials to developing novel manufacturing processes. This ecosystem of collaboration is vital for keeping the UK competitive in the global PEMD market. Looking ahead, continuous hairpin winding will continue to evolve. Innovations in materials, such as Litz wire, hollow conductors, and new approaches to stator core assembly promise to further reduce production complexity and improve motor performance in high-speed applications. As these advancements come to market, UK OEMs can position themselves to capitalise on the benefits of continuous hairpin technology and we’re here to support them to do so.”
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