Electric motors are at the heart of the electric vehicle (EV) powertrain, and their design choices directly influence efficiency, durability, and performance across vehicle types.
Marcus Hays, Founder and CTO of Orbis Electric.
For heavy-duty applications, such as commercial trucks to high-torque passenger vehicles, optimizing motor architecture and materials can mean the difference between peak performance and costly inefficiency.
As electrification scales, manufacturers face added pressure to deliver motors that perform under heavy payloads, frequent stop-start cycles, and demanding torque requirements, all while mitigating thermal challenges and reducing reliance on constrained materials.
Marcus Hays, Founder and CTO of Orbis Electric, is focused on meeting those demands head-on. Orbis Electric designs lightweight axial flux motors engineered to accelerate the global transition to low-carbon mobility solutions radically. With a career steeped in motor innovation, Hays has championed advancements that blend mechanical ingenuity with material efficiency, aiming to redefine the possibilities for EV propulsion systems.
In this Q&A, Hays shares his perspectives on the advantages of axial flux over radial flux architectures, the integration of mechanical gearing to reduce reliance on magnetic materials, and the engineering trade-offs of in-wheel motor systems. He also discusses thermal management strategies, predictive control algorithms, and how material choices can both reduce supply chain risks and unlock new performance gains.
Here’s what he has to say…
For larger EVs and commercial trucks, how can motor design and materials sustain efficiency under heavy loads, frequent stop-starts, and high torque?
Marcus Hays (MH): By simply substituting magnetic materials with mechanical gearing, it reduces the power needed to achieve an equivalent amount of torque, which lessens the thermal challenges while, counterintuitively, improving efficiency and durability.
How do axial flux motors compare to radial flux architectures in terms of power density, thermal performance, and scalability across different vehicle platforms?
MH: The physics of axial flux motors inherently offers significant improvements over radial flux, whether the measurement is power, torque, or thermal performance. Axial flux designs required overcoming the comparative complexity of the typical active materials configuration to reduce the amount of magnetic materials and attendant thermal losses, particularly at high RPM.
The switch from conventional cooling to an impingement oil cooling method allows for the replacement of the aluminum stator and its complex cooling channels with a highly simplified and low-cost injection-molded stator. By substituting almost 50% of the magnetic materials with a modular single-stage planetary that reduces weight, cost, and heat, it’s possible to design axial flux motors with a heat exchanger built into the motor case.
Another advantage is that the entire axial flux motor assembly can be modular, meaning the length of the motor can be changed and the number of rotors increased or decreased depending on the torque and power requirements. This allows them to serve a wide variety of vehicle platforms that currently range from passenger BEVs to medium and heavy-duty truck PHEVs.
What are the benefits and engineering challenges of in-wheel motor systems, and how do they influence vehicle dynamics such as ride quality, handling, and stability?
MH: In-wheel motors or IWMs reduce latency in dynamic control systems in conjunction with true torque vectoring with instantaneous wheel speed control (without deploying braking systems to control wheel speed). IWMs also reduce hundreds of pounds of weight and shift the center of mass from a typical passenger vehicle, impacting the future of mobility.
As an example, the weight difference between the corners of a conventional wheel and our motorized wheel is 5kg +/-, which is impossible to discern even for professional test drivers from behind the wheel.
The powertrain team at a top OEM passenger vehicle company recently shared that the real impediment to the broader adoption of IWMs has been the lack of torque. That’s changing, thanks to improvements in handling and control dynamics.
Overview of Orbis Electric’s lightweight axial flux motor with integrated planetary gearing, designed to improve efficiency, reduce reliance on magnetic materials, and streamline thermal management.
How does placing the motor within the wheel hub affect thermal management, especially during high-load operation or urban stop-start driving cycles?
MH: Given the various aerodynamic advances of contemporary cars, capturing the airflow that passes through the wheels and wheel wells is challenging. To address these challenges, the design incorporates a heat exchanger built into the motor case, which works in tandem with an oil-cooling system that uses the rotor as an oil pump.
Replacing the typical full reliance on permanent magnets with a single-stage planetary system helps reduce the temperature of the active materials. The final piece of the puzzle is the modularity of the assembly, which allows the planetary ratio to be altered from 2.5:1 to 5.2:1, allowing us to meet the rigors of stop-start driving cycles among a large cross-section of vehicles mechanically instead of electrically.
How can modern motor control strategies (such as FOC or predictive algorithms) be optimized to work in tandem with axial flux or in-wheel motors to improve responsiveness and overall vehicle efficiency?
MH: Field-Oriented Control (FOC) is essential for achieving high efficiency, especially at higher speeds. Fortunately, today’s advanced simulation tools, guided by experienced engineers, can run thousands of permutations based on known torque data in just weeks, replacing the time-consuming trial-and-error methods of the past.
Once the system is deployed, a predictive algorithm takes over, fine-tuning performance to extract maximum efficiency from the driving cycle or specific use case.
In our commercial vehicle applications, these algorithms are critical. They enable hybrid configurations to achieve a 60% or greater improvement in fuel economy using only a small battery. When driver input is removed by eliminating manual throttle and braking, the efficiency gains can be even more substantial.
What role can advanced materials play in reducing dependence on constrained supply chains without sacrificing torque, efficiency, or reliability?
MH: Advanced materials allow us to substantially reduce the volume, cost, and reliance on NdFeB without affecting performance. This points to how simple, often old-school solutions can alleviate even very large-scale problems, including supply chain and materials challenges.
To meet OEM passenger car torque and power requirements with zero neodymium, the simple addition of a gearset delivers unparalleled levels of torque.
How can electric motor designs be optimized to work synergistically with battery management systems for better overall range and thermal performance?
MH: Producing high levels of torque mechanically reduces power consumption (and heat), which allows for the replacement of NMC chemistry with LFP with no loss of range or performance.
What considerations go into selecting motor materials that avoid tariffs or export restrictions, while still meeting thermal, magnetic, and structural requirements for high-efficiency EV applications?
MH: To minimize supply chain risks and yield better, more resilient end products, reduce the volume of active materials, including magnetic materials, but also copper, aluminum, and various adhesives.
By depowering the magnetics and replacing that torque with mechanical alternatives, you can reduce heat and thermal loads significantly, thus yielding a more efficient and more robust motor (and in the end, a better vehicle by all accounts).
Filed Under: Electric Motor, FAQs, Q&As