Published July 18, 2012
Protean Electric hasn’t exactly reinvented the wheel, but what’s inside of it is a different story.
The Michigan-based company is set to begin production of compact, in-wheel electric motors that could revolutionize the plug-in car business.
With an $84 million investment from Chinese investor GSR Partners, Protean is building a manufacturing center in the city of Liyang, China, that will have an initial capacity to build 50,000 motors per year and will begin pre-production in early 2013.
Unlike many existing systems that use large motors to drive either a transmission or axles to get power to the wheels, Protean’s in-wheel motors are fully housed within the otherwise conventional wheels, which are bolted directly to them.
Versions of the motor measuring 18 inches in diameter weigh 68 pounds and provide 110 hp and an impressive 598 lb-ft of torque each, but can be scaled up to 24 inches for higher power applications. Two or four are used on each vehicle.
Protean’s innovative design packages the stationary, permanent magnet at the center of the device while the rotor is on the outside, making it easier for the wheel to be directly attached. Inverters and power electronics are housed between the two, rather than in a remote unit, further simplifying and reducing the weight of the complete system. Each motor is made up of between four and eight parallel submotors, so in the event that one fails the unit can continue to operate until it is serviced.
Protean CEO Bob Purcell is a General Motors veteran who was head of the automaker’s Advanced Technology Vehicles Group behind the EV-1 electric car program. He says the company has demonstrated the technology in both all-electric and plug-in hybrid applications, and that its small size makes it ideal for retrofitting existing vehicles while offering unique opportunities for designers to reimagine the basic shape of a car or truck designed from the ground up around the motors. GM's Autonomy concept from a decade ago is a perfect example of the latter, it's flat "skateboard" chassis optimized by the use of in-wheel electric motors.
Purcell says the company will handle early production in house at its new facility, but the business plan is to ultimately license the technology to large manufacturers that can build the product in very high volumes themselves.
No customers have been named yet, but Purcell says Protean is in talks with several automakers in China, the U.S. and Europe and that deals are in the works that could be announced soon, with full commercial production on track to begin at the Liyang facility in early 2014.