After more than a century, in-wheel technology is ready to help transform mobility as we know it
For more than a hundred years, the internal combustion engine (ICE) – in all its shapes and forms – has been propelling us across land, sea and air. Now, its long-term future appears bleak given the ever-growing concerns of fossil fuels affecting the environment, more so given their supply is finite. Enter e-Mobility – a simple term until you scratch the surface deep enough to reveal a multitude of new or different technologies that all need to come together to keep future generations on the move. The playing field of the automotive industry has significantly changed with the arrival of electric vehicles in the mainstream market. Today, electric vehicle design and production is not limited to only traditional players, but has become an open playing field. There is a vast number of competing powertrain architectures and technologies, some being simple adaptations of the traditional 100-year-old ICE concept, and others more advanced, which bring more radical changes to the vehicle as we know it. Since a lot of different technologies are possible and the development of mass-production compatible electric powertrains is practically in its infancy, vehicle makers are scrambling to find the right formula for the future user. Currently, electric vehicles are competing on acceleration performance and range. In the future, the discussion will be less about cars and more about mobility. Vehicle makers will bring cars to the streets that are connected, have autonomous driving capabilities, and are made to be shared between multiple users. Needless to say, these vehicles will mostly be built on electrified platforms. As battery technology, cost, and production capacity improve, the priorities for the powertrain are shifting. Some of the traditionally most important development drivers will become less important. As an example, one could postulate that the electric powertrain reached a level of efficiency where additional investments will bring only limited overall benefit compared to other possible improvements. And since some electric city cars currently exceed the performance of many ICE sports cars, there is not much need for performance improvement either. This thinking translates into the conclusion that the mechanical actuation of the next generation of vehicles will be much less in the spotlight, while function, safety and comfort, along with a high-level of autonomy and connectivity will become main drivers for vehicle design. E-Mobility activists and electric vehicle technology companies like Elaphe Propulsion Technologies, are creating innovative solutions for designers of current and future vehicles. They lend a much-needed helping hand to EV developers to meet passenger comfort, safety and road security objectives: advancing state of the art on batteries, fuel-cells, motors, drive trains (or lack of drive trains), electro-mechanical control, on-board electronics, sensors, mechanics, thermal- and power management, all packaged in lightweight but durable, minimal maintenance structures. For example, in-wheel electric propulsion can eliminate the entire conventional drivetrain, drastically simplifying and shortening the whole vehicle engineering process from concept to series production. Transmissions, gearboxes, drive shafts, and the associated space constraints are now becoming obsolete. Figure 1 – An in-wheel motor has only a single rotating part – the wheel bearing. The assembly fits in existing design space within the wheel, and is built around the (still, for now) required friction brake, making all the transmission and gearing found in traditional cars, unnecessary. Although the idea of an in-wheel motor platform was already proposed by Ferdinand Porsche at the turn of the 19th century, the underlying technology and the whole ecosystem at that time was in its infancy. A development of in-wheel propulsion over the past two decades has brought the technology to a mature, production-ready state where it now enables a fundamental shift in design for mobility. In-wheel motor platforms now have the potential to reshape the EV industry and support the shift away from performance focus, making way for innovation in packaging, user-experience, driving automation, new safety features, and optimization of the electric vehicle supply chain. The in-wheel concept plays a significant role in the development of compact, transmission-free drive systems. Increased safety, improved handling and unparalleled traction control are just some of the benefits of the decentralized in-wheel architecture. Having a lower overall powertrain weight, a lower center of gravity and optimized balance, the dynamic behavior of the vehicle changes dramatically. The drive architecture, with its weight distribution and contact pressure at precisely the point of traction, allows greater control over the vehicle’s behavior in comparison to standard drives. More so when we consider the possibilities for integration of advanced systems, such as: i) brake blending, which can greatly improve safety on different-adhesion surfaces, ii) active traction control that is constantly optimizing the grip between the wheel and the road and iii) torque vectoring, improving vehicle stability and keeping control over the vehicle’s dynamic behavior in unstable, critical situations, just to name a few. From early innovations to becoming an essential part of the future advances of electrified vehicles. In the late 1980s Elaphe’s co-founder imagined his ultimate powertrain concept by drawing inspiration from nature, in particular, the anatomy and mechanical energy generation of animals. He had good technical reasons to believe his research could be applied to cars and other vehicles in the future. The availability of more robust, new materials not available in the past and the advent of computer simulation methods, combined with a strong belief in the need for a simple, clean and highly efficient powertrain architecture with very few moving parts, drove further innovations. Most importantly, the envisioned potential to change how a vehicle looks like, how it is used and how to lower its environmental impact, spurred Elaphe’s commitment to technological innovation. The initial designs proved the conceptual feasibility, so the team set up a company to support the development of this great technology for the benefit of our green planet. Challenges along the way included how to deal with the influence of temperature and temperature variation. People rarely realize the effort that goes into designing a car component that works in conditions from -40°C to +85°C. Figure 2 – Housed entirely
