The Volkswagen e-Bora, a compact electric vehicle being manufactured in China, is actually not that new, being electrified some years ago, but will soon be upgraded by the installation of in-wheel electric motors developed by Protean Electric.
Protean Electric has been developing electric motors for electric vehicles that aren’t quite like the others. An electric vehicle conversion, aside from finding space for the battery packs, typically replaces the internal combustion engine with an electric motor, utilizing the same transmission and drivetrain. This introduces a lot of inefficiency in the system, which robs the vehicle of range, and doesn’t function as well for regenerative braking.
An electric vehicle, such as the Tesla Model S, which was built from the ground up, might use electric motors that are directly connected to the wheels, with what basically amounts to a single-speed transmission. Because there are fewer parts, the system is far more efficient. Protean Electric has taken things one step further and eliminated everything between the electric motor and the wheel, so there is zero efficiency-robbing friction in between them.
Protean Electric’s in-wheel motor can fit behind a minimum-18” wheel and is said to have the highest torque density of any of today’s electric drive systems. Volkswagen and Protean signed an agreement that will put two of these electric motors behind the rear wheels of the e-Bora, eliminating the existing inboard electric motor and transmission gear, for a total of 150kW. Protean Electric says their in-wheel motors are more efficient, and that the e-Bora electric vehicle will be able to recover up to 85% of the kinetic energy during regenerative braking.
Various companies have been exploring more-efficient in-wheel electric motor technology, such as German firm Schaeffler, who converted a standard Ford Focus Electric to a rear-wheel drive electric vehicle back in April, totally changing the vehicle’s driving dynamics. Choosing in-wheel electric motors frees up space in different parts of an electric vehicle that can be re-appropriated for cargo, passenger, or even battery capacity.
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