In-Wheel Electric Drive

Electric vehicles are very different from gasoline-powered vehicles, as we all know. But one unique thing about electric cars that might not have crossed your mind is that the wheels of an EV could potentially receive their power directly from electric motors.

Protean Electric, which has received tens of millions of dollars from Chinese and US investors, is reportedly working on building a manufacturing facility in China for such a technology.

Notably, Protean Electric’s CEO is a certain Bob Purcell, the “father” of the EV-1 (the world’s first modern electric vehicle) at his former employer, General Motors (GM).

“The Protean Drive™ system can improve vehicle fuel economy, add torque, increase power and enable improved vehicle handling to both new and existing vehicles,” Protean writes.

“The direct-drive configuration reduces part count, complexity and cost, so there is no need to integrate traditional drivetrain components such as external gearing, transmissions, driveshafts, axles and differentials.

“Direct-drive, in-wheel motors require no gearboxes, driveshafts or differentials thus giving far greater flexibility to vehicle designers while substantially reducing drivetrain losses. The reduced drivetrain losses mean less energy is wasted (during both acceleration and regenerative braking), resulting in more of the energy from the battery pack being available to propel the vehicle.”

Sounds pretty darn tasty.

With such a system, each individual wheel can actually be controlled separately, with better performance being the result.

Since an announcement of $84 million in venture funding back in July 2012, Protean hasn’t released any big news. However, its site states: “Prototype manufacturing will begin in early 2013 with volume production in 2014, out of Protean’s new manufacturing facility in Liyang, China”

Here’s a video for more on the technology, followed by the company’s full statement on the technology’s benefits:

Benefits

Protean’s system can increase fuel economy by over 30 percent depending on the battery size and driving cycle. It is also powerful enough to be the only source for traction on a variety of vehicles. Its ease of integration can simplify the adoption of hybrid and electrified powertrains across a broad range of vehicles.

Protean’s in-wheel motors have the highest torque and power density of any of today’s leading electric propulsion systems. Each Protean Drive™ in-wheel motor can deliver 81 kW (110 hp) and 800 Nm (590 lb-ft), yet weighs only 31 kg (68 lbs.) and is sized to fit within the space of a conventional 18- to 24-inch road wheel.

Protean Drive™ also has superior regenerative braking capabilities, which allow up to 85 percent of the available kinetic energy to be recovered during braking. This can increase driving range up to 30 percent and contribute to the reduction of battery size and cost.

Other benefits include:

• Can deliver hybrid and electric vehicle technology faster and with fewer new parts, less complexity, and at a lower total cost than other leading electric drive systems
• Can be developed as a retrofit application for existing fleets as well as for new vehicles
• Does not require external gearing, drive shafts or differentials
• Each motor has a built-in inverter, control electronics and software
• Does not require a separate motor power electronics module to be fitted to the vehicle
• Can be added to FWD, RWD or AWD platforms regardless of the fuel type
• Avoids costs of unique hybrid drive tooling changes to chassis, bodies and transmissions
• Can help create a hybrid vehicle with fewer changes to the base engine systems and components and is less disruptive in the assembly plant
• Can be a common system for HEV, PHEV and EV vehicles on the same platform